Hi, Le 24.01.2014 05:16, Varka Bhadram a écrit : > hai... > IEEE-802.15.4 devices that are there in the market right now are softmac > devices ex: cc2420,cc2520. So it can only detect whether the channel is > free or not. For example in case of cc2520 ,the h/w is providing us the > one GPIO pin which is CCA. It will be high when the channel is free. If > the channel is busy (GPIO_CCA = 0), generating the backoff and > resending the packet is *not * in the h/w (cc2520) provided the channel > is free.
I haven't used any of these radio but a quick glance through the data-sheet seems to indicate that you are wrong about that. Search for STXONCCA. So we need to take care of generating the backoff and > resending the packet if the channel is free from the microcontroller side. > For this to be implemented there are two approaches that i thought of,,, > 1. This logic can be at the mac level in kernel (mac802154). We can > export that symbol.... > 2. Logic can be at the driver code in the ieee802154_ops-> (*tx) : means > in the transmission function(by checking GPIO_CCA in case of cc2520) > If i am wrong please correct me.... > Regards, > Bhadram As already said by Dmitry the strict timing requirements make this task difficult for a Linux implementation. You probably want an RTOS to implement that. -- Christophe Aeschlimann Embedded Software Engineer & IT Manager ACN Advanced Communications Networks S.A. 2000 - Neuchâtel, Switzerland Tel. +41 32 724 74 31 ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Linux-zigbee-devel mailing list Linux-zigbee-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-zigbee-devel
