CAP (slotted CSMA-CA) is implemented. CFP (=GTS) is not yet implemented, but I guess it will be in near future, because different people seem to be implementing it.
Jan On Fri, Nov 19, 2010 at 3:54 AM, Daniel Schnit <[email protected]> wrote: > Hi all, > Thanks for help! But i have one more question, in tinyOs CAP, CFP and GTS > are implement? if are, how can i use? > Thanks, > Best regards. > On Thu, Nov 18, 2010 at 7:48 PM, Pablo Marcos Oltra > <[email protected]> wrote: >> >> Hi, >> Thank you very much for your response Aitor. I had two motes running for 3 >> days with BO=14 and I had no problems of sync using the TestSync >> application. Not even one beacon was missed. This was the first test I ran >> to check if I was about to have clock drift problems in later experiments. >> I'm currently using channels 19 and 20 because in my building there are just >> a few spare channels to use (20 are mainly being used right now). Besides, >> I always set up BO and SO < 7, using usually 5, but not even that way works >> properly. >> Anyway, I don't really know if it has something to do with using timers, >> but I have noticed that the losing of the sync is kind of periodically. I >> have noticed today as well that both devices lose sync even if they don't >> even start at the same time (I was hoping a different periodicity for each >> one), but they both were losing the same beacons. Hence, I'm thinking right >> now about the possibility that it has something to do with the coordinator, >> cause the other two devices are not even tx packets, just trying to me sync >> with the coordinator. >> I sent another mail a few days ago to the tinyos-help list cause I thought >> that maybe the problems were cause because I was using printf to debug the >> application, but without using it is losing sync as well, so... now I'm the >> one that is lost :S. >> Could you please check if the application attached is working for you? It >> is just the original TestData but with a Timer that once is fired sends the >> packets. When I try that, the device loses sync after a while. >> Thank you very much in advance. >> Regards, >> Pablo >> 2010/11/18 Aitor Hernandez <[email protected]> >>> >>> Hi, >>> We have been using this implementation for several wireless process and >>> we made a performance evaluation of it. We haven't found any problem with >>> the timers (used to start a transmission, or something else). The idea that >>> comes up is that maybe there are some interferences on the same channel that >>> you are using or you have a high beacon order. >>> As we have seen, if we receive packets on the period where we are waiting >>> the beacon, we could miss them. Moreover I've just realized that by using a >>> high beacon order (> 10) some motes could have problems to synchronize with >>> the beacon. I guess that I could be due to the clock drift, but Jan can >>> clarify this point. >>> What I recommend you, is to use a BO=6 and a SO =5,6 with this values you >>> shouldn't have any problems.... Furthermore, try to change the channel and >>> see if the problem persists. Channels between 22 and 26 don't have any >>> overlapping with WiFi channels. >>> At the moment, there is nothing else in my mind. I hope it will work for >>> you. >>> Good luck! >>> >>> On 18 November 2010 16:27, Pablo Marcos Oltra >>> <[email protected]> wrote: >>>> >>>> I found the error and the UserButton is now working in my test >>>> application. So, I wait for 3 nodes to have synchronization and then I push >>>> all of their buttons and they start tx data. However, after a while, they >>>> lose sync, as always, and I don't know why. >>>> Aitor, have you ever used timers that once they're fired they send the >>>> data (for example, to send data every minute or so)? Cause I'm having >>>> trouble with that (even with just one device), and don't if that could be >>>> something related with the problem you told us a few mails ago. >>>> Regards, >>>> Pablo >>>> 2010/11/18 Aitor Hernandez <[email protected]> >>>>> >>>>> In my case, I just program all the