METHOD FOR ASSIGNING THE CARRIER FREQUENCY IN A TRUNKED SYSTEM

• US 20090239515A1
• Filed: 03/03/2006
• Published: 09/24/2009
• Est. Priority Date: 03/03/2006
• Status: Active Grant

• Current Assignee: ZTE Corporation
• Original Assignee: ZTE Corporation
• Inventors: Jiang, Feng, Bai, Wei, Huang, Chi, Zhang, Zhihui, Tao, Rui
• Granted Patent: US 8,942,183 B2
• Time in Patent Office: Days
• US Class Current: 455/416
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems

Abstract

The present invention discloses a method for assigning the carrier frequency in a trunking system, which includes: after the base station subsystem receiving a group call request, it assigns a carrier frequency reference for this group call, by which to establish the forward channels of the group users managed by the base station subsystem. With the method offered by the present invention, all the group members under a base station subsystem could be established on the same carrier frequency reference as far as possible, thereby sharing of the wireless channels.

Claims

1. A method for assigning carrier frequency in a trunking system, comprising the steps:

after a base station subsystem has received a group call request, it assigns a carrier frequency reference to the group call and establishes forward channels of group members managed by the base station system at the carrier frequency reference.

2. The method of claim 1, wherein the group call request is a group access request by the user, including an originating request from the user or a response sent by the user after the user has received a paging request from a dispatch server.

3. The method of claim 1, wherein the carrier frequency reference assigned to the group call is statically configured in the dispatch server system as an attribute of the group.

4. The method of claim 1, wherein the group call is centrally processed by a processing board MP, the carrier frequency reference of the group is dynamically assigned by the MP according to predetermined rules and deleted after the call is completed.

5. The method of claim 4, wherein after the MP has assigned the carrier frequency reference, if group members at a carrier frequency F1 is more than the users at the original carrier frequency reference by a predetermined threshold, the MP updates the carrier frequency reference of the group call to the carrier frequency F1.

6. The method of claim 1, wherein the group call is processed by a plurality of MPs, the base station subsystem assigns a Master MP to the group, and others as Slave MPs;

when the base station subsystem receives the group call request, the following steps are performed;

(a) the base substation system selecting a MP and sending the group call request to the MP, performing step (b) if the MP is a Master MP;

performing step (c) if the MP is a Slave MP;

(b) after the Master MP having received the group call request, determining whether the carrier frequency reference of the group call exists, if yes, ending;

otherwise, assigning a carrier frequency reference to the group call and announcing it to all the Slave MPs, the Slave MPs determining or updating the local carrier frequency reference after receiving the carrier frequency reference, ending;

(c) after the Slave MP having received the group call request, determining whether the carrier frequency reference of the group call exists, if yes, ending;

otherwise, notifying the Master MP, then the Master MP determining the carrier frequency reference of the group call and announcing it to all the Slave MPs through a message, the Slave MPs determining or updating the local carrier frequency reference according to the carrier frequency reference in the message after having received the message, ending.

7. The method of claim 6, wherein after the Slave MP has received the group call request in said step (c), it firstly assigns a temporal carrier frequency reference for the call, and sends a carrier frequency reference registration request which carries the temporary carrier frequency reference to the Master MP;

after the Master MP has received the registration request, it checks whether the carrier frequency reference of the group call exists, if yes, it announces the carrier frequency reference to all the MPs, otherwise, the temporary carrier frequency reference is used as the carrier frequency reference of the group call, a registration response is returned to the Slave MP and a carrier frequency reference synchronization message is sent to other Slave MPs.

8. The method of claim 7, wherein the Master MP and the Slave MP assign the carrier frequency reference or the temporary carrier frequency reference according to a condition that the load is lightest and/or the resource is most sufficient, or according to a condition that the load is smaller than a predetermined threshold.

9. The method of claim 6, wherein comprising the steps of deleting the carrier frequency reference:

(i) after the Slave MP having received a release message from the user, if it determining that the user is the last user in the group call processed by the MP, sending a carrier frequency reference deleting request to the Master MP;

(j) after the Master MP having received the deleting request, checking locally whether there are still users in the call, if no, checking other Slave MPs and determining whether the user is the last user in the call managed by the Base Station System;

if yes, performing the next step, otherwise, ending;

(k) the Master MP deleting the carrier frequency reference of the group call and sending a carrier frequency reference deleting message to all the Slave MPs, the Slave MPs deleting the carrier frequency reference of the group call after having received the message.

