Specifically, a write quorum should collect
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nodes on a ???column??? as well as on a face of local maxima to perform updates,
so that read quorum collecting nodes on a ???row??? as well as on the face are
sure to get current data.
However, the frequency of new events detected by sensors and that of
data really needed by a soldier is not equivalent most of the time. The new
event sensed by a node is distributed in a large domain, while sometimes
soldiers are really interested in the data within some specific area. As a result,
collecting nodes in such a symmetrical way for both write and read quorums
will cost considerable system overhead, although only advertisement instead
of complete DATA is updated through write quorums by negotiation. The
way to reduce this consumption is let only one of the quorums execute face
routing while the other one will stop forwarding packets when they arrive
at local maxima. This mechanism should combine with the frequency of new
event advertisement and soldier requests. The more frequent an operation,
the fewer nodes the corresponding quorum must collect.
Thus, the quorum-based method can be enhanced by adding a minor modification
as follow: if sensors are assigned to disseminate whenever new information
is detected, then ADV will be only propagated to the end of each
???column???. It will stop if no further neighbor in the given direction can be
found. On the other hand, REQ have to finish the whole quorum.
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