Method and system for managing mass registration scenario in two-way radio system

Abstract

A method and apparatus are described for managing a mass registration scenario in a two-way radio system. A site controller in a trunked radio system detects a mass registration condition in which registration requests by subscriber units are likely to collide on an inbound control channel. During the mass registration condition, the site controller initiates a restriction period by instructing subscriber units that are members of particular talkgroups to temporarily cease registration requests. Those talkgroup members are permitted to resume their registration requests when a predetermined delay time has passed since the members were instructed to cease registration, or when a particular silence time has passed without registration activity over the control channel.

We claim: 
     
       1. A method comprising:
 detecting that an inbound control channel is in a mass registration condition; 
 during the mass registration condition, receiving a plurality of registration requests over the inbound control channel, including at least a first registration request from a member of a first talkgroup; 
 in response to the first registration request, initiating a first restriction period by sending a first restriction message on an outbound control channel, wherein the first restriction message instructs members of the first talkgroup to cease registration requests; and 
 when the first restriction period ends, sending a first invitation message on the outbound control channel inviting members of the first talkgroup to resume registration requests. 
 
     
     
       2. The method of  claim 1 , wherein the first invitation message invites only members of the first talkgroup to resume registration requests. 
     
     
       3. The method of  claim 1 , wherein the first restriction message is a registration grant that acknowledges registration of a member of the first talkgroup, and wherein the first restriction message includes a first restriction code that instructs members of the first talkgroup to cease registration requests. 
     
     
       4. The method of  claim 1 , wherein the first restriction period ends when a first predetermined delay time has passed since the initiation of the first restriction period. 
     
     
       5. The method of  claim 1 , wherein the first restriction period ends when a predetermined silence time has passed since the receipt of a registration request on the inbound control channel. 
     
     
       6. The method of  claim 1 , wherein the first restriction period ends at the earlier of the following times: (a) when a first predetermined delay time has passed since the initiation of the first restriction period; and (b) when a first predetermined silence time has passed since the receipt of a registration request on the inbound control channel. 
     
     
       7. The method of  claim 1 , further comprising:
 during the mass registration condition, receiving a second registration request from a member of a second talkgroup on the inbound control channel; 
 in response to the second registration request, initiating a second restriction period by sending a second restriction message on the outbound control channel, wherein the second restriction message instructs members of the second talkgroup to cease registration requests; and 
 when the second restriction period ends, sending a second invitation message on the outbound control channel inviting members of the second talkgroup to resume registration requests. 
 
     
     
       8. The method of  claim 7 , wherein the first restriction period overlaps with the second restriction period. 
     
     
       9. The method of  claim 7 , wherein the second restriction period ends when a second predetermined delay time has passed since the initiation of the second restriction period. 
     
     
       10. The method of  claim 9 , wherein the second predetermined delay time has the same duration as a first predetermined delay time. 
     
     
       11. The method of  claim 7 , wherein the second restriction period ends when a predetermined silence time has passed since the receipt of a registration request on the inbound control channel. 
     
     
       12. The method of  claim 7 , wherein the second restriction period ends at the earlier of the following times: (a) when a second predetermined delay time has passed since the initiation of the second restriction period; and (b) when a predetermined silence time has passed since the receipt of a registration request on the inbound control channel. 
     
     
       13. The method of  claim 1 , wherein a substantial majority of talkgroup members that are registered during the first restriction period are not members of the first talkgroup. 
     
     
       14. A system comprising:
 a transceiver for communicating on an inbound control channel and an outbound control channel; 
 a control module operatively coupled to the transceiver, wherein the control module includes a processor and a non-transient computer-readable medium storing executable instructions that, when executed on the processor, are operative: 
 (a) to detect that the inbound control channel is in a mass registration condition; 
 (b) during the mass registration condition, to receive a plurality of registration requests over the inbound control channel, including at least a first registration request from a member of a first talkgroup; 
 (c) in response to the first registration request, to initiate a first restriction period by sending a first restriction message on the outbound control channel, wherein the first restriction message instructs members of the first talkgroup to cease registration requests; and 
 (d) when the first restriction period ends, to send a first invitation message on the outbound control channel inviting members of the first talkgroup to resume registration requests. 
 
     
     
       15. The system of  claim 14 , wherein the first restriction period ends at the earlier of the following times: (a) when a first predetermined delay time has passed since the initiation of the first restriction period; and (b) when a first predetermined silence time has passed since the receipt of a registration request on the inbound control channel. 
     
     
       16. The system of  claim 14 , wherein the executable instructions, when executed on the processor, are further operative:
 during the mass registration condition, to receive a second registration request from a member of a second talkgroup on the inbound control channel; 
 in response to the second registration request, to initiate a second restriction period by sending a second restriction message on the outbound control channel, wherein the second restriction message instructs members of the second talkgroup to cease registration requests; and 
 when the second restriction period ends, to send a second invitation message on the outbound control channel inviting members of the second talkgroup to resume registration requests.