Method and apparatus for scheduling wireless LAN traffic

• US 8,117,299 B2
• Filed: 01/18/2005
• Issued: 02/14/2012
• Est. Priority Date: 01/18/2005
• Status: Active Grant

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Inventors: Narayanaswami, Chandrasekhar, Olsen, Claus Michael, Rosu, Marcel-Catalin
• Primary Examiner(s): Follansbee, John
• Assistant Examiner(s): CHOU, ALAN S
• Application Number:
  US11/037,962
• Publication Number:
  US 20060160508A1
• Time in Patent Office: 2,583 Days
• Field of Search: 709/224, 370/230.1
• US Class Current: 709/224
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/303 Terminal profiles
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02D 30/00 Reducing energy consumption in communication networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

To conserve energy, components in mobile devices normally have to transition less frequently between “active” and “sleep” modes, and to sleep for longer intervals. In accordance with at least one presently preferred embodiment of the present invention, there is broadly contemplated herein an approach to reduce energy consumption by using HTTP proxies to shape incoming WLAN traffic. Proxies contemplated herein use techniques specific to the HTTP payload to compensate for any negative impact that shaping may have. Thus, there is described herein the architecture of a “PowerAware Streaming Proxy” (PASP), built on a PowerAware x-Proxy (PAxP) framework. PASP preferably uses RTSP/RTP semantics to effectively schedule media streams across the WLAN. Herein, PASP is compared with PAWP, which is a PAxP extension for web traffic, and problem areas are identified.

Claims

1. An apparatus comprising:

one or more processors; and

a memory operatively connected to the one or more processors, the memory comprising proxy server code that when executed facilitates delivery of wireless communication traffic for one or more clients, wherein the one or more clients transition between a power save mode and an active mode, said proxy server further comprising;

a probing arrangement that probes the one or more clients to determine a power status of the one or more clients with respect to communication with an access point wherein said probing arrangement is adapted to ascertain a client time interval for staying in active mode; and

a providing arrangement that shapes the wireless communication traffic to said one or more clients via the access point, wherein shaping wireless communication traffic comprises transmitting the wireless communication traffic as a sequence of packet bursts synchronized to the active mode of the one or more clients;

wherein the client time interval for staying in active mode is ascertained via;

transmitting one or more probe packets to a client;

measuring a response delay of the client subsequent to transmission of at least one of the one or more probe packet; and

adjusting a packet send interval and awaiting a new beacon responsive to response delays not being substantially equivalent to a predetermined minimum round trip time.

2. The apparatus according to claim 1, wherein the wireless communication traffic comprises internet traffic.

3. The apparatus according to claim 1, wherein the access point comprises an 802.11 client interface.

4. The apparatus according to claim 1, wherein said probing arrangement is adapted to ascertain the time of receipt of an initial beacon solely at one client, prior to receipt of one or more further beacons at one or more further clients.

5. The apparatus according to claim 1, wherein said probing arrangement is adapted to ascertain a time of receipt of an initial beacon via:

transmitting a probe packet to a client;

measuring a response delay of the client subsequent to transmission of a probe packet; and

continuing to measure response delays of the client subsequent to transmission of additional probe packets, until the response delay is substantially equivalent to a predetermined minimum round trip time.

6. The apparatus according to claim 1, wherein said probing arrangement is adapted to ascertain at least one interval between which successive beacons are received by the one or more clients via:

transmitting a probe packet to a client;

measuring a response delay of the client subsequent to transmission of a probe packet;

calculating a new beacon multiple and awaiting a new beacon if the response delay is not substantially equivalent to a predetermined minimum round trip time; and

continuing to measure response delays of the client subsequent to transmission of additional probe packets, until the response delay is substantially equivalent to a predetermined minimum round trip time.

7. The apparatus according to claim 1, wherein ascertaining the client time interval further comprises:

continuing to measure response delays of the client subsequent to transmission of additional probe packets, until the response delay is substantially equivalent to a predetermined minimum round trip time; and

recording the client idle time interval responsive to response delays being substantially equivalent to the predetermined minimum round trip time.

8. An apparatus comprising:

one or more processors;

a memory operatively coupled to the one or more processors; and

a facilitating arrangement operatively connected to the memory, the facilitating arrangement facilitating wireless communication for at least one client, wherein the at least one client communicates with an access point and transitions between a power save mode and an active mode, said facilitating arrangement further comprising;

a probing arrangement that probes the at least one client to determine a power status of the at least one client with respect to communication with the access point wherein said probing arrangement is adapted to ascertain a client time interval for staying in active mode; and

an arrangement that releases data to an access point from a proxy server, said releasing arrangement being adapted to release data based upon one or more of the following (a) and (b);

(a) anticipated power related characteristics of the at least one client; and

(b) previously determined client parameters;

wherein the client time interval for staying in active mode is ascertained via;

transmitting one or more probe packets to a client;

measuring a response delay of the client subsequent to transmission of at least one of the one or more probe packet; and

adjusting a packet send interval and awaiting a new beacon responsive to response delays not being substantially equivalent to a predetermined minimum round trip time.

9. The apparatus according to claim 8, wherein said releasing arrangement releases data based upon all of (a) and (b).

10. The apparatus according to claim 8, wherein the wireless communication traffic comprises internet traffic.

11. The apparatus according to claim 8, wherein the access point comprises an 802.11 client interface.

12. The apparatus according to claim 8, wherein the power related characteristics comprises at least one of the following:

power mode, power state, power consumption, relationship between power consumption and incoming traffic characteristics, battery level, and battery consumption.

13. The apparatus according to claim 12, wherein the incoming traffic characteristics comprises at least one of the following:

rate and burstiness.

