On Jun 9, 2009, at 10:03 AM, Rémi Villé wrote: > 2009/6/8 Philip Levis <[email protected]> > > On May 29, 2009, at 5:53 AM, Rémi Villé wrote: > > Hi, > > In the topology file of TOSSIM we can see that we can choose a gain > for a link from a node A to a node B and a different one for the > link from B to A, so it may imply that, in real world, we have > different gain from a mote A to a mote B and from B to A. > > I would like to know if it's indeed the case in reality, if having > two very different gain between two motes is a rarity, if we can say > the gain difference between two mote directed link is often in a > range of one value. > If someone knows this value it would be perfect. > > Please read the work at USC on this. > > It is common in reality, due to hardware variations. While it is > very uncommon (but not impossible) for the actual RF attenuation to > be different in the two directions, the two transceivers can have > different frequency sensitivity. > > Phil > > Even between two telosb mote for example ?
Yes. There are variations in radio chip hardware. > > Have you got some publication title, key words, author names or > links to this subject ? http://www.marcozuniga.com/professional/ has the two seminal papers: "An Analysis of Unreliability and Asymmetry in Low-Power Wireless Links," and "Analyzing the Transitional Region in Low Power Wireless Links." SING tech report SING-08-03 has data on CC2420 nodes: http://sing.stanford.edu/pubs/sing-08-03.pdf Phil _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
