Random Multiple Access Communication Research Articles

New Multipriority and Variable Duration Triple Time Slot P-CSMA Protocol for Edge Servers Server Deployment

In this paper, we study the joint impact of task priority and transmission time slot variable computing services on a novel p-persistent random multiple access communication protocol (p-persistent CSMA) in an edge server network. The traditional p-persistent CSMA protocol performs better at low loads, and in order to make the protocol perform better even when the edge server network is accessed by a large number of smart terminals, we consider adding a variable success time slot length and a multichannel, multipriority access model. When the success time slot is longer, the nodes will take longer time to send data, which will reduce the number of nodes retransmitting data, thus improving channel utilization and making the throughput rate of the network increase accordingly. Then, different priority levels are assigned according to the user’s needs, and the higher the priority level, the more channels are occupied and the probability of successful message delivery increases. Finally, the superiority of the proposed protocol is verified by simulation.

A New Approach to Random Access: Reliable Communication and Reliable Collision Detection

This paper applies Information Theoretic analysis to packet-based random multiple access communication systems. A new channel coding approach is proposed for coding within each data packet with built-in support for bursty traffic properties, such as message underflow, and for random access properties, such as packet collision detection. The coding approach does not require joint communication rate determination either among the transmitters or between the transmitters and the receiver. Its performance limitation is characterized by an achievable region defined in terms of communication rates, such that reliable packet recovery is supported for all rates inside the region and reliable collision detection is supported for all rates outside the region. For random access communication over a discrete-time memoryless channel, it is shown that the achievable rate region of the introduced coding approach equals the Shannon information rate region without a convex hull operation. Further connections between the achievable rate region and the Shannon information rate region are developed and explained.

Error Performance of Channel Coding in Random-Access Communication

A new channel coding approach was proposed in [1] for random multiple access communication over the discrete-time memoryless channel. The coding approach allows users to choose their communication rates independently without sharing the rate information among each other or with the receiver. The receiver will either decode the message or report a collision depending on whether reliable message recovery is possible. It was shown that, asymptotically as the codeword length goes to infinity, the set of communication rates supporting reliable message recovery can be characterized by an achievable region which equals Shannon's information rate region possibly without a convex hull operation. In this paper, we derive achievable bounds on error probabilities, including the decoding error probability and the collision miss detection probability, of random multiple access systems with a finite codeword length. Achievable error exponents are obtained by taking the codeword length to infinity.

Optimal Algorithms for Two Group Testing Problems, and New Bounds on Generalized Superimposed Codes

Two variants of the well-known group testing problem are considered. In the first variant a finite set of items O and an unknown subset PsubeO are given, and one wants to identify the set P by asking the least number of questions of the form Is |QcapP|=1?, where QsubeO. This problem naturally arises in the design of efficient contention resolution algorithms for certain random multiple-access communication systems [Berger et al. Random multiple-access communication and group testing, IEEE Trans. Commun., vol. 32, no. 7, pp. 769-779, 1984]. In the second variant of the problem, the answer to the question Is |QcapP|=1? is correctly YES if |QcapP|=1 and NO if |QcapP|=0, and it is left to a (possibly malicious) adversary otherwise. This model was introduced in [Damaschke, Randomized group testing for mutually obscuring defectives, Inf. Process. Lett., vol. 67, pp. 131-135, 1998], in the context of chemical compound testing. In this correspondence several algorithms for these group testing problems are presented, trying to optimize different measures of performance: The overall number of tests performed by the algorithm, the number of stages in which tests can be arranged, and the decoding complexity of identifying the elements of P from tests outcomes. Some of the given algorithms are optimal with respect to more than one of the above criteria. Instrumental to the results presented in the correspondence are new and improved bounds on certain generalization of superimposed codes introduced in [Dyachkov and Rykov, A generalization of superimposed codes and its application to the multiple-access channel, in Proc. 1984 IEEE Int. Symp. Inf. Theory, pp. 62-64], [De Bonis and Vaccaro, Constructions of generalized superimposed codes with applications to group testing and conflict resolution in multiple access channels, Theoretic. Comput. Sci., vol. 306, no. 1-3, pp. 223-243, 2003] a result that it is believed to be of independent interest

Analysis of a Communication Network Governed by an Adaptive Random Multiple Access Protocol in Critical Load

A mathematical model of an adaptive random multiple access communication network is investigated. The value of the network critical load is found; in the critical load, asymptotic probability distributions for states of the information transmission channel and for the number of requests in the source of repeated calls are found. It is proved that distributions of the normalized number of requests belong to the class of normal and exponential distributions, and it is shown how conditional normal distributions pass in the limit to the class of exponential ones.

STABILITY AND PERFORMANCE OF STACK ALGORITHMS FOR RANDOM ACCESS COMMUNICATION MODELED AS A TREE STRUCTURED QBD MARKOV CHAIN

In this paper, we introduce an analytical model to study the stability and the main performance measures of a binary stack algorithm for random multiple access communication. The input traffic is a discrete time Batch Markovian Arrival Process (D-BMAP). The analytical model is nearly exact (one minor approximation is required) and the analysis is based on recent results obtained from tree structured Quasi-Birth-Death (QBD) Markov chains. Apart from studying the stability of the protocol, we are also able to calculate the mean delay and other important performance measures. The method deployed in this paper can also be extended to evaluate other medium access control (MAC) protocols with an underlying stack structure.

Ergodicity of Band Graph Markov Chains and Their Application to Problems of the Analysis of Existence of a Stationary Regime in a Dynamic Random Multiple Access Communication Network

A concept of the class of band graph Markov chains is introduced. Simple ergodicity criteria for this class of stochastic processes are found. We show how these criteria can be applied to prove the existence of a stationary operation regime in a dynamic access communication network with conflict warning.

Analysis of a stack algorithm for random multiple-access communication

An exact analysis is given of the main parameters that characterize the properties of the Capetanakis-Tsybakov-Mikhailov collision resolution algorithm with the free-access (continuous input) protocol. In particular, the distributions of the collision resolution interval, the delay experienced by a packet, and the state of the top level of the stack that is maintained by the algorithm are determined.

Delay analysis of interval-searching contention resolution algorithms

The intelligent design of a random multiple-access communication system involves analyzing the tradeoffs among throughput rate, transmission delay, and stability subject to additional restrictions imposed by distributed processing requirements. Interval-searching contention resolution algorithms have been found to achieve high throughput, and simulations have shown that they also possess short average delay. A general approach to the delay analysis of interval-searching contention resolution is proposed based on solving an integral equation for the distribution of a quantity called the transmission lag. For a certain multibit feedback algorithm, this analytical technique leads to exact determination of the throughput-delay characteristic. For the celebrated 0.487 algorithm, the method yields upper and lower bounds to the curve of expected delay versus throughput that are in close agreement with simulation results.

Random Multiple-Access Communication and Group Testing

We study the application of group testing to the design of efficient algorithms for random multiple-access communication systems. Both direct transmission and reservation systems are considered for various types of channel feedback. We propose and analyze algorithms based on conventional and generalized group testing techniques. The proposed algorithms outperform TDMA and algorithms based on binary tree search and possess certain optimality properties.