Alcatel B10 Dimensioning Methods
description
Transcript of Alcatel B10 Dimensioning Methods
-
BSS Dimensioning Methods
in B10
Eugen Marza
December 2008
-
Agenda
1. Air Interface (Cell) Dimensioning
2. Abis Interface Dimensioning
3. BSC Dimensioning
4. Ater CS Dimensioning
5. Ater PS Dimensioning
6. GPU/GP Dimensioning
7. Gb Interface Dimensioning
8. Location Area Dimensioning
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BSS Dimensioning Methods in B10
Overview
SGSN
speech
data
A-ter mux
Gb
A
CS
CS+ PS
PS
CSA-bisAir
TC
MT120
SMU TRCU TRCU
TRCU
MT120
SMU TRCU
TRCU
TRCU
TRX 2 M -EGC H link 1 PS
traffic TRX 3 M -EGC H link 2
M -EG CH link n
BTS
D ynam ic Abis
allocation GCH Extra
GCH Basic
GCH Basic
GCH Extra
GCH Bonus
T CH T CH TRX 1 CS
traffic
TRX n
Assessment ofbasic and bonus Abis nibbles from
TRX and BTS configuration
Calculate the needed extra Abis TS for real traffic on Abis Itf and
the number of needed Abis links
Assessment ofCS and PS traffic
over AterMux
Calculate the total number of Ater
channels and the required number of
AterMux links Evaluate the
required number of Gb 64K TS
per GPU
Check the traffic capacity limits basedon BSC configuration
Calculate the needed radio TS for SDCCH,
TCH and PDCH, then nb of TRXs
Evaluate the required number
of GPU/GP boards per BSC
Assessment of traffic values for
SDCCH, TCH and PDCH channels
Check the load and conectivity on
DSP and GPU boards of MFS
MxBSC CCP board
CCP board
SSW board
TP board
LIU board
LIU board
MxMFS GP board
DSP DSP DSP DSP
GP board DSP DSP DSP DSP
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Air Interface (Cell)
Dimensioning1
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Target
Find the needed number of RTCH and TRX for one Cell
Input (counters values):
CS Traffic
PS Traffic
SDCCH Traffic
CS Congestion
PS Congestion
SDCCH Congestion
Customer requirements for blocking probability
Output:
Nb of SDCCH channels
Nb of TCH
Nb of TRX
Real blocking
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for SDCCH:
Erlang B
Needed counters for SDCCH:
MC400 or GSDTRT (SDCCH_occy_total)
MC04 or GSDNACGN (SDCCH_assign_cong)
MC148 or GSDNACAN (SDCCH_assign_allocated)
Erlang B
Required SDCCH Traffic
GoS:
% SDCCH blocking
Nb of required SDCCH sub-channels
/ timeslots
INPUT OUTPUTMETHOD
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for SDCCH:
3600400MCtraffic_SDCCH_Measured =
%MCMC
MCcong_SDCCH% 100
1480404
+
=
%) ,cong_SDCCH(%Mintraffic_SDCCH_Measuredtraffic_SDCCH_quiredRe
301=
( )0.5% ic;DCCH_traffRequired_SangBInverseErlssubchannel SDCCH quiredRe of Nb =
=
8ssubchannel SDCCH_required_NbTSs_SDCCH_required_Nb
For BCCH not-combined cell:
For BCCH combined cell:
=
84ssubchannel SDCCH_required_NbTSs_SDCCH_required_Nb
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for TCH and PDCH:
Kaufmann-Roberts.
Needed counters for TCH:
MC380a, MC380b, MC703, MC812.
Needed counters for PDCH:
P451a, P451b,
P38e, P39f,
P14, P27,
P62x (x=a-c),
P438c, P507,
P91x (x=a-f),
P505.
PS_DL service
CS_FR service
CS_HR service
PS_UL service
Required Traffic
getMax
Nb RTS needed for CS and PS traffic
Kaufmann-Roberts
Algorithm
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for TCH and PDCH:
Kaufmann-Roberts.
Needed counters for TCH:
MC380a or GTCTRFT (RTCH_full_occy_total)
MC380b or GTCTRHT (RTCH_half_occy_total)
MC703 or GTCNACAN (RTCH_assign_allocated)
MC812 or GTCNACGN (RTCH_assign_cong)
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for TCH
703812 MCMCMC812
Request_nRTCH_AssigCong_nRTCH_Assig
ngCS_Real_Co+
==
Real_Cong)_CS %,min(Cong_CS 30=
Cong_CSbMCaMC
aMCCong_FR +
=
380380380
Cong_CSbMCaMC
bMCCong_HR +
=
380380380
)Cong_FR(aMC
Cong_FRTraffic_Successful_FRTraffic_FR_quiredRe cell
=
=
13600380
1
)Cong_HR(bMC
Cong_HRTraffic_Successful_HRTraffic_HR_quiredRe cell
=
=
13600380
1
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for TCH
The Required traffic for FR and HR is used together with Required traffic for PS as input for Kaufmann-Roberts algorithm.
The blocking probability used for CS services is 2%.
Note:
Required CS Bandwidth is:
1 TS for FR
0.5 TS for HR
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for PDCH
Needed counters for PDCH:
P451a or GARPDCTUBUT (GPRS_PDCH_used_UL_TBF_overall_time)
P451b or GARPDCTDBUT (GPRS_PDCH_used_DL_TBF_overall_time)
P38e or GARPDCUDBUT (GPRS_PDCH_DL_traffic_time)
P38f or GARPDCUUBUT (GPRS_PDCH_UL_traffic_time)
P14 or GQRDTECGN (GPRS_DL_TBF_estab_fail_radio_cong)
P27 or GQRUTECGN (GPRS_UL_TBF_estab_fail_radio_cong)
P62a+P62b+P62c- P438c+ P507 or GTRUTERQN (GPRS_UL_TBF_request)
P91a + P91b + P91c + P91d + P91e + P91f + P505 or GTRDTERQN
(GPRS_DL_TBF_request)
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for PDCH
3600451bPtraffic_PS_DL_Measured =
3600451aPtraffic_PS_UL_Measured =
%PfPePdPcPbPaP
Pcong_radio_TBF_DL% 100
50591919191919114
++++++
=
%PcPcPbPaP
Pcong_radio_TBF_UL% 100
50743862626227
+++
=
%) ,cong_radio_TBF(%Mintraffic_PS_Measuredtraffic_PS_quiredRe
301=
Final value for Required PS traffic is Max between required DL and UL PS traffic.
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for PDCH
Based on TBF usage:
For calculation 98% quantile and 0.01s delay are used.
Note:
Required PS Bandwidth (minimum number of TS per a request on each direction) is coming from:
Average Nb of DL TBF per PDCH = P451b/P38e
Average Nb of UL TBF per PDCH = P451a/P38f
If indicators are available, the required bandwidth is given by:
GARPDCTDPIN = GPRS_DL_TBF_Pilled_avg
GARPDCTUPIN = GPRS_UL_TBF_Pilled_avg
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Final aggregation:
Total nb of RTCH =
= 1 TS for BCCH + 1 TS for CCCH (if case) +
+ Nb of Required SDCCH TSs +
+ Nb of Required TSs for FR, HR and PS,
coming from Kaufmann-Roberts algorithm.
Total nb of TRX = Roundup [(Total nb of RTCH)/8]
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for PS throughput
Input (counters values):
DL PS Traffic
UL PS Traffic
Output:
DL PS Throughput
UL PS Throughput
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for PS throughput
Needed counters for PDCH DL throughput:
P38e or GARPDCUDBUT (GPRS_PDCH_DL_traffic_time)
P20a or GQRPDDR1N (GPRS_DL_RLC_block_PDTCH_CS1_retransmissing_ack)
P20b or GQRPDDR2N (GPRS_DL_RLC_block_PDTCH_CS2_retransmissing_ack)
P20c or GQRPDDR3N (GPRS_DL_RLC_block_PDTCH_CS3_retransmissing_ack)
P20d or GQRPDDR4N (GPRS_DL_RLC_block_PDTCH_CS4_retransmissing_ack)
P20f+P20g+P20h+P20i+P20j+P20k+P20l+P20m+P20n or GQRPDDRMN
(GPRS_DL_RLC_bytes_PDTCH_MCSx_retransmissing_ack from MCS1 to MSC9)(old P20e)
P55x (x=a-d) or GTRPDDC1N to GTRPDDC4N (GPRS_DL_useful_RLC_blocks_CS1_ack to
GPRS_DL_useful_RLC_blocks_CS4_ack)
P55x (x=e-m) or GTRPDDM1N to GTRPDDM9N (GPRS_DL_useful_RLC_blocks_MCS1_ack to GPRS_DL_useful_RLC_blocks_MCS9_ack)
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for PS throughput
Needed counters for PDCH UL throughput:
P38f or GARPDCUUBUT (GPRS_PDCH_UL_traffic_time)
P21a or GQRPDUR1N (GPRS_UL_RLC_block_PDTCH_CS1_retransmissing_ack)
P21b or GQRPDUR2N (GPRS_UL_RLC_block_PDTCH_CS2_retransmissing_ack)
P21c or GQRPDUR3N (GPRS_UL_RLC_block_PDTCH_CS3_retransmissing_ack)
P21d or GQRPDUR4N (GPRS_UL_RLC_block_PDTCH_CS4_retransmissing_ack)
P21f+P21g+P21h+P21i+P21j+P21k+P21l+P21m+P21n or GQRPDURMN
(GPRS_UL_RLC_bytes_PDTCH_MCSx_retransmissing_ack from MCS1 to MSC9)(old P21e)
P57x (x=a-d) or GTRPDUC1N to GTRPDUC4N (GPRS_UL_useful_RLC_blocks_CS1_ack to
GPRS_DL_useful_RLC_blocks_CS4_ack)
P57x (x=e-m) or GTRPDUM1N to GTRPDUM9N (GPRS_UL_useful_RLC_blocks_MCS1_ack to GPRS_DL_useful_RLC_blocks_MCS9_ack)
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BSS Dimensioning Methods in B10
Air Interface (Cell) Dimensioning
Method for PS throughput
DL and UL throughput:
==
n_Time_DLTransmisioData_DL]kbps[d DL_PS
==
UL_Time_nTransmisioUL_Data]kbps[d UL_PS
eP
PSize_Block_RLCPSize_Block_RLCPn
fxx
m
axxx
d
axxx
381000
2055208
++
=
===
fP
PSize_Block_RLCPSize_Block_RLCPn
fxx
m
axxx
d
axxx
381000
2157218
++
=
===
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Abis Interface
Dimensioning2
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Target
Find the required number of ExtraAbis TS
Check RSL congestion
Methods are applied at BTS level
Based on Abis allocation priorities
MAX_PDCH_High_Load Zone From MAX_PDCH_High_Load to MAX_PDCH
Basic nibbles of cell
Extra + Bonus nibbles of BTS
Priority N1
Priority N2
Priority N3
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Method for ExtraAbis TS
ErlangC
Input (counters values):
PS Traffic
Extra-Bonus Traffic
Available Extra-Bonus nibbles
PS Congestion (Abis)
Customer requirements for QoS (delay and quantile)
Customer requirements for number of basic and bonus nibbles
Output:
Nb of extra Abis nibbles
Nb of ExtraAbisTS
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Extra and Bonus Nibbles Method
(Method 1)
Erlang C
Required extra & bonus Abis nibble Traffic
GoS: % Quantile of x delay sec
Nb of required extra & bonus Abis Nibbles
INPUT OUTPUTMETHOD
Nb of required extra Abis Nibbles
Nb of bonus Abis Nibbles
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Extra and Bonus Nibbles Method
Needed counters:
P466 or GABGCHUSEBT (GPRS_transmission_GCH_use_bonus_and_extra_time),
P105i or GQRDTECBN (GPRS_DL_TBF_estab_fail_abis_cong),
P91a + P91b + P91c + P91d + P91e + P91f + P505 or GTRDTERQN
(GPRS_DL_TBF_request)
P105j or GQRUTECBN (GPRS_UL_TBF_estab_fail_abis_cong),
P62a+P62b+P62c- P438c+ P507 or GTRUTERQN (GPRS_UL_TBF_request)
Note:
The counters retrieved at cell level must be aggregated per BTS.
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Extra and Bonus Nibbles Method
3600466Ptraffic_Abis_bonus&extra_Measured =
%PfPePdPcPbPaP
iPcong_Abis_TBF_DL% 100
505919191919191105
++++++
=
%PcPcPbPaP
jPcong_Abis_TBF_UL% 100
507438626262105
+++
=
)cong_Abis_TBF_UL% ,cong_Abis_TBF_DL(%Maxcong_Abis_TBF% =
%) ,cong_Abis_TBF(%Mintraffic_Abis_bonus&extra_Measuredtraffic_Abis_bonus&extra_quiredRe
301=
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Extra and Bonus Nibbles Method
=nibbles bonus&extra quiredRe of Nb
( )delay quantile; fic;bonus_traf&xtraRequired_eangCInverseErl=where quantile = 99% and delay = 0.01s
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Extra and Bonus Nibbles Method
Number of required Extra Abis nibbles =
= Number of required extra & bonus Abis nibbles Nb of bonus Abis nibbles,
Note: Nb of bonus nibbles corresponds to Nb of BCCH and static SDCCH timeslots.
and
Number of required Extra Abis TS =
= Roundup[(Number of required extra Abis nibbles)/4].
Note: 1 Abis TS contains 4 Abis nibble
This method is recommended in case of BTSs with 2 or more cells.
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
GCH Method
(Method 2)
Erlang C
Required Data Traffic on Abis
GoS: % Quantile of x delay sec
Nb of required Abis Nibbles
INPUT OUTPUTMETHOD
Nb of required extra Abis Nibbles
Nb of basic & bonus Abis Nibbles
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
GCH Method
Needed counters for Data traffic:
P100c or GAAGCHUST (GPRS_transmission_GCH_busy_time)
Needed counters for Abis congestion:
P105i or GQRDTECBN (GPRS_DL_TBF_estab_fail_abis_cong),
P91a + P91b + P91c + P91d + P91e + P91f + P505 or GTRDTERQN
(GPRS_DL_TBF_request)
P105j or GQRUTECBN (GPRS_UL_TBF_estab_fail_abis_cong),
P62a+P62b+P62c- P438c+ P507 or GTRUTERQN (GPRS_UL_TBF_request)
Note:
The counters retrieved at cell level must be aggregated per BTS.
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
GCH Method
Abis congestion:
%PfPePdPcPbPaP
iPcong_Abis_TBF_DL% 100
505919191919191105
++++++
=
%PcPcPbPaP
jPcong_Abis_TBF_UL% 100
507438626262105
+++
=
)cong_Abis_TBF_UL% ,cong_Abis_TBF_DL(%Maxcong_Abis_TBF% =
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
GCH Method
Measured traffic:
Required traffic:
Required Abis nibbles for PS:
where quantile = 99% and delay = 0.01s
3600100cPtraffic_GCH_Measured =
%) ,cong_Abis_TBF(%Mintraffic_GCH_Measuredtraffic_GCH_quiredRe
301=
=nibbles Abis quiredRe of Nb
( )delay quantile; ;CH_trafficRequired_GangCInverseErl=
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
GCH Method
Number of required Extra Abis nibbles =
= Number of required Abis nibbles Nb of basic and bonus Abis nibbles,
Note: Nb of basic nibbles per cell = MAX_PDCH.
Nb of bonus nibbles corresponds to Nb of BCCH and static SDCCH timeslots.
and
Number of required Extra Abis TS =
= Roundup[(Number of required Extra Abis nibbles)/4].
Note: 1 Abis TS contains 4 Abis nibble
This method is recommended in case of BTSs with only 1 cell.
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Abis Dimensioning
Finally, at BTS level for Abis dimensioning
Total Number of Abis TS =
= 2*Total nb of TRX +
+ Nb of TS for RSL and OML (depending on MCB type)
+ Nb of required Extra Abis TS,
and
Number of required Abis Links =
= Roundup[(Total Number of Abis Ts)/31].
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Method for RSL
LAPD efficiency (in DL):
Needed counters
Conter Type: 7
Measured Object: LAPD
Conter L1.1 (NB_LAPD_INFO_FRAME_SENT)
Number of Information frames transmitted on the LapD link, excluding the re-transmissions.
Conter L1.15 (NB_LAPD_INFO_FRAME_RESENT)
Number of Information frames re-transmitted on the LapD link.
