Method and apparatus for evaluating performance of wireless LAN system

• US 20060133293A1
• Filed: 11/22/2005
• Published: 06/22/2006
• Est. Priority Date: 12/25/2003
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Sato, Shohei, Shiraki, Takashi, Pan, Huanxu, Kobayashi, Kazutomo
• Granted Patent: US 7,570,596 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 43/045 for graphical visualisation of monitoring data
• CPC Class Codes: H04L 43/0847 Transmission error
• CPC Class Codes: H04L 43/0852 Delays
• CPC Class Codes: H04L 43/0888 Throughput
• CPC Class Codes: H04W 16/22 Traffic simulation tools or models

Abstract

A method for evaluating the performance of a wireless LAN (local area network) system having a single access point and a plurality of transmission terminals, which share the same radio channel, comprises the steps of dividing the plurality of transmission terminals into groups in accordance with radio conditions, calculating a transmission probability and a post-transmission failure probability for each group using a transmission rate, an error rate, and the number of terminals of each group, and calculating a throughput based on the transmission probability and post-transmission failure probability. A characteristic value for packet transmission delay may also be calculated based on the transmission probability and post-transmission failure probability. According to this method, the performance such as the throughput and the packet transmission delay can be evaluated in a wireless LAN system even before the wireless LAN system is constructed.

Claims

1. A method for evaluating a performance of a wireless LAN system having a single access point and a plurality of transmission terminals, said access point and said transmission terminals sharing a same radio channel, said method comprising the steps of:

dividing said plurality of transmission terminals into groups in accordance with radio conditions; and

calculating a transmission probability and a post-transmission failure probability for each group using a transmission rate, an error rate, and the number of terminals of said each group.

2. The method according to claim 1, further comprising the step of calculating a throughput based on said transmission probability and said post-transmission failure probability.

3. The method according to claim 1, further comprising the step of calculating a characteristic value about packet transmission delay based on said transmission probability and said post-transmission failure probability.

4. The method according to claim 1, wherein said transmission rate and said error rate used in the calculations are actually measured for each group.

5. The method according to claim 1, further comprising the step of calculating said transmission rate and said error rate from a signal-to-noise ratio which is actually measured for each group with said access point being installed.

6. The method according to claim 1 further comprising the step of estimating said transmission rate and said error rate in accordance with a distance from said access point to a location at which a terminal in said each group is installed.

7. The method according to claim 2, wherein said transmission rate and said error rate used in the calculations are actually measured for each group.

8. The method according to claim 2, further comprising the step of calculating said transmission rate and said error rate from a signal-to-noise ratio which is actually measured for each group with said access point being installed.

9. The method according to claim 2 further comprising the step of estimating said transmission rate and said error rate in accordance with a distance from said access point to a location at which a terminal in said each group is installed.

10. The method according to claim 2, further comprising the step of calculating a characteristic value about packet transmission delay based on said transmission probability and said post-transmission failure probability.

11. A method for evaluating a performance of a wireless LAN system having a single access point and a plurality of transmission terminals, said access point and said transmission terminals sharing a same radio channel, said method comprising the steps of:

dividing said plurality of transmission terminals into groups in accordance with radio conditions;

an input device supplying a probability calculator with a number of the groups, a number of terminals in each group, a transmission rate of each group, an error rate for each group, and a system parameter; and

the probability calculator calculating a transmission probability and a post-transmission failure probability for each group using the system parameter, the transmission rate of said each group, the error rate for said each group, and the number of terminals in said each group,

wherein said input device comprises;

a group number input unit for entering the number of said groups;

a terminal number input unit for entering the number of terminals in said each group;

an transmission rate input unit for entering the transmission rate for said each group;

an error rate input unit for entering the error rate for said each group; and

system parameter input unit for entering the system parameter.

12. The method according to claim 11, further comprising the step of:

an evaluated value calculator calculating a throughput and/or a characteristic value about packet transmission delay, based on said transmission probability and said post-transmission failure probability.

13. The method according to claim 11, further comprising the steps of:

an input preparation unit calculating the transmission rate and error rate for said each group based on a signal-to-noise ratio which is actually measured for said each group with said access point being installed; and

said input preparation unit supplying said transmission rate input unit and said error rate input unit with the calculated transmission rate and the calculated error rate, respectively.

14. The method according to claim 11, further comprising the steps of:

an input preparation unit calculating the transmission rate and error rate for said each group in accordance with a distance from said access point to a location at which a terminal in said each group is installed; and

said input preparation unit supplying said transmission rate input unit and said error rate input unit with the calculated transmission rate and the calculated error rate, respectively.

15. An apparatus for evaluating a performance of a wireless LAN system having a single access point and a plurality of transmission terminals, said access point and said transmission terminals sharing a same radio channel, said system comprising:

means for entering a transmission rate, an error rate, and the number of terminals of each of groups into which said plurality of transmission terminals are divided in accordance with radio conditions; and

means for calculating a transmission probability and a post-transmission failure probability for each group using said transmission rate, said error rate, and said number of terminals of each group.

16. The apparatus according to claim 15, further comprising means for calculating a throughput based on said transmission probability and said post-transmission failure probability.

17. The apparatus according to claim 15, further comprising means for calculating a characteristic value about packet transmission delay based on said transmission probability and said post-transmission failure probability.

18. The apparatus according to claim 15, further comprising:

means for entering a signal-to-noise ratio actually measured for each group with said access point being installed; and

means for calculating said transmission rate and said error rate from said signal-to-noise ratio.

19. The apparatus according to claim 15, further comprising:

means for entering a distance from said access point to a location at which a terminal in said each group is installed; and

means for estimating said transmission rate and said error rate in accordance with the distance.

20. The apparatus according to claim 16, further comprising:

means for entering a signal-to-noise ratio actually measured for each group with said access point being installed; and

means for calculating said transmission rate and said error rate from said signal-to-noise ratio.

21. The apparatus according to claim 16, further comprising:

means for entering a distance from said access point to a location at which a terminal in said each group is installed; and

means for estimating said transmission rate and said error rate in accordance with the distance.

22. The apparatus according to claim 16, further comprising means for calculating a characteristic value about packet transmission delay based on said transmission probability and said post-transmission failure probability.