Pedro: Why don't you port the rf2xx stack (tos/chips/rf2xx) to TOSSIM? The code is organized such that only the lowermost layer is transceiver-specific. The transceiver-specific driver layer is responsible for powering on and off the radio, sending packets, downloading received packets and timestamping/synchronization. Everything else, including LPL, is implemented in a transceiver-independent manner in upper layers.
Janos On Mon, May 31, 2010 at 8:10 PM, Pedro Nunes <[email protected]> wrote: > Hello, Janos. > > Thank you a lot for your reply - it was very enlightening. > Now, I am trying to figure it out how to port that behavior to TOSSIM > (since it does not simulate Low Power Listening). > > I was trying to port the LPL used by CC2420 but it has a lot of > dependencies and therefore porting it would be a pain in the backside, I > guess. > > Maybe creating a new and simplified LPL from the scratch would be the best > thing to do? > > Any idea is more than welcomed! :) > > Kind regards, > Pedro Nunes > > > On Mon, May 31, 2010 at 7:49 PM, Janos Sallai > <[email protected]>wrote: > >> Pedro: >> >> Take a look at the radio control states on page 43 of the cc2420 >> datasheet. Apart from the IDLE state, there are two more low power modes, >> namely "power down" and "voltage regulator off". The difference between IDLE >> and "power down" is that the on-chip 16Mhz oscillator is turned off in the >> latter state. Not surprisingly, the transceiver draws about 1mA less in >> power down than in IDLE. On the other hand, it takes about 680us more to >> start a transmission or to enter receive mode from power down than from >> IDLE. >> >> To answer your question: the tinyos-2.x radio stack actually goes _below_ >> the IDLE state in terms of power consumption in LPL mode. In fact, as I >> recall, not only the oscillator, but also the voltage regulator is turned >> off when the transceiver "sleeps". >> >> Janos >> >> On Mon, May 31, 2010 at 1:01 PM, Pedro Nunes <[email protected]> wrote: >> >>> Hi all. >>> >>> I dug a little bit on mail archives and I found an old thread where it is >>> said that the IDLE state is not implemented on CC2420 radio stack (please >>> refer to >>> http://mail.millennium.berkeley.edu/pipermail/tinyos-help/2005-December/013742.html >>> to >>> see the whole thread). >>> >>> Don't you think it is very strange that a mote only has two states? >>> (Sending or Receiving?) >>> Why don't use IDLE state where battery could be saved? >>> This way, whenever a mode isn't in TX mode (transmitting), then it is in >>> RX mode (receiving). Accordingly to MICAz datasheet, RX state has a cost of >>> 19.7 mA which is higher than any TX state can be. >>> This kind of behavior will lead us to something like: one application >>> that sends shorter messages (and therefore is on TX mode for shorter periods >>> of time) will spend more energy than an application that sends bigger >>> messages (and therefore will be on TX mode for longer periods). Since the >>> former application will be on RX mode most of the time it will spend more >>> energy than the latter (since receiving a message is heavier than sending >>> one cf. MICAz datasheet: >>> http://www.xbow.com/Products/Product_pdf_files/Wireless_pdf/MICAz_Datasheet.pdf >>> ). >>> >>> Please, can anyone shed some light here? >>> >>> Kind regards, >>> Pedro Nunes >>> >>> On Mon, May 31, 2010 at 5:10 PM, Pedro Nunes <[email protected]> wrote: >>> >>>> Hello all. >>>> >>>> What are the different states of CC2420 radio stack in TinyOS? >>>> >>>> Regards, >>>> Pedro Nunes >>>> >>> >>> >>> _______________________________________________ >>> Tinyos-help mailing list >>> [email protected] >>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>> >> >> >
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