Formula:
LAPD efficiency [%] = L1.1/( L1.1+L1.15)*100
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BSS Dimensioning Methods in B10
Abis Interface Dimensioning
Method for RSL congestion
LAPD congestion detection:
Conter L1.18 (TIME_LAPD_CONG)
Conter Type: 7
Measured Object: LAPD
Time in seconds during which the LapD link is congested in transmission in the BSC.
In case LAPD congestion is present, the MCB load must be reduced:
If the multiplexing rule is applied per BTS by changing at BTS level the signaling
load from normal to high;
If the load is already high by changing the multiplexing rule from per BTS to per
Sector with the same load options normal or high.
Note: These changes may impact the Abis TS usage.
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BSC
Dimensioning3
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BSS Dimensioning Methods in B10
BSC Dimensioning
Target
Find the total CS traffic
Find the related CS signaling traffic
Decide what solution is required for signaling traffic: LSL or HSL
Check the HDLC occupancy to decide what type of TP GSM board is required:
TP GSM V1 or TP GSM STM1 (V3)
Find the required number of AterMux CS links
Find the total PS traffic
Find the required number of AterMux PS links
Find the required number of GPU/GP boards
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BSS Dimensioning Methods in B10
BSC Dimensioning
Method for BSC Dimensioning
ErlangB and ErlangC
Input (counters values):
CS Traffic
SS7 Traffic
PS Traffic
AterMux PS congestion
Customer requirements for CS and SS7 blocking and QoS for PS
Output:
Nb of TCH, CS dedicated links and real blocking
Nb of SS7 connections, links and real blocking
Nb of GCH
Nb of GPU boards per BSC
Nb of PS links per BSC and PS real quantile
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BSS Dimensioning Methods in B10
BSC Dimensioning
Method for CS Traffic
Needed counters for TCH:
MC380a or GTCTRFT (RTCH_full_occy_total)
MC380b or GTCTRHT (RTCH_half_occy_total)
Needed counters for SCCP:
MC01+MC02 or GSDNASUN (SDCCH_assign_success),
MC10 or GSDHOSUN (SDCCH_HO_success)
MC390 or GSDAHCAN (SDCCH_allocated),
MC400 or GSDTRT (SDCCH_occy_total),
MC380a+MC380b or GTCTRT (RTCH_occy_total)
or GQSTRSCE (SCCP_Erlang_BH)
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BSS Dimensioning Methods in B10
BSC Dimensioning
Method for CS Traffic
Max CS Traffic (during BH)
The required value of TCH traffic must be below the BSC Erlang capacity
(depending on BSC configuration), else the BSC capacity must be extended if
possible by adding one CCP board.
3600380380 bMCaMCtraffic_TCH_Measured +=
inargm%traffic_TCH_measuredtraffic_TCH_quiredRe 15+=
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BSS Dimensioning Methods in B10
BSC Dimensioning
Method for CS Traffic
Max SCCP Traffic (during BH)
Measured SCCP Traffic = SCCP traffic in Erlang during Busy Hour =
= ((MC400/MC390)*(MC01+MC02+MC10) + (MC380a+MC380b))/3600
If the required number of SS7 TSs is below or equal to 16, the LSL solution
may be used.
If the required number of SS7 TSs is above 16, the HSL solution is mandatory.
inargm%traffic_SCCP_measuredtraffic_SCCP_quiredRe 15+=
( )c;0.1%CCP_traffiRequired_SangBInverseErlsconnection SCCP quiredRe of Nb =
=
1037 channels_SCCP_required_NoTSs_SS_required_No
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BSS Dimensioning Methods in B10
BSC Dimensioning
Method for HDLC occupancy
Due to limited number of HDLC channels inside TP GSM board, it is important
to check the number of HDLC channels in use.
1090910staticMux{signallingLoadBts dummy}G62A12_3{ amecID 1, moiRdn 17}
65056noMux{signallingLoadBts dummy}G62B091{ amecID 1, moiRdn 11}
41101112statisticMux64{signallingLoadBts normal}G62B122{ amecID 1, moiRdn 134}
14045statisticMux64{signallingLoadBts dummy}G62B271{ amecID 1, moiRdn 100}
23034statisticMux64{signallingLoadBts high}G62B083{ amecID 1, moiRdn 10}
60667statisticMux64{signallingLoadBts high}G62B011{ amecID 1, moiRdn 1}
Total #
HDLC
Total #
TRX FR
Total #
TRX DR
Total #
TRE
Total #
LAPDMuxRuleMuxRateUserLabel
AlcatelBtsSiteManager
InstanceIdentifier
from AlcatelBtsSiteManager.csv from AlcatelBts_Sector.csv
Apply MCB rule
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BSS Dimensioning Methods in B10
BSC Dimensioning
Method for HDLC occupancy
This check is important especially when the BSC must be extended by adding
new cells.
If the total required number of HDLC channels is below 441, the TP GSM V1
board has enough capacity to be used.
If the required number of HDLC channels is above 441, the multiplexing rule
must be changed from noMux to statisticMux64.
If the resulted number of HDLC channels is still above 441, the TP GSM V1
board must be replaced by TP GSM STM1 (V3) board.
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44 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
BSC Dimensioning
Method for PS Traffic
Needed counters for GCH Traffic:
P100c or GAAGCHUST (GPRS_transmission_GCH_busy_time),
P383a or GQAGALCTT (GPRS_GPU_Ater_cong_time),
P384 or GQRGPUCDT (GPRS_GPU_DSP_cong_time),
Needed counters for GSL:
P41 or GTALAPDLN (GPRS_LAPD_DL_traffic_sent_to_BSC),
P42 or GTALAPULN (GPRS_LAPD_UL_traffic_received_from_BSC).
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45 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
BSC Dimensioning
Method for PS Traffic
Max GCH Traffic
Number of required GCH per BSC
3600100cPtraffic_GCH_Measured =
%aPcong_Ater_GCH% 1003600383
= %Pcong_GPU_GCH% 1003600
384=
)cong_GPU_GCH,%cong_Ater_GCH(%Maxcong_GCH% =
%) ;cong_GCH(% Mintraffic_GCH_Measuredtraffic_GCH_quiredRe
301=
( )delayquantile;;CH_trafficRequired_G angCInverseErlGCH quiredRe of Nb =where quantile = 99% and delay = 0.01s
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46 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
BSC Dimensioning
Method for PS Traffic
Number of GPU/GP boards per BSC
GPU Capacity is of max 480 GCH.
GP Capacity is of max 1560 GCH.
N_ATER_TS_MARGIN_GPU resources must not be taken into account. So, the max
number of GCH per GPU/GP is:
480 N_ATER_TS_MARGIN_GPU*4 (for legacy MFS)
1560 N_ATER_TS_MARGIN_GPU*4 (for Mx MFS)
=
Capacity GCH board GPU/GPGCH Required of Nbboard GPU/GP quiredRe of Nb
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47 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
BSC Dimensioning
Method for PS Traffic
Number of GSL links per BSC
288004241 )P,P(Maxtraffic_GSL_Measured =
inargm%traffic_GSL_Measuredtraffic_GSL_quiredRe 30+=
( )delayquantile;;SL_trafficRequired_G angCInverseErlGSL quiredRe of Nb =
where quantile = 99% and delay = 0.01s
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48 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
BSC Dimensioning
Method for PS Traffic
Number of GPU boards per BSC
At least 2 GSLs are recommended to be defined per GPU due to security reason.
Up to 4 GSLs can be defined per GPU.
Number of GP boards per BSC
At least 2 GSLs are recommended to be defined per GP due to security reason.
Up to 8 GSLs can be defined per GP.
=
8GSL Required of Nbboard GPU/GP quiredRe of Nb
=
4GSL Required of Nbboard GPU/GP quiredRe of Nb
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49 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
BSC Dimensioning
Method for PS Traffic
Number of GPU boards per BSC
The final number of required GPU/GP boards per BSC is the maximum value
between the number of boards needed for signaling traffic (GSL) and for user
traffic (GCH).
