[Tinyos-help] Documentation regarding exact contents of the MAC Protocol Data Unit frame

[Pedro Almeida]

Hello;

I'm trying to look for documentation where I can understand the exact
contents, byte by byte, of the MPDU. I've looked into the TEPs and the
source files themselves, butI wasn't completely clear.

I'm using now the TestNetwork demo, where I receive 32 bytes per message, of
which I know little about, except for the contents of the message_t itself:

typedef nx_struct TestNetworkMsg {
nx_am_addr_t source;
nx_uint16_t seqno;
nx_am_addr_t parent;
nx_uint16_t metric;
nx_uint16_t data;
nx_uint8_t hopcount;
nx_uint16_t sendCount;
nx_uint16_t sendSuccessCount;
} TestNetworkMsg;

That are not, by far, 32 bytes.
So far I understood the MPDU is made of

2 bytes - Frame Control
1 byte - Data Sequence Number
4 to 20 bytes - Address Information
n bytes - Data Payload
2 bytes - Frame Check Sequence

which adds 5 bytes of the SHR and 1 byte of the PHR. So what exactly are
those 32 bytes??? Which ones are the payload (MSDU) and which ones are not
(and what are they?)?

An example of the 32 bytes is as follows:

7E 45 00 FF FF 00 00 13 00 EE 00 01 00 00 00 07 80 EE 00 07 00 80 00 00 00
00 20 00 00 53 63 7E

Help!

Thank you!!!

Pedro
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