MINISLOTTED PACKET RESERVATION MULTIPLE ACCESS PROTOCOL

Abstract

Mobile personal communications have been experiencing rapid growth in the last few years with advancement in the related technologies and a corresponding drop in the price of such services. It has evolved from the first generation analogue frequency modulated systems like the Advanced Mobile Phone Service and Total Access Communication System into the implementation of second generation digital cellular mobile radio systems such as the Global System for Mobile Communication and Digital European Cordless Telecommunication. However, these systems are optimized for voice services and do not provide for efficient data services. To fully meet the expected huge demand in mobile telecommunications from both voice and data users by the end of this century, third generation systems utilising packet switching and transmission techniques have been proposed. The Packet Reservation Multiple Access (PRMA) technique has been proposed by Goodman et. al. [2] as the multiple access technique for third generation wireless information systems. However, a disadvantage of PRMA is that an entire slot time is wasted in the event of a packet collision. This can lead to increased channel access delay and higher packet dropping probability, thereby reducing the channel throughput and the quality of speech conversations. A variation of PRMA protocol, called minislotted PRMA, was proposed for improved performance in a congested channel [7]. We study the performance of the minislotted PRMA protocol under different user configurations in this thesis. In the voice-only system, minislotted PRMA is shown to yield good improvements over PRMA. Results from a mixed voice and data environment show that minislotted PRMA is able to accommodate low bit-rate data terminals gracefully without significantly degrading the performance of voice users. We further simulate the protocol in a metropolitan of microcells with user mobility and handoff events and show that user mobility has negligible impact on the performance of the system.