the Frequency Division Multiple Access (FDMA), a code of .4b.strac-Recently. the wireless mesh network attracts the intcmst of many people as a new broadband network of the next generation. The wireless mesh network only consists terminals, the code Division Multiple Access ( C D m ) , and on: Since then a terminal in tbr network can communicate with the other cochannel interference may occur, we cannot assign channels terminal beyond the transmission range by multihopping as randomly. Here, we constmct a graph from the network as S a m e as ad hoc networks. In this network a :ommunicatiofl follows. Each vertex represents a terminal and each edge link between two terminals which can communicate directly IS represents a link which can communicate directly, we need to required a channel. Since cochannel interference may occur, we need tn assign channels to communication links carefully. In this assip channels efficiently to achieve paper, we describe a channel assignment ~bategy which takes Ifl the network. A channel a s s i w e n t to terminal Pairs corthe degrep of cochannel interference into consideration. and we responds to an edge coloring in the graph & network theory. evaluate an effectiveness of this strategy by computer simulations. Strong edge coloring [7] is related to this channel assignment We show that thb strategy is more effective than u sbategy problem on WN. seong edge colo,i,,g is a strategy in wont cases of cochannel interference and does not take the which does not take the degree of cochannel interference into consideration.degree of interference into consideration. Therefore, in [SI we define a new edge coloring strategy which takes the dewee of wCtral

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SUMMARYParallel distributed systems in which multiple computers are connected through LAN and WAN are widely used at present. One of the important functions of parallel distributed systems is broadcasting to distribute data over an entire system. Broadcast processing greatly affects the performance of parallel distributed systems, and it is desirable to develop a distribution procedure that completes the processing in a short time. Consequently, there have been many approaches to the minimum broadcast time problem, aiming at the optimal distribution procedure. However, not many past studies of this problem consider a wide-area system in which multiple parallel distributed systems are connected. In this context, this paper considers the minimum broadcast time problem for a wide-area parallel distributed system whose topology can be represented by a certain kind of split graph. It is shown that the problem can be solved in polynomial time in the homogeneous parallel distributed system in which the time required for communication is uniform. In addition, a heuristic algorithm is proposed for a heterogeneous parallel distributed system in which the time required for communication is not uniform. Simulation results reveal that an efficient distribution procedure can be derived in a short time.