diff options
Diffstat (limited to 'doc/channel_release.txt')
| -rw-r--r-- | doc/channel_release.txt | 95 |
1 files changed, 0 insertions, 95 deletions
diff --git a/doc/channel_release.txt b/doc/channel_release.txt deleted file mode 100644 index c9cdfebca..000000000 --- a/doc/channel_release.txt +++ /dev/null @@ -1,95 +0,0 @@ - -GSM 04.08 7.1.7 / 9.1.7 RR CHANNEL RELESE - -RSL 08.58 3.4 / ? RLL Link Release Request - -RSL 08.58 4.6 / 8.4.5 DEACTivate SACCH - * Deactivate SACCH according to Channel Release Proc 04.08 - * to be sent after RR CHANNEL RELEASE is sent to MS - -RSL 08.58 4.7 / 8.4.14 RF CHANnel RELease - * tells the BTS to release a radio channel - * "when an activated radio channel is no longer needed" - * BTS responds with RF CHANnel RELease ACKnowledge - - -GSM 04.08 3.4.13: RR connection release procedure - -* network sends RR CHANNEL RELEASE to MS on the DCCH - * start T3109 - * deactivate SACCH -* MS disconnects main signalling link (by sending DISC) - * all other data links are disconnected by local end link release -* network receives DISC (BTS sends RLL REL IND to BSC) - * stop T3109 - * start T3111 -* when T3111 times out, the network can reuse the channls -* if T3109 times out, the network deactivates the channels - and can reuse them - * this probably means simply RF CHANnel RELease - - -== Implementation in OpenBSC == - -There are two possible reasons a gsm_subscriber_connection -will be released. One is a network failure, the other is -the completion of an operation/transaction. - -=== Failure === -The BSC API will call the gsm_04_08.c:gsm0408_clear_request callback -and the MSC part will release all transactions, operations and such -and the channels will be released as error case. - -=== Success === -Every time an 'operation' or 'transaction' is finished msc_release_connection -will be called and it will determine if the gsm_subscriber_connection can -be released. - -In case it can be released bsc_api.c:gsm0808_clear will be called -which will release all lchan's associated with the connection. For the -primary channel a SACH Deactivate will be send with the release -reason NORMAL RELEASE. - - -bsc_api.c:gsm0808_clear - * Release a channel used for handover - * Release the primary lchan with normal release, SACH deactivate - -chan_alloc.c:lchan_release(chan, sacch_deactivate, reason) - * Start the release procedure. It is working in steps with callbacks - coming from the abis_rsl.c code. - * Release all SAPI's > 0 as local end (The BTS should send a - REL_CONF a message) - * Send SACH Deactivate on SAPI=0 if required. - * Start T3109 (stop it when the main signalling link is disconnected) - or when the channel released. On timeout start the error handling. - * abis_rsl.c schedules the RSL_MT_RF_CHAN_REL once all SAPI's are - released and after T3111 has timed out or there is an error. - -RX of RELease INDication: - * Calls internal rsl_handle_release which might release the RF. - -RX of RELease CONFirmation: - * Calls internal rsl_handle_release which might release the RF. - -* RX of RF_CHAN_REL_ACK - * call lchan_free() - - -=== Integration with SMS === - -* RX of CP_ERROR or unimplemented MT - * trigger trans_free() which will msc_release_connection() - -* CP TC1* expired while waiting for CP-ACK - * trigger trans_free() which will msc_release_connection() - -* RX of RP_ERROR - * trigger trans_free() which will msc_release_connection() - -* TX of CP-ACK in MT DELIVER - * trigger trans_free() which will msc_release_connection() - -* RX of CP-ACK in MO SUBMIT - * trigger trans_free() which will msc_release_connection() - |