Method of scheduling data and signaling packets for push-to-talk over cellular networks

• US 20060088065A1
• Filed: 12/24/2004
• Published: 04/27/2006
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Sonim Technologies, Inc.
• Original Assignee: Sonim Technologies, Inc.
• Inventors: Khatter, Saryender
• Granted Patent: US 7,558,286 B2
• Time in Patent Office: Days
• US Class Current: 370/528
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/1083 In-session procedures
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/4061 Push-to services, e.g. push-to-talk or push-to-video
• CPC Class Codes: H04M 11/064 Data transmission during pauses in telephone conversation
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems

Abstract

A method and device for scheduling signaling and data packets during PTT sessions. An exemplary embodiment of the invention includes scheduling data packets and signaling packets during a push-to-talk session by detecting periods of silence in the talk-burst, inserting signaling packets between the data packets in the periods of silence in the talk-burst; and transmitting the signaling data packet along with the data packets. In another aspect of the invention, downlink signaling packets are suspended during the push-to-talk session.

Claims

1. In a communications network, a method for scheduling data packets and signaling packets for a client device coupled to the communications network during a Voice Over IP (VOIP) session, comprising the steps of:

detecting a period of silence data in a talk-burst;

inserting a signaling packet between data packets during the period of silence in the talk-burst; and

transmitting the signaling packet between the client device and the communications network.

3. The method recited in claim 1, further comprising the step of:

suspending downlink signaling packets to the client device during the VOIP session.

4. The method recited in claim 3, wherein the suspending step transmits a 486 message using SIP dialogue in reaction to start of a VOIP session, start of the talk burst, or start of transmission of an RTP packet.

5. The method recited in claim 4, wherein the suspension time is calculated so that the SIP dialogue remains active.

6. The method recited in claim 4, wherein a new SUBSCRIBE message is sent within the SIP dialogue at termination of the VOIP session, termination of the talk burst, or conclusion of transmission of an RTP packet.

7. The method recited in claim 1, wherein the data packets are based upon RTP and the signaling packets are based upon SIP.

9. The method recited in claim 1, further comprising the steps of:

determining the time between a packet equipped with a trigger is released to the communications network modem and a control message is received in response to the trigger packet being transmitted out on the communications network;

calculating real-time bandwidth of the communications network; and

based upon the real-time bandwidth, modifying the size of the signaling packets.

10. The method recited in claim 1, further comprising the steps of:

determining the time between a packet equipped with a trigger is released to the communications network modem and a control message is received in response to the trigger packet being transmitted out of the communications network;

calculating real-time bandwidth of the communications network; and

based upon the real-time bandwidth, transmitting a second signaling packet.

11. The method recited in claim 1, further comprising the steps of:

emptying signal packets stored in the client device; and

bypassing the detecting and inserting steps when the client device releases floor control.

12. The method recited in claim 1, wherein the VOIP session is a push-to-talk session.

2. The method recited in claim I, wherein the detecting of the period of silence is based upon a silence data packet present in the talk burst, and wherein the inserting of the signaling packet is behind the silence data packet in the talk-burst.

8. The method recited in claim 2, wherein the detecting step detects the period of silence when a SID_FIRST data packet is a data packet in the talk-burst;

and wherein the inserting step inserts the signaling packet behind the SID_FIRST data packet.

13. An improved push-to-talk enabled client device, the improvement comprising:

means for detecting a period of silence in a talk-burst during a push-to-talk session;

means for inserting a signaling packet between data packets during the period of silence in the talk-burst during the push-to-talk session.

14. The device recited in claim 13, wherein the means for detecting detects the period of silence based upon a silence data packet present in the talk burst, and wherein means for inserting inserts the signaling packet behind the silence data packet in the talk-burst.

15. The device recited in claim 13, further comprising:

means for suspending downlink signaling packets during the push-to-talk session.

16. The device recited in claim 15, wherein the means for suspending generates a 486 message using SIP

17. The device recited in claim 13, wherein the data packets are based upon RTP and the signaling packets are based upon SIP.

18. The device recited in claim 17, wherein the silence data packets detected by the silence detector are SID_FIRST data packets.

19. The device recited in claim 13, further comprising:

means for determining the time between a packet equipped with a trigger is released to the push-to-talk network modem and a control message is received in response to the trigger packet being transmitted out on the push-to-talk network;

means for calculating real-time bandwidth of the push-to-talk network; and

means for modifying the size of the signaling packets based upon the real-time bandwidth.

20. The device recited in claim 13, further comprising:

means for determining the time between a packet equipped with a trigger is released to the push-to-talk network modem and a control message is received in response to the trigger packet being transmitted out on the push-to-talk network;

means for calculating real-time bandwidth of the push-to-talk network; and

means for transmitting a second signaling packet based upon the real-time bandwidth.

21. The device recited in claim 13, further comprising:

means for disabling the means for detecting and means for inserting when the client device releases floor control.

22. A client device configured for use in a push-to-talk communications network, comprising:

a codec configured to create data packets representative of a input talk-burst;

a data packet queue coupled to the codec for the data packets;

a session controller configured to create signaling packets;

a signaling packet queue coupled to the session controller for the signaling packets.

a silence detector to identify, in the data packet queue, data packets representative of silence in the talk-burst; and

a signaling queue manager configured to control signaling packets output from the signaling packet queue;

wherein, in response to the silence detector detecting a silence data packet, the signaling queue manager directs the signaling packet queue to output at least one of the signaling packets behind the silence data packet.

23. The device recited in claim 22, further comprising:

means for suspending downlink signaling packets during the push-to-talk session.

24. The device recited in claim 23, wherein the means for suspending generates a 486 message using SIP

25. The device recited in claim 22, wherein the data packets are based upon RTP and the signaling packets are based upon SIP.

26. The device recited in claim 25, wherein the silence data packets detected by the silence detector are SID_FIRST data packets.

27. The device recited in claim 22,

wherein the signaling queue manager calculates real-time bandwidth of the push-to-talk network based upon the time between a packet equipped with a trigger is released to the push-to-talk network modem and a control message is received in response to the trigger packet being transmitted out of the push-to-talk network;

and

wherein the session controller modifies the size of the signaling packets based upon the real-time bandwidth.

28. The device recited in claim 22, further comprising:

wherein the signaling queue manager calculates real-time bandwidth of the push-to-talk network based upon the time between a packet equipped with a trigger is released to the push-to-talk network modem and a control message is received in response to the trigger packet being transmitted out of the push-to-talk network; and

wherein the signaling queue manager directs the signaling packet queue to output at least one additional of the signaling packets behind the silence data packet.

29. The device recited in claim 22, wherein the signaling packets in the signaling packet queue are released without delay when the device releases floor control.

30. The device recited in claim 22, wherein the signaling packet queue and the silence detector are disabled when the device releases floor control.