motes at the same time by using "&" >>>>> function on the shell, something like: >>>>> $ make tmote >>>>> $ make tmote reinstall,1 bsl,/dev/ttyUSB1 & make tmote >>>>> reinstall,2 bsl,/dev/ttyUSB2 >>>>> By the way, I've been using the UserButton for some time, and I've >>>>> never noticed the behaviour you explain, with or without TKN154_DEBUG >>>>> enabled. >>>>> Best, >>>>> Aitor >>>>> >>>>> On 18 November 2010 13:28, Pablo Marcos Oltra >>>>> <[email protected]> wrote: >>>>>> >>>>>> May I add other option to the Aitor ones? >>>>>> I thought about letting the motes synchronize first, and then start >>>>>> sending packets once they're all synchronized. How could you do this? I >>>>>> have >>>>>> tried doing that with the telosb user button, hence once you pressed it >>>>>> you >>>>>> change a flag that starts sending packets. The problem is that I have >>>>>> just >>>>>> been able to do that with the TKN154_DEBUG enabled, otherwise, the event >>>>>> void Notify.notify( button_state_t state ) is not working. >>>>>> You can see an example of how to use the telosb user button in >>>>>> $TOSROOT/apps/tests/telosb. >>>>>> Regards, >>>>>> Pablo >>>>>> 2010/11/18 Jan Hauer <[email protected]> >>>>>>> >>>>>>> yes - I can reproduce the problem and also believe that it is due to >>>>>>> wrong (beacon) timestamps. will look into it and try to fix it asap. >>>>>>> >>>>>>> thanks, >>>>>>> jan >>>>>>> >>>>>>> On Thu, Nov 18, 2010 at 10:02 AM, Aitor Hernandez <[email protected]> >>>>>>> wrote: >>>>>>> > Hi guys, >>>>>>> > I've seen this problem with TKN15.4. It is possible to synchronize >>>>>>> > N nodes >>>>>>> > with TKN15.4 the problem is that they need to start the app at the >>>>>>> > same >>>>>>> > time. From my experience I've realized that the problem comes from >>>>>>> > the >>>>>>> > cc2420_tkn154 (maybe it happens with the default cc2420 >>>>>>> > implementation as >>>>>>> > well). >>>>>>> > If we have a network with N nodes running and transmitting data >>>>>>> > between >>>>>>> > them, when we try to add another node we could have this problem. >>>>>>> > As far as >>>>>>> > we have the radio enabled for reception for a long period (Scan >>>>>>> > period), the >>>>>>> > cc2420 receives the beacons but data packets as well. Once it >>>>>>> > detects that >>>>>>> > the received packet is a beacon, it sets the timestamp, but >>>>>>> > sometimes the >>>>>>> > timestamp is wrong, due to the data packets, and then we lost the >>>>>>> > next >>>>>>> > beacons. >>>>>>> > Possible solutions: >>>>>>> > >>>>>>> > Check the CC2420ReceiveP.nc and the m_timestamp_queue. I guess that >>>>>>> > the >>>>>>> > problem should be there. I did some modifications on >>>>>>> > the CC2420ReceiveP.nc to solve this problem, but I haven't test it >>>>>>> > properly. >>>>>>> > If we lost the synchronization, scan again >>>>>>> > with MLME_SCAN.request(). It is a >>>>>>> > "fake" solution, because the problem is still there, but for some >>>>>>> > app it >>>>>>> > will work. >>>>>>> > Start the nodes at the same time. It is not possible in a real >>>>>>> > deployment. >>>>>>> > >>>>>>> > >>>>>>> > -- >>>>>>> > Aitor Hernandez >>>>>>> > KTH | Automatic Control >>>>>>> > Research engineer >>>>>>> > Stockholm >>>>>>> > Phone: +46 (0)704 26 87 99 >>>>>>> > >>>>>>> > _______________________________________________ >>>>>>> > Tinyos-help mailing list >>>>>>> > [email protected] >>>>>>> > >>>>>>> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>>>>>> > >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Tinyos-help mailing list >>>>>>> [email protected] >>>>>>> >>>>>>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> Aitor Hernandez >>>>> KTH | Automatic Control >>>>> Research engineer >>>>> Stockholm >>>>> Phone: +46 (0)704 26 87 99 >>>> >>> >>> >>> >>> -- >>> Aitor Hernandez >>> KTH | Automatic Control >>> Research engineer >>> Stockholm >>> Phone: +46 (0)704 26 87 99 >> >> >> _______________________________________________ >> Tinyos-help mailing list >> [email protected] >> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
