Dear YanYan, On Thu, Apr 23, 2009 at 9:49 PM, Jane <[email protected]> wrote: > I am trying to implement jamming signals using iris motes with mib520 chip. > My goal is to completely block other nodes' communication. In the program, I > broadcast a node ID using AMPacket. The ID is sent non stop by put a send > signal in the sendDone event and CCA has been disabled. Then I used > Basestation to monitor the traffic. It seems that most of the time, my > program wasn't able to block other traffic. There were very few collisions.
The job of the MAC is to avoid collisions, so that is why you do not see many. Even if you disable the CCA, the RF230 driver will receive messages if that started before you decided to transmit. So it is hard to jam the radio channel and your best option would be to write your own driver. However you can still can get decent blocking with the following (completely untested) steps: 1) In the RF230.h file (or RF230DriverLayer.h if you use the CVS version) change RF230_RX_ON to 9 (which is RF230_PLL_ON). This will disable all receive functionality, so the radio will not block your transmits when another message is in the air. 2) Change the RF230DriverConfig.requiresRssiCca(message_t* msg) command in the RF230ActiveMessageP.nc to always return FALSE. 3) Change the RandomCollisionConfig.getMinimumBackoff(), RandomCollisionConfig.getInitialBackoff(message_t* msg), RandomCollisionConfig.getCongestionBackoff(message_t* msg) commands in the RF230ActiveMessageP.nc to return with 100 microsecond delays. You can experiment with these values. This will reduce the amount of delay between subsequent transmissions. > 2. Is it possible to send tones on mib520? If so, could someone point a > light how? MIB520 has nothing to do with the radio, it just communicates with the IRIS. > 3. I remember seeing RF230Sniffer before, but couldn't find it after > searching the entire tinyos folder. Would someone point me the direction > please? apps/tests/rf230/RF230Sniffer Best, Miklos _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
