Floor control over high latency networks in an interoperability and collaboration system

• US 8,005,497 B2
• Filed: 08/20/2007
• Issued: 08/23/2011
• Est. Priority Date: 08/20/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Metzger, Larry R., Shaffer, Shmuel
• Primary Examiner(s): Pan; Yuwen
• Assistant Examiner(s): Ayotunde; Ayodeji
• Application Number:
  US11/841,299
• Publication Number:
  US 20090054010A1
• Time in Patent Office: 1,464 Days
• Field of Search: None
• US Class Current: 455/518
• CPC Class Codes: H04B 7/18532 Arrangements for managing transmission, i.e. for transporting data or a signalling message
• CPC Class Codes: H04L 65/4038 with floor control
• CPC Class Codes: H04L 65/4061 Push-to services, e.g. push-to-talk or push-to-video
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services

Abstract

Methods and apparatus for assigning floor control based upon when a floor control request was initiated are disclosed. In one embodiment, a method includes receiving a first request for floor control from a first endpoint and granting the floor control to the first endpoint. The method also includes receiving a second request for floor control from a second endpoint, that has approximately the same priority level as the first endpoint, and determining if the first request was initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint. If it is determined that the first request was not initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint, then floor control is preempted from the first endpoint and granted to the second endpoint.

Claims

1. A method comprising:

receiving a first request for floor control from a first endpoint;

granting the floor control to the first endpoint;

receiving a second request for floor control from a second endpoint;

determining if the first request was initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint, wherein

determining if the first request was initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint includes ascertaining a delay associated with the second endpoint;

preempting the floor control from the first endpoint if it is determined that the first request was not initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint; and

granting the floor control to the second endpoint after preempting the floor control from the first endpoint if it is determined that the first request was not initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint.

2. The method of claim 1 further including:

initiating the second request from the second endpoint; and

sending the second request on at least one relatively high latency link, wherein the delay is associated with the relatively high latency link.

3. The method of claim 2 wherein the relatively high latency link is a satellite link.

4. The method of claim 2 wherein the delay is determined based on a Network Time Protocol (NTP).

5. The method of claim 2 wherein the delay is approximately one half of a round trip delay associated with sending the second request.

6. The method of claim 1 wherein preempting the floor control from the first endpoint includes sending a preemption notification to the first endpoint and granting the floor control to the second endpoint includes sending a floor control notification to the second endpoint.

7. Logic encoded in one or more non-transitory tangible media for execution and when executed operable to:

receive a first request for floor control from a first endpoint;

grant the floor control to the first endpoint;

receive a second request for floor control from a second endpoint;

determine if the first request was initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint, wherein the logic operable to determine if the first request was initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint is further operable to ascertain a delay associated with the second endpoint;

preempt the floor control from the first endpoint if it is determined that the first request was not initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint; and

grant the floor control to the second endpoint after preempting the floor control from the first endpoint if it is determined that the first request was not initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint.

8. The logic of claim 7 further operable to:

initiate the second request from the second endpoint; and

send the second request on at least one relatively high latency link, wherein the delay is associated with the relatively high latency link.

9. The logic of claim 8 wherein the relatively high latency link is a satellite link.

10. The logic of claim 8 wherein the delay is determined using a Network Time Protocol (NTP).

11. An apparatus comprising:

means for receiving a first request for floor control from a first endpoint;

means for granting the floor control to the first endpoint;

means for receiving a second request for floor control from a second endpoint;

means for determining if the first request was initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint, wherein the means for determining if the first request was initiated from the first endpoint at approximately the same time or earlier than the second request include means for ascertaining a delay associated with the second endpoint;

means for preempting the floor control from the first endpoint if it is determined that the first request was not initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint; and

means for granting the floor control to the second endpoint after preempting the floor control from the first endpoint if it is determined that the first request was not initiated from the first endpoint at approximately the same time or earlier than the second request was initiated from the second endpoint.

12. The apparatus of claim 11 further including:

means for initiating the second request from the second endpoint; and

means for sending the second request on at least one relatively high latency link, wherein the delay is associated with the relatively high latency link.

13. The apparatus of claim 12 wherein the relatively high latency link is a satellite link.

14. The apparatus of claim 12 wherein the delay is determined based on a Network Time Protocol (NTP).

15. The apparatus of claim 12 wherein the delay is approximately one half of a round trip delay associated with sending the second request.

16. The apparatus of claim 11 wherein the means for preempting the floor control from the first endpoint includes means for sending a preemption notification to the first endpoint and means for granting the floor control to the second endpoint includes sending a floor control notification to the second endpoint.

17. An apparatus comprising:

a port arranged to obtain a first floor control request from a first endpoint and a second floor control request from a second endpoint;

a floor control service arranged to grant floor control to the first endpoint in response to the first floor control request when the first floor control request is obtained; and

a topology and delay identification service arranged to identify a delay associated with the second endpoint when the second floor control request is obtained, the floor control service being arranged to cooperate with the topology and delay identification service to use the delay to determine if the first floor control request was originated from the first endpoint no later than when the second floor control request was originated from the second endpoint, wherein if the first floor control request is determined to have originated from the first endpoint later than when the second floor request was originated from the second endpoint, the floor control service is arranged to preempt the floor control from the first endpoint and to grant the floor control to the second endpoint.

18. The apparatus of claim 17 wherein the first floor control request and the second floor control request have the same priority level.

19. The apparatus of claim 17 wherein at least the second floor control request is obtained via a relatively high latency link, and the delay is associated with the relatively high latency link.

20. The apparatus of claim 19 wherein the relatively high latency link is a satellite communications link.

21. The apparatus of claim 17 wherein the apparatus is an interoperability and collaboration system.

22. The apparatus of claim 17 wherein the first endpoint is a first push-to-talk device and the second endpoint is a second push-to-talk device.

23. The apparatus of claim 17 wherein if the first floor control request is determined not to have originated from the first endpoint later than when the second floor request was originated from the second endpoint, the floor control service is arranged to send a denial notification to the second endpoint, and wherein if the first floor control request is determined to have originated from the first endpoint later than when the second floor request was originated from the second endpoint, the floor control service is arranged to send a preemption notification to the first endpoint and a grant notification to the second endpoint.