Hello Henning, Thanks for the reply. I have a somewhat different problem. It's not exactly the hidden terminal problem in WLAN. The RTS/CTS mechanism will not work in this case because, the node which does the broadcast have a very high transmission range, and the recipient nodes of the broadcast have a low RF power. I don't want the broadcast of a high power node to collide with the low power communication that is going on between the other nodes.
Regards, Vikram On Wed, Oct 28, 2009 at 1:50 PM, Henning Kettler <hennin...@gmx.net> wrote: > Hello Vikram, > > your problem sounds like the hidden station problem in WLAN. > There is a soution described in IEEE 802.11 called RTS/CTS. Some basic > information about this mechanism is delivered by wikipedia ( > http://en.wikipedia.org/wiki/IEEE_802.11_RTS/CTS). But introducing this > mechanism will introduce more signalling in your network and decrease your > availiable bandwidth, if it is implementable in an efficient way at all... > > Hope this will help you a bit... > > Regards, > Henning > > -------- Original-Nachricht -------- > > Datum: Wed, 28 Oct 2009 10:52:48 +0530 > > Von: Vikram vik76 <vi...@sify.com> > > An: tinyos-help <tinyos-help@millennium.berkeley.edu> > > Betreff: [Tinyos-help] Nodes with different RF power > > > Hello everybody, > > I want to work for a scenario where in the WSN network (comprising of > > micaz > > motes), one of the node say node 'A' (base-station connected to PC) needs > > to > > do a broadcast to all the other nodes. The remaining nodes communicate > > via > > multi-hop communication. To achieve this, I want node 'A' to have a very > > high transmission power whereas for the remaining nodes low transmission > > power. I use the CC2420_DEF_RFPOWER variable to set the RF power. say > > for > > node 'A' this value is 31 and for the remaining nodes it is 2. > > Now, the problem is since, nodes have different transmission power, if > > there > > is a multi-hop communication going on between the other nodes, then node > > 'A' > > should not do the broadcast as this may lead to collisions. node 'A's > > broadcast is supposed to reach all other nodes without the packets being > > corrupted. > > How do I achieve this? Is there a way wherein I can increasing the > > carrier > > sensing capabilities of node 'A' so that node 'A' can sense the multi-hop > > communication that is going on between other nodes? Please suggest. > > > > Thanks > > Vikram > > -- > Jetzt kostenlos herunterladen: Internet Explorer 8 und Mozilla Firefox 3.5 > - > sicherer, schneller und einfacher! http://portal.gmx.net/de/go/chbrowser > _______________________________________________ > Tinyos-help mailing list > Tinyos-help@millennium.berkeley.edu > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >
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