[Tinyos-help] very strange code of sending on micaZ, Tinyos2.0

[Philip Levis]

On Nov 1, 2006, at 1:35 AM, Tie Luo wrote:


> Line 6: if congestion is true, even m_cca==false can enter  
> S_SAMPLE_CCA state, which is wrong.

Why is this wrong? If it's congested, continue sampling for a clear  
channel.

> Line 7: I do not find where the macro PLATFORM_MICAZ is defined.   
> And, if it is defined, then micaz will always backoff regardless of  
> congestion, which is a bit wield.

No. Read the code. Note that it says ABORT_PERIOD. Look at the state  
machine. There are times when on the micaz the radio says it is  
transmitting but the processor does not handle an SFD interrupt. It  
therefore needs to timeout and retry the transmission.

Phil