METHOD, SYSTEM AND APPARATUS FOR SYNCHRONIZING MULTIPLE STREAMS FOR OPTIMIZING DELAY AND TALK TIME

• US 20090163254A1
• Filed: 12/20/2007
• Published: 06/25/2009
• Est. Priority Date: 12/20/2007
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Lide, David Alston, Chandra, Praphul
• Application Number:
  US11/961,696
• Publication Number:
  US 20090163254A1
• Time in Patent Office: Days
• US Class Current: 455/574
• CPC Class Codes: H04L 65/1059 End-user terminal functionalities specially adapted for real-time communication
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 65/764 at the destination reformatting of additional data in video clients H04N21/4355
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04W 52/028 switching on or off only a part of the equipment circuit blocks
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method, system and apparatus for synchronizing multiple streams of a communication session between a wireless station device (STA) and one or more communication devices via a wireless access point (AP) of a wireless local area network (WLAN), includes a host processor determining a synchronization period in accordance with packetization periods of each of the multiple streams, switching the STA to a doze mode until expiration of the synchronization period, buffering packets generated during the synchronization period, and switching the STA from the doze mode to an active mode upon expiration of the synchronization period and decompressing or transmitting packets generated while the STA is in the active mode.

Claims

1. A method of synchronizing multiple media streams of a communication session between a wireless station device (STA) and one or more communication devices via a wireless access point (AP) of a wireless local area network (WLAN), the method comprising:

determining a synchronization period in accordance with packetization periods of each of the multiple streams;

switching the STA to a doze mode until expiration of the synchronization period;

buffering packets generated during the synchronization period; and

switching the STA from the doze mode to an active mode upon expiration of the synchronization period and decompressing or transmitting packets generated while the STA is in the active mode.

2. The method of claim 1, wherein the determining of the synchronization period further includes setting the synchronization period equal to one of the packetization periods of the multiple streams having the greatest value.

3. The method of claim 1, wherein the determining of the synchronization period further includes determining the synchronization period in accordance with one of user preferences and a battery level, wherein the buffering of the packets generated during the synchronization period further includes buffering the packets in a host processor included in the STA.

4. The method of claim 1, wherein the switching the STA to the doze mode further comprises switching off a media access control (MAC) included in the STA.

5. The method of claim 4, wherein the switching the STA to the active mode further comprises switching on the MAC.

6. The method of claim 1, wherein the determining of the synchronization period further includes setting the synchronization period equal to a greatest common divisor of packetization periods of the multiple streams.

7. A method of synchronizing multiple streams of a communication session between a real time wireless station device (RTSTA) and one or more communication devices via a wireless access point (AP), the RTSTA capable of entering an active mode in which the RTSTA exchanges packets with an AP and a doze mode in which the RTSTA can switch off one or more internal components in order to save power, the multiple streams including a first stream having a first packetization period at which the packets are received or transmitted and a second stream having a second packetization period different from the first packetization period, the method comprising:

determining a synchronization delay time for synchronizing the first and second streams;

buffering packets to be received from or transmitted on the first stream and the second stream for the predetermined delay time, wherein the RTSTA is in the doze mode during the synchronization delay time;

switching the RTSTA to the active mode to simultaneously receive or transmit the packets on the first stream and the second stream after the predetermined delay time;

switching the RTSTA back to the doze mode after receiving or transmitting the packets; and

repeatedly buffering the packets on the first stream and the second stream and switching the RTSTA to the active mode after the predetermined delay time and back to the doze mode until either the communication session has ended or a predetermined time duration has expired.

8. The method of claim 7, wherein the synchronization delay time is equal to the greater of the first packetization period and the second packetization period.

9. The method of claim 7, wherein the first stream is a transmit path to the one or more communication devices and the second stream is a receive path to the one or more communication devices, wherein the synchronization delay time is equal to one of the first packetization period of the transmit path and the second packetization period of the receive path.

10. The method of claim 7, wherein the synchronization delay time is equal to a greatest common divisor of packetization periods of the multiple streams.

11. A wireless station device (STA) operating in a wireless local area network for providing a communication session with a communication device via a wireless access point (AP), the STA comprising:

an interface for transmitting packets on a first stream having a first packetization period and receiving packets on a second stream having a second packetization period different from the first packetization period;

a processor coupled to the interface;

a memory coupled to the processor, the memory including instructions for configuring the processor to;

determine a synchronization period for synchronizing the first and second streams;

switch off the interface in order to save power during the synchronization period; and

switch on the interface after the synchronization period to transmit and receive the packets.

12. The STA of claim 11, wherein the synchronization period is equal to the greater of the first packetization period and the second packetization period.

13. The STA of claim 11, wherein the synchronization period is equal to one of the first and second packetization periods.

14. The STA of claim 11, wherein the synchronization period is equal to a greatest common divisor of packetization periods of the first and second streams.

15. The STA of claim 11, wherein the processor is further configured to:

compress media data into the packets for transmission and decompress received packets into media data; and

buffer the packets to be transmitted during the synchronization period.

16. A real time wireless station device (RTSTA) operating in a wireless local area network for providing a communication session having multiple streams with a communication device via a wireless access point (AP), the RTSTA comprising:

a digital signal processor for compressing media data into packets for transmission on a transmit stream having a first packetization period and decompressing packets received on a receive stream having a second packetization period different from the first packetization period into media data;

a host processor coupled to the digital signal processor for determining a synchronization period for synchronizing the transmission and reception of packets on the transmit and receive streams;

a media access control (MAC) coupled to the host processor for handling transmission and reception protocols of packets on the wireless local area network and providing the wireless connection with the AP; and

a wake up device coupled to the host processor and the MAC for switching the RTSTA to an active mode in which the RTSTA exchanges packets with the AP and a doze mode in which the STA can switch off the MAC in order to save power, wherein the wake up device periodically switches the RTSTA from the doze mode to the active mode in accordance with the synchronization period so that the transmission and reception of the packets on the transmit and receive streams is synchronized.

17. The RTSTA of claim 16, wherein the synchronization packetization period is equal to the greater of the first packetization period and the second packetization period.

18. The RTSTA of claim 16, wherein the synchronization packetization period is equal to a greatest common divisor of packetization periods of the multiple streams.

19. The RTSTA of claim 16, wherein when the RTSTA is in the doze mode, the host processor buffers the packets to be transmitted until the RTSTA is in the active mode.

20. The RTSTA of claim 16, wherein when the RTSTA is in the doze mode, the host processor buffers the packets to be received until the RTSTA is in the active mode.