PRACTICAL MEASUREMENT-BASED SESSION ADMISSION CONTROL FOR WI-FI LAN SYSTEMS

• US 20110058473A1
• Filed: 03/02/2010
• Published: 03/10/2011
• Est. Priority Date: 03/03/2009
• Status: Active Grant

• Current Assignee: Avaya Incorporated
• Original Assignee: Avaya Incorporated
• Inventors: SHINGNE, Tarak, BABIARZ, Jozef, LU, Xiao-Gao, KRYM, Marvin, VERBERK, Lambertus
• Granted Patent: US 8,385,197 B2
• Time in Patent Office: Days
• US Class Current: 370/232
• CPC Class Codes: H04W 48/06 based on traffic conditions

Abstract

A communication system is provided that can control which communication sessions with mobile devices are admitted to a wireless access point. The admission decisions are based on actual measurements of radio frequency (RF) utilization. The RF utilization is determined on a per access class basis. Access classes may be defined by protocol but are, generally, voice, video and data. Thus, the system provides the ability to determine admissions that allows for the incorporation of factors including collisions, the distance from the access point to which a mobile device is communicating, and other factors.

Claims

1. A method for determining whether to admit a new communication session at a wireless access point, the method comprising:

a processor measuring over-the-air utilization at an access point;

the processor receiving a request for the new communication session;

the processor determining an amount of bandwidth based on the over-the-air utilization and an amount of bandwidth requested for a new communication session;

based on the bandwidth for the over-the-air utilization and the bandwidth requested for the new communication session, the processor determining whether to admit the new communication session; and

if there is sufficient bandwidth for the new communication session, the processor admitting the new communication session at the access point.

2. The method as defined in claim 1, wherein over-the-air utilization is measured by radio frequency (RF) utilization for one or more radios associated with the access point.

3. The method as defined in claim 2, wherein measuring radio frequency (RF) utilization comprises:

the processor measuring a data rate (PHY) for the one or more frames, wherein PHY is a measurement of the data rate for a physical layer of the wireless access point;

based on the frame size and the PHY, the processor determining a transmission time for the one or more frames, wherein transmission time is determined by dividing the frame size by the PHY;

the processor adding overhead to the transmission time;

the processor summing the overhead and transmission times for at least two communication sessions associated to determine the data air time; and

the processor dividing the data air time by the measurement time to determine the RF utilization.

4. The method as defined in claim 3, wherein the data air time is for an access class.

5. The method as defined in claim 4, wherein there is two or more access classes each with a different data air time.

6. The method as defined in claim 4, wherein the access classes include at least two of a group comprising video, voice, and data.

7. The method as defined in claim 4, wherein each access class has a predetermined bandwidth allotment.

8. The method as defined in claim 2, the access point determines the RF utilization.

9. A computer readable medium, stored on a tangible medium, having stored thereon instructions that cause a computing system to execute a method for determining whether to admit a communication session at a wireless access point, the instructions comprising:

instructions to receive a summation of a measured radio frequency (RF) utilization and a requested bandwidth for a requested communication session between the wireless access point and a mobile device;

instructions to compare the summation to an allocated bandwidth;

if the summation is more than the allocated bandwidth, instructions to deny the requested communication system; and

if the summation is less than the allocated bandwidth, instructions to admit the requested communication system.

10. The computer readable medium as defined in claim 9, wherein the allocated bandwidth is allocated for an access class.

11. The computer readable medium as defined in claim 10, wherein the requested communication session is for a requested access class and wherein the comparison is made to the allocated bandwidth is for the requested access class, the instructions further comprising:

instructions to determine if there is bandwidth to borrow from a second access class;

if there is bandwidth to borrow from a second access class, allocate the borrowed bandwidth to the requested communication and admit the requested communication session; and

if there is no bandwidth to borrow from a second access class, deny the requested communication session.

12. The computer readable medium as defined in claim 11, wherein the borrowed bandwidth is borrowed for a limited time.

13. The computer readable medium as defined in claim 9, further comprising instructions to reserve bandwidth for inter-access point transfers of communication sessions.

14. The computer readable medium as defined in claim 9, further comprising instructions to reserve bandwidth for emergency communication sessions.

15. A communication system comprising:

two or more wireless access points, the wireless access points operable to measure radio frequency (RF) utilization and operable to receive a request for a communication session from a mobile device; and

a control server in communication with the two or more wireless access points, the control server operable to receive the RF utilization and the request from the wireless access point and operable to determine from the RF utilization and the request whether the requested communication session should be admitted by the access point.

16. The communication system as defined in claim 15, wherein each access point comprises:

a traffic measurements module operable to measure the RF utilization; and

a signal interface module operable to receive the request for the communication session.

17. The communication system as defined in claim 15, wherein the control server comprises:

a new flow estimator operable to determine a new bandwidth amount that will be used if the communication session is admitted; and

an admission decision module in communication with the new flow estimator, the admission decision module operable to compare the new bandwidth amount to an allotment of bandwidth and operable to, based on the comparison, admit signal the wireless access point to admit the communication session.

18. The communication system as defined in claim 17, wherein the new bandwidth amount is determined by adding the measured RF utilization from the traffic measurements module with a requested bandwidth received from the mobile device by the signal interface.

19. The communication system as defined in claim 17, wherein, if the communication session is admitted, the RF utilization is deemed to be full and attenuates to the measured RF utilization over a predetermined period of time.

20. The communication system as defined in claim 19, wherein the admission decision module is operable to allot borrowed bandwidth from a second access class to the communication session and is operable to admit the communication session with the borrowed bandwidth.