[Tinyos-help] Disable backoff CC2420 tmote sky

[David Moss]

The proper way to disable CCA is to tell the radio to transmit without CCA.

I don't support Tinyos 1.x, but if you look for a strobe command like
"STXONCCA" and change it to "STXON" then the radio will not use clear
channel assessments and there should never be a congestion backoff.  The
initial backoff should still be in play, and you will probably need to edit
the radio stack code to properly and completely remove it.

-David




-----Original Message-----
From: tinyos-help-bounces at millennium.berkeley.edu
[mailto:tinyos-help-bounces at millennium.berkeley.edu] On Behalf Of Bhavish
Aggarwal
Sent: Thursday, April 03, 2008 5:05 PM
To: tinyos-help
Subject: [Tinyos-help] Disable backoff CC2420 tmote sky

Hi,

I too tried the same solution for disabling backoffs i.e. setting the
value of the events initialBackoff and congestionbackoff to 0 and 1 in
CC2420RadioM. But it did not make any perceivable difference in the
time taken for a packet to be transmitted (the time difference between
the send call and sendDone signal). This time was 6 ms before and
after turning off backoff.

Is there something I missed in this procedure?

Thanks,

Bhavish

On Thu, Jan 24, 2008 at 7:31 PM, shamo <shamo2 at student.cityu.edu.hk> wrote:
>
>
>
>
> Dear Sir,
>
> I just read David's answer about how to disable backoff.I use tmote sky.As
> he said, I connect CC2420RadioM to MacBackoff, and write
initialBackoff(...)
> and congestionBackoff(...) event to return 0 or 1. However, it does not
> work. It seems that I can not disable the backoff in this way.I do not
know
> why.Please give me a help. Can you give me an example?
>
>
> Your answer:---------------
> TinyOS 1.x:
>
> configuration CC2420RadioC
> {
>   provides {
>     ...
>     interface MacControl;
>     interface MacBackoff;
>     ...
>   }
> }
>
>
> interface MacBackoff
> {
>   async event int16_t initialBackoff(TOS_MsgPtr m);
>   async event int16_t congestionBackoff(TOS_MsgPtr m);
> }
>
> Connect to MacBackoff, and when you get an initialBackoff(...) or
> congestionBackoff(...) event, return 0 or 1.  This method wasn't very
> friendly for systems that wanted to specify different backoff periods for
> different outbound AM types.  With extra programming, you can get the
event
> to set the backoff as you want it for any outbound message.
>
> -David
>
> ---------------------------------
>
>  ________________________________
>
>
>
>
> SHA Mo
> _______________________________________________
>  Tinyos-help mailing list
>  Tinyos-help at millennium.berkeley.edu
>  https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
>
_______________________________________________
Tinyos-help mailing list
Tinyos-help at millennium.berkeley.edu
https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help