Trunking System for CDMA Wireless Communication

• US 20090092116A1
• Filed: 11/18/2008
• Published: 04/09/2009
• Est. Priority Date: 08/15/2002
• Status: Active Grant

• Current Assignee: Yarnton Technologies LLC
• Original Assignee: ZTE Corporation
• Inventors: Bhalla, Rajesh, Chion, Mary, Fang, Yonggang, Jiang, James
• Granted Patent: US 8,072,919 B2
• Time in Patent Office: Days
• US Class Current: 370/340
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/08 Access security
• CPC Class Codes: H04W 12/76 Group identity
• CPC Class Codes: H04W 4/08 User group management
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems

Abstract

Methods and systems for implementing trunking techniques in CDMA systems for handling group calls and push-to-talk services.

Claims

1. A CDMA communication system, comprising:

a CDMA network having a mobile switching center connected to a public telephone switching network, operable to provide voice and data call services to mobile communication devices;

a packet data system coupled to said CDMA network to provide packet data services to the mobile communication devices; and

a trunking system coupled to said CDMA network and a packet data network to provide group call services to the mobile communication devices via the packet data network, said trunking system comprising (1) a plurality of dispatching clients in communication with said CDMA network to transmit data packets of a group call to and from mobile communication devices of a trunking group where members of each trunking group share a common trunking data link for transmission of data packets, and (2) a dispatching server connected to said packet data network and in communication with said dispatching clients to process group calls.

2. The system as in claim 1, wherein said CDMA network is configured to be compatible with CDMA2000 1X.

3. The system as in claim 1, wherein said CDMA network is configured to be compatible with CDMA2000 1xEV-DO.

4. The system as in claim 1, wherein said CDMA network is configured to be compatible with and CDMA2000 1xEV-DV.

5. The system as in claim 1, wherein said packet data system is coupled to provide the packet data services via the same packet data network shared by said trunking system.

6. The system as in claim 5, wherein the packet data network is an Internet Protocol network.

7. The system as in claim 1, wherein said packet data system is coupled to provide the packet data services via another packet data network that is separate from the packet data network used by said trunking system.

8. The system as in claim 1, wherein the packet data network is an Internet Protocol network, and wherein said trunking system is configured to transmit data packets between each dispatching client and said dispatching server via said packet data network without headers from the Point-To-Point Protocol.

9. A method for providing group call services in a CDMA communication system, the method comprising:

providing a plurality of dispatching clients in a CDMA system to dispatch group call requests via a packet data network to a dispatching server that controls and manages group calls;

using a common trunking message link through the packet data network to transmit trunking messages between a dispatching client and the dispatching server; and

using a single trunking data link to each trunking group between the dispatching server and each dispatching client such that a plurality of group members share the single trunking data link in transmitting user data over the packet data network.

10. The method as in claim 9, wherein the trunking messages are in a Short Data Burst (SDB) format.

11. The method as in claim 9, further comprising filtering signals from a base station controller in the CDMA system based on a service category information of the signals to route regular call messages to a mobile switching center in the CDMA system and to route trunking messages to the dispatching server via the common trunking message link.

12. The method as in claim 9, further comprising dividing groups for group calls into permanent groups that are registered in the CDMA system and temporary groups that are not registered in the CDMA system.

13. The method as in claim 12, further comprising:

providing a system mechanism to create and maintain identification information for permanent groups;

assigning a group head in each permanent group to manage group membership and group calls; and

providing a user mechanism to create and maintain temporary groups and to initiate a group call.

14. The method as in claim 9, further comprising:

authenticating a group call based on both group identification information for a trunking group and membership of the trunking group; and

checking whether a mobile station is registered in the CDMA system.

15. The method as in claim 9, further comprising:

providing an inactivity timer to monitor a data link for a group call;

after the inactivity timer expires, initiating a dormancy timer to place the data link in a dormant state where at least one physical channel is released; and

releasing a group call when the dormancy timer expires.

16. The method as in claim 15, further comprising providing a mechanism to bypass the inactivity timer to place a data link for a group call in dormant state prior to expiration of the inactivity timer.

17. The method as in claim 16, further comprising evoking the mechanism when a link resource in the system is low.

18. The method as in claim 9, further comprising providing a voice loop-back avoidance in handling a group call.

19. The method as in claim 9, further comprising providing a mechanism to disable slotted mode when the group call is in a dormancy state.

20. The method as in claim 9, further comprising:

paging members of a trunking group in response to a group call request from the trunking group in accordance with location information of the group members;

authenticating the group call request by checking identification information on the trunking group, membership information, and information on network registration of each member; and

disabling a slotted mode in a dormant state for each mobile communication device in the trunking group.

21. A CDMA communication system, comprising:

a CDMA trunking system coupled to a CDMA network and a packet data network to provide group call services to mobile communication devices in the CDMA network via the packet data network, said CDMA trunking system comprising;

a plurality of dispatching clients in communication with the CDMA network to transmit data packets of a group call to and from mobile communication devices of a trunking group where members of each trunking group share a common trunking data link for transmission of data packets, and

a dispatching server connected to said packet data network and in communication with said dispatching clients to process group calls.

22. The system as in claim 21, wherein said trunking system further includes a group registration database to store information on trunking groups and group membership, a security server to authenticate group calls, and a dispatching location server to provide location information of group members in a group call, and wherein said dispatching server is in communication with said group registration database, said security server, and said dispatching location server, and is coupled to receive group call information for processing a group call.

23. The system as in claim 22, wherein said trunking system includes a message router to direct, according to a service category, a trunking message to said dispatching server through a corresponding dispatching client, and other messages to the CDMA network.

24. The system as in claim 22, wherein said trunking system is configured to provide a common trunking message link between each dispatching client and said dispatching server to transmit trunking messages.

25. The system as in claim 22, wherein said trunking system is configured to have a protocol between each dispatching client and said dispatching server that does not have a point-to-point protocol layer.