| In this research, we design and develop a virtual cell approach for the transmission of IP datagrams in mobile computer communications. A virtual cell consists of a group of physical cells whose base stations are implemented by remote bridges and interconnected via high-speed datagram packet-switched networks. Host mobility is supported at the data link layer using the distributed hierarchical location information of mobile hosts. It eliminates the necessity of IP-level mobile host protocols that may interfere with the conventional IP protocol in a practical sense and achieves a logically flexible coverage area according to mobility and communication patterns among physical cells.;Given mobility and communication patterns among physical cells, the problem of deploying virtual cells is transformed to the optimization problem of finding a cover of disjoint clusters of physical cells. The objective is to minimize the total communication cost for the entire system where intercluster communication is more expensive than intracluster communication. Our problem differs from general graph partitioning problems in that it must meet the underlying topology constraints, such as the linear arrangement of physical cells in highway cellular systems and the hexagonal mesh arrangement of physical cells in cellular systems.;For highway cellular systems, we design an efficient optimal partitioning algorithm of ;Once an optimal partition of disjoint clusters is obtained, we can deploy the virtual cell system according to the topology of the optimal partition such that a cluster corresponds to a virtual cell. To analyze the performance of a virtual cell system, we adopt an open multiple class queueing network model. In addition to mobility and communication patterns among physical cells, the topology of the virtual cell system is used to determine service transition probabilities of the queueing network model. By solving the traffic equations of the queueing network model, we obtain various performance measures such as the network response time for each type of message and the utilization of the base station networks and the backbone network of the virtual cell system. |
