The Proposed Protocols Sample Clauses

The Proposed Protocols. In this section, the proposed protocols, FDAL and VRFC, will be introduced in more detail to solve the mixed faults on links in a general network with FDA compliance. The parameters used and the assumptions made are as follows: ■ Processors used in the underlying network are assumed to be fault-free. (This can be achieved using the FDAMIX protocol [5]) ■ Let Þ be the set of all processors in the general network, and  Þ =n. ■ Each processor in the network can be uniquely identified. ■ Each processor in the general network has exactly the same initial value. (Protocol GPBA [11] can be used to achieve this status.) ■ Let La be the maximum number of arbitrary faulty links in the general network. ■ Let Ld be the maximum number of dormant faulty links in the general network. ■ Let c be the connectivity of the general network, where c > 2La+ Ld. ■ A processor does not know the fault status of the links in the general network, however, dormant faulty links can be detected [9,14] FDAL can detect/locate arbitrary faulty links, La, and dormant faulty links, Ld, within the general network, where c > 2La+ Ld. The constraint of the inequality c > 2La+ Ld is necessary, because a fault-free processor can detect dormant faults when the protocol appropriately encodes a transmitted message using either the Non-Return-to-Zero code or the Manchester code [9,14] before transmission. In the worst situation, the receiver processor is able to obtain c- Ld copies of the value from the sender processor. Where c- Ld >2La, each receiver processor is able to take the majority value among these c-Ld values. Before exercising FDAL, both of GPBA and FDAMIX must be executed to ensure that the general network is free from arbitrary and dormant faulty processors. Each fault-free processor in the general network is able to reach a common value. Thus, the common value agreed by GPBA can be used as the initial value for each fault-free processor in the general network for executing FDAL. When executing FDAL, there are four sequential phases to be considered; the message exchange phase, the fault diagnosis phase, the result exchange phase and the reconfigure phase. Only two rounds are needed for message exchange; one round for transmitting the initial value, and the other for transmitting the fault diagnosis report. The detailed definition on the proposed protocol FDAL is shown in Figure 1. Protocol FDAL (For all fault-free processor Pi with the same initial value, where 1≤ i ≤ n)