.rs .\" Troff code generated by TPS Convert from ITU Original Files .\" Not Copyright ( c) 1991 .\" .\" Assumes tbl, eqn, MS macros, and lots of luck. .TA 1c 2c 3c 4c 5c 6c 7c 8c .ds CH .ds CF .EQ delim @@ .EN .nr LL 40.5P .nr ll 40.5P .nr HM 3P .nr FM 6P .nr PO 4P .nr PD 9p .po 4P .rs \v | 5i' .sp 1P .ce 1000 \v'3P' SECTION\ 4 .ce 0 .sp 1P .ce 1000 \fBDETERMINATION\ OF\ THE\ \fR \fBNUMBER\ OF\ CIRCUITS\fR .ce 0 .sp 1P .ce 1000 \fBIN\ AUTOMATIC\ AND\ SEMIAUTOMATIC\ OPERATION\fR .ce 0 .sp 1P .sp 2P .LP \fBRecommendation\ E.520\fR .RT .sp 2P .ce 1000 \fBNUMBER\ OF\ CIRCUITS\fR \fB\ TO\ BE\ PROVIDED\ IN\ AUTOMATIC\fR .EF '% Fascicle\ II.3\ \(em\ Rec.\ E.520'' .OF '''Fascicle\ II.3\ \(em\ Rec.\ E.520 %' .ce 0 .sp 1P .ce 1000 \fBAND/OR\ SEMIAUTOMATIC\ OPERATION,\ WITHOUT\ OVERFLOW\ FACILITIES\fR .ce 0 .sp 1P .PP This Recommendation refers to groups of circuits used: .sp 1P .RT .LP \(em in automatic operation; .LP \(em in semiautomatic operation; .LP \(em in both automatic and semiautomatic operations on the same group of circuits. .sp 2P .LP \fB1\fR \fBGeneral method\fR .sp 1P .RT .PP 1.1 The CCITT recommends that the number of circuits needed for a group should be read from tables or curves based on the classical Erlang\ B formula (see Supplements Nos.\ 1 and\ 2 at the end of this fascicle which refers to full availability groups). Recommended methods for traffic determination are indicated in Recommendation\ E.500. .sp 9p .RT .PP For \fIsemi\(hyautomatic operation\fR the loss probability \ \fIp\fR should be based on 3% during the mean busy hour. .PP For \fIautomatic operation\fR the loss probability\ \fIp\fR should be based on 1% during the mean busy hour. .PP Semiautomatic traffic using the same circuits as automatic traffic is to be added to the automatic traffic and the same parameter value of \fIp\fR \ =\ 1% should be used for the total traffic. .PP The values of 3% and 1% quoted above refer to the Erlang\ B formula and derived tables and curves. The 3% value should not be considered as determining a grade of service because with semiautomatic operation there will be some smoothing of the traffic peaks; it is quoted here only to determine the .PP value of the parameter\ \fIp\fR (loss probability) to use in the Erlang\ B tables and curves. .RT .PP 1.2 In order to provide a satisfactory grade of service both for the mean busy\(hyhour traffic and for the traffic on exceptionally busy days, it is recommended that the proposed number of circuits should, if necessary, be increased to ensure that the loss probability shall not exceed 7% during the mean busy hour for the average traffic estimated for \fIthe five busiest days\fR as specified in Recommendation\ E.500. .sp 9p .RT .PP 1.3 For \fIsmall groups of long intercontinental circuits\fR with automatic operation some relaxation could be made in respect to loss probability. It is envisaged that such circuits would be operated on a both\(hyway basis and that a reasonable minimum for automatic service would be a group of six circuits. A table providing relaxation in Annex\ A is based on a loss probability of 3% for six circuits, with a smooth progression to 1% for 20\ circuits. The general provision for exceptional days remains unchanged. .PP For exceptional circumstances in which very small groups (less than six intercontinental circuits) are used for automatic operation, dimensioning of the group should be based on the loss probability of 3%. .bp .sp 2P .LP \fB2\fR \fBTime differences\fR .sp 1P .RT .PP Time differences at the two terminations of intercontinental circuits are likely to be much more pronounced than those on continental circuits. In order to allow for differences on groups containing both\(hyway circuits it will be desirable to acquire information in respect to traffic flow both during the mean busy hour for both directions and during the mean busy hour for each direction. .PP It is possible that in some cases overflow traffic can be accepted without any necessity to increase the number of circuits, in spite of the fact that this overflow traffic is of a peaky nature. Such circumstances may arise if there is no traffic overflowing from high\(hyusage groups during the mean busy hour of the final group. .RT .sp 2P .LP \fB3\fR \fBBoth\(hyway circuits\fR .sp 1P .RT .PP 3.1 With the use of both\(hyway circuits there is a danger of simultaneous seizure at both ends; this is particularly the case on circuits with a long propagation time. It is advisable to arrange the sequence of selection at the two ends so that such double seizure can only occur when a single circuit remains free. .sp 9p .RT .PP When all the circuits of a group are operated on a both\(hyway basis, time differences in the directional mean busy hours may result in a total mean busy\(hyhour traffic flow for the group which is not the sum of the mean busy\(hyhour traffic loads in each direction. Furthermore, such differences in directional mean busy hour may vary with seasons of the year. However, the available methods of traffic measurement can determine the traffic flow during mean busy hour for this total traffic. .PP 3.2 Some intercontinental groups may include one\(hyway as well as both\(hyway operated circuits. It is recommended that in all cases the one\(hyway circuits should be used, when free, in preference to the both\(hyway circuits. The number of circuits to be provided will depend upon the one\(hyway and total traffic. .sp 9p .RT .PP The total traffic will need to be determined for: .LP a) each direction of traffic; .LP b) both\(hyway traffic. .PP This determination is to be made for the busy hour or the busy hours corresponding to the two cases a) and b) above. .PP In the cases where the number of one\(hyway circuits is approximately equal for each direction, no special procedure is necessary, and the calculation can be treated as for a simple two\(hygroup grading\ [1]. .PP If the number of one\(hyway circuits is quite different for the two directions, some correction may be needed for the difference in randomness of the flow of calls from the two one\(hyway circuit groups to the both\(hyway circuit group. The general techniques for handling cases of this type are quoted in Recommendation\ E.521. \v'1P' .RT .ce 1000 ANNEX\ A .ce 0 .ce 1000 (to Recommendation E.520) .sp 9p .RT .ce 0 .PP Table A\(hy1/E.520 may be applied to small groups of long intercontinental circuits. The values in column\ 2 are suitable for a random offered traffic with full availability access. .sp 1P .RT .PP The table is based on 1% loss probability for 20\ circuits and increases progressively to a loss probability of 2% at 9\ circuits and 3% at 6\ circuits (loss probabilities for these three values being based on the Erlang loss formula: see Supplement\ No.\ 1). The traffic flow values obtained from a smoothing curve coincide very nearly with those determined by equal marginal utility theory, i.e.\ an improvement factor of 0.05\ Erlang for an additional circuit. .PP For groups requiring more than 20\ circuits the table for loss probability of 1%, mentioned in Supplement\ No.\ 1, should be used. .bp .RT .ce \fBH.T. [T1.520]\fR .ce TABLE\ A\(hy1/E.520 .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(36p) | cw(36p) sw(36p) sw(36p) , ^ | c | c | c. Number of circuits Traffic flow (in erlangs) Offered Carried Encountering congestion _ .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . (1) (2) (3) (4) _ .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . \ 6 \ 2.54 \ 2.47 0.08 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . \ 7 \ 3.13 \ 3.05 0.09 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . \ 8 \ 3.73 \ 3.65 0.09 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . \ 9 \ 4.35 \ 4.26 0.09 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 10 \ 4.99 \ 4.90 0.09 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 11 \ 5.64 \ 5.55 0.10 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 12 \ 6.31 \ 6.21 0.10 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 13 \ 6.99 \ 6.88 0.10 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 14 \ 7.67 \ 7.57 0.10 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 15 \ 8.37 \ 8.27 0.11 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 16 \ 9.08 \ 8.96 0.11 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 17 \ 9.81 \ 9.69 0.11 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 18 10.54 10.42 0.11 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 19 11.28 11.16 0.12 .T& cw(36p) | cw(36p) | cw(36p) | cw(36p) . 20 12.03 11.91 0.12 _ .TE .nr PS 9 .RT .ad r \fBTable A\(hy1/E.520 [T1.520] p.1\fR .sp 1P .RT .ad b .RT .sp 2P .LP \fBReference\fR .sp 1P .RT .LP [1] TANGE (I.): Optimal use of both\(hyway circuits in cases of unlimited availability, \fITELE\fR , English Edition, No.\ 1,\ 1956. .sp 2P .LP \fBRecommendation\ E.521\fR .RT .sp 2P .ce 1000 \fBCALCULATION\ OF\ THE\ \fR \fBNUMBER\ OF\ CIRCUITS\fR \fB\ IN\ A\fR .EF '% Fascicle\ II.3\ \(em\ Rec.\ E.521'' .OF '''Fascicle\ II.3\ \(em\ Rec.\ E.521 %' .ce 0 .sp 1P .ce 1000 \fBGROUP\ CARRYING\ \fR \fBOVERFLOW\ TRAFFIC\fR .ce 0 .sp 1P .PP A calculation of the number of circuits in a group carrying overflow traffic should be based on this Recommendation and on Recommendation\ E.522 dealing with high\(hyusage groups. .sp 1P .RT .PP The objective grade of service used is that the average blocking during the busy\(hyhour of the 30\ busiest days of the year will not exceed\ 1%. .PP To determine the number of circuits in a group carrying overflow traffic , three traffic parameters are required: the average traffic offered to the group, the weighted peakedness factor , and the level of day\(hyto\(hyday traffic variations. .PP The level of day\(hyto\(hyday traffic variations indicates the degree to which the daily busy\(hyhour traffic deviates from the overall mean traffic, and is determined by the sample variance of the 30\ busy\(hyhour traffic. .PP The peakedness factor indicates the degree to which the variability of the traffic deviates from pure chance traffic within a single hour, and in statistical terms is the variance\(hyto\(hymean ratio of the distribution of simultaneous overflow traffic. .RT .sp 2P .LP \fB1\fR \fBDetermination of the level of \fR \fBday\(hyto\(hyday traffic\fR \fBvariations\fR .sp 1P .RT .PP Let\ \fIM\fR\d1\u, \fIM\fR\d2\u,\ . | | ,\ \fIM\fR\d3\\d0\udenote the 30\ busy\(hyhour loads of the traffic offered to the final group. Determine the mean traffic\ \fIM\fR of the daily traffic by \v'6p' .RT .LP \fIM\fR = [Formula Deleted] @ pile { 0 above sum above \fIj\fR~=1 } @ \fIM \dj\u\fR .bp .sp 1P .ce 1000 .ce 0 .sp 1P .PP Determine the sample variance\ \fIV\fR\d\fId\fR\uof the daily traffic by \v'6p' .sp 1P .ce 1000 \fIV \dd \u\fR = [Formula Deleted] @ pile { 0 above sum above \fIj\fR~=1 } @ (\fIM \dj\u\fR \(em \fIM\fR ) \u2\d .ce 0 .sp 1P .LP .sp 1 .PP Determine the point (\fIM\fR ,\ \fIV\fR\d\fId\fR\u) on Figure\ 1/E.521; \fIM\fR \ on the horizontal axis, and \fIV\fR\d\fId\fR\uon the vertical axis. .LP i) If the point (\fIM\fR ,\ \fIV\fR\d\fId\fR\u) is below the bottom curve, the level of variation is\ \fINull\fR . .LP ii) If the point is between the lower two curves, the level of variation is \fILow\fR . .LP iii) If the point is between the upper two curves, the level of variation is \fIMedium\fR . .LP iv) If the point is above the highest curve, the level of variation is \fIHigh\fR . .PP Default procedures: if the data are not available to compute the variance\ \fIV\fR\d\fId\fR\uuse the following guidelines: .LP a) If no more than 25\ per cent of the traffic offered to the final group is overflow from other groups, assume the level of day\(hyto\(hyday variation is Low. .LP b) Otherwise, assume a Medium level of variation. .LP .rs .sp 33P .ad r \fBFigure 1/E.521, p.2 (Recup.)\fR .sp 1P .RT .ad b .RT .LP .bp .sp 2P .LP \fB2\fR \fBDetermination of \fR \fBpeakedness factor\fR \fIz\fR .sp 1P .RT .PP Peakedness factors depend principally upon the number of high\(hyusage circuits over which random traffic has access. When the number of such high\(hyusage circuits does not exceed\ 30, the actual peakedness of the traffic overflowing from a high\(hyusage group will be only slightly below the maximum peakedness values .FS Tables giving: .PP \(em\ the exact mean of the overflow traffic, and .PP \(em\ the difference between variance and mean of the overflow .PP have been computed and are set out in\ [1]. .FE \u,\d | .FS Curves giving the exact mean and variance of overflow traffic are given in\ [2]. See also a more detailed description of the method in\ [3] and\ [4]. .FE . The maximum peakedness values are given in Table\ 1/E.521. .RT .ce \fBH.T. [T1.521]\fR .ce TABLE\ 1/E.521 .ce \fBMaximum peakedness factor\fR .ce \fIz\fR .ce \fIi\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(60p) | cw(55p) sw(4p) | cw(55p) sw(54p) , ^ | ^ | c s. { Number of high\(hyusage circuits (\fIn\fR \fIi\fR ) } { Peakedness factor (\fIz\fR \fIi\fR ) } { Peakedness factor (\fIz\fR \fIi\fR ) } { Number of high\(hyusage circuits (\fIn\fR \fIi\fR ) } _ .