如果CHGR=1,用EGSM頻點，且開啟跳頻的情況下，一定要將BCCD設(shè)為NO ，否則會影響SD的接通率！

附eircsson的文檔說明：

Published by the Implementation Technical Assistant Center, Guangzhou (ERICSSON INTERNAL)
Issued by Snow Kong



Low SDCCH connection rate in BSS R10

After BSS upgraded to R10 SDCCH connection rate is only 20% in some cells which mixed bands configuration (CHGR 0 with P-GSM frequency and CHGR 1 with E-GSM frequency). Those cells set hopping in both CHGR.

The reason is BSC system has one new parameter BCCD in R10 level. The operator can define which channel groups to include and exclude for Immediate Assignment with the parameter, BCCD. As the maximum number of frequencies in the CA list is 64 the sum of frequencies for all of the hopping CHGRs HFS shall be equal or less than 64. If the sum is higher then 64 then BCCD is used to prevent immediate/packet assignment in one or more CHGRs.

The Phase 1 MSs are not able to read a broadcast CA-list that includes any frequency outside the P-GSM frequency band. As a consequence, call setups and handovers may fail. Therefore, it is recommended not to include these frequencies in the CA-list if the amount of Phase 1 MSs is still significant in the network. This is done by setting BCCD to NO for all the channel groups with frequency hopping activated on frequencies outside the P-GSM frequency band.

But BCCD and HOP are set to “ON” in some cells which mixed bands configuration (CHGR 0 with P-GSM frequency and CHGR 1 with E-GSM frequency) after BSS upgrade to R10. So SDCCH establish will be failure in those cells.

Action:
Please check cell data configuration after BSS upgrade to R10.
Use following command:
<RLCFP:CELL=AAG2011;
CELL CONFIGURATION FREQUENCY DATA

CELL
AAG2011

CHGRSCTYPE SDCCHSDCCHACTNCBCHHSNHOPDCHNO
0 40 2NO 34ON10
22
37
56
61
71
10 02NO 13 ON 1016
1020





<RLCHP:CELL= AAG2011;
CELL CONFIGURATION FREQUENCY HOPPING DATA

CELL
AAG2011

CHGRHSNHOPMAIOBCCD
0 13ON YES
1 23ON YES


These are the frequency ranges for P-GSM and E-GSM.
GSM 900, P-GSM: ARFCN 1 - ARFCN 124
GSM 900, G1-GSM (Extended): ARFCN 0, ARFCN 975 - ARFCN 1023

If you find the cell configure like the above printout you need to set BCCD to “NO” in CHGR 1.

RLCHC:CELL= AAG2011,CHGR=1,BCCD=NO;


And then Low SDCCH connection rate will go back to normal.

[ 本帖最后由 namipan 于 2011-8-25 23:29 編輯 ]