We propose an Enhanced Resource Auction Multiple Access (ERAMA) protocol for the future wireless multi-media communications by enhancing the original Resource Auction Multiple Access (RAMA) protocol by N. Amitay. The enhanced features of the ERAMA protocol include the reduced control overhead caused by the auction mechanism, the capability of supporting variable bit rate services, the reduced channel allocation delay and delay variation, and the capability of supporting multiple quality of service levels. Simulation study shows that the ERAMA protocol gives shorter multiple access delay, smaller delay variation, less mean number of accesses and lower talk spurt loss probability than those of the RAMA.
The ERAMA system which includes the ERAMA protocol, the request buffer in the Base Station Controller (BSC) and the radio channels is analyzed by a two-stage queueing system. The first stage representing the ERAMA protocol id mofrlrf as an M/D/1 system, and the second stage representing the request buffer and the radio channel is modeled as an MMBP/Geo/$N_{ch}$/L queueing system. The output process of the M/D/1 system is approximated as a k-stae MMBP. We introduce a parameter $P_{\alpha,s}$ denoting the probability that a customer departing the first queueing stage enters the second stage waiting room. The $P_{\alpha,s}$ successfully describes the talk spurt loss caused by the multiple access delay. The analytical model yields upper estimates for the loss probability of talk spurt, the mean auction delay and the mean buffering delay of requests, and the channel utilization. We also make comparisons between the achievable multiplexing gain of speech connections of the ERAMA and the Packet Reservation Multiple Access (PRMA) protocol, and the results show that the proposed ERAMA protocol yields higher gain than the PRMA for the given parameters.
We investigate the performance of the ERAMA protocol in an environment accommodating voice and data traffic. We propose three schemes to accommodate data traffic. In scheme 1, requests from data terminals are distinguished from those of voice terminals by the priority bit (P-bit) only. In scheme 2, data terminals are distinguished by the P-bit and the data bursts always generate new requests. In the ERAMA protocol, the new requests cannot attend at the auction cycle when therre are retrial requests. Therefore, the priority of data terminals un the scheme 2 is lower than that in the scheme 1. In scheme 3, the excessively delayed data requests can have a higher priority level. The scheme 1 yields smaller delay for data traffic than the scheme 2. However, the effect of data traffic on the real-time services can be minimized by utilizing the scheme 2. We show that by utilizing the multiple slot allocation capability of the ERAMA protocol, we can fully utilize the bandwidth of radio links. And the comparison between the ERAMA and the PRME protocol in the integrated environment of voice and data traffic shows that the ERAMA yields higher voice multiplexing gain and smaller data burst delay characteristics.
Finally, we also propose a scheme to accommodate real-time video traffic. We assume that the video traffic is generated by a layered coding algorithm. We allocate a minimum bandwidth for each video connection. The more significant video components from the layered coding and the channel requests for the less significant components are transmitted through the minimum bandwidth. Under the environment that voice, data and real-time video traffic are integrated, the voice traffic loss probability, the video traffic loss probability for the lower significant components, and the channel utilization are investigated by simulations
