Method and system for preserving content timing across femtocell interfaces via timestamp insertion

• US 8,982,873 B2
• Filed: 04/30/2012
• Issued: 03/17/2015
• Est. Priority Date: 01/16/2009
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Chen, Xuemin (Sherman), Abraham, Charles, Diab, Wael William, Erceg, Vinko, Hou, Victor T., Karaoguz, Jeyhan, Kent, Mark
• Primary Examiner(s): Nguyen, Brian D
• Application Number:
  US13/460,147
• Publication Number:
  US 20120287918A1
• Time in Patent Office: 1,051 Days
• Field of Search: 370/252, 370/338, 370/350, 370/465, 370/466, 370/467
• US Class Current: 370/350
• CPC Class Codes: H04J 3/0664 unidirectional timestamps
• CPC Class Codes: H04J 3/0673 using intermediate nodes, e.g. modification of a received timestamp before further transmission to the next packet node, e.g. including internal delay time or residence time into the packet

Abstract

Aspects of a method and system for preserving content timing across femtocell interfaces via timestamp insertion are provided. In this regard, a femtocell may receive a first time-stamped packet via a first interface and transcode the time-stamped packet. The femtocell may buffer the transcoded packet based on a time-stamp recovered from the packet and may transmit the buffered transcoded packet via a second interface. One of the first interface and the second interface may utilize the Internet Protocol. One of the first interface and the second interface may be a non-cellular interface and the other interface may be a cellular interface. The femtocell may be operable to generate a timestamp corresponding to a time instant at which a time-stamped packet arrived via the first interface or the second interface. The timestamp may be referenced to a clock within a cellular enabled communication devices communicatively coupled to the femtocell.

Claims

1. A base station, comprising:

a first transceiver configured to receive a first time-stamped data packet via a first communications protocol;

a processor configured to transcode the first time-stamped data packet from a first format that is compatible with the first communications protocol to a second format that is compatible with a second communications protocol to provide a second time-stamped data packet; and

a second transceiver configured to transmit the second time-stamped data packet via the second communications protocol,

wherein the processor is further configured to control a transmission parameter of the second time-stamped data packet based on the first time-stamped data packet.

2. The base station of claim 1, wherein the first communications protocol comprises:

an internet protocol (IP).

3. The base station of claim 2, wherein the second communications protocol comprises:

a cellular data protocol.

4. The base station of claim 1, wherein the first time-stamped data packet corresponds to a first network clock domain, and

wherein the second time-stamped data packet corresponds to a second network clock domain.

5. The base station of claim 4, wherein the first network clock domain corresponds to a non-cellular network clock, and

wherein the second network clock domain corresponds to a cellular network clock.

6. The base station of claim 1, wherein the transmission parameter comprises:

a data buffer time duration, and

wherein the processor is further configured to control the data buffer time duration to control packet jitter.

7. The base station of claim 1, wherein the first time-stamped data packet includes a first timestamp,

wherein the second time-stamped data packet includes a second timestamp, and

wherein the second transceiver is further configured to transmit the second time-stamped data packet including the first timestamp and the second timestamp.

8. The base station of claim 1, wherein the first time-stamped data packet includes a first timestamp,

wherein the second time-stamped data packet includes a second timestamp, and

wherein the second transceiver is further configured to transmit the second time-stamped packet replacing the first timestamp with the second timestamp.

9. The base station of claim 1, wherein the transmission parameter comprises:

a data buffer time duration, and

wherein the processor is further configured to control the data buffer time duration based on a latency for the first time-stamped data packet.

10. In a network including a network node, a method comprising:

receiving a first data packet, including a first timestamp, via a first communications protocol;

transcoding the first data packet from a first format that is compatible with the first communications protocol to a second format that is compatible with a second communications protocol;

inserting a second timestamp into the transcoded data packet to provide a second data packet;

determining a time constraint corresponding to the first data packet; and

transmitting the second data packet based on the first timestamp and the time constraint via the second communications protocol.

11. The method of claim 10, wherein the inserting comprises:

inserting the second timestamp in place of the first timestamp.

12. The method of claim 10, wherein the first timestamp is associated with a first clock domain.

13. The method of claim 12, wherein the second timestamp is associated with a second clock domain.

14. The method of claim 10, wherein the determining comprises:

determining a data packet latency requirement or a data packet jitter requirement as the timing constraint.

15. In a network including a femtocell, a method comprising:

receiving a data packet including a first timestamp according to a first clock domain;

buffering the data packet for a time duration based on the first timestamp;

inserting a second timestamp into the data packet according to a second clock domain; and

transmitting the data packet.

16. The method of claim 15, wherein the first clock domain is associated with a non-cellular network, and

wherein the buffering comprises:

buffering the data packet for a time duration based on a length of time required for the data packet to traverse a portion of the non-cellular network.

17. The method of claim 15, wherein the first clock domain is associated with a non-cellular network, and

wherein the data packet is from among a plurality of sequentially received data packets, and

wherein the buffering comprises:

buffering the data packet for a time duration based on a length of time required for previous data packets of the plurality of sequentially received data packets to traverse a portion of the non-cellular network.

18. The method of claim 15, further comprising:

determining a latency corresponding to the data packet, and

wherein the buffering comprises;

buffering the data packet for a time duration based on the determining.

19. The method of claim 15, further comprising:

generating the second timestamp according to a receive time of the data packet.

20. The method of claim 19, wherein the inserting comprises:

inserting the second timestamp in place of the first timestamp.