Reply to this post | Go Back

View Post [edit]

Poster:	steffenyount	Date:	Oct 6, 2005 8:20am
Forum:	sflan	Subject:	Improving TCP fairness with 802.11e...

So, I was doing some research on 802.11b TCP throughput problems and also on the 2 hop node problem, and in the process I found the following article:

http://www.hamilton.ie/net/tcp-measure_final.pdf

It seems that the 802.11a/b MAC layer doesn't play nice with TCP and multiple nodes. The paper proposes using the newly availible 802.11e parameters to fix this.

Has anyone from SFLAN experimented with 802.11e parameters?

Does the SFLAN node hardware/software support 802.11e parameter configuration?

Would it be possible/desirable to implement the paper's suggestions on SFLAN's core nodes?

Basically the paper suggests two things:
1. Give all TCP ACK packets highest priority.

2. Give the AP node a larger slice of the channel bandwidth.
(The default slice for the AP and all nodes is 1/n of the channel bandwidth, where n is the number of nodes. The paper suggests that the AP should get closer to 1/2 of the channel bandwidth, since it provides the critical link to and from the internet.)

-Steffen

Reply to this post

Reply [edit]

Poster:	Kimo C	Date:	Oct 7, 2005 4:46am
Forum:	sflan	Subject:	Re: Improving TCP fairness with 802.11e...

some interesting discussion (or at least graphics) on fairness in the current issue of Scientific America article on wifi

http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=00036961-D024-1332-902483414B7F0000