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50 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
Ater CS
Dimensioning4
-
51 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
Target
Find the required number of AterMux CS links
Method: ErlangB
Input (counters values):
CS Traffic
SS7 Traffic
Customer requirements for CS and SS7 blocking and QoS for PS
Output:
Nb of SS7 connections, links and real blocking
Nb of TCH, CS dedicated links and real blocking
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52 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
Method
Find the max number of Ater CS links between TCH requirements and
signaling requirements (SCCP)
Erlang B
GoS: % TCH blocking
Nb of required SS7
per BSC
INPUT OUTPUTMETHOD
Signalling Traffic
User Traffic
Required SDCCH Traffic
Required TCH Traffic
GoS: % SS7 blocking
Erlang B
Nb of required
TCH per BSC
Nb of required
AterMUX-CS links per
BSC
Nb of required
AterMUX-CS links per
BSC
Choose Maxvalue
Final nb of required
AterMUX-CS links per
BSC
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53 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Traffic
Method for TCH
The number of required AterMux CS links can be obtained by dividing the number of
AterMux CS channels obtained from the dimensioning process by the AterMux CS link
capacity.
The total capacity of n AterMUX CS links is:
111TCH(link#1) + 111TCH(link#2) + 116TCH(link#3) + 116TCH(link#4) +
116TCH(link#5) + 116TCH(link#6) + 115TCH(link#7) + 115TCH (link#8) + 116TCH(link
#9) + 116TCH(link #10) + 116TCH(link #11)+ + 116TCH(link #N),
where N =< MaxNbAterMuxCS.
3600380380 bMCaMCtraffic_TCH_Measured +=
inargm%traffic_TCH_measuredtraffic_TCH_quiredRe 15+=
( );0.1%CH_trafficRequired_TangBInverseErlchannels TCH quiredRe of Nb =
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54 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Signaling Traffic
Method for SCCP
Measured SCCP Traffic = SCCP traffic in Erlang during Busy Hour =
= ((MC400/MC390)*(MC01+MC02+MC10) + (MC380a+MC380b))/3600
The result is obtained for 40% load at SS7 link level.
The final number of required AterMux CS links is the maximum value between the
number of links needed for signaling traffic (SS7) and for user traffic (TCH).
inargm%traffic_SCCP_measuredtraffic_SCCP_quiredRe 15+=
( )c;0.1%CCP_traffiRequired_SangBInverseErlsconnection SCCP quiredRe of Nb =
=
1037 channels_SCCP_required_Nolinks_SS_required_No
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55 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Signaling Traffic
Method for SS7 based on volume of data transferred
Counters for N7 at link level (Type 9):
N3.1 (NB_N7_SIF_SIO_SENT)
Number of octets of Signalling Information (SIF) and Service Information Octets (SIO) transmitted on the N7 SL.
N3.3 (NB_N7_MSU_SENT)
Number of Message Signalling Units (MSU) transmitted on the N7 SL.
N3.4 (NB_N7_SIF_SIO_REC)
Number of octets of Signalling Information Field (SIF) and Service Information Octets (SIO) received on the N7 SL.
N3.5 (NB_N7_MSU_REC)
Number of Message Signalling Units (MSU) received on the N7 SL.
N3.10 (NB_N7_MSU_DISC_DUE_CONG)
Number Message Signalling Units (MSU) discarded due to a message buffer overflow caused by an extended period of Signalling Link congestion.
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56 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Signaling Traffic
Method for SS7 based on volume of data transferred
Traffic evaluation in UL
Counter values must be aggregated for the link set
28800000336137 .N*.Ntraffic_SS_Measured +=
%) ;cong_SS(% Mintraffic_SS_Measuredtraffic_SS_quiredRe
307177
=
%.N.N
.Ncong_SS% 100
103331037
+=
( );0.1%S7_trafficRequired_S angBInverseErlTS SS7 quiredRe of Nb =
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57 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Signaling Traffic
Method for SS7 based on volume of data transferred
Traffic evaluation in DL
Counter values must be aggregated for the link set
The final number of SS7 TSs (links) is the max value between the results for
UL and DL.
If this number is greater than 16, HSL usage is mandatory.
28800000536437 .N*.Ntraffic_SS_Measured +=
inargm%traffic_SS_Measuredtraffic_SS_quiredRe 1577 +=
( );0.1%S7_trafficRequired_S angBInverseErlTS SS7 quiredRe of Nb =
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58 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Signaling Traffic
Method for SS7 based on volume of data transferred
N7 link efficiency based on couters (in UL):
N3.3 (NB_N7_MSU_SENT)
N3.10 (NB_N7_MSU_DISC_DUE_CONG)
Formula:
N7 efficiency [%] = N3.3/( N3.3+N3.10)*100
N7 link congestion detection:
N1.6 (NB_N7_LINK_FAIL_CONG)
Number of N7 SL failures due to congestion during an extended period of time.
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59 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Signaling Traffic
Method for SS7 link load based on volume of data transferred
LSL case
%N7 Utilization in UL = (N3.1 + (6 * N3.3)) / (3600*8,000)
%N7 Utilization in DL = (N3.4 + (6 * N3.5)) / (3600*8,000)
Explanation:
MSU contains 6 bytes (fix part) + SIF&SIO (variable part).
SIF is between 2 and 34 bytes.
SIO is 1 byte.
Note:
1 hour of usage of 1 E1 Time Slot (for N7) = 1hour * 64Kbps =
= 3600s * 8000 bytes/s = 28,800 Kbytes/h
Warning:
The load on one N7 link shall not exceed 40% (recommended).
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60 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Signaling Traffic
Method for SS7 link load based on volume of data transferred
HSL case
In B10, if HSL is actived, N7 can have 2 different frame formats:
Normal frame format
Extended frame format
Parameter: MTP_Sequence_Number_Format
(MtpSequenceNumberFormat in ACIE AlcatelManagedElementComplex.csv)
Range / default value: (0=Normal, 1=Extended) / 0
Note:
In case of Normal frame format
MSU contains 6 bytes (fix part) + SIF&SIO (variable part).
In case of Extended frame format
MSU contains 9 bytes (fix part) + SIF&SIO (variable part).
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61 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Signaling Traffic
Method for SS7 link load based on volume of data transferred
HSL case with Normal frame format
%N7 Utilization in UL = (N3.1 + (6 * N3.3)) / (3600*8,000*31)
%N7 Utilization in DL = (N3.4 + (6 * N3.5)) / (3600*8,000*31)
Explanation:
32 TSs of 64Kbps are available for one HSL link.
Note:
1 hour of usage of 1 E1 Time Slot (for N7) = 1hour * 64Kbps =
= 3600s * 8000 bytes/s = 28,800 Kbytes/h
For 32 TS per HSL link we get
3600s * 8000 bytes/s * 31TS = 892,800 Kbytes/h
Warning:
The load on one N7 link shall not exceed 40% (recommended).
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62 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater CS Dimensioning
CS Signaling Traffic
Method for SS7 link load based on volume of data transferred
HSL case with Extended frame format
%N7 Utilization in UL = (N3.1 + (9 * N3.3)) / (3600*8,000*31)
%N7 Utilization in DL = (N3.4 + (9 * N3.5)) / (3600*8,000*31)
Explanation:
32 TSs of 64Kbps are available for one HSL link.
Note:
1 hour of usage of 1 E1 Time Slot (for N7) = 1hour * 64Kbps =
= 3600s * 8000 bytes/s = 28,800 Kbytes/h
For 32 TS per HSL link we get
3600s * 8000 bytes/s * 31TS = 892,800 Kbytes/h
Warning:
The load on one N7 link shall not exceed 40% (recommended).
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63 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
Ater PS
Dimensioning5
-
64 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater PS Dimensioning
Target
Find the required number of AterMux PS links
Method: ErlangC
Input (counters values):
PS Traffic
Number of Available GCH
Number of Max Busy GCH
AterMux PS congestion
Customer requirements for PS QoS
Output:
Nb of GCH
Nb of GSL links per BSC and PS real quantile
Nb of PS links per BSC and PS real quantile
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65 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater PS Dimensioning
Method
Find the max number of Ater PS links between GCH requirements and
signaling requirements (GSL)
QoS: quantile delay
INPUT OUTPUTMETHOD
User Traffic
Required GCH Traffic Erlang C
Nb of required
GCH per BSC
Nb of required PS links per
BSC
QoS: quantile delay
Signaling Traffic
Required GSL Traffic Erlang C
Nb of required
GSL per BSC
Nb of required PS links per
BSC
Choose Maxvalue
Final nb of required
AterMUX-PS links per
BSC
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66 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater PS Dimensioning
Method for Ater PS
Needed counters for GCH:
P100c or GAAGCHUST (GPRS_transmission_GCH_busy_time),
P383a or GQAGALCTT (GPRS_GPU_Ater_cong_time),
P384 or GQRGPUCDT (GPRS_GPU_DSP_cong_time),
Needed counters for GSL:
P41 or GTALAPDLN (GPRS_LAPD_DL_traffic_sent_to_BSC),
P42 or GTALAPULN (GPRS_LAPD_UL_traffic_received_from_BSC).
