Question on 802.15.4 implementation

GNU Radio
1

Hi ,
I am trying to send a simple message between two USRPs using the new
message passing interface in GNU Radio 3.7 over 802.15.4 implementation.
I created a “message generator” which publishes a message to the “app
in” port of 802.15.4. Similarly on the receiver side a “message
consumer” gets the message from the “app out” port of 802.15.4, I see
that the message on the receiver is getting dropped at the 15.4 MAC
layer with the following debug message:

mac.cc:mac_in: pmt_is_pair
mac.cc::mac_in: data_len = 30
CRC at Reception: 0
MAC: Dropping packet self routed

I poked around mac.cc code a bit. It looks like the message received has
the same mac id as the mac id of the receiver. It seems that the MAC
layer does not use the real MAC id, rather it generates mac id using
“rand() % 100”. My understanding is that the receiver is also getting
the same mac-id as the sender and hence dropping packet.
Any idea how to fix the problem?

Note that I am not using RIME stack for communication (as done by
Bastian), but rather trying to send/receive message from/to MAC layer
itself.

thanks and regards

-Anirud

Anirudha “Anirud” Sahoo
Advanced Network Technology Div.
National Institute of Standards and Technology (NIST)
100 Bureau Drive,
Gaithersburg, MD - 20878
Room - B230, bldg.- 222
Phone- 301-975-4439

2

Hi Anirud,

On 28 May 2014, at 18:47, Sahoo, Anirudha [email protected]
wrote:

mac.cc:mac_in: pmt_is_pair
mac.cc::mac_in: data_len = 30
CRC at Reception: 0
MAC: Dropping packet self routed

I poked around mac.cc code a bit. It looks like the message received has the
same mac id as the mac id of the receiver. It seems that the MAC layer does not
use the real MAC id, rather it generates mac id using rand() % 100. My
understanding is that the receiver is also getting the same mac-id as the sender
and hence dropping packet.
Any idea how to fix the problem?

Which code are you using? I can neither find the debug output nor the
rand() % 100 code. Also what do you mean with MAC id? Sequence number or
MAC address?

Best,
Bastian

3

oops, I just found out that the code I have been working with, has been
modified in-house. So, the debug message is coming from changes made to
your code. Sorry about that.

thanks and regards

-Anirud

Anirudha “Anirud” Sahoo
National Institute of Standards and Technology
Advanced Network Technologies Division
100 Bureau Drive, Stop 8920
Gaithersburg, MD 20899-8920