Ap1.2.4 Distress Alert - Nera Inmarsat-c Service Manual

AP1.2.4 Distress Alert

( MES logged-in)
Tunes to NCS CC
Decodes BB
Tunes to CES TDM
Tunes to SES
Signalling
Channel
Tunes to CES TDM
( MES logged-out)
MES
NCS CC
(LES network data)
Permanently assigned TDM
Channel
SES Signalling Channel
(DISTRESS ALERT)
CES TDM
(DISTRESS ALERT ACK)
Demand Assigned TDM
Channel
SES Signalling Channel
(DISTRESS ALERT)
NCS CC
(DISTRESS ALERT ACK)
SES Signalling Channel
(DISTRESS ALERT)
NCS CC
(DISTRESS ALERT ACK)
Fig. AP1.2.5 Distress Alert flow
AP1-16
AP1.2 Message & Signal Transfer
LES NCS
(Continuous transmission on
defined frequency)
ISL
(DISTRESS ALERT)
(DISTRESS ALERT ACK)
(assigned temporarily on a
demand basis)
ISL
(DISTRESS)
(DISTRESS ALERT ACK)
Records MES distress alerted
Records MES distress alerted
Enforces a log-in for MES
sending distress alert.