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67 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater PS Dimensioning
Method for GCH
The number of required GCH
3600100cPtraffic_GCH_Measured =
%aPcong_Ater_GCH% 1003600383
=
%Pcong_GPU_GCH% 1003600
384=
)cong_GPU_GCH,%cong_Ater_GCH(%Maxcong_GCH% =
%) ;cong_GCH(% Mintraffic_GCH_Measuredtraffic_GCH_quiredRe
301=
( )delayquantile;;CH_trafficRequired_G angCInverseErlGCH quiredRe of Nb =where quantile = 99% and delay = 0.01s
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68 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater PS Dimensioning
Method for GCH
The number of required AterMux PS TSs for user traffic
The number of required AterMux PS links for user traffic
=
4GCH_required_NbTSs_AterPS_required_Nb
=
28TSs_AterPS_required_Nolinks_AterPS_required_Nb
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69 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Ater PS Dimensioning
Method for GSL
GSL load checking
It is recommended to increase the number of GSL per GPU if GSL load is greater than
80%.
The final number of required AterMux PS links is the maximum value between
the number of links needed for signaling traffic (GSL) and for user traffic (GCH).
288004241 )P,P(Maxtraffic_GSL_Measured =
inargm%traffic_GSL_Measuredtraffic_GSL_quiredRe 30+=
( )delayquantile;;SL_trafficRequired_G angCInverseErlGSL quiredRe of Nb =
GSL required of Nbtraffic_GSL_MeasuredGSL_traffic_Measured =1
%)Erlangs.(Capacity_GSLGSL_traffic_Measuredload_GSL 100
7801
=
=
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70 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
GPU/GP
Dimensioning6
-
71 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Target
Find the load and the required number of AterMux PS links per GPU/GP board
Method: ErlangC
Input (counters values):
PS Traffic
MS context average
MS context max
DSP congestion
GSL traffic
Average & Max CPU load
BSS failures rate
Output:
Max DL GCH Capacity
Max UL GCH Capacity
Max DL PDCH Capacity
Max UL PDCH Capacity
GSL load
MCS usage
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72 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
Check if GPU/GP board is not overloaded
QoS: quantile delay
INPUTOUTPUT
METHOD
User Traffic
Required GCH Traffic Erlang C Needed
GCH
GCH capacity of GPU
+
MS_context_handling (= 0/1)
+
Power_Limitation (= 0/1)
Number of GPU boards
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73 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
GPU/GP board limitation control
Power Limitation Memory Limitation Power Limitation Memory Limitation
Dimensioning indicators
P76a P77a
=> P402 (thr )P392aP392b
P201 (thr_1 )P202 (thr_2 ) P384
QoS indicators
(TBF establ)P105e P105f
UL TBF estab BSS Failure
P203P204
P105cP105d
GPU limitationPMU PTU
PPC/CPU DSP
MFS parameters:Thr = PMU_CPU_Overload (Default=95%)
Thr_1 = DSP_Load_Thr_1 (Default=85%)
Thr_2 = DSP_Load_Thr_2 (Default=95%)
CPU Cong BSS Fail DSP Load DSP Cong
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74 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
User traffic load (GCH)
Needed counters:
P100c or GAAGCHUST (GPRS_transmission_GCH_busy_time),
P383a or GQAGALCTT (GPRS_GPU_Ater_cong_time),
P384 or GQRGPUCDT (GPRS_GPU_DSP_cong_time),
P201 or GTRGPULDLT (GPRS_DSP_CPU_load_time),
P202 or GTRGPULDOLT (GPRS_DSP_CPU_overload_time),
GQRDTELDR (GPRS_DL_TBF_estab_fail_dsp_load_rate)
or P203 / (P91a + P91b + P91c + P91d + P91e + P91f + P505)
GQRUTELDR (GPRS_UL_TBF_estab_fail_dsp_load_rate)
or P204 / (P62a + P62b + P62c - P438c + P507)
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75 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
Signaling load
Needed counters:
P392a or GTRGPUMCA (GPRS_MS_idle_context_avg),
P392b or GTRGPUM (GPRS_MS_idle_context_max),
P76a or GTRGPUPBA (GPRS_PMU_CPU_power_budget_avg),
P77a or GTRGPUPBM (GPRS_PMU_CPU_power_budget_max),
P402 or GTRGPUOT (GPRS_PMU_overload_time),
GQRDTECCR (GPRS_DL_TBF_estab_fail_cpu_cong_rate)
or P105e / (P91a + P91b + P91c + P91d + P91e + P91f + P505)
GQRUTECCR (GPRS_UL_TBF_estab_fail_cpu_cong_rate),
or P105f / (P62a + P62b + P62c - P438c + P507)
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76 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
Required number of GPU/GP boards based on user traffic
3600100cPtraffic_GCH_Measured =
%aPcong_Ater_GCH% 1003600383
= %P
cong_DSP_GCH% 1003600
384=
%) ;cong_GCH(% Mintraffic_GCH_Measuredtraffic_GCH_quiredRe
301=
( )delayquantile;;CH_trafficRequired_G angCInverseErlGCH quiredRe of Nb =
%x)P,P(Maxload_DSP% 1003600
202201= %xPoverload_CPU% 1003600
402=
)overload_CPU,%load_DSP,%cong_DSP,%cong_Ater(%Maxcong_GCH% =
where quantile = 99% and delay = 0.01s
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77 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
Required number of GPU/GP boards based on user traffic
where the GPU board capacity is 480 GCH and the GP board capacity is 1560 GCH.
The result must be compared with the existing number of GPU/GP boards per BSC.
If the required number of GPU/GP boards is less than the existing one, there is no
need for change.
If the required number of GPU/GP boards is greater than the existing one, then the
number of GPU/GP boards per BSC must be increased by one unit.
For a BSC in multi GPU configuration, the method (GCH traffic) may be applied per
each GPU/GP board separately to check the load on each board.
=
Capacity GCH board GPU/GPGCH Required of Nbboard GPU/GP quiredRe of Nb
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78 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
Required number of GPU/GP boards
GPU power limitation from PTU (DSP/CPU)
If
MAX(P201;P202)/3600 > 0.1% for at least 12% of the observation period
and
dsp_load_fail_rate = MAX(GQRDTELDR; GQRUTELDR) > 1%
then PTU_Power_Limitation = 1
else PTU_Power_Limitation = 0
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79 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
Required number of GPU/GP boards
GPU power limitation from PMU (CPU)
If
P402/3600 > 0.1% or P76a > 70% for at least 12% of the observation period
and
cpu_cong_fail_rate = MAX (GQRUTECCR; GQRDTECCR) > 1%
then PMU_Power_Limitation = 1
else PMU_Power_Limitation = 0
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80 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
Required number of GPU/GP boards
GPU memory limitation from PMU (CPU)
If P392b = 1000 and P392a > 900 for at least 12% of the observation period
for Legacy MFS
or
if P392b = 4000 and P392a > 3600 for at least 12% of the observation period
for MxMFS
then MS_context_handling = 1
else MS_context_handling = 0
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81 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
GPU/GP load
Final result
The number of required GPU/GP boards =
= Number of required GPU/GP board (from user traffic) +
+ MAX(PTU_Power_Limitation; PMU_Power_Limitation; MS_context_handling)
Note:
If the required number of GPU/GP boards is greater than the existing one, it
is recommanded to add a single board at one time and redo the load
assessment after it.
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82 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Check the number of links from GCH and GSL requirements
QoS: quantile delay
INPUT OUTPUTMETHOD
User Traffic
Required GCH Traffic Erlang C
Nb of required
GCH per BSC
Nb of required
GPU boards per BSC
Nb of required PS links per GPU board
QoS: quantile delay
Signaling Traffic
Required GSL Traffic Erlang C
Nb of required
GSL per BSC
Nb of required PS links per GPU board
Choose Maxvalue
Final nb of required
AterMUX-PS links per GPU
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83 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Based on total GCH load and final number of required GPU/GP bords, the
number of Ater PS links per board is:
=
board GP/GPU_required_Nb/)GCH_required_Nb(GP/GPU_per_links_AterPS_required_Nb 112
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84 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Method based on total number of GSL links and final number of required
GPU/GP bords
OUTPUT
Nb of required GSL links per GPU
INPUT METHOD
QoS: quantile delay
Signaling Traffic
Required GSL Traffic Erlang C
Nb of required
GSL per BSC
Nb of required
GPU boards per BSC
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85 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Assessment based on GSL bandwidth
Needed counters:
P41 or GTALAPDLN (GPRS_LAPD_DL_traffic_sent_to_BSC),
P42 or GTALAPULN (GPRS_LAPD_UL_traffic_received_from_BSC).
