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Several channel-allocation algorithms have been proposed in the literature for traditional cellular networks with static base stations (BSs), while not much attention has been given to channel-allocation problems for cellular networks where BSs are mobile. In cellular networks with mobile BSs (MBSs), the network topology is dynamic due to the mobility of the BSs. This makes the channel-allocation problem in such networks more challenging. Moreover, the MBSs may fail and degrade the performance of the cellular network. Therefore, it is desirable that the channel-allocation algorithm be fault tolerant. Thus, even in the presence of failure of the MBSs, the channel-allocation algorithm should work reasonably well. It is also desirable to design a channel-allocation approach that guarantees that the request from a mobile host (MH) is responded to in a timely manner. In this paper, a distributed dynamic channel-allocation algorithm that addresses these problems in cellular networks with MBSs is proposed. The proposed algorithm is fault tolerant and guarantees that the time to respond to an MH's request for supporting a call is upperbounded. The performance evaluation of the proposed algorithm shows that the proposed algorithm performs well, even in the presence of failure of the MBSs. Index Terms--Cellular communication, cellular networks, distributed channel allocation, fault tolerance, mobile base stations (MBSs).

In mobile ad hoc and sensor networks, greedy-face-greedy (GFG) geographic routing protocols have been a topic of active research in recent years. Greedy routing is applied first and may fail at concave nodes, in which case, face routing is applied to recover from the greedy fail. This may cause extra hops in routing and decrease the routing efficiency in networks containing voids. In this paper, we propose a Hill-Area-Restricted (HAR) routing protocol. It avoids the extra hops as in the original GFG routing, which makes it more efficient in hop count. Compared with the previous work of Node Elevation Ad hoc Routing (NEAR), the proposed HAR guarantees the packet delivery and decreases the communication cost largely. Our simulation results show that the communication cost in bytes of all messages sent by each node in the proposed HAR is 99.2% less than that in NEAR. This makes the HAR more desirable for mobile ad hoc and sensor networks. [ABSTRACT FROM AUTHOR]

In cellular networks, it is vital to allocate communication channels efficiently because the bandwidth allocated for cellular communication is limited. If channels are statically allocated, as is the case in current cellular networks, a cell may run out of channels when a large number of mobile hosts move to the cell. To overcome this problem, dynamic channel allocation approaches have been proposed. Under dynamic channel allocation, channels are allocated to cells on demand, thus increasing channel utilization. Such channel allocation approaches fall under two categories, namely, centralized and distributed. Centralized approaches are neither scalable nor reliable, while distributed approaches have the potential to be both reliable and scalable. In the distributed approaches, a mobile service station is responsible for allocating channels to mobile hosts in the same cell. In cellular networks, mobile service stations may fail. In addition, the network may encounter intermittent network congestion and/or link failures. It is desirable for a channel allocation algorithm to work well, even in the presence of network congestion, link failures, and/or mobile service station failures. In this paper, we present a distributed dynamic channel allocation scheme for cellular networks that is fault-tolerant. Our approach can tolerate the failure of mobile service stations, link failure, and network congestion, and make efficient reuse of channels. We also provide results of the performance evaluation of our algorithm. [ABSTRACT FROM AUTHOR]