Geocasting, a variant of conventional multicasting, uses the location technology to deliver messages. However, recent geocast protocols extensively use flooding and broadcasting approaches. When network load is heavy, the chance of collision will be increased and then packets will probably be damaged or lost. The purpose of this paper is to propose an Adaptive Handshaking-Based Geocasting protocol (AHBG). In this protocol, we employ handshaking-based forwarding for data transmission instead of flooding. Simulation results show that AHBG achieves high delivery ratio (nearly 100%) with low overhead (at least 21% reduction compared with other protocols).

Torus/mesh-based machines have received increasing attention. It is natural to identify the maximum healthy submeshes in a faulty torus/mesh so as to lower potential performance degradation, because the time for executing a parallel algorithm tends to depend on the size of the assigned submesh. This paper proposes an efficient approach for identifying all the maximum healthy submeshes present in a faulty torus/mesh. The proposed approach is based on manipulating set expressions, with the search space reduced considerably by taking advantage of the interesting properties of a faulty torus/mesh. This procedure is a distributed one, because every healthy node performs the same procedure independently and concurrently. We show that the proposed scheme may outperform previous methods.