Push-to-talk and push-to-conference in a CDMA wireless communications system

• US 6,982,961 B2
• Filed: 07/19/2001
• Issued: 01/03/2006
• Est. Priority Date: 07/19/2001
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Sourour, Essam, Witter, Robert C., Refai, Wail M.
• Primary Examiner(s): Pezzlo, John
• Application Number:
  US09/909,395
• Publication Number:
  US 20030016632A1
• Time in Patent Office: 1,629 Days
• Field of Search: 370/328, 370/335, 370/336, 370/266, 370/263, 370/265, 370/260, 370/329, 370/341, 370/431, 370/330, 455/518, 455/422.1, 455/450, 455/422, 455/426, 380/271, 379/202.01
• US Class Current: 370/265
• CPC Class Codes: H04M 3/56 Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities video conference systems H04N7/15
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• 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 72/56 based on priority criteria
• 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

A method of providing push-to-talk and push-to-conference functionality in a CDMA system. Participants, in one embodiment, may be divided into active and inactive participants with active participants assigned a private uplink/downlink channel pair by the communication system. Inactive participants may be assigned a public downlink channel. In one embodiment, silent active participants of a conference or talk session are timed out and the private uplink/downlink channel pair previously assigned to such individuals are released for use elsewhere in the network or by other members of the conference. In a push-to-talk embodiment one private uplink/downlink channel pair may at any given time be passed between the presently active members of the group.

Claims

1. A method of handling a group call in a CDMA wireless communications system, comprising:

classifying members of a group call into a first class or a second class, said first class comprising members authorized to both talk and listen, said second class comprising members authorized to listen but not to talk;

initially assigning a private downlink channel to each member of said group call belonging to said first class;

assigning a public downlink channel to at least one member of said group call belonging to said second class;

changing the classification of a first member of said group call belonging to said first class to be said second class in response to said member not talking for a predetermined time period during said group call; and

changing the downlink channel assignment of said first member from said respective private channel to said public downlink channel assigned to said at least one member of said group call belonging to said second class in response to said change in classification.

2. The method of claim 1 further comprising providing both private and public downlink channels simultaneously.

3. The method of claim 1 further comprising changing the downlink channel assignment in response to a request to speak from at least one member of said group call belonging to said second class.

4. The method of claim 1 further comprising staggering a change of status for pilot channels and traffic channels as members of said first group transition to members of said second group.

5. The method of claim 1 further comprising placing a member of said second group on said respective private channel just freed by said changing the downlink channel assignment of said first member from said respective private channel to said public downlink channel.

6. A method of handling a group call in a CDMA wireless communications system, comprising:

classifying members of a group call into a first class or a second class, said first class comprising members authorized to both talk and listen, said second class comprising members authorized to listen but not to talk;

initially assigning a private downlink channel to each member of said group call belonging to said first class;

assigning a public downlink channel to at least one member of said group call belonging to said second class;

initially transmitting voice on a Reverse Traffic Channel and a pilot signal on a Reverse Pilot Channel, during said group call, by a first member of said group call belonging to said first class; and

thereafter, ceasing transmission on the Reverse Traffic Channel, during said group call, by a first member in response to said first member not talking for a first predetermined time period during said group call, while continuing to transmit the pilot signal on the Reverse Pilot Channel.

7. The method of claim 6 further comprising:

thereafter, ceasing transmission of the pilot signal on the Reverse Pilot Channel, during said group call, by said first member in response to said first member not talking for a second predetermined time period during said group call; and

changing the downlink channel assignment of said first member from said respective private channel to said public downlink channel in response to said first member not talking for said second predetermined time period during said group call.

8. The method of claim 6 further comprising ending said group call when all of said members are silent for a length of time greater than a predetermined threshold.

9. The method of claim 6 further comprising processing, at said base station both private and public downlink channels concurrently.

10. The method of claim 6 further comprising allowing members of said second class to move to said first class and further assigning such moving members a private downlink channel on which to communicate.

11. A method of handling a group call in a CDMA wireless communications system, comprising:

classifying members of a group call into one of either a first class or a second class, said first class comprising members authorized to both talk and listen, said second class comprising members authorized to listen but not to talk;

initially assigning a private downlink channel and a private uplink channel to a first member of said group call belonging to said first class;

initially assigning the remaining members of said group call to one or more public downlink channels; and

thereafter, during said group call, substantially simultaneously;

reclassifying said first member to said second class;

reassigning said first member to said public downlink channel;

reclassifying a second member of said group call belonging to said second class to said first class;

reassigning said private downlink channel and said private uplink channel to said second member.

12. A method of facilitating communication comprising:

establishing a group of users in a CDMA wireless communication system, each of said users having a mobile terminal;

initiating a call to at least one other user of the group from a first mobile terminal;

assigning a first private downlink channel to said first mobile terminal;

assigning other private downlink channels to mobile terminals associated with said at least one other user of the group as needed; and

assigning a public downlink channel to remaining users of the group.

13. The method of claim 12 further comprising timing out users such that private downlink channels are freed for other users within the group.

14. The method of claim 12 further comprising allowing inactive users associated with the public downlink channel to secure a private downlink channel upon actuation of a command on their mobile terminal.

15. The method of claim 12 further comprising limiting the other private downlink channels to a predetermined number.

16. A method of handling a group call in a CDMA wireless communications system, comprising:

dividing members of a group call to a first class or second class, said first class comprising members authorized to both talk and listen, said second class comprising members authorized to listen but not to talk;

assigning a private downlink/uplink channel pair to a member of said first class for communicating between said member of said first class and a base station;

assigning a public downlink channel without a corresponding uplink channel to a member of said second class for receiving downlink communications from said base station;

wherein, during a given group call, said first member and said second member receive downlink communications from said base station over their respective downlink channels.