A method for talkgroup scan without call missed
Original Publication Date: 2014-Oct-23
Included in the Prior Art Database: 2014-Oct-23
Zeng, Nico: INVENTOR [+3]
FNE only broadcasts call activity information on control channel, not allocates voice channel, if there is no subscriber is affiliated on current site. Subscriber affiliates to an active talk group in its scan list when receives call active message. Subscriber affiliates to home talk group after scanned talk group call is over.
A Method For Talkgroup Scan Without Call Missed
By Zeng Yong, Zhao Dong, Zhao Kangkai
Motorola Solutions, Inc.
In APCO25 trunking system, scan is an important feature and enable user to monitor multiple talkgroups. But under certain scenarios, the active calls will be missed during scan. For some user, missing the calls on priority monitor talkgroup is not acceptable. This innovation presents a solution to solve the problem.
Under the typical configuration, for voice channel efficiency purpose, if in a site there is no subscriber affiliated to an active talkgroup, FNE will not route the voice to that site. So if a subscriber is scanning a talkgroup but there is no other subscriber is affiliated to that talkgroup within the same site, the scanning subscriber will missed the call.
When a talkgroup is active and there is no subscriber affiliated in a site, FNE does not allocate voice channel immediately but broadcast a TSBK message on the control channel to inform the subscriber there is active talkgroup. A new TSBK may be introduced for this idea. The subscriber decode the new TSBK message, if there is match with the scan list member, the subscriber affiliate to the active talkgroup, after that, FNE allocate the voice channel and send grant message, then subscriber can move to the voice channel.
Figure 1 show an example of the invention. Radio 1 and Radio 2 are register on Site 1 and affiliate to TG7001; Radio 3 is register on Site 2, affiliate to TG7002 and scan TG7001....