8/12/2019 CORE Protocol Signalling Call Phases

1/5

8/12/2019 CORE Protocol Signalling Call Phases

2/5

BTS BSC MSC VLR

meas_report (facch)meas_report/result

disconnect (facch)dt1(disconnect)

dt1(release)

release (facch)

release_complete (facch)dt1(release_comp)

dt1(clear_com)ch_release (facch)

deactivate_sacchdisc (facch)

ua (facch)

rel_indicationrf_ch_rel

rf_ch_rel_ackdt1(clear_comp)

rlsd (sccp_rel)

rlc (sccp_rel_ack)

b_bsc

b_msc

MS

Legend:

Radio access part

Establishment part

Ciphering and encryption part call setup

Tch seized

Conversation part logical channel: tch

Release by MS

MS starts listening to bcch again

8/12/2019 CORE Protocol Signalling Call Phases

3/5

8/12/2019 CORE Protocol Signalling Call Phases

4/5

MS BTS BSC MSCrelease_indication

rf_channel_relrf_channel_rel_ack

b_bsc

dt1(clear_complete)rlsd (sccp_released)

rlsd (sccp_released_ack)

Legend:

Paging part

Radio access part

Establishment part

Ciphering and encryption part call setup

Tch seized

Conversation part logical channel: tch

Release by MS

MS starts listening to bcch again

8/12/2019 CORE Protocol Signalling Call Phases

5/5

BSC INTERNAL HANDOVER, INTER CELLMS BTS 1 BTS 2 BSC MSC

meas_rep (sacch)measurement_result

handover decision

ch_activationch_activation_ack

ho_commandho_command(facch)ho_access (facch)

ho_detectphysical_info (facch)

sabm (facch)establish_indication

ua (facch_ho_complete (facch)

rr (facch)ho_complete

dt1(ho_performed)rf_channel_release

rf_channel_release_ack

bish

bosh

(csh)

(mish)

(mosh)

bottabosa

bitta

bisa

(ctta)

(csa)

Legend:

Ho measurements and decisions

Tch reservation and activation in BTS 2

Signalling on facch-tch in BTS 1

Signalling on facch-tch in BTS 2 connection

Tch release in BTS 1