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . \ 1 1.17 16 2.44 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . \ 2 1.31 17 2.49 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . \ 3 1.43 18 2.55 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . \ 4 1.54 19 2.61 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . \ 5 1.64 20 2.66 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . \ 6 1.73 21 2.71 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . \ 7 1.82 22 2.76 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . \ 8 1.90 23 2.81 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . \ 9 1.98 24 2.86 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . 10 2.05 25 2.91 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . 11 2.12 26 2.96 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . 12 2.19 27 3.00 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . 13 2.26 28 3.05 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . 14 2.32 29 3.09 .T& cw(60p) | cw(54p) | cw(60p) | cw(54p) . 15 2.38 30 3.14 _ .TE .nr PS 9 .RT .ad r \fBTable 1/E.521 [T1.521] (Recup. + Corr.) p.3\fR .sp 1P .RT .ad b .RT .PP For more than 30\ circuits, the peakedness of the traffic overflowing from a high\(hyusage group\ \fIi\fR of\ \fIn\fR\d\fIi\fR\ucircuits is given by \v'6p' .sp 1P .ce 1000 \fIz\fR\d\fIi\fR\u= 1 \(em \(*b\fI\fI\d\fIi\fR\u+ @ { fIA\fR\d\fIi\fR\ } over { fIn\fR\d\fIi\fR\u+~1~+~\(*b\fI\fI\d\fIi\fR\u\(em~\fIA\fR\d\fIi\fR\ } @ .ce 0 .sp 1P .LP .sp 1 where .LP \fIA\fR\d\fIi\fR\u is the mean (random) traffic offered to the \fIn\fR\d\fIi\fR\ucircuits and .LP \(*b\fI\fI\d\fIi\fR\u is the traffic overflowing. The overflow traffic\ \(*b\fI\fI\d\fIi\fR\uis found by employing the standard Erlang loss formula \fIE\fR \d1, \fIn\fR\d\fIi\fR\u\u \ (\fIA\fR\d\fIi\fR\u): \v'6p' .sp 1P .ce 1000 \(*b\fI\fI\d\fIi\fR\u= \fIA \di \uE\fR \d1, \fIn\fR\d\fIi\fR\u\u (\fIA\fR\d\fIi\fR\u). .ce 0 .sp 1P .LP .sp 1 .PP The weighted mean peakedness factor\ \fIz\fR , is then calculated from: \v'6p' .sp 1P .ce 1000 \fIz\fR = @ { pile { fIh\fR above sum above \fIi\fR~=1 } \(*b\fI\fI\d\fIi\fR\ } over { pile { fIh\fR above sum above \fIi\fR~=1 } \(*b\fI\fI\d\fIi\fR\ } @ .EF '% \fIi'' .OF '''\fIi %' .ce 0 .sp 1P .LP .sp 1 for the \fIh\fR \ parcels of traffic being offered to the final group. .PP Note that for the traffic directly offered to the final group, the peakedness factor is \fIz\fR\d\fIi\fR\u\ =\ 1. .bp .sp 2P .LP \fB3\fR \fBDetermination of the \fR \fBmean traffic offered\fR \fBto the final group and the \fR \fBnumber of circuits\fR \fB required\fR .sp 1P .RT .PP 3.1 For planning future network requirements, the traffic overflowing to a final group should be determined theoretically from forecasts of traffics offered to the high\(hyusage groups. .sp 9p .RT .PP The mean traffic overflowing to the final group from a high\(hyusage group is determined in two steps: .LP i) the \*Qsingle\(hyhour\*U overflow traffic\ \(*b\fI\fI\d\fIi\fR\uoverflowing from\ \fIn\fR\d\fIi\fR\ucircuits is given as above by \v'6p' .sp 1P .ce 1000 \(*b\fI\fI\d\fIi\fR\u= \fIA \di \uE \di, n\fI\d\fIi\fR\u\u (\fIA\fR\d\fIi\fR\u), .ce 0 .sp 1P .LP .sp 1 when \fIA\fR\d\fIi\fR\uis the forecast of traffic offered to the \fIi\fR \ut\d\uh\d .LP high\(hyusage group; .LP ii) the average overflow traffic\ \(*b \fI\fI\d\fIi\fR\u overflowing from the \fIn\fR\d\fIi\fR\ucircuits is then determined by adjusting the single\(hyhour traffic\ \(*b\fI\fI\d\fIi\fR\ufor the effect of day\(hyto\(hyday traffic variations. .sp 1P .ce 1000 \(*b \fI\d\fIi\fR\u= \fIr\fR\d\fIi\fR\u\(*b\fI\fI\d\fIi\fR\u .ce 0 .sp 1P .PP The adjustment factor \fIr\fR\d\fIi\fR\uis given in Table\ 2/E.521; it is a function of: .LP \(em the offered traffic \fIA\fR\d\fIi\fR\u, .LP \(em the traffic \fIA \di \uE \di, n\fI \u\fR \d\(em1 \u (\fIA\fR\d\fIi\fR\u) \(em \(*b\fI\fI\d\fIi\fR\ucarried by the last trunk\ \fIi\fR , and .EF '% '' .OF ''' %' .LP \(em the level of day\(hyto\(hyday variations of the traffic offered to the high\(hyusage group. .PP This level can be determined using the method described in \(sc\ 1 above, but applying it to measurements of traffic offered to the high\(hyusage group. If such measurements are not available a \fImedium\fR level can be used. .PP The mean traffic offered to the final group is then the sum of all \(*b \fI\fI\d\fIi\fR\uover the \fIh\fR \ parcels of traffic: \v'6p' .RT .sp 1P .ce 1000 \fIM\fR = @ pile { fIh\fR above sum above \fIi\fR~=1 } @ \(*b \d\fIi\fR \u .ce 0 .sp 1P .LP .sp 1 .PP It can be assumed that the level of day\(hyto\(hyday traffic variations on the final group remains constant over the forecast time period. .PP Using the level of day\(hyto\(hyday traffic variation as determined in \(sc\ 1 above on the final group and the peakedness factor of \(sc\ 2 above, the appropriate table of Tables\ 3/E.521 to\ 6/E.521 is used to derive the number of circuits required. .PP \fINote\ 1\fR \ \(em\ This method of calculation of the mean traffic offered to the final group is valid only if the overflow traffic due to blocking encountered in the exchange in the attempts to connect to a high\(hyusage, is negligible. .PP \fINote\ 2\fR \ \(em\ Table\ 3/E.521 differs slightly from the previous tables published by CCITT, although in Table\ 3.1/E.521 there is no allowance for day\(hyto\(hyday variations. The new table takes into account a systematic bias in the measurement procedure that is based on a finite period of time (1\ hour), instead of an infinite period as was assumed in the previous table\ [5]. .bp .PP \fINote\ 3\fR \ \(em\ Tables 4/E.521, 5/E.521 and\ 6/E.521 are based on the calculation of the average blocking from the formula: \v'6p' .RT .sp 1P .ce 1000 \(*b = @ int @ \fIB\fR (\fIm\fR ) \fIf\fR (\fIm\fR )\fIdm\fR , .ce 0 .sp 1P .LP .sp 1 where .LP \fIB\fR (\fIm\fR ) is the single\(hyhour expected blocking and .LP \fIf\fR (\fIm\fR ) is the density distribution of day\(hyto\(hyday traffic (\fIm\fR ), assuming a Pearson Type\ III distribution: \v'6p' .sp 1P .ce 1000 @ left [ \fIf\fR (\fIm\fR ) = { \fIM\fR~/\fIV\fR ) \s7(\fIM\fR~\u2\d/\fIV\fR~\d\fId\fR~\u) \s9 } over { \(*g~\s7(\fIM\fR~\u2\d/\fIV\fR~\u\fId\fR~\d) \s } fR~~\fIm\fR~\s7[(\fIM\fR~\u2\d/\fIV\fR~\d\fId\fR~\u) \(em~1]~~\s9\fIe\fR~\s7\(em\fIM~\dm\u\fR~/\fIV\fR~\d\fId\fR~\u~\s9 right ] @ .RT .ce 0 .sp 1P .LP .sp 1 \fIM\fR and \fIV\fR\d\fId\fR\uare the mean and day\(hyto\(hyday variance of the traffic as calculated [5] in \(sc\ 1 above. .ce \fBH.T. [T2.521]\fR .ce TABLE\ 2/E.521 .ce \fBOverflow adjustment for high\(hyusage trunk groups\fR .ce Factor \fIr\fR .ce \fIi\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(48p) | cw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) sw(12p) , ^ | c s s s s | c s s s | c s s s ^ | c | c | c | c | c | c | c | c | c | c | c | c | c | c | c. { Offered traffic \fIA\fR \fIi\fR } Last trunk traffic Low daily variation Medium daily variation High daily variation 0.25 0.3 0.4 0.5 0.6 0.25 0.3 0.4 0.5 0.6 0.25 0.3 0.4 0.5 0.6 _ .T& cw(48p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) . \ 3 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 .T& cw(48p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) . \ 5 1.0 1.0 1.0 1.0 1.0 1.1 1.1 1.1 1.0 1.0 1.2 1.2 1.1 1.1 1.0 .T& cw(48p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) . \ 7 1.0 1.0 1.0 1.0 1.0 1.2 1.2 1.1 1.1 1.0 1.4 1.3 1.2 1.1 1.1 .T& cw(48p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) . 10 1.1 1.1 1.1 1.0 1.0 1.3 1.2 1.2 1.1 1.1 1.5 1.4 1.3 1.2 1.1 .T& cw(48p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) . 15 1.2 1.1 1.1 1.1 1.0 1.5 1.4 1.2 1.2 1.1 1.8 1.6 1.4 1.3 1.1 .T& cw(48p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) . 20 1.2 1.2 1.1 1.1 1.0 1.6 1.5 1.3 1.2 1.1 2.0 1.8 1.5 1.3 1.2 .T& cw(48p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) . 25 1.3 1.2 1.2 1.1 1.1 1.8 1.6 1.4 1.3 1.1 2.3 2.0 1.7 1.4 1.2 .T& cw(48p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) | cw(12p) . 30 1.3 1.3 1.2 1.1 1.1 1.8 1.7 1.4 1.3 1.2 2.4 2.1 1.7 1.5 1.3 _ .TE .nr PS 9 .RT .ad r \fBTable 2/E.521 (Recup. + Corr.) [T2.521], p.4\fR .sp 1P .RT .ad b .RT .ad r Blanc .ad b .RT .LP .bp .ce \fBH.T. [T3.521]\fR .ce TABLE\ 3/E.521 .ce \fBSingle\(hyhour capacity, in Erlangs, as a function of the number of trunks\fR .ce \fBand of the peakedness factor\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(54p) | lw(24p) | lw(150p) . \fIParameters:\fR \(em | lockage 0.01; .T& lw(54p) | lw(24p) | lw(150p) . { \(em | fINo\fR allowance for day\(hyto\(hyday variation; } .T& lw(54p) | lw(24p) | lw(150p) . { \(em | eighted mean peakedness factor. } .TE .TS box center ; lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . Number of trunks required 1.0\ 1.2\ 1.4\ 1.6\ 1.8\ 2.0\ 2.2\ 2.4\ 2.6\ 2.8\ 3.0\ 3.4\ 3.8\ 4.0\ \ 1 \ 0.06 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 2 \ 0.22 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 3 \ 0.53 \ 0.33 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 4 \ 0.94 \ 0.69 \ 0.50 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 5 \ 1.42 \ 1.14 \ 0.89 \ 0.67 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 6 \ 1.97 \ 1.64 \ 1.36 \ 1.08 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 7 \ 2.56 \ 2.19 \ 1.86 \ 1.58 \ 1.31 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 8 \ 3.19 \ 2.81 \ 2.44 \ 2.11 \ 1.81 \ 1.53 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 9 \ 3.83 \ 3.42 \ 3.03 \ 2.67 \ 2.36 \ 2.03 \ 1.75 \ 1.50 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ 10 \ 4.53 \ 4.08 \ 3.67 \ 3.28 \ 2.92 \ 2.58 \ 2.28 \ 2.00 \ 1.75 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ 11 \ 5.22 \ 4.75 \ 4.31 \ 3.89 \ 3.53 \ 3.17 \ 2.83 \ 2.53 \ 2.25 \ 1.97 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ 12 \ 5.94 \ 5.44 \ 4.97 \ 4.56 \ 4.14 \ 3.78 \ 3.42 \ 3.08 \ 2.78 \ 2.47 \ 2.22 \ 0.0\ \ 0.0\ \ 0.0\ 13 \ 6.67 \ 6.14 \ 5.64 \ 5.19 \ 4.81 \ 4.39 \ 4.03 \ 3.67 \ 3.33 \ 3.03 \ 2.72 \ 0.0\ \ 0.0\ \ 0.0\ 14 \ 7.42 \ 6.86 \ 6.36 \ 5.89 \ 5.44 \ 5.03 \ 4.67 \ 4.28 \ 3.94 \ 3.61 \ 3.28 \ 2.69 \ 0.0\ \ 0.0\ 15 \ 8.17 \ 7.58 \ 7.06 \ 6.58 \ 6.11 \ 5.69 \ 5.31 \ 4.92 \ 4.56 \ 4.19 \ 3.86 \ 3.22 \ 0.0\ \ 0.0\ 16 \ 8.94 \ 8.33 \ 7.78 \ 7.28 \ 6.81 \ 6.36 \ 5.94 \ 5.56 \ 5.17 \ 4.81 \ 4.44 \ 3.81 \ 3.19 \ 0.0\ 17 \ 9.72 \ 9.08 \ 8.50 \ 8.00 \ 7.50 \ 7.06 \ 6.61 \ 6.19 \ 5.81 \ 5.42 \ 5.06 \ 4.39 \ 3.75 \ 3.44 18 10.50 \ 9.83 \ 9.25 \ 8.72 \ 8.22 \ 7.75 \ 7.31 \ 6.86 \ 6.44 \ 6.06 \ 5.69 \ 4.97 \ 4.31 \ 4.00 19 11.31 10.61 10.00 \ 9.44 \ 8.92 \ 8.44 \ 7.97 \ 7.53 \ 7.11 \ 6.72 \ 6.33 \ 5.58 \ 4.89 \ 4.58 20 12.08 11.39 10.78 10.19 \ 9.67 \ 9.14 \ 8.67 \ 8.22 \ 7.81 \ 7.39 \ 6.97 \ 6.22 \ 5.50 \ 5.17 21 12.89 12.19 11.53 10.94 10.39 \ 9.86 \ 9.39 \ 8.92 \ 8.47 \ 8.06 \ 7.64 \ 6.86 \ 6.11 \ 5.78 22 13.72 13.00 12.31 11.69 11.14 10.61 10.08 \ 9.61 \ 9.17 \ 8.72 \ 8.31 \ 7.50 \ 6.75 \ 6.39 23 14.53 13.78 13.08 12.47 11.89 11.36 10.81 10.33 \ 9.86 \ 9.42 \ 8.97 \ 8.17 \ 7.39 \ 7.00 24 15.36 14.58 13.89 13.22 12.64 12.08 11.56 11.03 10.56 10.11 \ 9.67 \ 8.83 \ 8.03 \ 7.64 25 16.19 15.39 14.67 14.00 13.39 12.83 12.28 11.78 11.28 10.81 10.36 \ 9.50 \ 8.69 \ 8.31 26 17.03 16.22 15.47 14.81 14.17 13.58 13.03 12.50 12.00 11.53 11.06 10.19 \ 9.36 \ 8.94 27 17.86 17.03 16.28 15.58 14.94 14.33 13.78 13.22 12.72 12.22 11.75 10.86 10.03 \ 9.61 28 18.69 17.86 17.08 16.36 15.72 15.11 14.53 13.97 13.44 12.94 12.47 11.56 10.69 10.28 29 19.56 18.69 17.89 17.17 16.50 15.86 15.28 14.72 14.19 13.67 13.19 12.28 11.39 10.94 30 20.39 19.53 18.72 17.97 17.28 16.64 16.06 15.47 14.92 14.42 13.92 12.97 12.08 11.64 31 21.25 20.36 19.53 18.78 18.08 17.42 16.81 16.22 15.67 15.14 14.64 13.69 12.78 12.33 32 22.11 21.19 20.36 19.58 18.89 18.22 17.58 17.00 16.42 15.89 15.36 14.39 13.47 13.03 33 22.97 22.06 21.19 20.39 19.67 19.00 18.36 17.75 17.19 16.64 16.11 15.11 14.17 13.72 34 23.83 22.89 22.00 21.22 20.47 19.81 19.14 18.53 17.94 17.39 16.86 15.86 14.89 14.42 35 24.69 23.75 22.83 22.03 21.28 20.58 19.92 19.31 18.69 18.14 17.61 16.58 15.61 15.14 36 25.58 24.58 23.69 22.86 22.11 21.39 20.72 20.08 19.47 18.89 18.36 17.31 16.31 15.83 37 26.44 25.44 24.53 23.69 22.92 22.19 21.50 20.86 20.25 19.67 19.11 18.06 17.06 16.56 38 27.31 26.31 25.36 24.53 23.72 23.00 22.31 21.64 21.03 20.44 19.86 18.81 17.78 17.28 39 28.19 27.17 26.22 25.36 24.56 23.81 23.11 22.44 21.81 21.19 20.64 19.53 18.50 18.00 40 29.08 28.03 27.06 26.19 25.39 24.61 23.89 23.22 22.58 21.97 21.39 20.28 19.25 18.72 41 29.94 28.89 27.92 27.03 26.19 25.44 24.69 24.03 23.36 22.75 22.17 21.06 19.97 19.47 42 30.83 29.75 28.78 27.86 27.03 26.25 25.53 24.81 24.17 23.53 22.94 21.81 20.72 20.19 43 31.72 30.64 29.61 28.72 27.86 27.08 26.33 25.61 24.94 24.31 23.69 22.56 21.47 20.94 44 32.61 31.50 30.47 29.56 28.69 27.89 27.14 26.42 25.75 25.11 24.50 23.33 22.22 21.69 45 33.50 32.39 31.33 30.42 29.53 28.72 27.94 27.22 26.56 25.89 25.28 24.08 22.97 22.42 46 34.39 33.25 32.19 31.25 30.39 29.56 28.78 28.03 27.33 26.69 26.06 24.86 23.72 23.17 47 35.28 34.14 33.08 32.11 31.22 30.39 29.58 28.86 28.14 27.47 26.83 25.64 24.47 23.92 48 36.17 35.00 33.94 32.97 32.06 31.22 30.42 29.67 28.94 28.28 27.64 26.42 25.25 24.69 49 37.06 35.89 34.81 33.81 32.92 32.06 31.25 