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In parallel and distributed systems, multistage interconnection network (MIN) plays an important role for its efficient communication between processor and memory at a very low cost. A major class of MIN called Gamma network is known for its redundant network topology and is being used in broadband communication systems. The increased redundancy incorporation makes these networks more complex and hence reliability evaluation becomes complex. The performance evaluation of these network topologies requires reliability evaluation utilizing routing mechanism or techniques. In this paper, we have proposed four topologies of Gamma-Minus network using MUX and DEMUX. Terminal Reliability (TR), fault tolerance and routing schemes of Gamma-Minus network topologies proposed have been computed by utilizing different connection patterns of MUX/DEMUX. Also, performance indices such as TR, Reliability Cost Ratio (RCR), Fault Tolerance, etc. computed for different Gamma-Minus architectures have been compared with the existing Gamma networks, other than Gamma-Minus. All the performance indices for different Gamma-Minus topologies show improvement over the performance indices of different Gamma networks. The proposed Gamma-Minus architectures have been compared among themselves and also Gamma-Minus2 shows the best performance for all performance indices. To the best of our knowledge, most of the researchers have not compared fault tolerance and RCR performance measure.

Gamma Interconnection Network (GIN) is characterized as Redundant Multistage Interconnection Network (MIN) which is considered as a potential candidate for use in broadband communications. Several advancements have been made to improve Reliability indices such as Terminal Reliability (TR), Broadcast Reliability (BR) and Network Reliability (NR) of these networks. But inspite of these advancements, there are certain issues which are yet to be explored such as Complexity, Cost, Number of disjoint paths on presumption that source/destination are failure free. Most of the work done in the literature addresses TR only and less work has been done on analysis of BR and NR. In literature networks, $8\times 8$ size has been explored and no attention has been paid to bigger network sizes although reliability of bigger size network is important for parallel processing systems. In this paper, existing class of Gamma Networks has been studied extensively and modifications have been proposed in existing Gamma Network which minimizes or resolves most of the limitations mentioned above. The proposed Gamma-Minus Network has more redundant paths than other networks. Proposed Network has been compared with some recently introduced members of this class. The results show that newly proposed Gamma-Minus Network has better reliability with lowest cost and path length and provides disjoint minimal-path set for $8\times 8$ to $1024\times 1024$ network size. The routing used in this paper eliminates the backtracking overhead which minimizes transmission delay.

The increase in demand for mobile telecommunication systems, and the limited bandwidth allocated to these systems, have led to systems with smaller cell dimensions, which in turn led to the increase of control messages. In order to prevent controller bottle necks, it is desirable to distribute the network control functions throughout the network. To satisfy this requirement, a mobile network structure characterized by its hierarchical and decentralized network control is presented in this paper. The area served by the mobile system is divided into regions, and the regions are further divided into cells. Each cell is served by a base station, each base station is connected to a regional network through a base station interface unit (BIU). Each region has its own regional network. Connected to each regional network are the cellular controller, the home database, the visitor database, the trunk interface unit (TIU) and the gateway interface unit (GIU). The TIU connects the regional network to the public switched telephone network (PSTN). The GIU connects the regional network to other regional networks through the gateway network. This architecture distributes the network control functions among a large number of processing elements, thus preventing controller bottle necks — a problem faced by centralized controlled systems. The information and network control messages are transferred in the form of packets across this network. Processes inherent to the operation of this network structure are illustrated and discussed. These processes include the location update process, the setting up of a call, the handoff process (both the intra-region handoff process and the inter-region handoff process are considered), and the process of terminating a call.

Now, the dynamic solution is put forward for the QoS of network service problems, the solution is to integrate the mixture of differential evolutionary algorithm and ant colony algorithm into the QoS routing, and the solution adjusts the local pheromone updating strategy dynamically. The optimal global pheromone improves the global convergence of the algorithm. The simulation results show that DE-ACO algorithm is effective to deal with the problem of routing. At the same time, DE-ACO algorithm compares with the traditional QoS multicast routing algorithm in convergence and convergence speed. DE-ACO algorithm has been greatly improved.