Integrated Random-Access Reservation Schemes for Multi-Access Communication Channels,

摘要

Under Integrated Random-Access Reservation (IRAR) access-control schemes, newly arrived packets can be designated for reserved or random-access transmissions. In the latter case, if a collision occurs, each colliding packet is assigned for transmission by reservation, rather than attempt another random-access transmission. Performance of the IRAR schemes expressed in terms of the associated channel delay-throughput curves. Single packet messages are assumed. Analytical expressions are derived for the limiting average packet delay for a broadcast multi-access channel, under various IRAR schemes. The performance curves under IRAR access-control schemes are compared with those resulting when pure reservation and pure random-access procedures are used. It is shown that for channels with low propagation delays (such as terrestrial radio or line channels), an IRAR scheme yields an excellent performance curve over the whole throughput range. For channels with high propagation delays (such as a satellite communication channel), an IRAR scheme is shown to yield delay-throughput performance characteristics superior to those obtained under pure reservation and random-access schemes, for medium and low network throughput values. At higher throughput values, an efficiently designed integrated access control scheme will be appropriately switched from an IRAR mode into a reservation procedure.