8/2/2019 Call Flowchart

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CALL ESTABLISHMENT (TO LAND)

MS L1 ABIS RRSM CRM SM SSM MTP/MSC

RACH channal

T3120 request ok_acc_proc_suc_rach (could be decoded)

access_per_rach (all received)

channel

request inv_est_cause_on_rach(included phantom)channel

AGCH immediate assign. request chan_req_cause_atmpt (1510)

"123 tone" reject channelT3126 start T3122 required received

expire T3122channal channel

request assigned alloc_sdcch

busy_sdcchRSS

channel activation

channel activetion

acknowledge

immediate assignment

AGCH immediate command start T3101

assignmentaccess_per_agch (how many im_assign_cmd/rej was s ent out, 1 msg may include upto 2 MS)

expire T3101chan_req_ms_fail

SDCCH L2 SABM estabish indiction

T3230 L3 (intial msg) CM service request stop T3101T303 UA ok_acc_proc

(SDCCH) ms_access_by_type (1510)

initial L3 informationCM Service request

immediate assignment reject conn_req_to_msc

alloc_sdcch_failchan_req_ms_blk SCCP conn

classmark3(if needed)

conn_refused

SDCCH setup

identity request (if MSC need more MS information)identity response call setup

call proceeding (MSC have got enough information to setup the connection)

T310 facility (if MS have some supplementary services, such as call divert)

assignment

request start MSC timer forma_req_from_msc assignment, =30s

initiate assignment maybe efr_req_from_msc

start assign_successfulassignment resource expire MSC timer without

request UDT(reset circuit) assignment complete' orresouce not available assignment failure'

alloc_tch_fail expire assign_successful

ma_cmd_to_ms_blkd assignment failureunsuccessful assignment

assignment failureforce queuestart T11

assignment queued

queuing indicationexpire T11 release request

clear request

assignment channel clr_req_to_mscassigned

stop T11

alloc_tchphysical context request tch_usage .

physical context confirmed busy_tchchannel activation

channel activation ack.

SDCCH assignment commandstart T10

ma_cmd_to_ms

expire T10 release request clear request

assignment failure

ma_fail_from_msstop T10 release request clear request

FACCH L2 SABMUA

assignment completedstop T10

assignment successful

stop assign_successful PSTNconnection

required

connection responsesuccess assignment complete

stop MSC timer for

total_call assignmentma_complete_to_msc

(total call+intracellHO) IFAM (initial and final address)

ACM (address complete)alerting

connectconn ack. T313 billing start billing

total_call and alloc_tch counter works before alerting signalwas sent. For drive test, the drop call should be consideredafter this point.

Only at this time, the MSCbegain to send the calledaddress to PSTN

BSCBTS