[Tinyos-help] CC2420 micaz real data rate?different from MIB manual

[Munaretto, Daniele]

Hi all,

I was wondering if someone of u has some experience on the real MicaZ data rate.

The MIB manual says 250Kbit/s as MAX data rate, but it will mean that if u have a packet of 127 bytes to transmit, your transmission time is around 4 ms.
However I feel the transmission time has to be quite larger than this one, because I get a lot of collisions in my experiments, that can be explained with a transmission time greater than ~20 ms per packet(127 bytes).

In the mailing list I saw about mica2 experiments, where the real data rate is 25 messages of 29 bytes (or 36 bytes with header and CRC?) per second, which means ~725 bytes per second, so 5.66 Kbit/s. While in the MIB manual is 38.4 Kbit/s. 

While for MicaZ I found in the mailing list by Michael Schippling:

'..
Without ACKs, in a point-to-point mode, under ideal conditions where there 
is little chance of transmit overlap and CSMA backoff, successful messages 
are around 66 per second with almost no failures.
..'

Does it mean 66 messages of 29 bytes of payload? In a scheme with broadcast is it still valid?
 

Any suggestion, explanation and help will be really appreciated!
Thank u very much
Cheers

 

 
Daniele Munaretto
Researcher
 
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