| msc { |
| hscale=2; |
| ms [label="MS"], bts [label="BTS"], bsc[label="BSC"], bsc_lchan[label="BSC lchan FSM"]; |
| |
| ms note bsc_lchan [label="lchan allocation sequence for RSL Channel Request"]; |
| |
| ms => bts [label="RR Channel Request"]; |
| bts => bsc [label="RSL Channel Request"]; |
| bsc box bsc [label="rsl_rx_chan_rqd()"]; |
| bsc note bsc [label="Obtain RACH data from Request: - Reference - Access Delay (TA) |
| - Request Reason - Channel Type"]; |
| bsc note bsc [label="If the reason is PDCH, the RACH Request is forwarded to PCU and BSC is no |
| longer concerned (rsl_rx_pchan_rqd())."]; |
| bsc note bsc [label="Always try to allocate an SDCCH regardless of the requested type, only if no |
| SDCCH is available, look for the actually requested channel type."]; |
| bsc box bsc [label="lchan_select_by_type(SDCCH)"]; |
| |
| --- [label="IF no lchan is available (neither SDCCH nor requested type)"]; |
| bsc note bsc [label="Figure out T3122 value from bts->T3122, network->T3122 or |
| GSM_T3122_DEFAULT"]; |
| bsc box bsc [label="rsl_send_imm_ass_rej(wait_ind=T3122)"]; |
| bsc note bsc [label="..."]; |
| bts <= bsc [label="RR Immediate Assign Reject"]; |
| ms <= bts [label="RR Immediate Assign Reject (possibly grouped with up to 4 others)"]; |
| bsc note bsc [label="rsl_rx_pchan_rqd() exits, no channel is allocated."]; |
| --- [label="END: no lchan is available"]; |
| |
| bsc box bsc [label="Store RACH data in lchan->rqd_ref, rqd_ta"]; |
| bsc -> bsc_lchan [label="lchan_allocate(FOR_MS_CHANNEL_REQUEST)"]; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_WAIT_ACTIV_ACK\nT3103"]; |
| bsc_lchan note bsc_lchan [label="The lchan FSM knows that FOR_MS_CHANNEL_REQUEST is about |
| Immediate Assignment."]; |
| bts <= bsc_lchan [label="RSL Chan Activ (Immediate Assignment)"]; |
| ...; |
| --- [label="on any error"]; |
| bts <= bsc_lchan [label="RR Immediate Assign Reject"]; |
| ms <= bts [label="RR Immediate Assign Reject (possibly grouped with up to 4 others)"]; |
| ---; |
| ...; |
| bts => bsc_lchan [label="RSL Chan Activ ACK"]; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_WAIT_\nRLL_ESTABLISH\ncontinue T3103"]; |
| ...; |
| --- [label="on timeout"]; |
| bsc_lchan box bsc_lchan [label="lchan_error_release(deact_sacch=true)"]; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_WAIT_RF_RELEASE_ACK"]; |
| bts <= bsc_lchan [label="RLL Release Request (Local End)..."]; |
| bts <= bsc_lchan [label="...for all SAPIs including [0]"]; |
| bts <= bsc_lchan [label="RSL Deactivate SACCH"]; |
| bts <= bsc_lchan [label="RSL RF Channel Release"]; |
| ...; |
| bts => bsc_lchan [label="RSL RF Channel Release ACK"]; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_WAIT_AFTER_ERROR"]; |
| ...; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_UNUSED"]; |
| ---; |
| ms => bsc_lchan [label="RLL Establish Ind"]; |
| bsc_lchan box bsc_lchan [label="associate lchan FSM with new conn FSM"]; |
| bsc_lchan abox bsc_lchan [label="LCHAN_ST_ACTIVE"]; |
| } |