30.47 29.75 29.08 28.42 27.19 26.00 25.44 50 37.97 36.78 35.67 34.67 33.75 32.89 32.08 31.31 30.58 29.89 29.22 27.97 26.78 26.19 .TE .nr PS 9 .RT .ad r \fBTable 3/E.521 (Recup.) [T3.521], p.5\fR .sp 1P .RT .ad b .RT .LP .bp .ce \fBH.T. [T4.521]\fR .ce TABLE\ 4/E.521 .ce \fBSingle\(hyhour capacity, in Erlangs, as a function of the number of trunks\fR .ce \fBand of the peakedness factor\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(54p) | lw(24p) | lw(150p) . \fIParameters:\fR \(em | lockage 0.01; .T& lw(54p) | lw(24p) | lw(150p) . { \(em | fILow\fR day\(hyto\(hyday variation allowance; } .T& lw(54p) | lw(24p) | lw(150p) . { \(em | eighted mean peakedness factor. } .TE .TS center box; lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . Number of trunks required 1.0\ 1.2\ 1.4\ 1.6\ 1.8\ 2.0\ 2.2\ 2.4\ 2.6\ 2.8\ 3.0\ 3.4\ 3.8\ 4.0\ \ 1 \ 0.06 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 2 \ 0.22 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 3 \ 0.53 \ 0.33 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 4 \ 0.94 \ 0.69 \ 0.50 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 5 \ 1.39 \ 1.14 \ 0.89 \ 0.67 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 6 \ 1.89 \ 1.64 \ 1.36 \ 1.08 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 7 \ 2.44 \ 2.14 \ 1.86 \ 1.58 \ 1.31 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 8 \ 3.03 \ 2.69 \ 2.42 \ 2.11 \ 1.81 \ 1.53 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 9 \ 3.64 \ 3.28 \ 2.97 \ 2.67 \ 2.36 \ 2.03 \ 1.75 \ 1.50 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 10 \ 4.25 \ 3.89 \ 3.56 \ 3.22 \ 2.92 \ 2.58 \ 2.28 \ 2.00 \ 1.75 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 11 \ 4.92 \ 4.53 \ 4.17 \ 3.83 \ 3.50 \ 3.17 \ 2.83 \ 2.53 \ 2.25 \ 1.97 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 12 \ 5.58 \ 5.17 \ 4.78 \ 4.44 \ 4.08 \ 3.78 \ 3.42 \ 3.08 \ 2.78 \ 2.47 \ 2.22 \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 13 \ 6.25 \ 5.81 \ 5.42 \ 5.06 \ 4.69 \ 4.36 \ 4.03 \ 3.67 \ 3.33 \ 3.03 \ 2.72 \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 14 \ 6.94 \ 6.50 \ 6.08 \ 5.69 \ 5.33 \ 4.97 \ 4.64 \ 4.28 \ 3.94 \ 3.61 \ 3.28 \ 2.69 \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 15 \ 7.64 \ 7.17 \ 6.75 \ 6.33 \ 5.97 \ 5.61 \ 5.25 \ 4.92 \ 4.56 \ 4.19 \ 3.86 \ 3.22 \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 16 \ 8.33 \ 7.86 \ 7.42 \ 7.00 \ 6.61 \ 6.25 \ 5.89 \ 5.53 \ 5.17 \ 4.81 \ 4.44 \ 3.81 \ 3.19 \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 17 \ 9.06 \ 8.56 \ 8.11 \ 7.67 \ 7.28 \ 6.89 \ 6.53 \ 6.17 \ 5.81 \ 5.42 \ 5.06 \ 4.39 \ 3.75 \ 3.44 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 18 \ 9.81 \ 9.28 \ 8.81 \ 8.36 \ 7.94 \ 7.56 \ 7.17 \ 6.81 \ 6.44 \ 6.06 \ 5.69 \ 4.97 \ 4.31 \ 4.00 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 19 10.53 10.00 \ 9.50 \ 9.06 \ 8.61 \ 8.22 \ 7.83 \ 7.44 \ 7.08 \ 6.72 \ 6.33 \ 5.58 \ 4.89 \ 4.58 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 20 11.28 10.72 10.22 \ 9.75 \ 9.31 \ 8.89 \ 8.50 \ 8.11 \ 7.72 \ 7.36 \ 6.97 \ 6.22 \ 5.50 \ 5.17 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 21 12.03 11.44 10.94 10.44 10.00 \ 9.56 \ 9.17 \ 8.78 \ 8.39 \ 8.03 \ 7.64 \ 6.86 \ 6.11 \ 5.78 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 22 12.78 12.19 11.67 11.17 10.69 10.25 \ 9.83 \ 9.44 \ 9.06 \ 8.67 \ 8.31 \ 7.56 \ 6.75 \ 6.39 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 23 13.53 12.94 12.39 11.89 11.42 10.94 10.53 10.11 \ 9.72 \ 9.33 \ 8.94 \ 8.19 \ 7.39 \ 7.00 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 24 14.31 13.69 13.14 12.61 12.11 11.67 11.22 10.81 10.39 10.00 \ 9.61 \ 8.86 \ 8.03 \ 7.64 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 25 15.08 14.44 13.86 13.33 12.83 12.36 11.92 11.50 11.08 10.67 10.28 \ 9.50 \ 8.67 \ 8.31 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 26 15.86 15.22 14.61 14.08 13.56 13.08 12.61 12.19 11.75 11.36 10.94 10.17 \ 9.33 \ 8.94 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 27 16.64 15.97 15.36 14.81 14.28 13.81 13.33 12.89 12.44 12.03 11.64 10.83 10.00 \ 9.61 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 28 17.42 16.75 16.14 15.56 15.03 14.53 14.06 13.58 13.14 12.72 12.31 11.50 10.67 10.28 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 29 18.22 17.53 16.89 16.31 15.78 15.25 14.78 14.31 13.86 13.42 13.00 12.19 11.36 10.94 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 30 19.00 18.31 17.67 17.06 16.50 16.00 15.50 15.03 14.56 14.11 13.69 12.86 12.06 11.64 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 31 19.81 19.08 18.44 17.83 17.25 16.72 16.22 15.72 15.28 14.83 14.39 13.56 12.75 12.33 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 32 20.61 19.89 19.19 18.58 18.00 17.47 16.94 16.47 16.00 15.53 15.11 14.25 13.44 13.03 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 33 21.39 20.67 19.97 19.36 18.78 18.22 17.69 17.19 16.72 16.25 15.81 14.94 14.14 13.72 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 34 22.22 21.47 20.75 20.11 19.53 18.97 18.42 17.92 17.44 16.97 16.53 15.67 14.83 14.42 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 35 23.03 22.25 21.56 20.89 20.28 19.72 19.17 18.67 18.17 17.69 17.22 16.36 15.56 15.11 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 36 23.83 23.06 22.33 21.67 21.06 20.47 19.92 19.39 18.89 18.42 17.94 17.08 16.25 15.81 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 37 24.64 23.86 23.14 22.44 21.83 21.25 20.67 20.14 19.64 19.14 18.67 17.78 16.94 16.50 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 38 25.47 24.67 23.92 23.25 22.61 22.00 21.44 20.89 20.36 19.89 19.42 18.50 17.64 17.19 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 39 26.28 25.47 24.72 24.03 23.39 22.78 22.19 21.64 21.11 20.61 20.14 19.22 18.33 17.89 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 40 27.11 26.28 25.53 24.81 24.17 23.53 22.94 22.39 21.86 21.36 20.86 19.94 19.06 18.61 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 41 27.92 27.08 26.31 25.61 24.94 24.31 23.72 23.14 22.61 22.11 21.61 20.67 19.78 19.31 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 42 28.75 27.92 27.11 26.39 25.72 25.08 24.47 23.92 23.36 22.83 22.33 21.39 20.47 20.03 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 43 29.58 28.72 27.92 27.19 26.50 25.86 25.25 24.67 24.11 23.58 23.08 22.11 21.19 20.75 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 44 30.42 29.56 28.75 28.00 27.31 26.64 26.03 25.44 24.89 24.33 23.83 22.86 21.92 21.44 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 45 31.25 30.36 29.56 28.81 28.08 27.44 26.81 26.22 25.64 25.11 24.58 23.58 22.64 22.17 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 46 32.08 31.19 30.36 29.61 28.89 28.22 27.58 26.97 26.42 25.86 25.33 24.33 23.36 22.89 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 47 32.92 32.03 31.17 30.42 29.69 29.00 28.36 27.75 27.17 26.61 26.08 25.06 24.11 23.64 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 48 33.75 32.83 32.00 31.22 30.47 29.81 29.14 28.53 27.94 27.39 26.83 25.81 24.83 24.36 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 49 34.58 33.67 32.81 32.03 31.28 30.58 29.94 29.31 28.72 28.14 27.58 26.56 25.56 25.08 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 50 35.44 34.50 33.64 32.83 32.08 31.39 30.72 30.08 29.50 28.92 28.36 27.31 26.31 25.83 .TE .nr PS 9 .RT .ad r \fBTable 4/E.521 (Recup.) [T4.521], p.6\fR .sp 1P .RT .ad b .RT .LP .bp .ce \fBH.T. [T5.521]\fR .ce TABLE\ 5/E.521 .ce \fBSingle\(hyhour capacity, in Erlangs, as a function of the number of trunks\fR .ce \fBand of the peakedness factor\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(54p) | lw(24p) | lw(150p) . \fIParameters:\fR \(em | lockage 0.01; .T& lw(54p) | lw(24p) | lw(150p) . { \(em | fIMedium\fR day\(hyto\(hyday variation allowance; } .T& lw(54p) | lw(24p) | lw(150p) . { \(em | eighted mean peakedness factor. } .TE .TS center box; lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . Number of trunks required 1.0\ 1.2\ 1.4\ 1.6\ 1.8\ 2.0\ 2.2\ 2.4\ 2.6\ 2.8\ 3.0\ 3.4\ 3.8\ 4.0\ \ 1 \ 0.06 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 2 \ 0.22 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 3 \ 0.53 \ 0.33 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 4 \ 0.94 \ 0.69 \ 0.50 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 5 \ 1.39 \ 1.14 \ 0.89 \ 0.67 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 6 \ 1.86 \ 1.61 \ 1.36 \ 1.08 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 7 \ 2.39 \ 2.11 \ 1.83 \ 1.58 \ 1.31 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 8 \ 2.94 \ 2.64 \ 2.36 \ 2.08 \ 1.81 \ 1.53 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 9 \ 3.53 \ 3.19 \ 2.89 \ 2.61 \ 2.33 \ 2.03 \ 1.75 \ 1.50 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ 10 \ 4.11 \ 3.78 \ 3.47 \ 3.17 \ 2.86 \ 2.58 \ 2.28 \ 2.00 \ 1.75 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ 11 \ 4.72 \ 4.39 \ 4.03 \ 3.72 \ 3.42 \ 3.14 \ 2.83 \ 2.53 \ 2.25 \ 1.97 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ 12 \ 5.36 \ 4.97 \ 4.64 \ 4.31 \ 4.00 \ 3.69 \ 3.39 \ 3.08 \ 2.78 \ 2.47 \ 2.22 \ 0.0\ \ 0.0\ \ 0.0\ 13 \ 6.00 \ 5.61 \ 5.25 \ 4.89 \ 4.56 \ 4.25 \ 3.94 \ 3.67 \ 3.33 \ 3.03 \ 2.72 \ 0.0\ \ 0.0\ \ 0.0\ 14 \ 6.64 \ 6.22 \ 5.86 \ 5.50 \ 5.17 \ 4.83 \ 4.53 \ 4.22 \ 3.92 \ 3.61 \ 3.28 \ 2.69 \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 15 \ 7.31 \ 6.89 \ 6.47 \ 6.11 \ 5.78 \ 5.42 \ 5.11 \ 4.78 \ 4.47 \ 4.19 \ 3.86 \ 3.22 \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 16 \ 7.97 \ 7.53 \ 7.11 \ 6.75 \ 6.39 \ 6.03 \ 5.69 \ 5.39 \ 5.06 \ 4.75 \ 4.44 \ 3.81 \ 3.19 \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 17 \ 8.64 \ 8.19 \ 7.78 \ 7.36 \ 7.00 \ 6.64 \ 6.31 \ 5.97 \ 5.64 \ 5.33 \ 5.03 \ 4.39 \ 3.75 \ 3.44 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 18 \ 9.33 \ 8.86 \ 8.42 \ 8.03 \ 7.64 \ 7.28 \ 6.92 \ 6.58 \ 6.25 \ 5.92 \ 5.61 \ 4.97 \ 4.31 \ 4.00 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 19 10.03 \ 9.53 \ 9.08 \ 8.67 \ 8.28 \ 7.89 \ 7.53 \ 7.19 \ 6.86 \ 6.53 \ 6.19 \ 5.58 \ 4.89 \ 4.58 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 20 10.69 10.19 \ 9.75 \ 9.33 \ 8.92 \ 8.53 \ 8.17 \ 7.81 \ 7.47 \ 7.14 \ 6.81 \ 6.17 \ 5.50 \ 5.17 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 21 11.42 10.89 10.42 \ 9.97 \ 9.56 \ 9.17 \ 8.81 \ 8.44 \ 8.08 \ 7.75 \ 7.42 \ 6.75 \ 6.11 \ 5.78 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 22 12.11 11.58 11.11 10.64 10.22 \ 9.83 \ 9.44 \ 9.06 \ 8.69 \ 8.36 \ 8.03 \ 7.36 \ 6.72 \ 6.39 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 23 12.83 12.28 11.78 11.33 10.89 10.47 10.08 \ 9.69 \ 9.33 \ 8.97 \ 8.64 \ 7.97 \ 7.33 \ 7.00 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 24 13.53 13.00 12.47 12.00 11.56 11.14 10.72 10.36 \ 9.97 \ 9.61 \ 9.25 \ 8.58 \ 7.94 \ 7.61 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 25 14.25 13.69 13.17 12.69 12.25 11.81 11.39 11.00 10.61 10.25 \ 9.89 \ 9.19 \ 8.56 \ 9.19 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 26 14.97 14.42 13.86 13.39 12.92 12.47 12.06 11.64 11.28 10.89 10.53 \ 9.83 \ 9.17 \ 8.81 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 27 15.69 15.11 14.58 14.08 13.61 13.14 12.72 12.31 11.92 11.53 11.17 10.44 \ 9.78 \ 9.42 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 28 16.44 15.83 15.28 14.78 14.28 13.83 13.39 12.97 12.58 12.19 11.81 11.08 10.39 10.06 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 29 17.17 16.56 16.00 15.47 14.97 14.53 14.08 13.64 13.25 12.83 12.47 11.72 11.03 10.67 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 30 17.92 17.28 16.72 16.17 15.67 15.19 14.75 14.31 13.92 13.50 13.11 12.36 11.64 11.31 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 31 18.64 18.03 17.42 16.89 16.39 15.89 15.44 15.00 14.58 14.17 13.78 13.03 12.28 11.94 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 32 19.39 18.75 18.14 17.58 17.08 16.58 16.11 15.67 15.25 14.83 14.44 13.67 12.92 12.56 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 33 20.14 19.47 18.86 18.31 17.78 17.28 16.81 16.36 15.92 15.50 15.11 14.33 13.58 13.19 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 34 20.89 20.22 19.61 19.03 18.50 18.00 17.50 17.06 16.61 16.17 15.78 14.97 14.22 13.86 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 35 21.64 20.97 20.33 19.75 19.22 18.69 18.19 17.75 17.28 16.86 16.44 15.64 14.86 14.50 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 36 22.39 21.69 21.06 20.47 19.92 19.42 18.92 18.44 17.97 17.53 17.11 16.31 15.53 15.14 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 37 23.14 22.44 21.81 21.19 20.64 20.11 19.61 19.14 18.67 18.22 17.81 16.97 16.19 15.81 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 38 23.89 23.19 22.53 21.94 21.36 20.83 20.31 19.83 19.36 18.92 18.47 17.64 16.86 16.47 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 39 24.64 23.94 23.28 22.67 22.08 21.56 21.03 20.53 20.06 19.61 19.17 18.33 17.53 17.11 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 40 25.42 24.69 24.03 23.39 22.81 22.25 21.75 21.25 20.75 20.31 19.86 19.00 18.19 17.78 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 