Distributed Processing in Multi-Hop Packet Radio Networks.

摘要

This report is concerned with the integrated evaluation of distributed processing scenarios in a highly dynamic environment such as a multi-hop packet radio network. To aid in this process, a simulation model was developed that has a network of identical packet radio nodes using spread spectrum random access protocols, an error model for multiple access interference and on-off partial band jammer, and end-to-end transport functions. An abstract description of a typical distributed processing scenario with hierarchical primary and subtask structures has been devised based on a 'script' that specifies processing time, sequences of subtasks (distributed over other nodes) and lengths of request and response messages and was integrated with the packet radio simulation. Extensive numerical results, primarily in the form of percent of successfully completed tasks and the mean task delay, were obtained through simulation runs representing a wide variety of task scenarios. Different processing scenarios such as assignment of task deadlines, levels of task-subtask hierarchy, and redundant processing of a subtask on multiple hosts, have also been examined. (Author)