PCH – AGCH - LAC

Page 2 © Siemens, 2004

BSC Paging capacity

The maximum delivery rate of 1 paging/15ms = 240.000 pagings per hour which is applied in releases starting from BR70/30 (the slightly slower delivery rate was applied in order to avoidunnecessary buffer congestion situations in the BTS).

It is recommended to plan LAC-splitting or BSC re-homing if the PCH-Load reaches 80% and before PCH-Load reaches 90%, perform LAC-splitting or BSC re-homing.80% load = 192.000 pagings per hour/LAC90% load = 216.000 pagings per hour/LAC

The maximum number of configurable LAC is restricted to 20, the number of paging blocks possible are 9 (cells with number of paging blocks greater than 8 are handled all together in the fastest delivery rate)

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BTS Paging capacity

Uncombined BCCH:

33% CCCH-Utiliz.:33% x 8 x 3 x 4.25 x 3600 / 1.3 = 93,212

66% CCCH-Utiliz.:66% x 8 x 3 x 4.25 x 3600 / 1.3 = 186,424

Combined BCCH:

33% CCCH-Utiliz.:33% x 2 x 3 x 4.25 x 3600 / 1.3 = 23,303

66% CCCH-Utiliz.:66% x 2 x 3 x 4.25 x 3600 / 1.3 = 46,606

BTS Paging capacityCCCH UtilizationNBLKACGR=13 Subscriber pages/CCCH TMSI Reallocation =ONPaging Repetition Factor = 1.3

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AGCH Capacity

• The logical Channels PCH and AGCH share the same CCCH-Blocks whereas the PCH takes precedence over the AGCH when a PCH-Command is waiting in the queue.

• Reserved AGCH using parameter NBLKACGR = 1 (value: 0..7)

• Up to BR7 the number of AGCH events that can be served per AGCH

message = 1 (one) immediate assignment (IMASS)

NBLKACGR = 1: AGCH Capacity = 4.25 IMASS/sec or 15,300 IMASS/hr

With refer to this, whenever the threshold of NBLKACGR = 1 is exceeded additional reserved AGCH is required accordingly

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Simulation CCCH

Note: Maximum Allowed AGCH reserved based on the simulation is proposed NBLKACGR = 3 in

order to have safety margin of CCCH utilization for shared PCH & AGCH

Parameter Blocks 51 Multi-frames/s Pages/CCCH Paging Rep Ref. Max. Pages/h CCCH-PCH UtilizationCCCH Blocks 9

CCCH-AGCH 1 4.25 1 15,300CCCH-PCH 8 4.25 3 1.3 180,000 64%

CCCH-AGCH 2 4.25 1 30,600CCCH-PCH 7 4.25 3 1.3 180,000 73%

CCCH-AGCH 3 4.25 1 45,900CCCH-PCH 6 4.25 3 1.3 180,000 85%

CCCH-AGCH 4 4.25 1 61,200CCCH-PCH 5 4.25 3 1.3 176,538 100%

CCCH-AGCH 5 4.25 1 76,500CCCH-PCH 4 4.25 3 1.3 141,231 100%

CCCH-AGCH 6 4.25 1 91,800CCCH-PCH 3 4.25 3 1.3 105,923 100%

CCCH-AGCH 7 4.25 1 107,100CCCH-PCH 2 4.25 3 1.3 70,615 100%

CCCH-AGCH 8 4.25 1 122,400CCCH-PCH 1 4.25 3 1.3 35,308 100%

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Counter

PCH:TACCBPRO 1: Number of accesses to the PCHNTDMPCH:1 Number of transmitted messages for CS traffic2 Number of transmitted messages for PS traffic3 Number of messages discarded from the paging queue (NTDMPCH)

resp. packet paging queue (NTDMPPCH) for CS traffic4 Number of messages discarded from the paging queue (NTDMPCH)

resp. packet paging queue (NTDMPPCH) for PS traffic

AGCH:TACCBPRO 2: Number of accesses to the AGCH NTDMAGCH:1 Number of transmitted messages on the AGCH CS traffic2 Number of transmitted messages on the AGCH PS traffic3 Number of messages discarded from the AGCH queue CS traffic4 Number of messages discarded from the AGCH queue PS traffic

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LAC Splitting - Guideline

- High Season Factor- Measurement PCH & AGCH:

TACCBPRONTDM

Calculate High Season Load Estimation:

PCH & AGCH

AGCH Reserved

Requirement

NBLKACGR

Max Paging 150,000 pages/h per LAC

If required with max NBLKACGR=5 as limit, with dimensioning parameter:Max Paging 120,000 pages/h per LAC

> 3

Dimensioning Result:# LAC# NBLKACGR

Note: For NBLKACGR is based on 15,300 IMASS/hr per 1(one) reserved AGCH therefore the AGCH reserved requirement for High

Season is defined by using NBLKACGR = [Estimated Load AGCH]/ 15,300

≤ 3

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LAC Splitting

1. Guideline for AGCH is NBLKACGR=1 with 4.25 IMASS/sec or 15,300 IMASS/hr

2. Guideline for PCH with max NBLKACGR = 3 (45,900 IMASS/hr) is proposed resulting CCCH-PCH utilization 85% with refer to 180,000 pages/h. Though, for dimensioning 150,000 pages/h is proposed as max paging per LAC to have a safety margin

3. For the case where the estimation of AGCH reserved requirement >3 then LAC dimensioning will be based on 120,000 pages/h as max paging per LAC to have a safety margin (Note: NBLKACGR = 5 as the limitation)

4. HO Attempt should be used as reference to split the LAC border in the urban area

Page 9 © Siemens, 2004