41 26.17 25.44 24.78 24.14 23.56 22.97 22.44 21.94 21.47 21.00 20.56 19.69 18.86 18.44 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 42 26.94 26.19 25.50 24.86 24.28 23.72 23.17 22.67 22.17 21.69 21.25 20.36 19.53 19.11 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 43 27.72 26.97 26.25 25.61 25.00 24.44 23.89 23.36 22.86 22.39 21.94 21.06 20.19 19.81 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 44 28.47 27.72 27.00 26.36 25.75 25.17 24.61 24.08 23.58 23.08 22.64 21.75 20.89 20.47 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 45 29.25 28.47 27.78 27.11 26.47 25.89 25.33 24.81 24.31 23.81 23.33 22.44 21.56 21.14 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 46 30.03 29.25 28.53 27.86 27.22 26.64 26.06 25.53 25.00 24.50 24.03 23.14 22.25 21.83 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 47 30.81 30.00 29.28 28.61 27.97 27.36 26.78 26.25 25.72 25.22 24.75 23.83 22.94 22.50 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 48 31.58 30.78 30.03 29.36 28.72 28.11 27.53 26.97 26.44 25.94 25.44 24.53 23.64 23.19 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 49 32.36 31.56 30.81 30.11 29.44 28.83 28.25 27.69 27.17 26.64 26.17 25.22 24.33 23.89 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 50 33.14 32.31 31.56 30.86 30.19 29.58 29.00 28.42 27.89 27.36 26.86 25.92 25.03 24.58 .TE .nr PS 9 .RT .ad r \fBTable 5/E.521 (Recup.) [T5.521], p.7\fR .sp 1P .RT .ad b .RT .LP .bp .ce \fBH.T. [T6.521]\fR .ce TABLE\ 6/E.521 .ce \fBSingle\(hyhour capacity, in Erlangs, as a function of the number of trunks\fR .ce \fBand of the peakedness factor\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(54p) | lw(24p) | lw(150p) . \fIParameters:\fR \(em | lockage 0.01; .T& lw(54p) | lw(24p) | lw(150p) . { \(em | fIHigh\fR day\(hyto\(hyday variation allowance; } .T& lw(54p) | lw(24p) | lw(150p) . { \(em | eighted mean peakedness factor. } .TE .TS center box; lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . Number of trunks required 1.0\ 1.2\ 1.4\ 1.6\ 1.8\ 2.0\ 2.2\ 2.4\ 2.6\ 2.8\ 3.0\ 3.4\ 3.8\ 4.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 1 \ 0.06 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 2 \ 0.22 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 3 \ 0.53 \ 0.33 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 4 \ 0.94 \ 0.69 \ 0.50 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 5 \ 1.36 \ 1.14 \ 0.89 \ 0.67 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 6 \ 1.86 \ 1.61 \ 1.36 \ 1.08 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 7 \ 2.36 \ 2.08 \ 1.83 \ 1.58 \ 1.31 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 8 \ 2.89 \ 2.61 \ 2.33 \ 2.06 \ 1.81 \ 1.53 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . \ 9 \ 3.44 \ 3.14 \ 2.86 \ 2.58 \ 2.31 \ 2.03 \ 1.75 \ 1.50 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 10 \ 4.03 \ 3.69 \ 3.39 \ 3.11 \ 2.83 \ 2.56 \ 2.28 \ 2.00 \ 1.75 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 11 \ 4.61 \ 4.25 \ 3.94 \ 3.64 \ 3.36 \ 3.08 \ 2.81 \ 2.53 \ 2.25 \ 1.97 \ 0.0\ \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 12 \ 5.19 \ 4.83 \ 4.50 \ 4.19 \ 3.89 \ 3.61 \ 3.33 \ 3.06 \ 2.78 \ 2.47 \ 2.22 \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 13 \ 5.81 \ 5.42 \ 5.08 \ 4.78 \ 4.44 \ 4.17 \ 3.86 \ 3.58 \ 3.31 \ 3.03 \ 2.72 \ 0.0\ \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 14 \ 6.42 \ 6.03 \ 5.67 \ 5.33 \ 5.03 \ 4.72 \ 4.42 \ 4.14 \ 3.83 \ 3.58 \ 3.28 \ 2.69 \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 15 \ 7.03 \ 6.64 \ 6.28 \ 5.92 \ 5.61 \ 5.28 \ 4.97 \ 4.69 \ 4.39 \ 4.11 \ 3.83 \ 3.22 \ 0.0\ \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 16 \ 7.67 \ 7.25 \ 6.86 \ 6.53 \ 6.19 \ 5.86 \ 5.56 \ 5.25 \ 4.94 \ 4.67 \ 4.36 \ 3.81 \ 3.19 \ 0.0\ .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 17 \ 8.31 \ 7.86 \ 7.47 \ 7.11 \ 6.78 \ 6.44 \ 6.11 \ 5.81 \ 5.50 \ 5.22 \ 4.92 \ 4.36 \ 3.75 \ 3.44 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 18 \ 8.94 \ 8.50 \ 8.11 \ 7.72 \ 7.36 \ 7.03 \ 6.69 \ 6.39 \ 6.08 \ 5.78 \ 5.47 \ 4.89 \ 4.31 \ 4.00 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 19 \ 9.58 \ 9.14 \ 8.72 \ 8.33 \ 7.97 \ 7.64 \ 7.31 \ 6.97 \ 6.64 \ 6.33 \ 6.03 \ 5.44 \ 4.89 \ 4.58 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 20 10.22 \ 9.78 \ 9.36 \ 8.94 \ 8.58 \ 8.22 \ 7.89 \ 7.56 \ 7.22 \ 6.92 \ 6.61 \ 6.00 \ 5.44 \ 5.14 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 21 10.89 10.42 \ 9.97 \ 9.58 \ 9.19 \ 8.83 \ 8.50 \ 8.14 \ 7.83 \ 7.50 \ 7.19 \ 6.58 \ 6.00 \ 5.69 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 22 11.53 11.06 10.61 10.22 \ 9.83 \ 9.44 \ 9.08 \ 8.75 \ 8.42 \ 8.08 \ 7.78 \ 7.17 \ 6.56 \ 6.25 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 23 12.19 11.72 11.28 10.83 10.44 10.06 \ 9.69 \ 9.36 \ 9.00 \ 8.67 \ 8.36 \ 7.72 \ 7.14 \ 6.83 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 24 12.86 12.36 11.92 11.47 11.08 10.69 10.31 \ 9.94 \ 9.61 \ 9.28 \ 8.94 \ 8.31 \ 7.69 \ 7.39 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 25 13.53 13.03 12.56 12.11 11.69 11.31 10.94 10.56 10.22 \ 9.89 \ 9.56 \ 8.92 \ 8.28 \ 7.97 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 26 14.19 13.69 13.22 12.75 12.33 11.94 11.56 11.19 10.83 10.47 10.14 \ 9.50 \ 8.86 \ 8.56 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 27 14.89 14.36 13.86 13.42 12.97 12.58 12.19 11.81 11.44 11.08 10.75 10.08 \ 9.44 \ 9.14 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 28 15.56 15.03 14.53 14.06 13.64 13.22 12.81 12.42 12.06 11.69 11.36 10.69 10.03 \ 9.72 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 29 16.25 15.69 15.19 14.72 14.28 13.86 13.44 13.06 12.69 12.33 11.97 11.31 10.64 10.31 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 30 16.92 16.36 15.86 15.36 14.92 14.50 14.08 13.69 13.31 12.94 12.58 11.89 11.22 10.92 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 31 17.61 17.06 16.53 16.03 15.58 15.14 14.72 14.33 13.94 13.56 13.19 12.50 11.83 11.50 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 32 18.31 17.72 17.19 16.69 16.22 15.78 15.36 14.94 14.56 14.19 13.83 13.11 12.44 12.11 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 33 18.97 18.42 17.86 17.36 16.89 16.44 16.00 15.58 15.19 14.81 14.44 13.72 13.06 12.69 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 34 19.67 19.08 18.53 18.03 17.56 17.08 16.67 16.25 15.83 15.44 15.08 14.36 13.67 13.31 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 35 20.36 19.78 19.22 18.69 18.22 17.75 17.31 16.89 16.47 16.08 15.69 14.97 14.28 13.92 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 36 21.06 20.47 19.89 19.36 18.89 18.42 17.97 17.53 17.11 16.72 16.33 15.61 14.89 14.53 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 37 21.75 21.14 20.58 20.06 19.56 19.08 18.61 18.19 17.78 17.36 16.97 16.22 15.50 15.14 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 38 22.44 21.83 21.25 20.72 20.22 19.72 19.28 18.83 18.42 18.00 17.61 16.86 16.14 15.78 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 39 23.17 22.53 21.94 21.39 20.89 20.39 19.94 19.50 19.06 18.64 18.25 17.50 16.75 16.39 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 40 23.86 23.22 22.64 22.08 21.56 21.06 20.58 20.14 19.72 19.31 18.89 18.11 17.39 17.00 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 41 24.56 23.92 23.33 22.75 22.22 21.75 21.25 20.81 20.36 19.94 19.53 18.75 18.00 17.64 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 42 25.28 24.61 24.00 23.44 22.92 22.42 21.92 21.47 21.03 20.58 20.19 19.39 18.64 18.29 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 43 25.97 25.31 24.69 24.14 23.58 23.08 22.58 22.14 21.67 21.25 20.83 20.03 19.28 18.89 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 44 26.67 26.03 25.39 24.81 24.28 23.75 23.25 22.78 22.33 21.92 21.47 20.67 19.89 19.53 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 45 27.39 26.72 26.08 25.50 24.94 24.44 23.94 23.44 23.00 22.56 22.14 21.33 20.53 20.17 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 46 28.08 27.42 26.78 26.19 25.64 25.11 24.61 24.14 23.67 23.22 22.78 21.97 21.17 20.81 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 47 28.81 28.14 27.47 26.89 26.33 25.81 25.28 24.81 24.33 23.89 23.44 22.61 21.81 21.44 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 48 29.53 28.83 28.19 27.58 27.00 26.47 25.97 25.47 25.00 24.56 24.11 23.28 22.47 22.08 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 49 30.22 29.53 28.89 28.28 27.69 27.17 26.64 26.14 25.67 25.19 24.75 23.92 23.11 22.72 .T& lw(24p) | rw(12p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) | rw(18p) | rw(12p) . 50 30.94 30.25 29.58 28.97 28.39 27.83 27.31 26.81 26.33 25.86 25.42 24.58 23.75 23.36 .TE .nr PS 9 .RT .ad r \fBTable 6/E.521 (Recup.) [T6.521], p.8\fR .sp 1P .RT .ad b .RT .LP .bp .sp 1P .LP 3.2 \fIComputer implementation\fR .sp 9p .RT .PP When computer facilities are available, it is possible to automate the use of Tables 3/E.521 to 6/E.521. For that purpose, numerical algorithms have been developed and are described in\ [5]. .RT .sp 2P .LP \fB4\fR \fBExample\fR .sp 1P .RT .sp 1P .LP 4.1 \fILevel of day\(hyto\(hyday traffic variations\fR .sp 9p .RT .PP If the traffics offered to a final group over the 30\ busiest days are given (\fIM\fR\d1\u\ to\ \fIM\fR\d3\\d0\u) and if the mean load and variance are calculated to be 10\ and\ 20 respectively, then applying Figure\ 1/E.521, a \fIhigh\fR level of day\(hyto\(hyday traffic variations should be used. .RT .sp 1P .LP 4.2 \fIFuture traffic offered to the final group and peakedness factor\fR .sp 9p .RT .PP If the forecast of future traffics indicates that three parcels of traffic will be offered to the final group: .RT .LP \(em the overflow from 6\ circuits offered 7.8\ Erlangs, .LP \(em the overflow from 12\ circuits offered 10\ Erlangs, .LP \(em 7\ Erlangs offered directly, .LP then Table\ 7/E.521 can be developed. .LP .rs .sp 24P .ad r \fBTable 7/E.521 (Recup. + Corr.) T7.521 p.9\fR .sp 1P .RT .ad b .RT .PP Note that the values of \fIr\fR\d\fIi\fR\uare derived from Table\ 2/E.521 for \fImedium\fR level of day\(hyto\(hyday traffic variations; if the 30\ busiest day traffics for each of the high\(hyusage groups were available, a more appropriate level could be used for each group. .PP Now all the information required is available: using the capacity Table\ 6/E.521 for \fIhigh\fR level of day\(hyto\(hyday traffic variations, the average traffic offered to the final group\ \fIM\fR \ =\ 11.39 and a peakedness factor \fIz\fR \ =\ 1.3 (from interpolating between \fIz\fR \ =\ 1.2 and \fIz\fR \ =\ 1.4), it is calculated that 23\ circuits are required. .PP Note that if the measurements used in \(sc\ 4.1 above were not available, then to determine the level of day\(hyto\(hyday traffic variations it would have been necessary to use the default procedure of \(sc\ 1 above. .bp .PP Overflow traffic offered to the final group\ =\ 4.15\ Erlangs. .PP Total traffic offered to the final group\ =\ 11.15\ Erlangs. .PP The ratio\ 4.15/11.15\ =\ 0.37 is higher than\ 0.25 and hence a \fImedium\fR level of day\(hyto\(hyday traffic variations would have been used. .RT .sp 2P .LP \fBReferences\fR .sp 1P .RT .LP [1] \fITabellen f\*:ur die Planung von Fernsprecheinrichtungen\fR , Siemens u. Halske, M\*:unchen, 1961. .LP [2] WILKINSON (R. | .): Theories for toll traffic engineering in the USA (Figures 12 and 13), \fIBell System Technical Journal\fR , Vol.\ 35, March\ 1956. .LP [3] WILKINSON (R. | .): Simplified engineering of single stage alternate routing systems, \fIFourth International Teletraffic Congress\fR , London,\ 1964. .LP [4] WILKINSON (R. | .): Non\(hyrandom traffic curves and tables, \fIBell\fR \fITelephone Laboratories\fR , 1970. .LP [5] HILL (D. | .) and NEAL (S. | .): The traffic capacity of a probability\(hyengineered trunk group, \fIBell System Technical Journal\fR , September\ 1976. .sp 2P .LP \fBRecommendation\ E.522\fR .RT .sp 2P .sp 1P .ce 1000 \fBNUMBER\ OF\ CIRCUITS\fR \fB\ IN\ A\ \fR \fBHIGH\(hyUSAGE\ GROUP\fR .EF '% Fascicle\ II.3\ \(em\ Rec.\ E.522'' .OF '''Fascicle\ II.3\ \(em\ Rec.