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Base Station SubsystemTypically• 60 - 80 % of the Investment
Cell
TRX 1TRX 2TRX 3TRX 4TRX 5TRX 6
BTS
Fq 1, 7
Fq 3, 9
TS 0 TS 1 TS 2 TS 3 TS 4 TS 7TS 6TS 5
TRX: 8 timeslots
Signalling Traffic
10
Erlang B FormulaErlang loss formulae
Prob. loss 0,001 0,002 0,005 0,010 0,020 0,030 0,050 0,070 0,100 0,200No.of lines
1 0,001 0,002 0,005 0,010 0,020 0,031 0,053 0,075 0,111 0,2502 0,046 0,065 0,105 0,153 0,223 0,282 0,381 0,470 0,595 1,0003 0,194 0,249 0,349 0,455 0,602 0,715 0,899 1,057 1,271 1,9304 0,439 0,535 0,701 0,869 1,092 1,259 1,525 1,748 2,045 2,9455 0,762 0,900 1,132 1,361 1,657 1,875 2,218 2,504 2,881 4,0106 1,146 1,325 1,622 1,909 2,276 2,543 2,960 3,305 3,758 5,1097 1,579 1,798 2,157 2,501 2,935 3,250 3,738 4,139 4,666 6,2308 2,051 2,311 2,730 3,128 3,627 3,987 4,543 4,999 5,597 7,3699 2,557 2,855 3,333 3,783 4,345 4,748 5,370 5,879 6,546 8,522
10 3,092 3,427 3,961 4,461 5,084 5,529 6,216 6,776 7,511 9,68511 3,651 4,022 4,610 5,160 5,842 6,328 7,076 7,687 8,487 10,85712 4,231 4,637 5,279 5,876 6,615 7,141 7,950 8,610 9,474 12,03613 4,831 5,270 5,964 6,607 7,402 7,967 8,835 9,543 10,470 13,22214 5,446 5,919 6,663 7,352 8,200 8,803 9,730 10,485 11,473 14,41315 6,077 6,582 7,376 8,108 9,010 9,650 10,633 11,434 12,484 15,60816 6,722 7,258 8,100 8,875 9,828 10,505 11,544 12,390 13,500 16,80717 7,378 7,946 8,834 9,652 10,656 11,368 12,461 13,353 14,522 18,01018 8,046 8,644 9,578 10,437 11,491 12,238 13,385 14,321 15,548 19,21619 8,724 9,351 10,331 11,230 12,333 13,115 14,315 15,294 16,579 20,42420 9,411 10,068 11,092 12,031 13,182 13,997 15,249 16,271 17,613 21,63521 10,108 10,793 11,860 12,838 14,036 14,885 16,189 17,253 18,651 22,84822 10,812 11,525 12,635 13,651 14,896 15,778 17,132 18,238 19,692 24,06423 11,524 12,265 13,416 14,470 15,761 16,675 18,080 19,227 20,737 25,28124 12,243 13,011 14,204 15,295 16,631 17,577 19,031 20,219 21,784 26,49925 12,969 13,763 14,997 16,125 17,505 18,483 19,985 21,215 22,833 27,72026 13,701 14,522 15,795 16,959 18,383 19,392 20,943 22,212 23,885 28,94127 14,439 15,285 16,598 17,797 19,265 20,305 21,904 23,213 24,939 30,16428 15,182 16,054 17,406 18,640 20,150 21,221 22,867 24,216 25,995 31,38829 15,930 16,828 18,218 19,487 21,039 22,140 23,833 25,221 27,053 32,61430 16,684 17,606 19,034 20,337 21,932 23,062 24,802 26,228 28,113 33,84031 17,442 18,389 19,854 21,191 22,827 23,987 25,773 27,238 29,174 35,06732 18,205 19,176 20,678 22,048 23,725 24,914 26,746 28,249 30,237 36,29533 18,972 19,966 21,505 22,909 24,626 25,844 27,721 29,262 31,301 37,52434 19,743 20,761 22,336 23,772 25,529 26,776 28,698 30,277 32,367 38,75435 20,517 21,559 23,169 24,638 26,435 27,711 29,677 31,293 33,434 39,98536 21,296 22,361 24,006 25,507 27,343 28,647 30,657 32,311 34,503 41,21637 22,078 23,166 24,846 26,378 28,254 29,585 31,640 33,330 35,572 42,44838 22,864 23,974 25,689 27,252 29,166 30,526 32,624 34,351 36,643 43,680
TRX in cell Traffic timeslots1 72 143 224 305 376 457 53