topic Rate Shifting in Wireless

Rate Shifting

reinke — Sun, 04 Jul 2021 16:25:49 GMT

Please help a rf beginner:

Can the rate between AP and client been shiftet (e. g. from 11 to 5.5 mbps) during the transmission of a frame? Or only between two frames?

How does an AP recognize the sending speed of an ap (and vice versa)? Do both use a preamble which is long enough to synchronize transmitter and receiver?

Even if those questions are basic and only nice-to-know, any answer is welcome.

Thanks

Edgar

Re: Rate Shifting

Thu, 11 Mar 2004 19:32:15 GMT

Answering your second question, you have to set the clients to auto data rates, and then set the APs to be optimised for range, and this will adjust the data rates to:

1Mbps = basic

2Mbps = yes

5.5Mbps = yes

11Mbps = yes

Re: Rate Shifting

reinke — Fri, 12 Mar 2004 07:44:55 GMT

That is the configuration part, but it didn´t answer my question.

E.g.: Client send packet with 2 Mbps. How does the AP detect the speed of the incoming frame ... there is no dedicated clock signal between them.

Edgar

Re: Rate Shifting

ashish_gupta — Sat, 13 Mar 2004 18:09:57 GMT

The is rate when the client first associates with the AP. The messages are exchanged between APs in the form of beacons which tell which speeds are there and a Time syncronization occurs at this time so that clients know which station they are hooked to and when to listen for requests.

Also the rate is changed only before the transmission of any frame and not in between. If the AP sees that the messages are not received clearly or it has too many retries it then changes the rate and sends the frames.

Do rate this if this solved your problem