Required number of GSL links per BSC:
288004241 )P,P(Maxtraffic_GSL_Measured =
inargm%traffic_GSL_Measuredtraffic_GSL_quiredRe 30+=
( )delayquantile;;SL_trafficRequired_G angCInverseErlGSL quiredRe of Nb =
where quantile = 99% and delay = 0.01s
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86 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Assessment based on GSL bandwidth
Checking the GSL load:
GSL link load is:
Compare GSL_load with GSL_link_band_capacity
where GSL_link_band_Capacity = 0.78 Erlang
(corresponding to max rate of 50 Kbps in a 64 Kbps Time slot).
GSL load on a given GPU/GP should not exceed 0.78 Erlang.
It is recommended to increase the number of GSL per GPU/GP if GSL load is greater
than 0.78 Erlang.
links GSL required of Nbtraffic_GSL_Measuredload_GSL =
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87 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Assessment based on the number of GSL messages per second
Number of GSL messages/s per GPU is calculated as a function of PS traffic (UL and
DL TBF establish requests) and of the number of cells mapped to the GPU/GP.
GSL_link_Max_capacity per GPU is defined as:
K_GSL * (1000ms/GSL_round_trip_delay) * Nb of GSL links per GPU/GP, where
K_GSL is the maximum number of outstanding I frames on a GSL link
(Min = 1, Max = 32, Default = 7)
For terrestrial links: GSL_round_trip_delay < 500ms
(default value = 60ms)
For satellite links: GSL_round_trip_delay > 500ms
(default value = 500ms)
BSC
GPU
K_GSL
GSL messages buffer
GSL_round_trip_delay
A message is kept in the buffer during GSL_round_trip_delay
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88 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Assessment based on the number of GSL messages per second
How to estimate the number of GSL messages per second:
Msg on GSL due to RAE4 mechanism 0.3 Msg/s x Nb_cell
Msg on GSL due to PS traffic
Msg on GSL due to PS/CS paging: Nb_PS_paging/s+ Nb_CS_paging/s
Msg on GSL due to PS data traffic (TBF requests):
TBF (UL & DL) corresponding to RA update 1.7 x Nb_TBF_Sig_req/s
TBF (UL & DL) corresponding to PS data (3 cases)
Low GSL usage (eg. Ping 5 s) 2.5
Medium GSL usage 3.5 x Nb_TBF_Data_req/s
High GSL usage (worst case) 5
The Sum of all rates above gives the Total Nb of Msg/s.
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89 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Assessment based on the number of GSL messages per second
The GSL usage condition can be defined through the following table:
The values provided in the table above are relibale if T_GCH_INACTIVITY = 3s and
T_GCH_INACTIVITY_LAST = 20s (default setting).
Otherwise (I.e. T_GCH_INACTIVITY = 2s and T_GCH_INACTIVITY_LAST = 6s) GSL load will be
greater due to the consequent increase of deallocation/allocation messages.
3.52.5Low
53.5HighAvailable
GCH
LowHigh
PS traffic
(TBF req)Nb of Msg on GSL
per TBF_data_req
If #TBF req /s < 20 TBF/s
If Ater congestion observed
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90 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Assessment based on the number of GSL messages per second
Nb_cell: number of cell (at BSC level or managed by the GPU, depending if the
method is applied at BSC or GPU level)
Nb_PS_paging: number of processed PS paging requests/s is measured by
P391a/3600
Nb_CS_paging: number of processed CS paging requests/s is measured by P391b/3600
Nb_UL_TBF_req: the total number of UL TBF requests/s
(P62a+P62b+P62c-P438c+P507)/3600
Nb_DL_TBF_req: the total number of DL TBF requests/s
(P91a+P91b+P91c+P91d+P91e+P91f+P505)/3600
Nb_UL_TBF_req_noGSL: number of UL TBF requests/s which will not generate any
message on the GSL is counted by P62b.
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91 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Assessment based on the number of GSL messages per second
Nb_TBF_Sig_req: the number of TBF (UL and DL)/s which correspond to signalling
traffic. The part of DL TBF signalling requests is estimated with %_DL_TBF_Sig_req =
P160 / Nb_DL_TBF_succ.
where P160 = NB_DL_TBF_1_succ (Number of DL TBF establishment requests
requesting 1 slot which are satisfied) and
Nb_DL_TBF_succ = P90a+P90b+P90c+P90d+P90e+P90f+P506. So,
Nb_TBF_Sig_req = %_DL_TBF_Sig_req x (Nb_UL_TBF_req - Nb_UL_TBF_req_noGSL +
Nb_DL_TBF_req)
Nb_TBF_Data_req: the number of TBF (UL and DL)/s which correspond to data
traffic.
Nb_TBF_Data_req = Nb_UL_TBF_req + Nb_DL_TBF_req - Nb_UL_TBF_req_noGSL -
Nb_TBF_Sig_req
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92 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Assessment based on the number of GSL messages per second
GSL load (in terms of treated messages)
GSL load in terms of treated messages per second on a given GPU/GP should not
exceed 75%
It is recommended to increase the number of GSL per GPU/GP if GSL load is greater
than 75%.
%Capacity_Max_Link_GSL
sec_per_messages_GSL_Nbload_GSL 100=
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93 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
GPU/GP Dimensioning
Number of AterMux PS links per GPU/GP board
Based on total GSL load and final number of required GPU/GP bords, the
number of GSL links per board is:
If the result is greater than 4 (8), we must increase the number of GPU (GP)
boards with 1, and redo the calculations.
The final number of required AterMux PS links per GPU/GP boards is the
maximum value between the number of links needed for signaling traffic
(GSL) and for user traffic (GCH).
=
board GPU/GP quiredRe of NbBSC per GSL Required of Nb
GPU/GP per GSL quiredRe of Nb
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94 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
Gb Interface
Dimensioning7
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95 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over Frame Relay
Target
Find the required number of Gb TS
Input (counters values):
PVC downlink Traffic
PVC uplink Traffic
PVC downlink average throughput
PVC uplink average throughput
Customer requirements for QoS (delay and quantile)
Output:
Nb of Gb TS
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96 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over Frame Relay
Method: ErlangC
Needed counters:
P45 or GTGPVCDLN (GPRS_PVC_DL_traffic_from_SGSN),
P46 or GTGPVCULN (GPRS_PVC_UL_traffic_to_SGSN).
Erlang C
Required Gb Traffic
QoS: % Quantile of x delay sec
Nb of required Gb Timeslot per
link
INPUT OUTPUTMETHOD
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97 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over Frame Relay
The required Gb traffic is:
The required number of Gb TS is:
The maximum number of Gb links from one GPU/GP board to the SGSN is 8.
Maximum 31 Gb TS (TS no. 1 to 31) can be configured per one Gb link.
