[ns] MCPS_DATA_request overflow

Hi all

I have a problem with the MCPS_DATA_request primitive in the IEEE 802.15.4 ns-2 implementation. I build a new packet and send it peridically using this primitive (broadcast transmission). The thing is that this error does not always happen because I can send the packet, and it is received successfully by the receiver nodes, but at some point, the simulation stops and outputs the following message:

[wpan/p802_15_4mac.cc::checkTaskOverflow][504.894498](node 16) task overflow: MCPS-DATA.request

I suppose that this is due to two packets (frames) collide at MAC layer, that is, these two frames are being managed by the MAC layer at same time, and it overflows. If this is the reason, do you know how can I manage and solve it? I searched for a solution but I din not find anything. My problem is similar to the following recent post: http://mailman.isi.edu/pipermail/ns-users/2011-June/070485.html.

I appreciate all the help possible. Thanks in advance.
 
David