\ E.522 %' .ce 0 .sp 1P .sp 2P .LP \fB1\fR \fBIntroduction\fR .sp 1P .RT .PP For the economic planning of an alternate routing network the number of circuits in a high\(hyusage group should be determined so that the annual charges for the whole network arrangement are at a minimum. This is done under the constraint that given requirements for the grade of service are fulfilled. In the optimum arrangement, the cost per erlang of carrying a marginal amount of traffic over the high\(hyusage route or over the alternative route is the same. .RT .LP .rs .sp 7P .ad r \fBFigure 1/E.522 p.10\fR .sp 9p .RT .ad b .RT .PP The optimum number of high\(hyusage circuits, \fIn\fR , from one exchange\ (1) to another exchange\ (2) is therefore obtained from the following expression when the overflow traffic is routed over a transit exchange\ T (route\ 1\(hyT\(hy2, see Figure\ 1/E.522). \v'6p' .sp 1P .ce 1000 \fIF \dn\u\fR (\fIA\fR ) = \fIA\fR { fIE\fR \d1, \fIn\fR \u(\fIA\fR ) \(em \fIE\fR \d1, (\fIn\fR + 1) \u (\fIA\fR } = \fIM\fR \(mu @ { nnual~charge (1\(hy2) } over { nnual~charge (1\(hyT\(hy2) } @ .ce 0 .sp 1P .LP .sp 1 .PP \fIA\fR is the traffic flow offered, for the relation \*Q1\(hy2\*U, in the Erlang loss formula for a full availability group . The expression \fIF\fR\d\fIn\fR\u(\fIA\fR ) gives the marginal occupancy .FS Marginal occupancy is often called LTC (last trunk capacity). .FE (improvement function) for the high\(hyusage group, if one more circuit were added. .PP \fIM\fR is the \fImarginal utilization factor\fR .FS Marginal utilization factor is often called ATC (additional trunk capacity). .FE \fIfor the final route\fR \*Q1\(hyT\(hy2\*U (which has nothing to do with cost ratio), if one additional circuit were provided. The annual charges are marginal charges for adding one additional circuit to route \*Q1\(hy2\*U and likewise to route \*Q1\(hyT\(hy2\*U. .PP Planning of an alternate routing network is described in the technical literature (see [1] to\ [10]). .PP Annual charge as used in this Recommendation refers to investment costs. .bp .RT .sp 2P .LP \fB2\fR \fBRecommended practical method\fR .sp 1P .RT .sp 1P .LP 2.1 \fIField of application\fR .sp 9p .RT .PP It must be recognized that the conditions applying to alternative routing will vary widely between the continental network and the intercontinental network. Significant differences between the two cases apply to the length and cost of circuits, the traffic flow and the different times at which the busy hours occur. The method described attempts to take account of these factors in so far as it is practicable to do so in any simplified procedure. .RT .sp 1P .LP 2.2 \fITraffic statistics\fR .sp 9p .RT .PP The importance of reliable traffic estimates should be emphasized. Traffic estimates are required for each of the relations in question, for both the busy hour of the relation and for the busy hour of each link of the routes to which the traffic overflows. Since this may be affected by the .PP high\(hyusage arrangements finally adopted, it will be necessary to have traffic estimates for each relation covering most of the significant hours of the day. This applies particularly to the intercontinental network where the final routes carry traffic components with widely differing busy hours. .RT .sp 1P .LP 2.3 \fIBasis of the recommended method\fR .sp 9p .RT .PP The method is based on a simplification of the economic dimensioning equations described under\ 1. Introduction. The simplifying assumptions are: .RT .LP i) the ratios of the alternative high\(hyusage annual charges are grouped in classes and a single ratio selected as representative for each class. This is acceptable because total network costs are known to be relatively insensitive to changes in the annual charges ratio; .LP ii) the marginal utilization factor\ \fIM\fR applicable to the overflow routes is regarded as constant within a range of circuit group sizes; .ce \fBH.T. [T1.522]\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(72p) | lw(48p) . .T& cw(72p) | cw(48p) . { Size of group (number of circuits) } Value of \fIM\fR _ .T& cw(72p) | cw(48p) . For less than 10 0.6 .T& cw(72p) | cw(48p) . For 10 or more 0.8 _ .TE .nr PS 9 .RT .ad r \fBTable 1/E.522 (Recup.) [T1.522], p.11\fR .sp 1P .RT .ad b .RT .LP iii) each high\(hyusage group will be dimensioned against the cheapest alternative route to which traffic overflows. (That is, the effect of parallel alternative routes is ignored.) .PP Where greater precision is required in either network or individual route dimensioning, more sophisticated methods may be employed (see [5] and\ [7]). .sp 1P .LP 2.4 \fIDetermination of cost ratio\fR .sp 9p .RT .PP In continental and intercontinental working, the number of circuits to be provided in high\(hyusage circuit groups depends upon the ratio of the annual charges estimated by the Administrations involved. The annual charge ratio (see Table\ 1/E.522) is defined as: .RT .sp 1P .ce 1000 \fIR\fR = @ { nnual~charge~of~one~additional~circuit~on~the~alternative~route } over { nnual~charge~of~one~additional~circuit~on~the~high\(hyusage~route } @ .ce 0 .sp 1P .PP The \*Qannual charge of one additional circuit on the alternative route\*U is calculated by summing: .LP \(em the annual charge per circuit of each link comprising the alternative route, and .LP \(em the annual charge of switching one circuit at each intermediate switching centre. .bp .PP When a third Administration is involved, it may be necessary to calculate the annual charge for switching at the intermediate centre from the transit switching charge per holding minute .FS It may be necessary to calculate transit switching charge per holding minute from charge per conversation minute (efficiency factor is described in Recommendation\ E.506). .FE . This may be done as follows: .sp 1P .ce 1000 Annual charges for switching = \fIM\fR \(mu 60 \(mu \fIF\fR \(mu 26 \(mu 12 \(mu transit switching charge per holding minute. .ce 0 .sp 1P .PP In the calculation of the conversion factor \fIF\fR from busy hour to day, its dependence on the traffic offered to the high usage route, the overflow probability and the time difference should be taken into account. As a guideline, Table\ 1/E.522, which is calculated using the standard traffic profiles of Table\ 1/E.523, may be used. .ce \fBH.T. [T2.522]\fR .ce TABLE\ 1/E.522 .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(24p) | cw(33p) | cw(9p) sw(15p) sw(15p) sw(15p) sw(9p) sw(15p) sw(15p) sw(15p) sw(9p) sw(15p) sw(15p) sw(15p) sw(9p) , ^ | ^ | r | r | r | r | r | r | r | r | r | r | r | r | r. Offered traffic (erlangs) Overflow probability (%) Time difference 0 1 2 3 4 5 6 7 8 9 10 11 12 _ .T& lw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 1 2.6 3.2 3.7 3.8 2.7 2.3 2.3 1.7 3.2 2.4 2.2 2.0 2.7 .T& lw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 10 3.7 4.5 4.8 4.7 3.5 3.1 3.0 2.5 4.1 3.2 2.9 2.8 3.6 .T& lw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 20 4.5 5.2 5.4 5.3 4.0 3.7 3.5 3.1 4.7 3.8 3.4 3.4 4.2 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 5 30 5.1 5.8 6.0 5.8 4.6 4.2 4.0 3.7 5.1 4.3 3.9 4.0 4.8 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 40 5.7 6.4 6.5 6.3 5.1 4.7 4.5 4.2 5.6 4.8 4.4 4.6 5.3 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 50 6.3 6.9 7.0 6.8 5.6 5.2 5.0 4.7 6.0 5.3 5.0 5.1 5.8 _ .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 1 2.1 2.6 3.3 3.5 2.5 2.1 2.1 1.4 2.8 2.0 2.0 1.8 2.4 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 10 3.2 4.0 4.4 4.3 3.1 2.7 2.6 2.1 3.8 2.8 2.6 2.4 3.2 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 20 4.0 4.8 5.1 4.9 3.6 3.3 3.1 2.7 4.3 3.4 3.0 3.0 3.8 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 10 30 4.7 5.4 5.6 5.4 4.2 3.8 3.6 3.3 4.8 3.9 3.4 3.6 4.4 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 40 5.3 6.0 6.1 5.9 4.7 4.4 4.2 3.8 5.3 4.4 4.0 4.2 4.9 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 50 5.9 6.6 6.7 6.4 5.3 4.9 4.7 4.4 5.7 5.0 4.6 4.8 5.5 _ .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 1 1.6 2.0 2.8 3.1 2.2 1.8 2.0 1.2 2.4 1.7 1.8 1.6 2.1 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 10 2.7 3.3 3.9 3.9 2.7 2.4 2.3 1.7 3.3 2.4 2.3 2.0 2.7 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 20 3.5 4.2 4.6 4.4 3.2 2.8 2.7 2.2 3.9 3.0 2.6 2.5 3.3 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 25 30 4.2 5.0 5.2 5.0 3.7 3.4 3.2 2.8 4.4 3.5 3.0 3.1 3.9 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 40 4.8 5.6 5.8 5.5 4.3 3.9 3.8 3.4 4.9 4.0 3.5 3.7 4.5 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 50 5.5 6.2 6.3 6.1 4.9 4.5 4.3 4.0 5.4 4.6 4.1 4.4 5.1 _ .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 1 1.3 1.7 2.4 2.9 2.1 1.6 2.0 1.1 2.1 1.5 1.6 1.4 2.0 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 10 2.3 2.8 3.5 3.6 2.5 2.2 2.1 1.4 3.1 2.2 2.2 1.8 2.4 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 20 3.1 3.9 4.3 4.2 3.0 2.6 2.4 1.9 3.7 2.7 2.5 2.2 3.0 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 50 30 3.9 4.7 5.0 4.8 3.4 3.1 2.9 2.5 4.2 3.3 2.8 2.8 3.6 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 40 4.6 5.4 5.6 5.3 4.0 3.7 3.5 3.2 4.7 3.8 3.2 3.5 4.3 .T& cw(24p) | rw(33p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) | rw(15p) | rw(15p) | rw(15p) | rw(9p) . 50 5.3 6.0 6.1 5.9 4.7 4.3 4.2 3.8 5.2 4.3 3.8 4.2 4.9 .TE .LP \fINote\fR \ \(em\ Linear interpolation may be used to obtain intermediate results. .nr PS 9 .RT .ad r \fBTable 1/E.522 [T2.522], p.12\fR .sp 1P .RT .ad b .RT .LP .bp .PP The value determined for \fIR\fR should then be employed to select in Table\ 2/E.522 the precise (or next higher) value of annual charges ratio for use in traffic tables. The value of annual charges ratios may be grouped in the following general sets: .LP a) Within a single continent or other smaller closely connected land mass involving distances up to 1000\ miles, high traffic and frequently one\(hyway operation: \v'3p' .sp 1P .ce 1000 These values are tentative. Ranges and representative values of annual charges ratio require further study. .FE Annual charges ratio:\ \fIR\fR \ =\ 1.5; 2.0 ; 3.0; 4.0; 5.0; 6.0 and 7.0 \v'3p' .ce 0 .sp 1P .LP b) Intercontinental working involving long distances, small traffic and usually two\(hyway operation: \v'3p' .sp 1P .ce 1000 Annual charges ratio:\ \fIR\fR \ =\ 1.1; 1.3 ; 1.5; 2.0; 3.0; 4.0 and 5.0. .ce 0 .sp 1P .LP 2.5 \fIUse of method\fR .sp 9p .RT .PP High\(hyusage circuit groups carrying random traffic can be dimensioned from Table\ 2/E.522. .RT .LP \fIStep\ 1\fR \ \(em\ Estimate the annual charges ratio\ \fIR\fR as described under\ 2.4\ above. (There is little difference between adjacent ratios.) If this ratio is difficult to estimate, the values underlined in\ a) and\ b) of \(sc\ 2.4\ above, should be used. .LP \fIStep\ 2\fR \ \(em\ Consult Table\ 2/E.522 to determine the number of high\(hyusage circuits\ \fIN\fR . .PP \fINote\fR \ \(em\ When two values of\ \fIN\fR are given the right\(hyhand figure applies to alternative routes of more than 10\ circuits, the left\(hyhand figure applies to smaller groups. The left\(hyhand figure is omitted when it is no longer possible for the alternative route to be small. .sp 2P .LP \fB3\fR \fB24\(hyhour traffic profiles\fR .sp 1P .RT .PP The traffic value used in the method in \(sc\ 2 should be the value of traffic offered to the high\(hyusage route during the busy hour of the final .PP route. In the case that some of the busy hours of the circuit groups or links forming an alternative route do not coincide with the busy hour of the relation, the ensuing method should be followed to take 24\(hyhour traffic profiles into account (see [6], [8] and\ [9]). .PP The method consists of the following three basic steps: .RT .LP i) prepare hourly traffic demands for which dimensioning is to be done; .LP ii) size all circuit groups, high usage and final, for one hourly traffic demand; .LP iii) iterate the process in step ii) for each additional hourly matrix. .sp 1P .LP 3.1 \fIPreparation of hourly traffic demands\fR .sp 9p .RT .PP Each Administration gathers historical traffic data on an hourly basis in accordance with Recommendations\ E.500 and\ E.523. Using historical data and information contained in Recommendation\ E.506, hourly traffic demand forecasts are made, resulting in a series of hourly demands for each exchange to every other exchange. .RT .sp 1P .LP 3.2 \fISizing circuit groups for one\(hyhourly traffic demand\fR .sp 9p .RT .PP Using the methods in \(sc\ 2 and Recommendation E.521, trunk group sizes are prepared for the first hourly traffic demand disregarding other hourly traffic demands. .bp .RT .ce \fBH.T. [T3.522]\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(342p) . TABLE\ 2/E.522 .T& cw(342p) . { \fBNumber of high\(hyusage circuits for different values\fR \fBof offered traffic, annual charges ratios and sizes\fR \fBof overflow groups\fR } .TE .TS center box; cw(36p) | cw(30p) sw(30p) sw(30p) sw(30p) sw(30p) sw(30p) sw(30p) sw(30p) sw(30p) | cw(36p) , ^ | c | c | c | c | c | c | c | c | c | ^ , ^ | l s s s s s s s s ^ | c | c | c | c | c | c | c | c | c | ^ , ^ | l s s s s s s s s. { Traffic offered during network busy hour (erlangs) } Annual charges ratios { Number of circuits if there is no overflow route, for \fIp\fR = 0.01 } 1.1 1.3 1.5 2.0 3.0 4.0 5.0 6.0 7.0 { Minimum circuit occupancies for high\(hyusage traffic } 0.545/0.727 0.46/0.615 0.4/0.53 0.3/0.4 0.2/0.26 0.15/0.2 0.12/0.16 0.1/0.13 0.085/0.114 { \fIN\fR , | umber of high usage circuits \fIA/B\fR , where \fIA\fR | s for less than 10 circuits in the overflow group (\fIM\fR = 0.6) \fIB\fR | s for 10 or more circuits in the overflow group (\fIM\fR = 0.8) } _ .