[handover] first functional handover implementation
With this commit, we can successfully hand over a channel from one cell to
another cell. We implement asynchronous intra-BSC (but inter-BTS) handover.
Changes:
* introduce new DHO log category
* extend rsl_chan_activate_lchan() with argument for HO reference
* introduce actual minimal handover decision making in handover_decision.c
* various fixes to bsc_handover_start() in handover_logic.c
diff --git a/openbsc/include/openbsc/abis_rsl.h b/openbsc/include/openbsc/abis_rsl.h
index b76d0fa..6d0ab61 100644
--- a/openbsc/include/openbsc/abis_rsl.h
+++ b/openbsc/include/openbsc/abis_rsl.h
@@ -497,7 +497,7 @@
u_int8_t bs_power, u_int8_t ms_power,
u_int8_t ta);
int rsl_chan_activate_lchan(struct gsm_lchan *lchan, u_int8_t act_type,
- u_int8_t ta);
+ u_int8_t ta, u_int8_t ho_ref);
int rsl_chan_mode_modify_req(struct gsm_lchan *ts);
int rsl_encryption_cmd(struct msgb *msg);
int rsl_paging_cmd(struct gsm_bts *bts, u_int8_t paging_group, u_int8_t len,