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Harald Welte laforge at gnumonks.orgHi!
I've just committed the current state of the handover code to git.
What is working so far:
* receiving + parsing the measurement reports from both MS and BTS
* performing the actual handover process, i.e. allocating / activating
the new logical channel on the new BTS, waiting for the ACK, sending
handover command to the MS, waiting for HO complete, HO fail or timeout,
...
* a minimalistic handover decision making. without any averaging: If we
have a cell that's >= 3dB better than the current one, try a handover.
What's missing:
* switching the actual traffic channel contents (i.e. re-configuring the RTP
streams in the ip.access case, or reconfiguring the TRAU mux in E1 case)
* better handover algorithm implementation including averaging
I'm on a business trip tomorrow, but the code is already seeming to work quite
fine, and it looks like:
<0400> abis_rsl.c:980 MEASUREMENT RESULT NR=13 RXL-FULL-ul=-47dBm RXL-SUB-ul=-47dBm RXQ-FULL-ul=0 RXQ-SUB-ul=0 BS_POWER=0 L1_MS_PWR= 10dBm L1_FPC=0 L1_TA=0 RXL-FULL-dl=-61dBm RXL-SUB-dl=-56dBm RXQ-FULL-dl=6 RXQ-SUB-dl=4 NUM_NEIGH=1
<0400> abis_rsl.c:1010 ARFCN=868 BSIC=63 => -70 dBm
<80000> handover_decision.c:61 process meas res: No better cell
<0400> abis_rsl.c:980 MEASUREMENT RESULT NR=14 RXL-FULL-ul=-47dBm RXL-SUB-ul=-47dBm RXQ-FULL-ul=0 RXQ-SUB-ul=0 BS_POWER=0 L1_MS_PWR= 10dBm L1_FPC=0 L1_TA=0 RXL-FULL-dl=-87dBm RXL-SUB-dl=-83dBm RXQ-FULL-dl=6 RXQ-SUB-dl=4 NUM_NEIGH=1
<0400> abis_rsl.c:1010 ARFCN=868 BSIC=63 => -69 dBm
<80000> handover_decision.c:61 process meas res: Cell on ARFCN 868 is better, starting handover
<80000> handover_logic.c:92 (old_lchan on BTS 0, new BTS 1): <0010> abis_rsl.c:1107 channel=(bts=1,trx=0,ts=2) chan_nr=0x0a CHANNEL ACTIVATE ACK
<80000> handover_logic.c:151 handover activate ack, send HO Command
<0002> gsm_04_08_utils.c:144 (bts 0 trx 0 ts 2 pd 06) Sending 0x2b to MS.
<0010> abis_rsl.c:1107 channel=(bts=1,trx=0,ts=2) chan_nr=0x0a <0010> abis_rsl.c:1082 HANDOVER DETECT access delay = 0
<0010> abis_rsl.c:1107 channel=(bts=1,trx=0,ts=2) chan_nr=0x0a <0010> abis_rsl.c:1082 HANDOVER DETECT access delay = 0
<0001> abis_rsl.c:1396 channel=(bts=1,trx=0,ts=2) chan_nr=0x0a sapi=0 ESTABLISH INDICATION
<0001> abis_rsl.c:1396 channel=(bts=1,trx=0,ts=2) chan_nr=0x0a sapi=0 DATA INDICATION
<0008> gsm_04_08.c:1595 HANDOVER COMPLETE cause = Normal event
<0002> handover_logic.c:203 lchan (bts=0,trx=0,ts=2,ch=0) decreases usage to: 0
Regards,
Harald
--
- Harald Welte <laforge at gnumonks.org> http://laforge.gnumonks.org/
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