Accession Number : ADA192233

Title :   A Random Access Algorithm for Environments with Capture and Limited Feedback Capabilities.

Descriptive Note : Technical rept. 1 Sep 86-31 Aug 88,

Corporate Author : VIRGINIA UNIV CHARLOTTESVILLE DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Papantoni-Kazakos, P ; Lyons, Daniel F

PDF Url : ADA192233

Report Date : Mar 1988

Pagination or Media Count : 24

Abstract : We consider synchronous packet radio systems, deploying spread-spectrum encoding. In such systems, capture events occur, where in the presence of k simultaneous packet transmissions, a single packet is captured with probability P(k). We adopt the case where P(k) = p q to the (k-1) power, k = or 1, for some system probabilities p and q, where ternary feedback per slot is available, where in the event of capture the identity of the captured packet is not revealed, and where capture in the presence of a single packet transmission and capture in the presence of multiple transmissions are not distinguishable events. For the above system, we present and analyze a full sensing window random access algorithm. Due to the system model considered, the algorithm inevitably induces losses. Its performance characteristics are the fraction of lost traffic and the per successfully transmitted packet expected delays. We compute the values of those characteristics, for various values of the system and the algorithmic parameters, and for the limit Poisson user model. The algorithm can attain low delays while simultaneously inducing relatively few losses.

Descriptors :   *ALGORITHMS, *PACKETS, *RADIO TRANSMITTERS, *SLOTS, CODING, FEEDBACK, MATHEMATICAL MODELS, MULTIPATH TRANSMISSION, PARAMETERS, POISSON DENSITY FUNCTIONS, RADIO EQUIPMENT, RANDOM ACCESS COMPUTER STORAGE, SPREAD SPECTRUM, SYNCHRONISM, USER NEEDS

Subject Categories : Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE