Extension-Agreement Phase. The goal of the “extension-agreement phase” is to allow return processor to compute an agreement value which is the same as other fault-free mobile processors’ agreement value. In the “extension-agreement phase”, each return processor receives the agreement values from other mobile processors which join whole the “message-exchange phase”. The VOTE function is used on the values received to obtain the agreement value. The return processor can then obtain the same agreement value as other fault-free mobile processors. The reason is that each fault-free mobile processor can reach an agreement value if z>⎣(z-1)/3⎦+2Zm+Za. Hence, there are at least z-⎣(z-1-Za)/3⎦-Za zones that are fault-free and have the same agreement value. That is, in the worst case, a return processor can receive z-⎣(z-1-Za)/3⎦-Za copies of the same value, which is large then ⎣(z-1-Za)/3⎦. Therefore, a return processor can then decide the agreement value bye using the function VOTE.
Extension-Agreement Phase. The goal of the extension-agreement phase is to allow return nodes to compute a common agreement value the same as that of other fault-free nodes’ function VOTEad(s) value. In the extension-agreement phase, each return node receives the agreement values from the other nodes. The VOTEad function is used on the values received to obtain the agreement value. The return nodes can then obtain the same agreement value as other fault-free nodes. The reason is that each fault-free node can reach a common agreement value if n>3fm+fa. Thus, there are at least n-⎣(n-1-fa)/3⎦-fa nodes that are fault-free and have the same agreement value. That is, in the worst case, a return node can receive n-⎣(n-1-fa)/3⎦-fa copies of the same value, which is larger than ⎣(n-1-fa)/3⎦. A return node can then decide which agreement value using the VOTEad function. The MAHAP protocol definition is shown in Figure 2, and the flow chart of the MAHAP is shown in Appendix I. MOBILE AD-HOC AGREEMENT PROTOCOL (MAHAP) Definition: ◆ For the “Table-driven” Ad-Hoc routing protocols, each node has common knowledge of the entire graphic information G=(E,N), where N is the set of nodes in the network and E is a set of node pairs (Ni,Nj) indicating a physical link (the radio range is covered) between node Ni and node Nj ,where 1 ≤ i,j ≤ n. ◆ For the “On-demand” Ad-Hoc routing protocols, each node has partial common knowledge of the graphic information G=(E,N). ◆ Each node can transmit a message to all other nodes in the MANET through the “On-demand“ or the “Table-driven” or the “Hybrid” protocol. ◆ Three node roles: sender node, relay node and receiver node, depending on the message flow. A message sent from a sender node to a receiver node may be passed through some intermediate (relay node). ◆ A relay node cannot falsify a message from a sender node to a receiver node. This is achieved using authentication technology. ◆ The return node, a node that moves away from the MANET in the message-exchange phase, and returns to the MANET before the decision-making phase. ◆ Each node receives other nodes’ messages at each message exchange round. If no message is received, the value is replaced with δ0. Message-Exchange Phase: Compute the number of rounds required γ: γ=t+1, where t= ⎣(n-1)/3⎦. For i = 1 to γ If i=1, then:
Extension-Agreement Phase. The goal of the extension-agreement phase is to allow return nodes reach a common agreement value VOTE(s) with other fault-free nodes. In the extension-agreement phase, each return node receives the agreement values of the other fault-free nodes. The VOTE function is used on the values received to obtain the agreement value. The return nodes can then obtain the same agreement value as the other fault-free nodes. The reason is that each fault-free node can reach a common agreement value if n>3fm+fa. Hence, there are at least n-(n-1-fa)/3-fa nodes that are fault-free and have the same agreement value. That is, in the worst case, a return node can receive n-(n-1-fa)/3-fa copies of the same value, which is larger than (n-1-fa)/3. A return node can then decide which agreement value to be used in the VOTE function.
Extension-Agreement Phase. For the return processor only Step 1: Receive other mobile processors ' VOTE(s) values.
