[Tinyos-devel] RE: [Tinyos-help] shorter (cc2420/telosb) radio range in t2 compared tot1?

[John Griessen]

Hi,

How about using a priority category variable built into the radio stack that can be set at the same time you set serial numbers of 
motes in a a network of any kind, grid, CTP, etc.
That priority would cause a different congestion backoff per individual mote.  High priority --> short congestion backoff.

That seems to me a way to do priority routing that could be there in the
most tested radio stack, almost for free, and use it or don't.

John Griessen

David Moss wrote:
> Here's one possible explanation: the CSMA backoff changed between T1 and T2.
> 
> In T1, the CSMA backoff wasn't very fair, allowing one transmitter to
> possibly hog the channel.  The CSMA congestion and initial backoffs were
> flipped in T2, making the initial backoff longer and the congestion backoff
> shorter.  This causes less throughput but an increase in fairness.
> 
> This brings up a good point though: more energy is consumed in T2 to deliver
> the same amount of information because throughput is diminished. We should
> explore turning the radio to IDLE during CSMA backoff wait periods to see
> how that impacts energy consumption and throughput.


-- 
Ecosensory   Austin TX
tinyOS devel on:  ubuntu Linux;   tinyOS v2.0.2;   telosb ecosens1