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 1.5\ 1/0\ \ 1/0\ \ \ 2/1\ \ \ 2/2\ \ \ 3/2\ \ \ 3/3\ \ \ 4/3\ \ 4/3\ \ 4/4\ \ \ 6 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 1.75 1/0\ \ 2/1\ \ \ 2/1\ \ \ 3/2\ \ \ 3/3\ \ \ 4/3\ \ \ 4/4\ \ 4/4\ \ 4/4\ \ \ 6 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 2.0\ 1/0\ \ 2/1\ \ \ 2/2\ \ \ 3/2\ \ \ 4/3\ \ \ 4/4\ \ \ 4/4\ \ 5/4\ \ 5/5\ \ \ 7 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 2.25 2/0\ \ 2/1\ \ \ 3/2\ \ \ 3/3\ \ \ 4/4\ \ \ 5/4\ \ \ 5/4\ \ 5/5\ \ 5/5\ \ \ 7 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 2.5\ 2/0\ \ 3/1\ \ \ 3/2\ \ \ 4/3\ \ \ 5/4\ \ \ 5/5\ \ \ 5/5\ \ 6/5\ \ 6/5\ \ \ 7 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 2.75 2/1\ \ 3/2\ \ \ 3/2\ \ \ 4/3\ \ \ 5/4\ \ \ 5/5\ \ \ 6/5\ \ 6/6\ \ 6/6\ \ \ 8 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 3.0\ 3/1\ \ 3/2\ \ \ 4/3\ \ \ 4/4\ \ \ 5/5\ \ \ 6/5\ \ \ 6/6\ \ 6/6\ \ 7/6\ \ \ 8 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 3.5\ 3/1\ \ 4/2\ \ \ 4/3\ \ \ 5/4\ \ \ 6/5\ \ \ 7/6\ \ \ 7/6\ \ 7/7\ \ 7/7\ \ \ 9 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 4.0\ 4/2\ \ 4/3\ \ \ 5/4\ \ \ 6/5\ \ \ 7/6\ \ \ 7/7\ \ \ 8/7\ \ 8/7\ \ 8/8\ \ 10 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 4.5\ 4/2\ \ 5/3\ \ \ 6/4\ \ \ 6/6\ \ \ 7/7\ \ \ 8/7\ \ \ 8/8\ \ 9/8\ \ 9/8\ \ 10 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 5.0\ 5/3\ \ 6/4\ \ \ 6/5\ \ \ 7/6\ \ \ 8/7\ \ \ 9/8\ \ \ 9/9\ \ 9/9\ 10/9\ \ 11 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 5.5\ 5/3\ \ 6/5\ \ \ 7/5\ \ \ 8/7\ \ \ 9/8\ \ \ 9/9\ \ 10/9\ 10/10 10/10\ \ 12 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 6.0\ 6/3\ \ 7/5\ \ \ 7/6\ \ \ 8/7\ \ \ 9/9\ \ 10/9\ \ 11/10 11/10 11/11 \ 13 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 7.0\ 7/4\ \ 8/6\ \ \ 8/7\ \ 10/8\ \ 11/10\ 11/11\ 12/11 12/12 13/12 \ 14 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 8.0\ 8/5\ \ 9/7\ \ 10/8\ \ 11/10\ 12/11\ 13/12\ 13/13 14/13 14/13 \ 15 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ \ 9.0\ \ /6\ \ \ /8\ \ \ \ /9\ \ \ \ /11\ \ \ /12\ \ \ /13\ \ \ /14 \ \ /14 \ \ /15 \ 17 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 10.0\ \ /7\ \ \ /9\ \ \ \ /10\ \ \ /12\ \ \ /14\ \ \ /15\ \ \ /15 \ \ /16 \ \ /16 \ 18 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 12.0\ \ /9\ \ \ /11\ \ \ /12\ \ \ /14\ \ \ /16\ \ \ /17\ \ \ /18 \ \ /18 \ \ /19 \ 20 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 15.0\ \ /12\ \ /14\ \ \ /16\ \ \ /18\ \ \ /20\ \ \ /21\ \ \ /21 \ \ /22 \ \ /22 \ 24 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 20.0\ \ /16\ \ /19\ \ \ /21\ \ \ /23\ \ \ /25\ \ \ /27\ \ \ /28 \ \ /28 \ \ /29 \ 30 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 25.0\ \ /21\ \ /24\ \ \ /26\ \ \ /29\ \ \ /31\ \ \ /33\ \ \ /33 \ \ /34 \ \ /35 \ 36 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 30.0\ \ /26\ \ /29\ \ \ /31\ \ \ /34\ \ \ /37\ \ \ /38\ \ \ /39 \ \ /40 \ \ /41 \ 42 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 40.0\ \ /36\ \ /39\ \ \ /42\ \ \ /45\ \ \ /48\ \ \ /50\ \ \ /51 \ \ /52 \ \ /52 \ 53 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 50.0\ \ /45\ \ /49\ \ \ /52\ \ \ /55\ \ \ /59\ \ \ /61\ \ \ /62 \ \ /63 \ 64 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 60.0\ \ /55\ \ /60\ \ \ /62\ \ \ /66\ \ \ /70\ \ \ /72\ \ \ /73 \ 75 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . \ 80.0\ \ /74\ \ /80\ \ \ /83\ \ \ /87\ \ \ /92\ \ \ /94\ \ \ /95 \ 96 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(36p) . 100.0\ \ /94\ \ /100 \ \ /103 \ \ /108 \ \ /113 \ \ /116 117 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | lw(90p) | cw(36p) . 120.0\ \ /113 \ /120 \ \ /124 \ \ /129 \ \ /134 \ \ /137 { Direct final circuit groups are } 138 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | lw(90p) | cw(36p) . 150.0\ \ /143 \ /150 \ \ /154 \ \ /160 \ \ /166 \ \ /169 economical within this area. 170 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | lw(30p) | lw(30p) | lw(30p) | lw(30p) | cw(36p) . 200.0\ \ /192 \ /200 \ \ /205 \ \ /212 \ \ /219 221 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | lw(30p) | lw(30p) | lw(30p) | lw(30p) | cw(36p) . 250.0\ \ /241 \ /250 \ \ /256 \ \ /263 \ \ /271 273 .T& cw(36p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | cw(30p) | lw(30p) | lw(30p) | lw(30p) | lw(30p) | cw(36p) . 300.0\ \ /290 \ /300 \ \ /306 \ \ /315 \ \ /323 324 _ .TE .nr PS 9 .RT .ad r \fBTable 2/E.522 (Recup. + Corr.) [T3.522], p.13\fR MONTAGE\ \ \fB\*`a l'italienne, reprendre des originaux\fR .ad b .RT .LP .bp .sp 1P .LP 3.3 \fIIterating for each additional hourly traffic matrix\fR .sp 9p .RT .PP In sizing the circuit groups for the second hourly traffic demand, the method is provided with the circuit quantities resulting from the previous step, and is constrained solely to increasing circuit group sizes; i.e., if the circuit group sizes for the first hourly traffic demand were greater than for the second hourly demand, then the circuit group sizes for the first hourly traffic demand would be retained. .PP All additional hourly traffic demands are processed in the same iterative manner. The resulting circuit group sizes then satisfy the traffic demands for all hours being considered (see Annex\ A for a computational example). .RT .sp 1P .LP 3.4 \fIProcessing sequence\fR .sp 9p .RT .PP Processing may start with the first hour of traffic demand, .PP however, experiments have indicated that efficiencies of the network can be improved if processing starts with the hour with the smallest total traffic demand. It should be noted that this method gives us suboptimal networks, which may be improved by manual refinements. .RT .sp 2P .LP \fB4\fR \fBMinimum outlay alternate routing networks\fR .sp 1P .RT .PP The method below allows Administrations to adjust alternate routing networks to take into account existing revenue accounting divisions. .PP The method consists of the following steps: .RT .LP i) Obtain 24\(hyhour traffic profiles in accordance with Recommendations\ E.500 and\ E.523; .LP ii) Compute circuit quantities and costs for a no\(hyoverflow network in accordance with Recommendation\ E.520; .LP iii) Compute monthly overflow minutes (holding time) at varying percentages of busy\(hyhour overflow. This is done by applying three conversion factors to the busy hour overflow erlangs: .LP \(em Ratio of holding minutes to erlangs: a fixed value of 60. .LP \(em Daily overflow to busy\(hyhour overflow ratio: a value that depends on the 24\(hyhour traffic profile and the degree of overflow. .LP \(em Monthly overflow to daily overflow ratio (Recommendation\ E.506): a value that depends on the day\(hyto\(hyday pattern within a month and the degree of overflow. .LP iv) Starting with the network calculated in step ii): .LP \(em reduce the high usage circuits by one circuit, .LP \(em calculate overflow to final circuit groups, .LP \(em dimension final circuit groups in accordance with Recommendation\ E.521, .LP \(em calculate circuit costs and transit charges; .LP v) Iterate step iv) until the minimum outlay (circuit costs plus transit charges) for terminal administrations is reached (see Annex\ B for computational example). .sp 2P .LP \fB5\fR \fBService considerations\fR .sp 1P .RT .PP On intercontinental circuits, where both\(hyway operation is employed, a minimum of two circuits may be economical. Service considerations may also favour an increase in the number of direct circuits provided, particularly where the annual charges ratio approaches unity. .PP Although the dimensioning of high\(hyusage groups is normally determined .PP by traffic flows and annual charges ratios, it is recognized that such groups form part of a network having service requirements relative to the subscriber. The ability to handle the offered traffic with acceptable traffic efficiency should be tempered by the overall network considerations on quality of service. .PP The quality of service feature, which is of primary importance in a system of high\(hyusage and final circuit groups, is the advantage derived from direct circuits versus multi\(hylink connections. A liberal use of direct high\(hyusage circuit groups, taking into account the economic factors, favours a high quality of service to the subscriber. It is recommended that new high\(hyusage groups should be provided whenever the traffic flow and cost ratios are not conclusive. This practice may result in direct high\(hyusage groups of two circuits or more. .bp .PP The introduction of high\(hyusage groups improves the overall grade of service and provides better opportunities of handling traffic during surges and breakdown conditions. When high\(hyusage links bypass the main final routes the introduction of high\(hyusage routes can assist in avoiding expenses which might otherwise be incurred in keeping below the maximum number of long\(hydistance links in series. In the future, more measurements of traffic flows may be necessary for international accounting purposes and high\(hyusage circuits should make this easier. \v'1P' .RT .ce 1000 ANNEX\ A .ce 0 .ce 1000 (to Recommendation E.522) .sp 9p .RT .ce 0 .ce 1000 \fBExample of\fR \fBnetwork dimensioning\fR \fBtaking into account\fR .sp 1P .RT .ce 0 .ce 1000 \fB24\(hyhour traffic profiles\fR .ce 0 .LP A.1 \fIAssumptions\fR (see also Figure A\(hy1/E.522) .sp 1P .RT .PP Calculations are performed under the following conditions: .RT .LP 1) Time difference: .LP A is\ \ 9 hours west of B .LP C is\ \ 5 hours west of A .LP B is\ 10 hours west of C .LP 2) Traffic profiles: .LP 24\(hyhour traffic profiles as per Table 1/E.523 are used. .LP 3) Busy hour traffic: .LP A\(hyB\ \ 50 erlangs .LP A\(hyC\ 100 erlangs .LP C\(hyB\ \ 70 erlangs .LP 4) Cost ratio: .LP \fIR\fR = 1.3 .LP .rs .sp 9P .ad r \fBFigure A\(hy1/E.522 p.14\fR .sp 1P .RT .ad b .RT .sp 1P .LP A.2 \fINumerical results\fR .sp 9p .RT .PP 24 hourly traffic demands are processed. The order of processing are from the hour with the smallest total\ traffic demand to the hour with the largest total traffic demand. Computational results are given in Table\ A\(hy1/E.522. .bp .RT .ce \fBH.T. [T4.522]\fR .ce TABLE\ A\(hy1/E.522 .ce \fBNumerical results\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(18p) | cw(57p) | cw(51p) | cw(51p) | cw(51p) . Hour Hourly traffic demand { Number of circuits obtained by single hour dimensioning (disregarding lower bounds imposed by the previous iterative stage) } { Number of circuits obtained considering lower bounds imposed by the previous iterative stage } { Number of circuits required to meet multiple hourly traffic demands } _ .TE .TS center box; cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | lw(17p) . A\(hyB A\(hyC C\(hyB A\(hyB A\(hyC C\(hyB A\(hyB A\(hyC C\(hyB A\(hyB A\(hyC C\(hyB _ .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 6 17.50 \ \ 5.00 \ 3.50 17 \ 19 17 17 \ 19 17 17 \ 19 17 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 7 20.00 \ \ 5.00 \ 3.50 19 \ 20 18 19 \ 20 18 19 \ 20 18 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 5 \ 2.50 \ \ 5.00 28.00 \ 1 \ 14 41 19 \ 11 39 19 \ 20 39 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 4 \ 2.50 \ \ 5.00 35.00 \ 1 \ 14 49 19 \ 11 47 19 \ 20 47 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 8 37.50 \ \ 5.00 \ 3.50 37 \ 23 22 19 \ 38 37 19 \ 38 47 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 9 40.00 \ \ 5.00 \ 3.50 39 \ 24 23 19 \ 41 40 19 \ 41 47 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 3 \ 2.50 \ \ 5.00 45.50 \ 1 \ 14 61 19 \ 11 59 19 \ 41 59 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 18 \ 2.50 \ 50.00 \ 3.50 \ 1 \ 66 12 19 \ 64 \ 9 19 \ 64 59 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 10 50.00 \ \ 5.00 \ 3.50 49 \ 26 25 \ 9 \ 61 59 19 \ 64 59 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 19 \ 2.50 \ 60.00 \ 3.50 \ 1 \ 77 12 19 \ 75 \ 9 19 \ 75 59 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 20 \ 2.50 \ 60.00 \ 3.50 \ 1 \ 77 12 19 \ 75 \ 9 19 \ 75 59 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 22 12.50 \ 30.00 24.50 12 \ 45 39 12 \ 45 39 19 \ 75 59 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 2 \ 2.50 \ \ 5.00 63.00 \ 1 \ 14 80 19 \ 11 78 19 \ 75 78 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 17 \ 2.50 \ 70.00 \ 3.50 \ 1 \ 87 12 19 \ 85 \ 9 19 \ 85 78 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 1 \ 2.50 \ \ 5.00 70.00 \ 1 \ 14 87 19 \ 11 85 19 \ 85 85 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 23 20.00 \ 20.00 42.00 19 \ 36 60 19 \ 36 60 19 \ 85 85 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 11 47.50 \ 25.00 17.50 47 \ 46 38 \ 3 \ 85 77 19 \ 85 85 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 21 12.50 \ 55.00 24.50 12 \ 73 39 12 \ 73 39 19 \ 85 85 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 12 42.50 \ 30.00 21.00 42 \ 50 41 \ 3 \ 85 76 19 \ 85 85 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 16 \ 2.50 \ 90.00 \ 3.50 \ 1 109 12 19 107 \ 9 19 107 85 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . \ 0 20.00 \ 20.00 66.50 19 \ 36 87 19 \ 36 87 19 107 87 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 13 30.00 \ 65.00 35.00 29 \ 86 54 \ 5 107 76 19 107 87 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 15 17.50 100.00 28.00 17 121 44 19 120 43 19 120 87 .T& cw(18p) | cw(23p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) | cw(17p) . 