Random Multiple Access Algorithm Research Articles

Analyzing and stabilizing multichannel ALOHA with the use of the preamble-based exploration phase

Introduction: Internet of Things devices are actively used within the framework of Massive Machine-Type Communication scenarios. The interaction of devices is carried out by random multiple-access algorithms with limited throughput. To improve throughput one can use orthogonal preambles in the ALOHA-type class of algorithms. Purpose: To analyze ALOHA-based algorithms using the exploration phase and to calculate the characteristics for the algorithm with and without losses with a finite number of channels. Results: We have described a system model that employs random access for data transmission over a common communication channel with the use of orthogonal preambles and exploration phase. We have obtained a formula for numerical calculation of the throughput of an algorithm channel with losses with an infinite number of preambles and a given finite number of channels. The calculation results for several values of the number of independent channels are presented. A modification of the algorithm using the exploration phase and repeated transmissions is proposed and described. The system in question can work without losses. For this system, we have given the analysis of the maximum input throughput up to which the system operates stably. Also, the average delay values for the algorithm that were obtained by simulation modeling are shown. By reducing the number of available preambles, the results obtained can be used as an upper bound on the system throughput. Practical relevance: The results obtained allow to assess the potential for improving the throughput of random multiple-access systems in 6G networks through the application of the exploration phase.

РАСЧЕТ СВОЕВРЕМЕННОСТИ ПЕРЕДАЧИ ЗАПРОСА В РЕЖИМЕ ДВОЙНОГО ИСПОЛЬЗОВАНИЯ КАНАЛА СИГНАЛИЗАЦИИ

Introduction: it is shown that when organizing the collection of short digital messages in a trunking radio communication network, service request communication channels can be used, transmitting packets-requests to establish a connection. With this approach, the question arises about the size of the bandwidth of the request communication channel, allocated for collecting information, at which the fulfillment of the requirements for establishing a connection will be preserved. Purpose: the purpose of the work is to develop a methodology for calculating the timeliness of transmission of requests for establishing a connection in the context of transmission of short digital messages This technique is the basis of the technique for determining the bandwidth of the request communication channel, allocated for solving the problem of collecting short digital messages. Results: A mathematical description of the revealed feature was carried out, which is the scientific novelty of the research results. An analytical rule for calculating the matrix of transition probabilities and the procedure for calculating the vector of initial probabilities of the request transmission process are presented, which allow, based on the Kolmogorov-Chapman equation, to mathematically describe the request transmission process based on the random multiple access algorithm and calculate the probabilistic-temporal characteristics of the request transmission. The method of calculating the probabilistic-temporal characteristics of the request transmission based on the compiled mathematical model of the request transmission and the mathematical model of the operation of the request channel is presented. The effect of taking into account the revealed features is shown, expressed in increasing the timeliness of the request transmission. Practical relevance: Formed a methodology, which is the basis of the methodology for determining the optimal values of the parameters of the double use of the request channel, which makes it possible to organize the transmission of deterministic traffic of short digital messages over the request channel with a given level of timeliness of transmission of requests to establish a connection. Discussion: the use of the developed methodology will allow organizing a periodic collection of short digital messages in the trunking radio access network without using traffic channels.

Lower bound for average delay in unblocked random access algorithm with orthogonal preambles

Introduction: Currently, the first versions of 5G communication standard networks are being deployed and discussions are underway on the further development of cellular networks and the transition to the 6G standard. The work of the currently popular idea of ​​the Internet of Things (IoT) is supposed to be in the framework of a Massive Machine-Type Communications scenario, which has a number of requirements for operation characteristics: very high energy efficiency, relatively low delay and fairly reliable communication. It is assumed that random multiple access procedures are used, since, due to the nature of the traffic, it is impossible to develop a channel resource sharing policy. To increase the efficiency of random access, a class of unblocked algorithms using orthogonal preambles can be used. Purpose: to calculate the lower bound of the average delay for the class of unblocked random multiple access algorithms using orthogonal preambles. Methods: system analysis, a theory of random processes, queuing theory, and simulation. Results: A model of a system with a potentially unlimited number of users who use random unblocked access to transmit data over a common communication channel using orthogonal preambles is proposed. A closed expression is obtained for calculating the lower bound of the average delay in such a system depending on the intensity of the input arrival rate. The limit value of the intensity of the input arrival rate to which the system operates stably is determined. Shown are the results of simulation with respect to the obtained bound. Practical relevance: the obtained boundary allows us to estimate the lower average delay in the described class of algorithms. Its application allows us to determine the possibility of using the considered class of algorithms from the point of view of limitations on the average delay at the stage of designing random multiple access systems.