14. A method comprising:

facilitating wireless communication traffic for at least one client, wherein the client communicates with an access point and transitions between a power save mode and an active mode, said facilitating further comprising;

probing the at least one client to determine its status with respect to communication with the access point, said probing step comprising performing the following steps (a), (b) and (c);

(a) ascertaining the time of receipt of an initial beacon at the at least one client;

(b) ascertaining at least one interval between which successive beacons are received by the at least one client; and

(c) ascertaining a client time out interval for staying in active mode via;

transmitting one or more probe packets to a client;

measuring a response delay of the client subsequent to transmission of at least one of the one or more probe packets;

adjusting a packet send interval and awaiting a new beacon responsive to response delays not being substantially equivalent to a predetermined minimum round trip time.

15. The method according to claim 14, wherein the wireless communication traffic comprises internet traffic.

16. The method according to claim 14, wherein the access point comprises an 802.11 client interface.

17. The method according to claim 14, wherein said probing step comprises ascertaining the time of receipt of an initial beacon solely at one client, prior to receipt of one or more further beacons at one or more further clients.

18. The method according to claim 14, wherein said probing step comprises ascertaining the time of receipt of an initial beacon via:

transmitting a probe packet to a client;

measuring a response delay of the client subsequent to transmission of a probe packet; and

continuing to measure response delays of the client subsequent to transmission of additional probe packets, until the response delay is substantially equivalent to a predetermined minimum round trip time.

19. The method according to claim 14, wherein said probing step comprises ascertaining at least one interval between which successive beacons are received by the client via:

transmitting a probe packet to a client;

measuring a response delay of the client subsequent to transmission of a probe packet;

calculating a new beacon multiple and awaiting a new beacon if the response delay is not substantially equivalent to a predetermined minimum round trip time; and

continuing to measure response delays of the client subsequent to transmission of additional probe packets, until the response delay is substantially equivalent to a predetermined minimum round trip time.

20. The method according to claim 14, wherein ascertaining a client time interval for staying in active mode further comprises:

continuing to measure response delays of the client subsequent to transmission of additional probe packets, until the response delay is substantially equivalent to a predetermined minimum round trip time; and

recording the client idle time interval responsive to response delays being substantially equivalent to the predetermined minimum round trip time.

21. The method according to claim 14, further comprising a step of scheduling wireless communication traffic from a proxy server to the at least one client based on parameters determined via at least one of (a), (b) and (c).

22. The method according to claim 21, wherein said step of scheduling wireless communication traffic from a proxy server to the at least one client comprises scheduling traffic based on parameters determined via all of (a), (b) and (c).

23. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform steps comprising:

facilitating wireless communication traffic for at least one client, wherein the client communicates with an access point and transitions between a power save mode and an active mode, said facilitating further comprising;

probing the at least one client to determine its status with respect to communication with the access point, said probing step comprising performing the following steps (a), (b) and (c);

(a) ascertaining the time of receipt of an initial beacon at the at least one client;

(b) ascertaining at least one interval between which successive beacons are received by the at least one client; and

(c) ascertaining a client time out interval for staying in active mode via;

transmitting one or more probe packets to a client;

measuring a response delay of the client subsequent to transmission of at least one of the one or more probe packets; and

adjusting a packet send interval and awaiting a new beacon responsive to response delays not being substantially equivalent to a predetermined minimum round trip time.

24. A method comprising:

facilitating wireless communication traffic for at least one client, wherein the client communicates with an access point and transitions between a power save mode and an active mode, said facilitating further comprising;

releasing data to an access point from a proxy server, said releasing step comprising releasing data based on the following steps (a) and (b);

(a) anticipated power related characteristics of the at least one client; and

(b) previously determined client parameters; and

probing the at least one client to determine its status with respect to communication with the access point, said probing step comprising performing the following steps (c), (d) and (e);

(c) ascertaining the time of receipt of an initial beacon at the at least one client;

(d) ascertaining at least one interval between which successive beacons are received by the at least one client; and

(e) ascertaining a client time out interval for staying in active mode via;

transmitting one or more probe packets to a client;

measuring a response delay of the client subsequent to transmission of at least one of the one or more probe packets; and

adjusting a packet send interval and awaiting a new beacon responsive to response delays not being substantially equivalent to a predetermined minimum round trip time.

25. The method according to claim 24, wherein the wireless communication traffic comprises internet traffic.

26. The method according to claim 24, wherein the access point comprises an 802.11 client interface.

27. The method according to claim 24, wherein the power related characteristics comprises at least one of the following:

power mode, power state, power consumption, relationship between power consumption and incoming traffic characteristics, battery level, and battery consumption.

28. The method according to claim 27, wherein the incoming traffic characteristics comprises at least one of the following:

rate and burstiness.

29. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps comprising:

facilitating wireless communication traffic for at least one client, wherein the client communicates with an access point and transitions between a power save mode and an active mode, said facilitating further comprising;

releasing data to an access point from a proxy server, said releasing step comprising releasing data based on the following steps (a) and (b);

(a) anticipated power related characteristics of the at least one client; and

(b) previously determined client parameters; and

probing the at least one client to determine its status with respect to communication with the access point, said probing step comprising performing the following steps (c), (d) and (e);

(c) ascertaining the time of receipt of an initial beacon at the at least one client;

(d) ascertaining at least one interval between which successive beacons are received by the at least one client; and

(e) ascertaining a client time out interval for staying in active mode via;

transmitting one or more probe packets to a client;

measuring a response delay of the client subsequent to transmission of at least one of the one or more probe packets; and

adjusting a packet send interval and awaiting a new beacon responsive to response delays not being substantially equivalent to a predetermined minimum round trip time.