[Tinyos-help] CSMA-CA on CC2420micaz,tinyos-1.x
Dear all, i would like to ask you some questions about CC2420 and micaz energy consumption. I read, from reports and data sheets, that the Basic RF library in CC2420 contains only a small subset of the 802.15.4 standard: beacons is not implemented, no defined coordinator/device roles, it does not check CCA twice , it does not retransmit packets, it cannot communicate with other networks. 1)I would like to understand if, by default, any collision avoidance mechanism is implemented or may be available for motes, as our micaz, which have this chipcon (for example, in the CC2420 folder in TinyOS 1.x, is it implemented a simple CSMA or a CSMA-CA?). Because my research group needs to know if and how to provide a "good" collision avoidance mechanism on our micaz motes. 2)Exactly, what are the bounds of "the limited ability of the user" on defining the MAC layer by TinyOS code? i mean, what can i modify, if possible, in the MAC layer and how/where? 3)I've just discovered that using the flash on our motes, so reading and writing on flash, the batteries are insufficient. I was using 1.3 V rechargeble batteries, but it seems i need more power. Is it a known problem?is it possible to source the mote over 3V?because, it is written 1.5 V on the motes... Thanks for your availability, any further help will be really appreciated cheers Daniele Munaretto ___ Tinyos-help mailing list Tinyos-help@Millennium.Berkeley.EDU https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] CSMA-CA on CC2420micaz,tinyos-1.x
As far as I understand it the micaz uses a simple CSMA, where it listens for a radio signal above a "squelch" value just before transmitting. If it hears anything it does a randomized backoff/retry. For power voltage, I run on regulated 3.3v. I looked at the spec sheets for the chips (actually the mica2 w/ CC1000) and it "seems" that 5v is OK, but have not tried it. Let me know if you get smoke... MS Munaretto, Daniel wrote: Dear all, i would like to ask you some questions about CC2420 and micaz energy consumption. I read, from reports and data sheets, that the Basic RF library in CC2420 contains only a small subset of the 802.15.4 standard: beacons is not implemented, no defined coordinator/device roles, it does not check CCA twice , it does not retransmit packets, it cannot communicate with other networks. 1)I would like to understand if, by default, any collision avoidance mechanism is implemented or may be available for motes, as our micaz, which have this chipcon (for example, in the CC2420 folder in TinyOS 1.x, is it implemented a simple CSMA or a CSMA-CA?). Because my research group needs to know if and how to provide a "good" collision avoidance mechanism on our micaz motes. 2)Exactly, what are the bounds of "the limited ability of the user" on defining the MAC layer by TinyOS code? i mean, what can i modify, if possible, in the MAC layer and how/where? 3)I've just discovered that using the flash on our motes, so reading and writing on flash, the batteries are insufficient. I was using 1.3 V rechargeble batteries, but it seems i need more power. Is it a known problem?is it possible to source the mote over 3V?because, it is written 1.5 V on the motes... Thanks for your availability, any further help will be really appreciated cheers Daniele Munaretto ___ Tinyos-help mailing list Tinyos-help@Millennium.Berkeley.EDU https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help ___ Tinyos-help mailing list Tinyos-help@Millennium.Berkeley.EDU https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] CSMA-CA on CC2420micaz,tinyos-1.x
Hi, My question follows the same line as that of Daniel, but I'm working on MICA2 motes, not MICAZ. What is not very clear to me is exactly what MAC is implemented in TinyOS 1.1 for MICA2 motes. I saw there was something called S-MAC (for a description, u can see "Enery-efficient MAC Protocol for Wireless Sensor Networks" by John Heidemann and Deborah Estrin), but again a frnd of mine who has worked on it claims that the MAC is something called B-MAC, developed by some Berkley guys. I'm going thru a paper named "Versatile Low Power Media Access for Wireless Sensor Networks" by Polastre et al, but this paper on B- MAC mentions some interfaces like MacControl, MacBackoff and LowPowerListening, which unfortunately I'm yet unable to locate in my installation of TinyOS 1.x version. Can anyone tell me something exactly how to use the MAC features that are already existing, and how they handle message collision, RTS-CTS exchange, etc? Does anyone know any good document that teaches on application-layer protocol design for sensor motes using the exisiting MAC? Thanks and regards > As far as I understand it the micaz uses a simple CSMA, where it listens > for a radio signal above a "squelch" value just before transmitting. If > it hears anything it does a randomized backoff/retry. > > For power voltage, I run on regulated 3.3v. I looked at the spec sheets > for the chips (actually the mica2 w/ CC1000) and it "seems" that 5v is OK, > but have not tried it. Let me know if you get smoke... > > MS > > > Munaretto, Daniel wrote: > > Dear all, > >i would like to ask you some questions about CC2420 and micaz energy consumption. > > I read, from reports and data sheets, that the Basic RF library in CC2420 contains only a small subset of the 802.15.4 standard: beacons is not implemented, no defined coordinator/device roles, > > it does not check CCA twice , it does not retransmit packets, it cannot communicate with other networks. > > 1)I would like to understand if, by default, any collision avoidance mechanism is implemented or may be available for motes, as our micaz, which have this chipcon (for example, in the CC2420 folder in TinyOS 1.x, is it implemented a simple CSMA or a CSMA-CA?). > > Because my research group needs to know if and how to provide a "good" collision avoidance mechanism on our micaz motes. > > 2)Exactly, what are the bounds of "the limited ability of the user" on defining the MAC layer by TinyOS code? i mean, what can i modify, if possible, in the MAC layer and how/where? > > 3)I've just discovered that using the flash on our motes, so reading and writing on flash, the batteries are insufficient. I was using 1.3 V rechargeble batteries, but it seems i need more power. > > Is it a known problem?is it possible to source the mote over 3V?because, it is written 1.5 V on the motes... > > > > Thanks for your availability, any further help will be really appreciated > > cheers > > Daniele Munaretto > > > > > > > > > > ___ > > Tinyos-help mailing list > > Tinyos-help@Millennium.Berkeley.EDU > > https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > ___ > Tinyos-help mailing list > Tinyos-help@Millennium.Berkeley.EDU > https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > ___ Tinyos-help mailing list Tinyos-help@Millennium.Berkeley.EDU https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
