Minimization of performance impact in overlying 802.11b & 802.11g networks

• US 20050135303A1
• Filed: 12/19/2003
• Published: 06/23/2005
• Est. Priority Date: 12/19/2003
• Status: Active Grant

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Cromer, Daryl Carvis, Locker, Howard Jeffrey, Jakes, Philip John
• Granted Patent: US 7,352,772 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/101 Access control lists [ACL]
• CPC Class Codes: H04W 72/1268 of uplink data flows
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

A wireless network access point is described which provides the resources of a backbone network to wireless clients. The access point is able to minimize the performance impact on 802.11g clients in the presence of mixed in 802.11g/802.11b traffic by isolating wireless network traffic based on protocol. At least one 802.11g timer is maintained for 802.11g traffic. Request for transfers by 802.11b clients which are blind to 802.11g traffic are delayed until after the expiration of the 802.11g timer. Traffic for 802.11g clients proceeds unimpeded while the 802.11g timer is active. A similar timer is optionally maintained for 802.11b traffic.

Claims

1. Apparatus comprising:

a wireless network interface which supports a plurality of wireless protocols including a physical carrier-sense protocol and a virtual carrier-sense protocol, wherein the virtual carrier-sense protocol is utilized by provided clients which are unable to detect the physical carrier-sense protocol; and

a flow controller which is coupled to said wireless network interface and which maintains a physical timer corresponding to traffic conforming to physical carrier-sense protocol, wherein the flow controller isolates traffic over said wireless network interface based on protocol by delaying virtual-carrier-sense-protocol traffic until after the physical timer elapses.

2. Apparatus of claim 1 wherein the flow controller further maintains a virtual timer corresponding to traffic conforming to virtual carrier-sense protocol and further isolates traffic over said wireless network interface by delaying physical-carrier-sense-protocol traffic until after the virtual timer elapses.

3. Apparatus of claim 2 wherein the physical timer commences in response to a first instance of physical-carrier-sense-protocol traffic following a first wireless network event and is set to elapse after a first predetermined amount of time, wherein the first wireless network event is selected from the group consisting of an idle network event and a virtual-carrier-sense-protocol traffic event.

4. Apparatus of claim 3 wherein the virtual timer commences in response to a first instance of virtual-carrier-sense-protocol traffic following a second wireless network event and is set to elapse after a second predetermined amount of time wherein the second predetermined amount of time is selected from the group consisting of the first predetermined amount of time and an amount of time other than the first predetermined amount of time, and wherein the second wireless network event is selected from the group consisting of an idle network event and a physical-carrier-sense-protocol traffic event.

11. The method of claim 10 wherein the virtual timer commences in response to a first instance of virtual-carrier-sense-protocol traffic following a second wireless network event and is set to elapse after a second predetermined amount of time wherein the second predetermined amount of time is selected from the group consisting of the first predetermined amount of time and an amount of time other than the first predetermined amount of time, and wherein the second wireless network event is selected from the group consisting of an idle network event and a physical-carrier-sense-protocol traffic event.

5. Apparatus comprising:

a wireless network interface which supports a carrier sense multiple access/collision avoidance (CSMA/CA) protocol and an 802.11b protocol, wherein the 802.11b protocol is utilized by provided clients which are unable to detect the CSMA/CA protocol; and

a flow controller which is coupled to said wireless network interface and which maintains a CSMA/CA timer corresponding to CSMA/CA traffic and an 802.11b timer corresponding to 802.11b traffic, wherein the flow controller isolates traffic over said wireless network interface based on protocol by delaying 802.11b traffic until after the CSMA/CA timer elapses and by delaying CSMA/CA traffic until after the 802.11b timer elapses.

6. Apparatus of claim 5 wherein the CSMA/CA timer commences in response to a first instance of CSMA/CA traffic following a first wireless network event and is set to elapse after a first predetermined amount of time, wherein the first wireless network event is selected from the group consisting of an idle network event and a 802.11b traffic event.

7. Apparatus of claim 6 wherein the 802.11b timer commences in response to a first instance of 802.11b traffic following a second wireless network event and is set to elapse after a second predetermined amount of time wherein the second predetermined amount of time is selected from the group consisting of the first predetermined amount of time and an amount of time other than the first predetermined amount of time, and wherein the second wireless network event is selected from the group consisting of an idle network event and a CSMA/CA traffic event.

8. A method comprising:

maintaining a physical timer in relation to a wireless network which supports a plurality of wireless protocols including a physical carrier-sense protocol and a virtual carrier-sense protocol, wherein the virtual carrier-sense protocol is utilized by provided clients which are unable to detect the physical carrier-sense protocol and wherein the maintained physical timer corresponds to traffic which conforms to physical carrier-sense protocol; and

isolating traffic over the wireless network based on protocol by delaying virtual-carrier-sense-protocol traffic until after the physical timer elapses.

