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Packet scheduling problem experienced in wireless ad hoc networks is presented. Flow of packets coming from different node locations and concurring at intermediate nodes could overflow resources rapidly, stressing packet forwarding and increasing packet dropping. An intelligent packet priority control technique named weighted hop priority control scheme is used, that assures a data arrival end-to-end and reduced packet dropping ratio. Technique is based on periodically calculating two hop threshold values by weighting hop information carried by incoming and outgoing packet flows (hops already traversed and still remaining) respectively with their correspondent data rates, and using these thresholds to prioritize packet forwarding. Proposed scheme is compared with conventional queuing control based on first-in first-out queue dispatcher. Data arrival ratio and downloading response time are evaluated as our main estimator parameters. An ad hoc network scenario is simulated and results show that our proposed priority control scheme is a promising technique to efficiently handle packet flow forwarding in wireless ad hoc communications

A measuring method for the crossing rate distribution characteristics of band-limited signal that is sampled at equal time spaces and coded to n/sub c/ bits is described. The measuring principle is to detect the time segment that a measured signal increases or decreases monotonously and to count independently the events that each measuring reference level becomes the lowest and highest levels in the segment, during a measuring time, and is to calculate the difference of occurrence number of two kinds of event at each reference level and to obtain the cumulative distribution of the difference. In the method, to obtain high accuracy, it is necessary that the measured signal is sampled over the several times of the maximum frequency component.