14 27.50 \ 95.00 38.50 27 117 57 19 124 64 19 124 87 _ .TE .nr PS 9 .RT .ad r \fBTable A\(hy1/E.522 [T4.522], p.15\fR .sp 1P .RT .ad b .RT .PP This example relates to an intercontinental network where busy hours of the three traffic relations are widely different among each other. The busy hour of the relation A\(hyC, i.e.\ hour\ 15, is a low traffic period for the relations\ A\(hyB and\ C\(hyB. The busy hour of the relation C\(hyB, i.e.\ hour\ 1, is a low traffic period for the relations A\(hyB and\ A\(hyC. Similarly, the busy hour of the relation A\(hyB, i.e.\ hour\ 10, is a low traffic period for the relations A\(hyC and C\(hyB. .PP In this case, the single hour dimensioning method, where traffic data during the busy hour of the final circuit group are used for dimensioning, cannot be applied. If the single hour dimensioning method is applied, this results in considerable under\(hydimensioning. .PP If all the circuit groups are dimensioned as final, the required number of circuits are\ 64, 117 and\ 85 for the circuit groups A\(hyB, A\(hyC and\ C\(hyB, respectively. About 14% of the total number of circuits is saved by the use of alternate routing. .bp .RT .ce 1000 ANNEX\ B .ce 0 .ce 1000 (to Recommendation E.522) .sp 9p .RT .ce 0 .ce 1000 \fBExample of minimum outlay network dimensioning\fR .sp 1P .RT .ce 0 .LP .rs .sp 9P .ad r \fBFigure B\(hy1/E.522 p.16\fR .sp 1P .RT .ad b .RT .LP B.1 \fIAssumptions\fR (see also Figure B\(hy1/E.522) .sp 1P .RT .PP Calculations are performed under the following conditions: .RT .LP 1) Time difference: .LP A is 3 hours west of B .LP A is 3 hours west of C .LP No time difference between B and C .LP 2) Traffic profiles: .LP 24\(hyhour traffic profiles as per Table 1/E.523 are used. .LP 3) Busy hour traffic: .LP A\(hyB\ 16 erlangs .LP A\(hyC\ 33 erlangs .LP C\(hyB\ 33 erlangs .LP 4) Each Administration monthly cost per circuit: .LP A\(hyB\ 1000 units .LP A\(hyC\ 1000 units .LP C\(hyB\ \ 800 units .LP 5) Transit charge per holding minute to each terminal Administration: .LP 1/2 unit .LP 6) Conversion factors: .LP i) Holding minutes/erlangs:\ 60 .LP ii) Daily overflow/busy hour overflow .LP This conversion factor (\fIF\fR ) is calculated according to the guideline given in \(sc\ 2.4. .LP iii) Monthly overflow/daily overflow:\ 26 .LP where medium social contact per Recommendation E.502 is assumed. .LP 7) Grade\(hyof\(hyservice (GOS) on final circuit groups:\ 0.01 .sp 1P .LP B.2 \fINumerical results\fR .sp 9p .RT .PP Numerical results are shown in Table B\(hy1/E.522. The number of circuits C\(hyB does not increase because of the 24\(hyhour traffic profiles matching. The number of high usage circuits A\(hyB in the minimum outlay network is larger than that in the minimum cost network. The impact of considering transit charges in dimensionings is always in the direction of less overflow. .bp .RT .ce \fBH.T. [T5.522]\fR .ce TABLE\ B\(hy1/E.522 .ce \fBNumerical results\fR .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; cw(84p) | cw(144p) . Network results { Economic results (\(mu 1000 units/month) } _ .TE .TS center box; cw(36p) | cw(48p) | cw(48p) | cw(48p) | cw(48p) . { Busy\(hyhour overflow probability } Number of circuits Circuit costs Transit charges Total outlay _ .TE .TS center box; cw(36p) | cw(20p) | cw(14p) | cw(14p) | cw(20p) | cw(14p) | cw(14p) | cw(20p) | cw(14p) | cw(14p) | cw(20p) | cw(14p) | lw(14p) . A\(hyB A\(hyC C\(hyB A B C A B C A B C _ 0.0000 25 45 45 70 61 81 \(em \(em \(em 70.0 61.0 81.0 0.0090 25 45 45 70 61 81 0.3 0.3 \ (0.7) 70.3 61.3 80.3 0.0151 24 45 45 69 60 81 0.6 0.6 \ (1.3) 69.6 60.6 79.7 0.0221 23 45 45 68 59 81 0.9 0.9 \ (1.9) 68.9 59.9 79.1 0.0331 22 46 45 68 58 82 1.4 1.4 \ (2.9) 69.4 59.4 79.1 0.0471 21 46 45 67 57 82 2.1 2.1 \ (4.2) 69.1 59.1 77.8 0.0641 20 46 45 66 56 82 3.0 3.0 \ (6.0) 69.0 59.0 76.0 Minimum outlay for A and B 0.0861 19 47 45 66 55 83 4.2 4.2 \ (8.4) 70.2 59.2 74.5 0.1121 18 47 45 65 54 83 5.7 5.7 (11.5) 70.7 59.7 71.5 Minimum cost network 0.142\ 17 48 45 65 53 84 7.6 7.6 (15.1) 72.6 60.6 68.9 .TE .nr PS 9 .RT .ad r \fBTable B\(hy1/E.522 [T5.522], p.17\fR .sp 1P .RT .ad b .RT .sp 2P .LP \fBReferences\fR .sp 1P .RT .LP [1] WILKINSON (R. | .): Theories for toll traffic engineering in the USA, \fIBell Syst. Tech. J.\fR , 1956, No.\ 35, pp.\ 421\(hy514. .LP [2] WILKINSON (R. | .): Simplified engineering of single stage alternate routing systems, \fIFourth International Teletraffic Congress\fR , London,\ 1964. .LP [3] RAPP (Y.): Planning of junction network in a multi\(hyexchange area. 1.\ General Principles, \fIEricsson Tech\fR ;\ 1964, No.\ 20,\ 1, pp.\ 77\(hy130. .LP [4] LEVINE (S. | .) and WERNANDER (M. | .): Modular engineering of trunk groups for traffic requirements, \fIFifth International Teletraffic Congress\fR , New York,\ 1967. .LP [5] PRATT (C. | .): The concept of marginal overflow in alternate routing, \fIFifth International Teletraffic Congress\fR , New York, 1967. .LP [6] EISENBERG (M.): Engineering traffic networks for more than one busy hour, \fIBell System Tech. \ J.\fR , 1977, Vol.\ 56, pp.\ 1\(hy20. .LP [7] AKIMARU (H.) \fIet al.\fR : Derivatives of Wilkinson formula and their application to optimum design of alternative routing systems, \fINinth\fR \fIInternational Teletraffic Congress\fR , Torremolinos,\ 1979. .LP [8] HORN (R. | .): A simple approach to dimensioning a telecommunication network for many hours of traffic demand, \fIInternational Conference on\fR \fICommunications\fR , Denver, 1981. .LP [9] BESHAI (M. | .): Traffic data reduction for multiple\(hyhour network dimensioning, \fISecond International Network Planning Symposium\fR , Brighton,\ 1983. .LP [10] LINDBERGER (K.): Simple approximations of overflow system quantities for additional demands in the optimization, \fITenth International Teletraffic\fR \fICongress\fR , Montreal, 1983. .bp .sp 2P .LP \fBRecommendation\ E.523\fR .RT .sp 2P .ce 1000 \fBSTANDARD\ \fR \fBTRAFFIC\ PROFILES\ FOR\fR .EF '% Fascicle\ II.3\ \(em\ Rec.\ E.523'' .OF '''Fascicle\ II.3\ \(em\ Rec.\ E.523 %' .ce 0 .sp 1P .ce 1000 \fBINTERNATIONAL\ TRAFFIC\ STREAMS\fR .ce 0 .sp 1P .PP The worldwide nature of the international telephone network, spanning as it does all possible time zones , has stimulated studies of the traffic streams between countries in different relative time locations. These studies have led to the development of standardized 24\(hyhour traffic profiles which, theoretically based and verified by measurements, would be useful for engineering purposes. In fact, these concepts can be applied to a variety of network situations: .sp 1P .RT .LP i) variable access satellite working where a large number of traffic streams with possibly differing traffic profiles share the pool of satellite circuits; .LP ii) combining of traffic streams on groups of terrestrial circuits which may be either high\(hyusage or final choice routes; .LP iii) detour routing of traffic between origin and destination countries to take advantage of prevailing low load conditions on the detour path. .PP In developing any such applications, account must be taken of the International Routing Plan (Recommendation\ E.171\ [1]) and of accepted accounting principles (Recommendation\ D.150\ [2]). .PP It must be recognized that the preferred basis for dimensioning consists of traffic profiles based on real traffic. Nevertheless, many countries have found the standard profiles presented in this Recommendation very useful where streams are too small to obtain reliable measurements or where no measurements are available. .PP For both\(hyway profiles , two equivalent methods of presentation are given in chart and tabular form. In Figure\ 1/E.523 hour\(hyby\(hyhour traffic volumes are shown in diagrammatically as percentages of the total daily traffic volume; such percentages are particularly convenient for tariff studies. In Table\ 1/E.523, hourly traffics are expressed as percentages of the busy hour\fR traffic , and this is convenient for engineering purposes. Time zone differences are given in whole hours only. Directional profiles are given in Tables\ 2/E.523 and\ 3/E.523. .PP Although tables are given for both\(hyway and directional traffic streams, it must be emphasized that at this stage only the both\(hyway profiles can be regarded as soundly supported by measurement. The directional profiles are theoretically based and supported by some measurements, but should be used with caution until adequate verification has been achieved. .PP The theoretical basis for the profiles presented here is contained in Annex\ A. It depends on a convenience function \fIf\fR (\fIt\fR )\fR which represents the profile of \fIlocal\fR daily traffic , where of course no time zone difference exists. The function \fIf\fR (\fIt\fR )\fR used for computation of the standard profile was derived by mathematical manipulation of measurements of the Tokyo\(hyOakland and Tokyo\(hyVancouver streams. Although these results have been supported by other measurements, it leaves open the possibility that the convenience function may vary from one country to another and that, strictly, these should be derived independently and then used to obtain a calculated profile for the international relation. It also seems that the convenience function for the country of destination should be given greater weight than that for the country of origin. These remarks suggest possible refinements, but are not quantified in this Recommendation. .RT .LP .rs .sp 10P .LP .bp .LP .rs .sp 47P .ad r \fBFigure 1/E.523 p.18\fR .sp 1P .RT .ad b .RT .LP .bp .ce \fBH.T. [T1.523]\fR .ce TABLE\ 1/E.523 .ce \fBStandard hourly bothway traffic patterns\fR .ce Local time in the more westerly country .ps 9 .vs 11 .nr VS 11 .nr PS 9 .TS center box; lw(216p) | cw(12p) . BH { 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 % } .TE .ce Unable to Convert Table .LP \fINote\ 1\fR \ \(em\ The 24\(hyhour profile of both\(hyway traffic between any two countries is read from left to right from the appropriate row of the table; all time differences can be expressed in the range 0\(hy12\ hours. Each entry is expressed as a percentage of the busy hour traffic. .LP \fINote\ 2\fR \ \(em\ The \fImore westerly\fR country of a traffic relation is the one from which we can proceed eastwards to the other through time zones not exceeding 12\ hours. .LP \fINote\ 3\fR \ \(em\ For network planning studies, UTC (Universal Coordinated Time) would normally be used so that all traffic streams are processed time consistently. Clearly if the more westerly country is \fIW\fR hours ahead of UTC (ignoring the international dateline), then the traffic at 0000\(hy0100\ UTC is obtained from the row corresponding to the time difference between the two countries at the column headed \fIW\fR . Alternatively, the first entry in the appropriate row gives the relative traffic intensity for the hour (24\(hy\fIW\fR ) to (25\(hy\fIW\fR ). .LP Example:\ For the traffic stream between the U.K. (UTC | | \ hour) and the central zone of USA (UTC + | 8\ hours), the time difference is 7 hours and the USA is regarded as the more westerly country, hence \fIW\fR | | 8. Thus from the table, the traffic during 0000\(hy0100\ UTC is 5 | of the busy hour traffic, and the busy hour is 1500\(hy1600\ UTC. .LP \fINote\ 4\fR \ \(em\ The column headed \*QBH %\*U gives the busy hour traffic volume as a percentage of the daily traffic volume. .LP \fBMONTAGE\fR \ \ \ Time difference (in hours) between two countries .nr PS 9 .RT .ad r \fBTable 1/E.523 [T1.523] p.19\fR .sp 1P .RT .ad b .RT .LP .bp .ce \fBH.T. [T2.523]\fR .ce TABLE\ 2/E.523 .ce \fBDiurnal distributions of eastbound international telephone traffic\fR .ce .ce Local time in the more westerly country .ps 9 .vs 11 .nr VS 11 .nr PS 9 .ce Unable to Convert Table .LP \fINote\fR \ \(em\ This table is based on \fIp\fR | | .4, \fIq\fR | | .6, i.e. greater weight is given to the convenience function of the called party (see Annex\ A). .LP \fBMONTAGE\fR \ \ \ Time difference (in hours) between two countries .nr PS 9 .RT .ad r \fBTable 2/E.523 [T2.523] p.20\fR .ad b .RT .ce \fBH.T. [T3.523]\fR .ce TABLE\ 3/E.523 .ce \fBDiurnal distributions of westbound international telephone traffic\fR .ce .ce Local time in the more westerly country .ps 9 .vs 11 .nr VS 11 .nr PS 9 .ce Unable to Convert Table .LP \fINote\fR \ \(em\ This table is based on \fIp\fR | | .4, \fIq\fR | | .6, i.e. greater weight is given to the convenience function of the called party (see Annex\ A). .LP \fBMONTAGE\fR \ \ \ Time difference (in hours) between two countries .nr PS 9 .RT .ad r \fBTable 3/E.523 [T2.523] p.21\fR .ad b .RT .LP .bp .ce 1000 ANNEX\ A .ce 0 .ce 1000 (to Recommendation E.523) .sp 9p .RT .ce 0 .ce 1000 \fBMathematical expression for the\fR \fBinfluence of time differences\fR .sp 1P .RT .ce 0 .ce 1000 \fBon the traffic flow\fR .ce 0 .PP A telephone call is initiated when a person wishes to call someone else, but both parties have to be on the line before the call is established. It is considered that a telephone call is made at a time which tends to be convenient for both the calling and called parties. The \fIdegree of\fR \fIconvenience\fR for making a telephone