Showing papers on "Wireless mesh network published in 1996"

Architectural considerations for mobile mesh networking

Abstract: Mobile communications is central to many military operations and is necessary to communicate simultaneously with multiple warfighters engaged in a common task. This paper describes the problem of routing and resource reservation in mobile mesh networks and presents architectural recommendations necessary for Internet protocols to operate effectively in these environments. A "mobile mesh" network is an autonomous system of mobile routers connected by wireless links, the union of which form an arbitrary graph. The routers are free to move randomly; thus, the network's wireless topology may change rapidly and unpredictably.

Method for installing a wireless network which transmits node addresses directly from a wireless installation device to the nodes without using the wireless network

Abstract: A method for installing a wireless network, which includes the steps of physically installing a plurality of nodes in respective different locations in a building, connecting the nodes to a power supply and powering up the nodes, using a wireless installation device to program a respective address into the nodes, using the wireless installation device to program one or more default settings into the nodes, using the wireless installation device to verify operation of the nodes, and, using the wireless installation device to dump at least information regarding the physical location and associated address of the nodes to a building computer. In a presently preferred embodiment, the wireless installation device is preferably an RF portable computer which has an RF transmitter which has a variable power setting, and an RF receiver which also has a variable power setting. During installation of each node, the RF portable computer assigns a unique address to that node, and then loads the assigned address and all appropriate default settings into that node. The address data and default settings are preferably stored in nonvolatile memory provided in each node. The wireless programming of the nodes is preferably accomplished using a software "handshaking" procedure which ensures that the address and default setting data is only loaded into the node currently being programmed, and not inadvertently into one or more other nearby nodes. In this connection, an iterative power reduction scheme can be utilized to prevent multiple nodes from being inadvertently assigned the same address. Also disclosed is a method for installing one or more nodes in an existing wireless network, which method is performed in essentially the same manner as that described above in connection with the original installation of the wireless network itself, with the exception being that instead of an entire network of nodes being installed, only one or more nodes are installed in a pre-existing wireless network.

Efficient algorithms for performing packet broadcasts in a mesh network

Abstract: A common task for network protocols is the broadcasting of information from one node to the rest of the nodes in the network. This task is often required during the execution of parallel algorithms in a network of processors, or other situations where the nodes of a mesh network generate packets to be broadcast at random time instances. We consider processors communicating over a mesh network with the objective of broadcasting information among each other. One instance of the problem involves a number of nodes all with the same message to be broadcasted. For that problem, a lower-bound on the time to complete the broadcast, and an algorithm which achieves this bound are presented. In another instance, every node in the mesh has packets to be broadcast arriving independently, according to a Poisson random process. The stability region for performing such broadcasts is characterized, and broadcast algorithms which operate efficiently within that region are presented. These algorithms involve interacting queues whose analysis is known to be very difficult. Toward that end we develop an approximation which models an n-dimensional infinite Markov chain as a single-dimensional infinite Markov chain together with an n-dimensional finite Markov chain. This approximate model can be analyzed and the results compare favorably with simulation.

Mesh connected computers with fixed and reconfigurable buses: packet routing and sorting

Abstract: Mesh connected computers have become attractive models of computing because of their varied special features. In this paper we consider two variations of the mesh model: 1) a mesh with fixed buses, and 2) a mesh with reconfigurable buses. Both these models have been the subject matter of extensive previous research. We solve numerous important problems related to packet routing and sorting on these models. In particular, we provide lower bounds and very nearly matching upper bounds for the following problems on both these models: 1) Routing on a linear array; and 2) k-k routing and k-k sorting on a 2D mesh for any k/spl ges/12. We provide an improved algorithm for 1-1 routing and a matching sorting algorithm. In addition we present greedy algorithms for 1-1 routing, k-k routing, and k-k sorting that are better on average and supply matching lower bounds. We also show that sorting can be performed in logarithmic time on a mesh with fixed buses. Most of our algorithms have considerably better time bounds than known algorithms for the same problems.

Evaluation of a Mesh of Clos wormhole network

Abstract: The pursuit of high connectivity in network design for multicomputers is often complicated by wiring constraints, resulting in a trade-off between efficiency and realizability. The Mesh of Clos topology addresses this trade-off by combining a multistage network with a mesh network. In this paper, a simulation study is presented in order to evaluate wormhole-routed Mesh of Clos communication networks. It is shown that this type of network can substantially reduce contention in comparison with flatter mesh networks. Furthermore, we found that increasing the number of flit-buffers on router devices does not necessarily lead to improved communication performance. For some application loads it may even result in a degradation of performance.

Modeling and traffic evaluation of an integrated ATM-wireless network

Abstract: We introduce an integrated ATM-wireless network and evaluate the traffic performance of this network. The wireless section is comprised of five base stations each with a number of hand-sets. The data rate generated by each hand-set is 64 kbs while base stations communicate with one another at 384 kbs. In the ATM section, there are six nodes each is connected to a number of workstations. We assume 50% of the packets generated at hand-sets are destined for ATM section while the rest are forwarded to destinations within the wireless network. A fixed base station is connected to the ATM network in addition to other hand-sets and mobile base stations. The combined ATM-Wireless network was simulated and the simulation results demonstrate the effectiveness of buffers used in base stations. On all radio links, packets transmitted by any hand-set or base station, are dynamically defined by the radio frequency. The performance evaluation results show the communication delay within the wireless network, and between the ATM and the wireless networks.