10. The method of claim 6, wherein comprising the steps of deleting the carrier frequency reference:

(o) after the Master MP having received the release message from the user, it locally checking whether the user is the last user in the call managed locally, if yes, performing the next step, otherwise, ending;

(p) the Master MP checking each of the Slave MPs of the group to determine whether the user is the last user in the call managed by the Base Station Subystem, if yes, performing the next step, otherwise, ending;

(q) the Master MP deleting the carrier frequency reference of the group call and sending the carrier frequency reference deleting message to all the Slave MPs, the Slave MPs deleting the carrier frequency reference of the group call after having received the message.

11. The method of claim 6, wherein whenever there is user handoffing or releasing, the Master MP obtains a using condition of the carrier frequency from all users in the group call, if the number of the users at a carrier frequency F1 exceeds the number of users at the carrier frequency reference by a predetermined threshold, the carrier frequency reference on all the MPs is updated to the carrier frequency F1.

12. The method of claim 11, wherein the process of updating the carrier frequency reference includes the following steps of:

(A) after the user handoffing and releasing processed by the Slave MP, the Slave MP checking a number of the group users on the carrier frequency F1 locally, if the number of users at the carrier frequency F1 exceeds the number of users at the original carrier frequency reference by the predetermined threshold, performing the next step, otherwise, ending;

(B) the Slave MP sending a carrier frequency reference update request with information of the carrier frequency F1 to the Master MP;

after the Master MP having received the message, it checking at the local and in other Slave MPs to obtain the using condition of the carrier frequencies by all the group users managed by the Base Station Subystem, if the number of users at the carrier frequency F1 exceeds the number of users at the carrier frequency reference by the predetermined threshold, performing the next step, otherwise, ending;

(C) the Master MP updating its carrier frequency reference and sending a carrier frequency reference update message with the information of the carrier frequency F1 to all the Slave MPs, the Slave MPs updating the carrier frequency reference locally after receiving the update message.

13. The method of claim 11, wherein comprising the steps of updating the carrier frequency reference:

(I) after the user switching and releasing processed by the Master MP, the Master MP checking the assignment condition of the carrier frequency of the group users on the current MP, performing the next step if the number of users at one carrier frequency F1 exceeds the number of users at the carrier frequency reference by the predetermined threshold, otherwise, ending;

(J) the Master MP checking each Slave MP to acquire the using condition of the carrier frequency by all the group users managed by the Base Station System, performing the next step if the number of users at the carrier frequency F1 exceeds the number of users at the carrier frequency reference by the predetermined threshold, otherwise, ending;

(K) the Master MP updating its carrier frequency reference and sending the carrier frequency reference update message with the information of the carrier frequency F1 to all the Slave MPs, the Slave MPs updating the information of the basic carrier frequency on the local MP after receiving the update message.

14. The method of claim 9, wherein comprising the steps of deleting the carrier frequency reference:

(o) after the Master MP having received the release message from the user, it locally checking whether the user is the last user in the call managed locally, if yes, performing the next step, otherwise, ending;

(p) the Master MP checking each of the Slave MPs of the group to determine whether the user is the last user in the call managed by the Base Station Subystem, if yes, performing the next step, otherwise, ending;

(q) the Master MP deleting the carrier frequency reference of the group call and sending the carrier frequency reference deleting message to all the Slave MPs, the Slave MPs deleting the carrier frequency reference of the group call after having received the message.

15. The method of claim 12, wherein comprising the steps of updating the carrier frequency reference:

(I) after the user switching and releasing processed by the Master MP, the Master MP checking the assignment condition of the carrier frequency of the group users on the current MP, performing the next step if the number of users at one carrier frequency F1 exceeds the number of users at the carrier frequency reference by the predetermined threshold, otherwise, ending;

(J) the Master MP checking each Slave MP to acquire the using condition of the carrier frequency by all the group users managed by the Base Station System, performing the next step if the number of users at the carrier frequency F1 exceeds the number of users at the carrier frequency reference by the predetermined threshold, otherwise, ending;

(K) the Master MP updating its carrier frequency reference and sending the carrier frequency reference update message with the information of the carrier frequency F1 to all the Slave MPs, the Slave MPs updating the information of the basic carrier frequency on the local MP after receiving the update message.