Multihop Wireless Networks: Opportunistic Routing

1.5 Book Contribution

The main contributions of this book are as follows:

• Chapter 2
  • We generalize the definition of EPA for an arbitrary number of forwarding candidates that follow a specific priority rule to relay the packet in OR.
  • Through theoretical analysis we prove that the maximum EPA can only be achieved by giving higher relay priorities to the forwarding candidates closer to the destination. This proof convinces us that given a forwarding candidate set, the relay priority among the candidates is only relevant to the advancement achieved by the candidate to the destination, but irrelevant to the packet delivery ratio between the transmitter and the forwarding candidate. The analysis result is the upper bound of the EPA that any GOR can achieve.
  • We find that given a set of M nodes that are available as next-hop neighbors, the candidate set achieving the maximum EPA with r (r ≤ M − 1) nodes is contained in at least one candidate set achieving the maximum EPA with r + 1 nodes.
  • We prove that the maximum EPA of selecting r(r ≤ M) nodes is a strictly increasing and concave function of r. This property indicates that although involving more forwarding candidates in GOR will increase the maximum EPA, the extra EPA gained by doing so becomes less significant.
• Chapter 3
  • We investigate the energy efficiency of GOR and propose two localized candidate selection algorithms with O(M3) and O(M2) running time in the worst case respectively and Ω(M) in the best case, where M is the number ...