288004645 )P,Pmax(traffic_Gb_Measured =
inargm%traffic_Gb_Measuredtraffic_Gb_quiredRe 15+=
)delay;quantile;traffic_Gb_quired(Re ErlangClink_per_TS_Gb_No =
where quantile = 99% and delay = 0.01s
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98 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over Frame Relay
The Gb over FR configuration
Parameters:
Tc (Measurement interval) = 1s
CBS (Committed Burst Size)
CIR (Committed Information Rate)
CIR = (CBS*8)/Tc
NIR (Normal Information Rate)
NIR CIR
EBS (Excess Burst Size)
EIR (Excess Information Rate)
EIR = CIR+EBS*8/Tc
AC (Access Rate Bearer Channel)
AC CIR(1+EBS/CBS)
NbGbTS = AC/64kbps
Tc
EBS
CBS
Bit rate
time
EIR
CIRNIR
ACCESS_RATE_BC
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99 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over Frame Relay
The Gb over FR configuration
Rules if no direct access is used between MFS and SGSN:
CIR NIR CIR x (1 + EBS/CBS) ACCESS_RATE_BC
Example:
number16NbGbTS
kbps 1008AC
kbps1008EIR
kbyte2EBS
kbps 992NIR
kbps992CIR
kbyte124CBS
s1Tc
unitvalueParameter
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100 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over Frame Relay
The Gb over FR configuration
Rules if direct access is used between MFS and SGSN:
CIR = 0 CBS = 0 => EBS > 0 (mandatory)
NIR = 0 (recommanded)
EBS = ACCESS_RATE_BC (expressed in kbit/s)/8, if CIR = 0 (recommanded)
Example:
For CBS = 0; CIR = 0 and NIR = 0:
number20NbGbTS
kbps1280EIR
kbps 1280AC
kbyte160EBS
s1Tc
unitvalueParameter
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101 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over IP
Using Gigabit Ethernet link to the aggregation Router, the max load is:
For MxMFS: 1560 GCHperGP * 16 Kbps = 24.96 Mbps
Assuming all this traffic coming from SGSN for one MxMFS with 21 GP boards we get:
21 boards*24.96 Mbps = 524.16 Mbps Half of the GigaEthernet link capacity
For Legacy MFS: 480 GCHperGPU * 16 Kbps = 7.68 Mbps
Assuming all this traffic coming from SGSN for one MFS DS10 with 30 GPU boards we
get:
30 boards*7.68 Mbps = 230.4 Mbps Quarter of the GigaEthernet link capacity
Congestion is not expected at the level of the link to the aggregation router.Any Congestion seen afterwards is dependent on bandwidth management of the core IP network.
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102 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over IP
Target
Find the DL and UL traffic during BH
Input (counters values):
Ip Endpoint downlink data volume
Ip Endpoint uplink data volume
Output:
DL and UL data rate
Counters in the MFS
New counters per IP Endpoint are defined in case of GboIP:
P34a (TIME_SGSN_IP_ENDPOINT_NOT_AVAIL_GBIP),
P45a (NB_KBYTES_RECEIVED_FROM_SGSN_GBIP),
P46a (NB_KBYTES_SENT_TO_SGSN_GBIP).
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103 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over IP
Data rate calculation in DL (SGSN to MFS) and in UL (MFS to SGSN)
Data rate DL/UL, at IP Endpoint level or aggregated at GP or MFS level:
DL Data rate [Kbps] = 1.233*(P45a*8 )/(3600-P34a)
UL Data rate [Kbps] = 1.233*(P46a*8)/(3600-P34a)
Explanation:
Assuming LLC PDU and BSSGP payload are 300 bytes, NS, UDP, IP and Fast Ethernet
overhead are 70 bytes (i.e. 4+28+38),
SNS layer (where Kbytes counts is done) overhead ratio at this layer is 0.23% (i.e.
70/300).
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104 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Gb Interface Dimensioning
Gb over IP
GboIP traffic estimation based on actual GboFR traffic
Estimated Traffic:
Estimated DL IP Data rate [Kbps] = (370/306)*(P45*8)/(3600-P34)
Estimated UL IP Data rate [Kbps] = (370/306)*(P46*8)/(3600-P34)
Explanation:
Assuming LLC PDU and BSSGP payload are 300 bytes, NS, UDP, IP and Fast Ethernet
overhead are 70 bytes (i.e. 4+28+38), NS and FR overhead are 6 bytes (i.e. 4+2).
Packet size increase ratio = Total IP packet (i.e. 370) / Total FR packet (i.e. 306)
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105 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
Location Area
Dimensioning8
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106 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Location Area definition
Set of cells which are paged each time one Terminating Call is initiated
Specified with a unique Location Area Code (LAC)
Position of each MS in a specific Location Area stored in HLR / VLR
MS tells mobile network (using SDCCH resources)
when it moves from one LAC to another (Location Update)
periodically its current LAC position (Periodical LU)
Location Area size
Trade off between
Signalling load in cells located at LAC border
SDCCH resources in each cell has to be sized accordingly
Number of simultaneous pagings in each cell of the LAC
All MS in LAC and in MT call are paged simultaneously
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107 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
CCCH Sharing
Air interface
Pagings sent in DL on CCCH
Sharing between PCH & AGCH within one CCCH M-51 frame (235 mS duration)
CCCH_CONF
Combined mode 3 blocks
Non combined mode 9 blocks
Nb of AGCH blocks = BS_AG_BLKS_RES
Nb of PCH blocks = Nb of total CCCH blocks - BS_AG_BLKS_RES
6 CCCH blocks are available for the PCHReserved for AGCH
CCCH 8CCCH 7CCCH 6CCCH 5CCCH 4 CCCH 3CCCH 2CCCH 1CCCH 0
Example of AGCH and PCH organisation when BS_AG_BLKS_RES = 3 (Non combined mode)
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108 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
PCH content
Air interface
Nb of pagings per CCCH block, depends on
Paging request type
Subscribers behavior (mobile often on/off)
Paging efficiency
between 1.5 3
2.5 pagings / PCH block considered usually in dimensioning
TYPE 1 TYPE 2 TYPE 3 - IMSI - (P)TMSI - IMSI,IMSI - IMSI, (P)TMSI - (P)TMSI, (P)TMSI
- (P)TMSI, (P)TMSI, (P)TMSI - (P)TMSI, (P)TMSI,IMSI
- (P)TMSI, (P)TMSI, (P)TMSI, (P)TMSI
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109 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
PCH content
BTS
BSCCellMS
GPUMFS
TC MSC
SGSN
AbisAterMUX-PS
AterMUX-CS
Gb
APaging request message
(type 1, 2 or 3)Paging command
Message (RSL)
Paging commandor
Immediate assign command message
(RSL)
PCH blockson CCCH
CS Paging(SS7)
(GSL)PS/CS Paging
orChannel assignment downlink message
Paging request or
Packet downlink assignment
message
Gs
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110 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
PCH capacity
Non-Combined cell
BS_AG_BLKS_RES = 4 (AGCH blocks) 9 - 4 = 5 PCH blocks (default configuration)
5 PCH blocks/Multiframe * (3600s / 235 ms) =
76 594 PCH blocks/ hour
2.5 paging / Block x 76 594 Blocks =
191 485 paging/hour at 100% load
If 60 % engineering limit applied: 114 891 paging/hour
31.91 paging/s
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111 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
PCH capacity
Combined cell
BS_AG_BLKS_RES = 1 3 - 1 = 2 PCH blocks
2 PCH blocks/Multiframe x (3600s / 235 ms) =
30 638 PCH blocks/ hour
2.5 paging / Block x 30 638 Blocks =
76 595 paging/hour at 100% load
If 60 % engineering limit applied: 45 957 paging/hour
12.76 paging/s
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112 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
AGCH content
BTS
BSCCellMS
GPUMFS
AbisAterMUX-PS
Access grant message
(IA, IAE or IAR)Immediate assign
command message(RSL)
Immediate assign command message
(RSL)
AGCH blockson CCCH
Immediate assignment orImmediate assignment reject message
Access grant message
(PUA, PDA or IAR)(GSL)
Channel assignment uplink (EGPRS Uplink assign.),Channel assignment downlink(Downlink assign.)orChannel assignment uplink message (Assign. reject)
Note: IA= Immediate Assign; IAE=Immediate Assign Extended; IAR= Immediate Assign Reject;
PUA= Packet Uplink Assignment; PDA= Packet Downlink Assignment.
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113 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
AGCH capacity
Non-Combined cell
BS_AG_BLKS_RES = 4
4 AGCH blocks/Multiframe x (3600s / 235 ms) =
61 272 AGCH blocks/ hour
1 Immediate Assign message / Block x 61 272 Blocks =
61 272 paging/hour at 100% load
If 60 % engineering limit applied: 36 763 IA message/hour
10.21 IA message/s
AGCH efficiency: between 1 2 (2 if Immediate Assign Extended)
1 Immediate Assign message / AGCH block used usually in dimensioning
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114 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
AGCH capacity
Combined cell
BS_AG_BLKS_RES = 1
1 AGCH block/Multiframe x (3600s / 235 ms) =
15 318 AGCH blocks/ hour
1 Immediate Assign message / Block x 15 318 Blocks =
15 318 paging/hour at 100% load
If 60 % engineering limit applied: 9 180 IA message/hour
2.55 IA message/s
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115 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
AGCH and PCH capacity
Non-Combined cell
PCH blocks
AGCH blocks
Paging Request/s (PCH blocks/s)
Access Grant msgs/s (AGCH blocks/s)
Paging msgs/s at 60% limit
ImmAs msgs/s at 60% limit
PCH msgs/h at 60% limit
ImmAs msgs/h at 60% limit
Total # msgs sent/h at 60% limit
6 3 25.53 12.75 38.29 7.65 137851 27540 165391 5* 4 21.27 17.02 31.91 10.21 114893 36763 151656 4** 5 17.02 21.27 25.53 12.76 91908 45936 137844
Notes: * Alcatel recommended default configuration.
