2010-03-05 02:27:30

by Gus Wirth

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Subject: RTL8187 coverage class

I'm trying to implement a first go at getting coverage class working for
a Realtek RTL8187L chip similar to the way it is in ath5k. I know I need
to change the ack timeout and the slot times but I can't quite decipher
the register use. I can see some hints in the function rtl8187_conf_erp
but that doesn't seem enough.

It seems that the values for SLOT, DIFS and EIFS aren't directly
converted to microseconds, so I'm not sure how those values were arrived at.

I want to start by just hard coding some different initial values to
allow for testing. My test device right now is an Alfa AWUS036H which is
a high power USB (500mW claimed) RTL8187L and testing at a range of
about 2 kilometers, making the coverage class=5.

Gus


2010-03-05 04:09:29

by Larry Finger

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Subject: Re: RTL8187 coverage class

On 03/04/2010 08:20 PM, Gus Wirth wrote:
> I'm trying to implement a first go at getting coverage class working for
> a Realtek RTL8187L chip similar to the way it is in ath5k. I know I need
> to change the ack timeout and the slot times but I can't quite decipher
> the register use. I can see some hints in the function rtl8187_conf_erp
> but that doesn't seem enough.
>
> It seems that the values for SLOT, DIFS and EIFS aren't directly
> converted to microseconds, so I'm not sure how those values were arrived at.

Those values come from the vendor driver where they are not explained. The
difference between short and long slot values may be instructive.

Larry