Review of random multiple access methods for massive machine type communication

Introduction: Intensive research is currently underway in the field of data transmission systems for the Internet of Things in relation to various scenarios of Massive Machine Type Communication. The presence of a large number of devices in such systems necessitates the use the methods of random multiple access to a common communication channel. It is proposed in some works to increase the channel utilization efficiency by the use of error correction coding methods for conflict resolution (Coded Random Access). The vast variety of options for using such communication systems has made it impossible to compare algorithms implementing this approach under the same conditions. This is a problem that restrains the development of both the theory and practice of using error correction code methods for conflict resolution. Purpose: Developing a unified approach to the description of random multiple access algorithms; performing, on the base on this approach, a review and comparative analysis of algorithms in which error correction code methods are used for conflict resolution. Results: A model of a random multiple access system is formulated in the form of a set of assumptions that reflect both the features of various scenarios of Massive Machine Type Communication and the main features of random multiple access algorithms, including Coded Random Access approaches. The system models are classified by the following features: 1) a finite or infinite number of subscribers; 2) stable, unstable or metastable systems; 3) systems with retransmissions or without them; 4) systems with losses or without them. For a lossy system, the main characteristics are Throughput (the proportion of successfully delivered messages) and Packet Loss Rate (probability of a message loss). For a lossless system, the basic characteristics are the algorithm speed and the average delay. A systematic review and comparative analysis of Coded Random Access algorithms have been carried out. The result of the comparative analysis is presented in a visual tabular form. Practical relevance: The proposed model of a random multiple access system can be used as a methodological basis for research and development of random multiple access algorithms for both existing and new scenarios of Massive Machine Type Communication. The systematic results of the review allow us to identify the promising areas of research in the field of data transmission systems for the Internet of Things.

Random multiple access in a vector disjunctive channel

We consider a random multiple access (RMA) procedure in a vector disjunctive channel. We show that exploiting properties of the channel allows one to reduce collision resolution time and thus increase the maximal stable throughput (MST) of RMA algorithms in this channel. We propose an algorithm, belonging to the class of splitting algorithms, which achieves the MST of 0.603.

Estimation of the efficiency of bandwidth request piggybacking to data packets in the wireless network controlled by the IEEE 802.16 protocol

A data transmission process of the centralized wireless network controlled by IEEE 802.16 protocol, in which a set of subscriber stations utilizes the common channel to transmit data to the base station, is discussed. The developed analytical model makes it possible to investigate the efficiency of upstream traffic transmission, including channel reservation using the random multiple access algorithm and packet sending with allowance for bandwidth request piggybacking onto data. The analytical estimates of packet registration and service durations are presented.

Capacity analysis of reservation-based random access for broadband wireless access networks

In this paper we propose a novel model for the capacity analysis on the reservation-based random multiple access system, which can be applied to the medium access control protocol of the emerging WiMax technology. In such a wireless broadband access system, in order to support QoS, the channel time is divided into consecutive frames, where each frame consists of some consequent mini-slots for the transmission of requests, used for the bandwidth reservation, and consequent slots for the actual data packet transmission. Three main outcomes are obtained: first, the upper and lower bounds of the capacity are derived for the considered system. Second, we found through the mathematical analysis that the transmission rate of reservation-based multiple access protocol is maximized, when the ratio between the number of mini-slots and that of the slots per frame is equal to the reciprocal of the random multiple access algorithm's transmission rate. Third, in the case of WiMax networks with a large number of subscribers, our analysis takes into account both the capacity and the mean packet delay criteria and suggests to keep such a ratio constant and independent of application-level data traffic arrival rate.

One stochastic process and its application to multiple access in supercritical region

A discrete-argument stochastic process is presented. The process is a generalization of the Cinlar (1975) semiregenerative process and process /spl eta/(t) given in Tsybakov (1993). For this process, the theorem, which is similar to the Smith regenerative process theorem, is given. We use this theorem to find the transmission rate and mean packet delay for stack and part-and-try random multiple access algorithms in their supercritical regions. For the part-and-try algorithm, the results are new. For the stack algorithm, we give a new method of finding the rate and delay.

A robust random multiple-access algorithm for packet transmissions over noisy channels with error memory

In this paper, a noisy slotted channel is considered. It is assumed that channel feedback might be misinterpreted due to the existence of noise on the channel. Furthermore, this disturbance is dependent on the channel state (either good or bad) which varies from slot to slot according to a Markov chain. Consequently, the occurrence of the a channel feedback error is dependent on previous occurrences of errors (i.e., with error memory). Under this assumption, the throughput performance of a random multiple-access algorithm, called the Two-Cell algorithm, is analyzed and the results are compared with the throughputs of the Capetanakis (1979) tree-splitting algorithm operating over the same channels. It is shown that the Two-Cell algorithm retains positive throughputs for all possible values of channel state parameters, and for all practical purposes, it outperforms the Capetanakis algorithm in terms of insensitivity to channel feedback errors. >

A Method for the Delay Analysis of Random Multiple-Access Algorithms Whose Delay Process is Regenerative

Random multiple-access algorithms are used to control the accessing of a common communication channel by a large population of bursty channel users. For such algorithms, the induced transmission delay is a key performance measure. A systematic method for finding the delay characteristics of random multiple-access algorithms, whose delay process is regenerative, is presented. The method uses a powerful result from the theory of regenerative processes, in effect, to reduce the problem of determining the delay moments to the problem of solving denumerable dimensional systems of linear equations. Techniques for finding tight bounds on the solutions of such systems are presented. The "0.487" algorithm is used to exemplify the method.

Survey of USSR contributions to random multiple-access communications

A survey is presented of most of the principal results on random multiple-access (RMA) theory obtained in the USSR up to the end of 1983. Relevant background material is provided on the various RMA algorithms discussed.