** Recommended for 16 TRX cells with CS only.
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116 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
B9 limitations
Abis interface limitation
max paging load of 33 paging commands per second = 118 800 paging/hour
G2 BSC limitation
max paging load of 70 paging commands per second = 252 000 paging/hour
MxBSC limitation
max paging load of 95 paging commands per second = 342 000 paging/hour
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117 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Location Area dimensioning in B9
G2 BSC:
MxBSC:
2 Location Areas with an average of 132 cells per LA
3 Location Areas with an average of 88 cells per LA
G2 BSC
(max 264 cells)
AAbis
70 paging/s33 paging/s
LA
LA
Mx BSC
(max 264 cells)
AAbis
95 paging/s33 paging/s
LA
LA
LA
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118 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
B10 limitations
Abis interface limitation
max paging load of 33 paging commands/second 118 800 paging/hour
max paging load of 66 paging commands/second 237 600 paging/hour with mCCCH
G2 BSC limitation
max paging load of 70 paging commands/second = 252 000 paging/hour
MxBSC limitation
max paging load of 120 paging commands/second= 432 000 paging/h
(expected in B10)
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119 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
B10 limitations
CCCH capacity in B10 with mCCCH
(rounded figures)
Nb CCCH TS BS_AG_BLKS_RES
PCH blocks AGCH blocks Max paging/s at 60% load
Max assign/s at 60% load
1 3 6 3 38 7 1 4 5 4 32 10 1 5 4 5 25 12 2 3 12 6 76 15 2 4 10 8 63 20 2 5 8 10 51 25 2 6 6 12 38 31
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120 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Location Area dimensioning in B10
G2 BSC without mCCCH:
1 Location Area with up to 264 cells per LA
G2 BSC with mCCCH:
G2 BSC
(max 264 cells)
AAbis
70 paging/s33 paging/s
LA
LA2 Location Areas with an average of 132 cells per LA
G2 BSC
(max 264 cells)
AAbis
70 paging/s66 paging/s
LA
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121 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Location Area dimensioning in B10
MxBSC without mCCCH:
4 Location Areas with an average of 125 cells per LA
2 Location Areas with an average of 250 cells per LA
Mx BSC
(max 500 cells)
AAbis
120 paging/s2 CCCH 66 paging/s
LA
LA
Mx BSC
(max 500 cells)
AAbis
120 paging/s1 CCCH 33 paging/s
LA
LA
LA
LA
MxBSC with mCCCH:
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122 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Location Area dimensioning in B10
There is no relationship between the BSC paging mechanism and CCCH
configuration.
The BSC has just the task of broadcasting paging messages per LAC.
If paging coming from MSC has a high rate, the BSC will send on Abis paging
commands at high speed, ignoring the fact that some cells are not able to
send it.
As a consequence, some paging commands shall be discarded by cells with
less radio capacity compared with BSC capacity for sending paging on Abis.
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123 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Location Area dimensioning in B10
The Paging load must be assessed during busy hour.
If the paging rate on Abis doesnt exceed 33 paging/s, cells with 1 CCCH TS
may be used without loses.
If the paging rate is higher (up to 66 paging/s), all the cells in LAC should be
configured with 2 CCCH TS, to avoid paging messages to be discarded.
If the paging rate per LAC is higher than 66 paging/s, the LAC should be split.
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124 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Dimensioning Target
Verify if the Location Area size is OK
Method:
Check the BSC and Abis limits
Check the related parameters
Check the load on CCCH (PCH, AGCH, RACH)
Input (counter values):
Paging rate, Nb of paging messages discarded, PS Paging rate, AGCH load, Nb of IA
messages discarded
Output
Location area load
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125 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Method for Location area:
Needed telecom parameters:
BS_AG_BLKS_RES
CCCH_CONF
Needed counters for PCH and AGCH:
MC8a = NB_CELL_PAGING_CMD
MC8b = NB_CELL_IMM_ASS_CMD
MC8d = NB_CELL_IMM_ASS_REJ
P49 = NB_IMM_ASS_AGCH
MC27 = CCCH_TS_Cell_available
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126 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Method for Location area:
New counters for CCCH in B10:
MC925a = NB_AGCH_USEFUL_BLOCKS_SENT
MC925b = NB_PCH_USEFUL_BLOCKS_SENT
MC925c = NB_BUSY_RACH_SLOTS
MC925d = NB_CHANNEL_RQ_RADIO
MC925e = NB_ASSIGN_CMD_RECEIVED_ABIS
MC925f = NB_ASSIGN_CMD_DISCARDED
MC925g = NB_PAGING_CMD_RECEIVED_ABIS
MC925h = NB_PAGING_CMD_DISCARDED
MC930 = NB_ABIS_PAGING_MESSAGE_RECEIVED
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127 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Method for Location area:
B9 Method
Total MC8a > 252000(Total for all LA in the BSC)
Re-Design LA, and/orReduce nb of LA per BSC
All Cells in a LA are non-combined
MC8a > 57,446 MC8a >114,891
Yes
No
No
No
NoYes Yes
Yes
OK OK Re-Design LAChange to non-combined Re-Design LA
Check BSC Limitation
Check Um Limitation
This value represents G2 BSC limit.
For MX BSC the limit is 342 000.
This value represents 60% of PCH channel capacity.
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128 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Method for Location area:
B10 Method
Total MC8a > 252000(Total for all LA in the BSC)
Re-Design LA, and/orReduce nb of LA per BSC
All Cells in a LA are non-combined
MC8a > 57,446 MC8a >114,891
Yes
No
No
No
NoYes Yes
Yes
OK OK Re-Design LAChange to non-combined Re-Design LA
Check BSC Limitation
Check Um Limitation
This value represents G2 BSC limit.
For MX BSC the limit is 432 000.
This value represents 60% of PCH channel capacity.
This value must be double in case of 2 CCCH TS.
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129 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Method for Location area (and Routing Area):
Abis approach
If (CS+PS) Paging load is less than 60% of PCH channel capacity:
The LA size is OK (no overload)
It is possible to keep RA size = LA size
LA RA
Note: Total PCH channel capacity is 191 485 paging/hour for 1 CCCH TS and
382 970 paging/hour for 2 CCCH TSs (for BS_AG_BLKS_RES = 4).
(CS+PS) Paging load = MC8a
60% represents engineering limit
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130 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Method for Location area (and Routing Area):
Abis approach
If (CS+PS) Paging load is greater than 60% of PCH channel capacity and if
PS Paging load/(CS+PS) Paging load is greater than 20% then:
Is necessary to have RA size < LA size, so LA must be splitted in two or more RAs.
Note: (CS+PS) Paging load = MC8aPS Paging load = P53a
LA
RA1RA2
RA
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131 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Method for Location area (and Routing Area):
Abis approach
If (CS+PS) Paging load is still greater than 60% of PCH channel capacity after
PS Paging load/(CS+PS) Paging load has been changed to be under 20%, then:
Is necessary to splitt the initial LA in two or more LAs.
LA LA1
LA2
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132 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
BSS Dimensioning Methods in B10
Location Area Dimensioning
Method for Location area (and Routing Area):
CCCH frame tuning at cell level
Checking during busy hour
Check BS_AG_BLKS_RES value
Check AGCH load (MC925e/AGCH capacity) and congestion (MC925f/ MC925e)
Check PCH load (MC925g/PCH capacity) and congestion (MC925h/ MC925g)
Tuning
If PCH load is below 60% and no congestion but AGCH load is above 60% and with
congestion => BS_AG_BLKS_RES may be increased by 1.
If PCH load is above 60% and with congestion but AGCH load is below 60% and without
congestion => BS_AG_BLKS_RES may be decreased by 1.
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133 | Presentation Title | Month 2008 All Rights Reserved Alcatel-Lucent 2008, XXXXX
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