9. The method of claim 8 further comprising:

maintaining a virtual timer which corresponds to traffic which conforms to virtual carrier-sense protocol;

wherein said isolation of traffic further includes delaying physical-carrier-sense-protocol traffic until after the virtual timer elapses.

10. The method of claim 9 wherein the physical timer commences in response to a first instance of physical-carrier-sense-protocol traffic following a first wireless network event and is set to elapse after a first predetermined amount of time, wherein the first wireless network event is selected from the group consisting of an idle network event and a virtual-carrier-sense-protocol traffic event.

12. A method comprising:

maintaining a carrier sense multiple access/collision avoidance (CSMA/CA) timer in relation to a wireless network which supports CSMA/CA and 802.11b protocols wherein the 802.11b protocol is utilized by provided clients which are unable to detect the CSMA/CA protocol and wherein the maintained CSMA/CA timer corresponds to CSMA/CA traffic on the wireless network;

maintaining an 802.11b timer which corresponds to 802.11b traffic;

isolating traffic over the wireless network based on protocol by delaying 802.11b traffic until after the CSMA/CA timer elapses and by delaying CSMA/CA traffic until after the 802.11b timer elapses.

13. The method of claim 12 wherein the CSMA/CA timer commences in response to a first instance of CSMA/CA traffic following a first wireless network event and is set to elapse after a first predetermined amount of time, wherein the first wireless network event is selected from the group consisting of an idle network event and a 802.11b traffic event.

14. The method of claim 13 wherein the 802.11b timer commences in response to a first instance of 802.11b traffic following a second wireless network event and is set to elapse after a second predetermined amount of time wherein the second predetermined amount of time is selected from the group consisting of the first predetermined amount of time and an amount of time other than the first predetermined amount of time, and wherein the second wireless network event is selected from the group consisting of an idle network event and a CSMA/CA traffic event.

15. A product comprising:

a computer usable medium having computer readable program code stored therein, the computer readable program code in said product being effective to;

maintain a physical timer in relation to a wireless network which supports a plurality of wireless protocols including a physical carrier-sense protocol and a virtual carrier-sense protocol, wherein the virtual carrier-sense protocol is utilized by provided clients which are unable to detect the physical carrier-sense protocol and wherein the maintained physical timer corresponds to traffic which conforms to physical carrier-sense protocol; and

isolate traffic over the wireless network based on protocol by delaying virtual-carrier-sense-protocol traffic until after the physical timer elapses.

16. The product of claim 15 wherein the code is further effective to:

maintain a virtual timer which corresponds to traffic which conforms to virtual carrier-sense protocol;

wherein said isolation of traffic further includes delaying physical-carrier-sense-protocol traffic until after the virtual timer elapses.

17. The product of claim 16 wherein the physical timer commences in response to a first instance of physical-carrier-sense-protocol traffic following a first wireless network event and is set to elapse after a first predetermined amount of time, wherein the first wireless network event is selected from the group consisting of an idle network event and a virtual-carrier-sense-protocol traffic event.

18. The product of claim 17 wherein the virtual timer commences in response to a first instance of virtual-carrier-sense-protocol traffic following a second wireless network event and is set to elapse after a second predetermined amount of time wherein the second predetermined amount of time is selected from the group consisting of the first predetermined amount of time and an amount of time other than the first predetermined amount of time, and wherein the second wireless network event is selected from the group consisting of an idle network event and a physical-carrier-sense-protocol traffic event.

19. A product comprising:

a computer usable medium having computer readable program code stored therein, the computer readable program code in said product being effective to;

maintain a carrier sense multiple access/collision avoidance (CSMA/CA) timer in relation to a wireless network which supports CSMA/CA and 802.11b protocols wherein the 802.11b protocol is utilized by provided clients which are unable to detect the CSMA/CA protocol and wherein the maintained CSMA/CA timer corresponds to CSMA/CA traffic on the wireless network;

maintain an 802.11b timer which corresponds to 802.11b traffic;

isolate traffic over the wireless network based on protocol by delaying 802.11b traffic until after the CSMA/CA timer elapses and by delaying CSMA/CA traffic until after the 802.11b timer elapses.

20. The product of claim 19 wherein the CSMA/CA timer commences in response to a first instance of CSMA/CA traffic following a first wireless network event and is set to elapse after a first predetermined amount of time, wherein the first wireless network event is selected from the group consisting of an idle network event and a 802.11b traffic event.

21. The product of claim 20 wherein the 802.11b timer commences in response to a first instance of 802.11b traffic following a second wireless network event and is set to elapse after a second predetermined amount of time wherein the second predetermined amount of time is selected from the group consisting of the first predetermined amount of time and an amount of time other than the first predetermined amount of time, and wherein the second wireless network event is selected from the group consisting of an idle network event and a CSMA/CA traffic event.