call is considered to be a periodical function of time\ \fIt\fR , whose period is 24\ hours. When the time difference between both parties is zero, the degree of convenience is denoted by\ \fIf\fR (\fIt\fR ), where\ \fIt\fR is local standard time. The graphic shape of the basic function\ \fIf\fR (\fIt\fR ) will be determined by the daily pattern of human activities, and will resemble, or fairly closely coincide with, the hour by hour traffic distribution in the national (or local) telephone network. .sp 1P .RT .PP It is assumed that the hourly traffic distribution F\d\\u(*t(\fIt\fR ), when a time difference of \(*t\ hours exists between the originating and called locations, is expressed as the geometric mean of convenience functions of two locations \(*t\ hours apart: \v'6p' .sp 1P .ce 1000 \fIF\fR \d\(*t, \u (\fIt\fR ) = k @ left { \fIf\fR (\fIt\fR ) \(mu~\fIf\fR (\fIt\fR~+~\(*t) right } @ \u1/2\d .ce 0 .sp 1P .LP .sp 1 where \v'6p' .ce 1000 k = 1/ @ pile { int above 24~hours } @ @ left { \fIf\fR (\fIt\fR ) \(mu~\fIf\fR (\fIt\fR~+~\(*t) right } @ \u1/2\d \fIdt\fR .ce 0 .ad r (A\(hy1) \v'1P' \v'2p' .ad b .RT .LP .sp 1 The sign of\ \(*t is positive when the time at the destination is ahead of the reference time, and negative when the time of destination is behind the reference time. .PP The distribution of equation\ (A\(hy1) represents the sum of the outgoing and incoming traffics. Expressions for the one\(hyway hourly traffic distributions can also be obtained by extending the concept of convenience function as follows. .PP Define convenience functions both for the caller\ \fIf\fR\d0\u(\fIt\fR )\fR and for the called party\ \fIf\fR\d\fIi\fR\u(\fIt\fR )\fR .Then the one\(hyway traffic distributions of east\(hybound and west\(hybound telephone calls, for the case of \(*t\ hour time\(hydifference, are similarly expressed as follows: \v'6p' .RT .LP .sp 1P .ce 1000 \fIF\fR \d\(*t, east \u (\fIt\fR ) = k @ left { \fIf\fR~\d0\u (\fIt\fR ) \(mu~\fIf\fR~\d\fIi\fR~\u (\fIt\fR~+~\(*t) right } @ \u1/2\d \v'6p' .ce 0 .sp 1P .ce 1000 k = 1/ @ pile { int above 24~hours } @ @ left { \fIf\fR~\d0\u (\fIt\fR ) \(mu~\fIf\fR~\d\fIi\fR~\u (\fIt\fR~+~\(*t) right } @ \u1/2\d \fIdt\fR .ce 0 .ad r (A\(hy2) \v'1P' .ad b .RT .sp 1P .ce 1000 \fIF\fR \d\(*t, west \u (\fIt\fR ) = k @ left { \fIf\fR~\d\fIi\fR~\u (\fIt\fR ) \(mu~\fIf\fR~\d0\u (\fIt\fR~+~\(*t) right } @ \u1/2\d \v'6p' .ce 0 .sp 1P .ce 1000 k = 1/ @ pile { int above 24~hours } @ @ left { \fIf\fR~\d\fIi\fR~\u (\fIt\fR ) \(mu~\fIf\fR~\d0\u (\fIt\fR~+~\(*t) right } @ \u1/2\d \fIdt\fR .ce 0 .ad r (A\(hy3) \v'1P' \v'2p' .ad b .RT .LP .sp 1 where .LP \fIt\fR is the local standard time of the west station and .LP \(*t is positive. .bp .PP It is natural that a caller makes a call considering the convenience of the called person, and therefore the convenience function of the called person\ \fIf\fR\d\fIi\fR\ucontributes more than the convenience of the caller\ \fIf\fR\d0\uto the directional distribution\ F. They can be written as follows: \v'6p' .ce 1000 \fIf\fR \d\fIi\fR \u (\fIt\fR ) = k \d1\u @ left { \fIf\fR (\fIt\fR ) right } @ $$2x:\fIp\fR _,\ \ \ \ \ \fIf\fR \d0\u (\fIt\fR ) = k \d2\u @ left { \fIf\fR (\fIt\fR ) right } @ $$2x:\fIq\fR _, .ce 0 .ad r (A\(hy4) .ad b .RT .LP .sp 1 .LP where .sp 1P .ce 1000 \fIp\fR \ >\ \fIq\fR \ \ and\ \ \fIp\fR \ +\ \fIq\fR \ =\ 2, .ce 0 .sp 1P .LP and where\ k\d1\uand\ k\d2\uare normalizing coefficients to ensure that: \v'6p' .sp 1P .ce 1000 @ pile { int above 24~hours } @ \fIf\fR \d\fIi\fR \u (\fIt\fR ) \fIdt\fR = 1,\ \ \ \ \ @ pile { int above 24~hours } @ \fIf\fR \d0\u (\fIt\fR ) \fIdt\fR = 1. .ce 0 .sp 1P .PP .sp 1 As to the values of\ \fIp\fR and\ \fIq\fR in equation\ (A\(hy4), it has been found empirically that the convenience of the called side\ \fIp\fR is considerably larger than that of originating side\ \fIq\fR , and appropriate values are roughly \fIp\fR \ =\ 1.4 and consequently \fIq\fR \ =\ 0.6. .sp 2P .LP \fBReferences\fR .sp 1P .RT .LP [1] CCITT Recommendation \fIInternational telephone routing plan\fR , Rec.\ E.171. .LP [2] CCITT Recommendation \fINew system for accounting in international\fR \fItelephony\fR , Rec.\ D.150. .LP .sp 2P .LP \fBBibliography\fR .sp 1P .RT .LP CASEY (J. | r.) and SHIMASAKI (N.): Optimal dimensioning of a satellite network using alternate routing concepts, \fISixth International Teletraffic\fR \fIConvention\fR , Munich,\ 1970. .LP RAPP (Y.): Planning of a junction network with non\(hycoincident busy hours, \fIEricsson Technics\fR , No.\ 1,\ 1971. .LP CABALLERO (P. | .) and D\o"I\(aa"AZ (F.): Optimization of networks of hierarchical structure with non\(hycoincident busy hours, \fISeventh International Teletraffic\fR \fIConvention\fR , Stockholm,\ 1973. .LP OTHA (T.): Network efficiency and network planning considering telecommunication traffic influenced by time difference, \fISeventh\fR \fIInternational Teletraffic Convention\fR , Stockholm,\ 1973. .LP .rs .sp 18P .LP .bp .sp 2P .LP \fBRecommendation\ E.524\fR .RT .sp 2P .sp 1P .ce 1000 \fBOVERFLOW\ APPROXIMATIONS\ FOR\ NON\(hyRANDOM\ INPUTS\fR .EF '% Fascicle\ II.3\ \(em\ Rec.\ E.524'' .OF '''Fascicle\ II.3\ \(em\ Rec.\ E.524 %' .ce 0 .sp 1P .LP \fB1\fR \fBIntroduction\fR .sp 1P .RT .PP This Recommendation introduces approximate methods for the calculation of blocking probabilities for individual traffic streams in a circuit group arrangement. It is based on contributions submitted in the Study Period 1984\(hy1988 and is expected to be amended and expanded in the future (by adding the latest developments of methods). .PP The considered methods are necessary complements to those included in the existing Recommendation\ E.521 when it is required to take into account concepts such as cluster engineering with service equalization, service protection and end\(hyto\(hyend grade of service. Recommendation\ E.521 is then insufficient as it is concerned with the grade of service for only one non\(hyrandom traffic stream in a circuit group. .PP Design methods concerning the above\(hymentioned areas are subject to further study and this Recommendation will serve as a reference when, in the future, Recommendation\ E.521 is complemented or replaced. .PP In this Recommendation the proposed methods are evaluated in terms of accuracy, processing time, memory requirements and programming effort. Other criteria may be relevant and added in the future. .PP The proposed methods are described briefly in \(sc\ 2. Section\ 3 defines a set of examples of circuit group arrangements with exactly calculated (exact resolution of equations of state) individual blocking probabilities, to which the result of the methods can be compared. This leads to a table in \(sc\ 4, where for each method the important criteria are listed. The publications cited in the reference section at the end contain detailed information about the mathematical background of each of the methods. .RT .sp 2P .LP \fB2\fR \fBProposed methods\fR .sp 1P .RT .PP The following methods are considered: .RT .LP a) Interrupted Poisson Process (IPP) method, .LP b) Equivalent Capacity (EC) method, .LP c) Approximative Wilkinson Wallstr\*:om (AWW) method. .sp 1P .LP 2.1 \fIIPP method\fR .sp 9p .RT .PP IPP (Interrupted Poisson Process) is a Poisson process interrupted by a random switch. The on\(hy/off\(hyduration of the random switch has a negative exponential distribution. Overflow traffic from a circuit group can be accurately approximated by an IPP, since IPP can represent bulk characteristics of overflow traffic. IPP has three parameters, namely, on\(hyperiod intensity and mean on\(hy/off\(hyperiod durations. To approximate overflow traffic by an IPP, those three parameters are determined so that some moments of overflow traffic will coincide with those of IPP. .PP The following two kinds of moment match methods are considered in this Recommendation: .RT .LP \(em three\(hymoment match method [1] \(em where IPP parameters are determined so that the first three moments of IPP will coincide with those of overflow traffic; .LP \(em four\(hymoment ratio match method [2] where IPP parameters are determined so that the first moment and the ratios of the 2nd/3rd and 7th/8th\ binomial moments of IPP will coincide with those of overflow traffic. .bp .PP To analyze a circuit group where multiple Poisson and overflow traffic streams are simultaneously offered, each overflow stream is approximated by an IPP. The IPP method is well suited to computer calculation. State transition equations of the circuit group with IPP inputs can be solved directly and no introduction of equivalent models is necessary. Characteristics of overflow traffic can be obtained from the solution of state transition equations. The main feature of the IPP method is that the individual means and variances of the overflow traffic can be solved. .sp 1P .LP 2.2 \fIEC method\fR .sp 9p .RT .PP The EC (Equivalent Capacity) method [3] does not use the traffic\(hymoments but the transitional behaviour of the primary traffic, by introducing a certain function\ \(*r"(\fIn\fR ) versus the equivalent capacity\ (\fIn\fR ) of the partial overflow traffic, as defined by the recurrent process: \v'6p' .RT .ad r .ad b .RT .LP if \fIn\fR | is a positive integer and approximated by linear interpolation, if not. .PP A practical approximation, considering the predominant overflow congestion states only, leads to the equations: \v'6p' .ad r .ad b .RT .LP with: \v'6p' .ce 1000 \fID\fR\d\fIi\fR\u(\fIn\fR ) = 1 + \fIa\fR\d\fIi\fR\u @ left [ \(*r"\fI\fI\d\fIi\fR\u(\fIn\fR ) \(em~\(*r"\fI\fI\d\fIi\fR\u(\fIn\fR~\(em~1) right ] @ .ce 0 .ad r (2\(hy3) .ad b .RT .LP .sp 1 defining the equivalent capacity (\fIn\fR\d\fIi\fR\u) of the partial overflow traffic labelled\ \fIi\fR , and influenced by the mutual dependency between the partial overflow traffic streams. .PP The mean value of the partial second overflow is: \v'6p' .ce 1000 \fIO\fR\d\fIi\fR\u= \fIa\fR\d\fIi\fR\u\(*p \(*r"\fI\fI\d\fIi\fR\u(\fIn\fR .EF '% \fIi)'' .OF '''\fIi) %' .ce 0 .ad r (2\(hy4) .ad b .RT .LP .sp 1 .LP where \(*p is the time congestion of the overflow group. .PP The partial GOS (grade of service) equalization is fulfilled if: \v'6p' .ce 1000 \(*r"\fI\fI\d\fIi\fR\u(\fIn\fR\d\fIi\fR\u) = \fIC\fR .ce 0 .ad r (2\(hy5) .ad b .RT .LP .sp 1 \fIC\fR | eing a constant to be chosen. .sp 1P .LP 2.3 \fIAWW method\fR .sp 9p .RT .PP The AWW (Approximative Wilkinson Wallstr\*:om) method uses an approximate ERT (Equivalent Random Traffic) model based on an improvement of Rapp's approximation. The total overflow in traffic is split up in the individual parts by a simple expression, see Equations\ (2\(hy7) and\ (2\(hy9). To calculate the total overflow traffic, any method can be used. An approximate .PP Erlang formula calculation for which the speed is independent of the size of the calculated circuit group is given in\ [4]. .bp .PP The following notations are used: .RT .LP \fIM\fR mean of total offered traffic; .LP \fIV\fR variance of total offered traffic; .LP \fIZ\fR \fIV\fR /\fIM\fR ; .LP \fIB\fR mean blocking of the studied group; .LP \fIm\fR\d\fIi\fR\u,\ \fIv\fR\d\fIi\fR\u,\ \fIz\fR\d\fIi\fR\u,\ \fIb\fR\d\fIi\fR\u corresponding quantities for an individual traffic stream; .LP ~ is used for overflow quantities. .sp 1P .LP 2.3.1 \fIBlocking of overflow traffic\fR .sp 9p .RT .PP For overflow calculations, an approximate ERT\(hymodel is used. By numerical investigations, a considerable improvement has been found to Rapp's classical approximation for the fictitious traffic. The error added by the approximation is small compared to the error of the ERT\(hymodel. It is known that ERT underestimates low blockings when mixing traffic of diverse peakedness\ [2]. The formula, which was given in\ [4] (although with one printing error), is for \fIZ\fR \ >\ 1: \v'6p' .RT .sp 1P .ce 1000 \fIA\fR * \( = \fIV\fR + \fIZ\fR (\fIZ\fR \(em 1) (2 + \(*g\uD\dlF`) .ce 0 .sp 1P .LP .sp 1 where \v'6p' .sp 1P .ce 1000 \(*g = (2.36 \fIZ\fR \(em 2.17) log { + (\fIz\fR \(em 1)/[\fIM\fR (\fIZ\fR + 1.5) } .ce 0 .sp 1P .LP .sp 1 .LP and \v'6p' .ce 1000 \(*b = \fIZ\fR /(1.5\fIM\fR + 2\fIZ\fR \(em1.3) .ce 0 .ad r (2\(hy6) .ad b .RT .sp 1P .LP .sp 1 2.3.2 \fIWallstr\*:om formula for individual blocking\fR .sp 9p .RT .PP There has been much interest in finding a simple and accurate formula for the individual blocked traffic \fI\*~m\fI\d\fIi\fR\u. Already in\ 1967, Katz [5] proposed a formula of the type \v'6p' .RT .ce 1000 \fI\*~m\fI\d\fIi\fR\u= \fIm\fR\d\fIi\fR\u\fIB\fR (1 \(em \fIw\fR + \fIwz\fI\d\fIi\fR\u/\fIZ\fR ) .ce 0 .ad r (2\(hy7) .ad b .RT .LP .sp 1 with \fIw\fR | eing a suitable expression. Wallstr\*:om proposed a very simple one but with reasonable results\ [6],\ [2]: \v'6p' .ce 1000 \fIw\fR = 1 \(em \fIB\fR .ce 0 .ad r (2\(hy8) .ad b .RT .PP .sp 1 One practical problem is, however, that a small peaked substream could have a blocking \fIb\fR\d\fIi\fR\u\ >\ 1 with this formula. To avoid such unreasonable results a modification is used in this case. Let \fIz\fR\dm\\da\\dx\ube the largest individual\ \fIz\fR\d\fIi\fR\u. .LP Then the value used is \v'6p' .ad r [Formula Deleted]