A method of establishing two calls simultaneously in one group for dual watch and dual radio system
Original Publication Date: 2015-Jul-10
Included in the Prior Art Database: 2015-Jul-10
Kong, De.Ting.: INVENTOR [+3]
This method introduces a way to support two calls simultaneously in one talk group in dual radio and dual watch trunked system. Based on this method, some services which can?t be supported in current trunked system could be supported. For example: 1) Supports two voice group calls simultaneously while dual or multi call requests happens in high priority talk group. 2) Supports large data service (such as transmit photos or over the air programming) without blocking normal immediate service such as voice call and data call in high priority talk group.
A METHOD OF ESTABLISHING TWO CALLS IN ONE GROUP FOR DUAL WATCH AND DUAL RADIO SYSTEM
By Deting Kong, Jianhai Qi, Ying Fang
This paper provides a method of establishing two calls simultaneously in one talk group call in dual radio and dual watch trunked system.
The dual watch / dual radio firstly monitoring the higher priority talk group on the primary receiver and monitoring the lower priority channel, if one call is requested on the higher priority talk group, the secondary receiver of the receiving radios land to the granted traffic channel 1 and the primary receiver keeps monitoring the control channel. If another group call is requested during previous call is still ongoing, the primary receiver of the receiving radios in this group land to the granted traffic channel 2.
The flow chart of establishing two calls is presented.
In typical trunked system, only one call (voice call / data call) can be supported in one talk group. Once one call is established in a talk group, receiving radios can’t monitoring the control channel simultaneously due to limitation of the terminal equipment and FDMA technology which trunked system based on (control channel and traffic channel are configured as different frequencies). So another call request from the other users in this group can’t be granted except the ongoing call dropped, or the granted package can’t be received even through infrastructure assigns another traffic channel for this new talk group call request.
Dual watch / dual radio is the ability to listen to two talk groups simultaneously and multi-watch extends this capability to three or more calls. Usually the primary receiver is monitoring the high priority talk group meanwhile the secondary receiver is monitoring the normal priority talk group.
For police officer or some other specific users, while he/she is transmitting one voice call, meanwhile he/she also need to transmit more data information in the same talk group such as the photo of the criminal and the scene of the crime. So this will need the trunked system to support establishing two calls simultaneously in one talk group.
Dual watch/dual radio offers a ability to receive two different RF signals on one terminal equipment. A method of establishing two calls simultaneously in one group based on dual watch/dual radio trunked system is introduced in this paper. Some definitions are given out to expatiate on this method.
§ Primary Control Channel: The control channel is monitored by the primary receiver.
§ Secondary Control Channel: The control channel is monitored by the secondary receiver.
§ Secondary Traffic Channel: The traffic channel is assigned by Secondary Control Channel.
§ High Priority Talk Group: The talk group is assigned to the primary receiver in dual watch or dual radio user equipment (UE).
§ Idle Status: No call is establ...