Just a guess, Before asking the routing layer whether a new route to a neighbor is promising, the estimator asks physical layer whether the white bit of the incoming packet (from the sender of the new link) is set. Only if the white bit is set then estimator proceeds. Since the set white bit already indicates that local link is good (may be interpreted as ETX=1), it may not be required to verify the local ETX values of the existing neighbors.
Please correct me if I am wrong. Manjunath D ################################################################################################################ *************************************************************************************************************** On Tue, 10 Aug 2010, Xiaohui Liu wrote: > Hi, > > The estimator can use the compare bit to ask for network layer's decision > whether a new link to a neighbor is promising. The network layer checks if > there are neighbors with worse ETX (ETX from a neighbor to the root, > excluding ETX from myself to the neighbor). If there is, it recommends to > include the neighbor, then the estimator will randomly kick out a existing > neighbor to accommodate this new neighbor, *without* considering ETX of > neighbors. Why? Neighbors with smaller ETX than the new neighbor can be > evicted. > > Thanks in advance for helping me to understand. > > -- > -Xiaohui Liu > _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
