| Harald Welte | d26d3d9 | 2009-08-10 11:35:33 +0200 | [diff] [blame] | 1 | |
| 2 | GSM 04.08 7.1.7 / 9.1.7 RR CHANNEL RELESE |
| 3 | |
| 4 | RSL 08.58 3.4 / ? RLL Link Release Request |
| 5 | |
| 6 | RSL 08.58 4.6 / 8.4.5 DEACTivate SACCH |
| 7 | * Deactivate SACCH according to Channel Release Proc 04.08 |
| 8 | * to be sent after RR CHANNEL RELEASE is sent to MS |
| 9 | |
| 10 | RSL 08.58 4.7 / 8.4.14 RF CHANnel RELease |
| 11 | * tells the BTS to release a radio channel |
| 12 | * "when an activated radio channel is no longer needed" |
| 13 | * BTS responds with RF CHANnel RELease ACKnowledge |
| 14 | |
| 15 | |
| 16 | GSM 04.08 3.4.13: RR connection release procedure |
| 17 | |
| 18 | * network sends RR CHANNEL RELEASE to MS on the DCCH |
| 19 | * start T3109 |
| 20 | * deactivate SACCH |
| 21 | * MS disconnects main signalling link (by sending DISC) |
| 22 | * all other data links are disconnected by local end link release |
| 23 | * network receives DISC (BTS sends RLL REL IND to BSC) |
| 24 | * stop T3109 |
| 25 | * start T3111 |
| 26 | * when T3111 times out, the network can reuse the channls |
| 27 | * if T3109 times out, the network deactivates the channels |
| 28 | and can reuse them |
| 29 | * this probably means simply RF CHANnel RELease |
| 30 | |
| 31 | |
| 32 | == Implementation in OpenBSC == |
| 33 | |
| 34 | chan_alloc.c:lchan_auto_release() |
| 35 | * checks if use count still > 0 (abort) |
| 36 | * calls gsm48_send_rr_release() |
| 37 | * which calls rsl_deact_sacch() |
| 38 | * calls rsl_release_request() |
| 39 | * which sends RLL Link Release request |
| 40 | |
| 41 | RX of RELease INDication: |
| 42 | * call rsl_rf_chan_release() (send RF_CHAN_REL) |
| 43 | |
| 44 | RX of RELease CONFimem: |
| 45 | * call rsl_rf_chan_release() (send RF_CHAN_REL) |
| 46 | |
| 47 | * RX of RF_CHAN_REL_ACK |
| 48 | * call lchan_free() |
| 49 | * subscr_put() |
| 50 | * delete release_timer |
| 51 | |
| 52 | |
| 53 | === Integration with SMS === |
| 54 | |
| 55 | * RX of CP_ERROR or unimplemented MT |
| 56 | * trigger trans_free() which will lchan_auto_release() |
| 57 | |
| 58 | * CP TC1* expired while waiting for CP-ACK |
| 59 | * trigger trans_free() which will lchan_auto_release() |
| 60 | |
| 61 | * RX of RP_ERROR |
| 62 | * trigger trans_free() which will lchan_auto_release() |
| 63 | |
| 64 | * TX of CP-ACK in MT DELIVER |
| 65 | * trigger trans_free() which will lchan_auto_release() |
| 66 | |
| 67 | * RX of CP-ACK in MO SUBMIT |
| 68 | * trigger trans_free() which will lchan_auto_release() |
| 69 | |
| 70 | * RX of RP-ACK in MT DELIVER (and no more messages) |
| 71 | * trigger rsl_release_request() for SAPI3 |
| 72 | |
| 73 | * RX of RP-SMMA in MT DELIVER (and no more messages) |
| 74 | * trigger rsl_release_request() for SAPI3 |