-compute the bi-directional link quality. One popular way to define the
-bi-directional link quality between a node pair (A,B) as the
-probability that a packet transmitted by A will be successfully
-received and acknowledged by B. This approach computes the
-bi-directional link quality of a node pair (A,B) as the product of the
-link quality of (A,B) and (B,A).
+compute the bi-directional link quality. Routing protocols often
+compute the bi-directional link quality of a node pair (A,B) as a
+function (product, min, etc.) of the link quality of (A,B) and (B,A).