Persistent Carrier Sense Multiple Access Research Articles

Generalized $p$ -Persistent CSMA for Asynchronous Multiple-Packet Reception

This paper considers a multiple-access system with multiple-packet reception (MPR) capability $\gamma $ , i.e., a packet can be successfully received as long as it overlaps with $\gamma -1$ or fewer other packets at any instant during its lifetime. To efficiently utilize the MPR capability, this paper generalizes $p$ -persistent carrier-sense multiple access (CSMA) to consider that a user with carrier sensing capability $c$ adopts the transmission probability $p_{n}$ if this user has sensed $n$ ongoing transmissions for $n=0,1,\ldots ,c-1$ . This paper aims to model the characteristics of such CSMA and to design transmission probabilities for achieving maximum saturation throughput. To this end, we first formulate such CSMA as a parameterized Markov decision process (MDP) and use the long-run average performance to evaluate the saturation throughput. Second, by observing that the exact values of optimal transmission probabilities are in general infeasible to find, we modify this MDP to establish an upper bound on the maximum throughput, and modify this MDP again to propose a heuristic design with near-optimal performance. Simulations with respect to a wide range of configurations are provided to validate our study. The throughput performance under more general models and the robustness of our design are also investigated.

Implementation and performance analysis of random multiple access protocol with variable collision length of multimedia video information

In recent years, multimedia video services have developed rapidly. However, the increasing number and variety of videos is likely to cause packet loss and delay during video transmission. Therefore, how to use channel resources more effectively becomes an urgent problem to be solved. This paper improves the existing random multiple access protocol and designs the 1-persistent CSMA (Carrier Sense Multiple Access) protocol with variable collision length. At the same time, considering the different requirements of different video services, multi-priority 1-persistent CSMA random multiple access control protocol with variable collision length is proposed, which sets different priorities and then competes fairly. Finally, the paper analyzes the performance of the multimedia video service access algorithm: the 1-persistent CSMA access protocol with variable collision length is higher than the traditional 1-persistent CSMA throughput, the performance is better, at the same time, in the case of a relatively high arrival rate, the advantage of throughput is more obvious.

Hardware Circuit Implementation and Performance Analysis of Three-Slot NP-CSMA

The development of wireless communication technology has become increasingly important in the communications industry. How to allocate limited channel resources reasonably and reliably to each competing user is a problem that the access protocol of the MAC (Multiple Access Control) layer needs to solve. As an important way of random access, NP-CSMA (Non Persistent Carrier Sense Multiple Access) has a higher network throughput rate when the arrival rate is higher. This paper analyzes and improves the implemented NP-CSMA model, and obtains a three-slot NP-CSMA model. The mathematical tool MATLAB is used to analyze the network throughput, delay and energy efficiency of the model, and compare several random multiple access protocols adheres to the network throughput, they are NP-CSMA, Three-slot NP-CSMA, 1-persistent CSMA, P-persistent CSMA, and concludes that the three-slot NP-CSMA is significantly letter than several other multiple access protocols. Finally, using Quartus to design the three-slot NP-CSMA circuit, the statistical value of the circuit system is compared with the theoretical value of the model, and the error is less than 0.01, which proves that the system is reasonable in design and can be applied to wireless communication networks.

State Estimation for Communication-Based Train Control Systems With CSMA Protocol

Train positioning is of critical importance for communication-based train control (CBTC) systems. The objective of this paper is to provide an algorithm to generate the precise estimates of the train position and velocity for CBTC systems with carrier-sense multiple access (CSMA) protocol scheduling, thereby improving the accuracy of train positioning as well as the availability of CBTC systems. First, the dynamics of a train with $N$ cars linked by couplers is described based on Newton’s motion equations. Then, the transmission model reflecting the behaviors of $p$ -persistent CSMA protocol is presented by using a Bernoulli distributed sequence whose probability distribution is dependent on the number of trains sharing with one communication channel [i.e., $N(k)$ ]. Furthermore, the value of $N(k)$ is assumed to be unknown but bounded by two known positive integers. The purpose of the problem addressed is to design an estimator, such that the estimation error is exponentially ultimately bounded (with a certain asymptotic upper bound) in mean square subject to the external resistive force. By utilizing the stochastic analysis approach, sufficient conditions are established to guarantee the ultimate boundedness of the estimation error in mean square. For the purpose of designing the desired estimator gains under different requirements (e.g., smallest ultimate bound and fastest decay rate), two optimization problems are solved in terms of linear matrix inequalities. Finally, a simulation example is given to illustrate the effectiveness of the estimator design scheme.

Efficient LTE/Wi-Fi Coexistence in Unlicensed Spectrum Using Virtual Network Entity: Optimization and Performance Analysis

Long-term evolution (LTE) operation in the unlicensed spectrum is a promising solution to address the scarcity of licensed spectrum for cellular networks. Although this approach brings higher capacity for LTE networks, the Wi-Fi performance operating in this band can be significantly degraded. To address this issue, we consider a coordinated structure, in which both networks are controlled by a higher level network entity. In such a model, LTE users can transmit in the assigned time-slots, while Wi-Fi users can compete with each other by using $p$ -persistent carrier sense multiple access (CSMA) in their exclusive time-share. In an unsaturated network, at each duty cycle, the time-division multiple access (TDMA) scheduling for LTE users and $p$ values for Wi-Fi users should be efficiently updated by the central controller. The corresponding optimization problem is formulated and an iterative algorithm is developed to find the optimal solution using complementary geometric programming and monomial approximations. Aiming to address the quality-of-service assurance for LTE users, an upper bound for average delay of these users is obtained. This analysis could be a basis for the admission control of LTE users in unlicensed bands. The simulation results reveal the performance gains of the proposed algorithm in preserving the Wi-Fi throughput requirement.

Protocol Sequences With Carrier Sensing for Wireless Sensor Networks

Protocol sequences are deterministic binary sequences of a common period, which enjoy some special Hamming cross-correlation property by design. In contrast to random or contention-based medium access control schemes, a protocol sequence-based scheme can serve to provide at least a certain number of contention-free packet transmissions within a bounded delay for each asynchronous user in a feedback-free multiple access system. However, all protocol sequence-based schemes in the literature require that all sequence entries are mapped to slots with the same time duration, which produces a relatively low channel utilization. To overcome this inefficiency that is undesirable in delay-constrained wireless sensor networks, building on the idea of combining sequence-based access and carrier sensing, this paper proposes a new protocol sequence-based scheme, called the PS-CS. We derive the theoretical average throughput, average access delay, worst-case delay, and average energy consumption of the PS-CS. It is shown that the PS-CS produces average throughput close to the optimal capacity of ${p}$ -persistent carrier sense multiple access (CSMA), and enjoys smaller access delay than the optimal ${p}$ -persistent CSMA. In addition, we study the energy-delay tradeoff, impact of carrier sensing fault and channel error, and how to modify the PS-CS to support real-time downlink for feedback control.

Stability Region of $p$ -Persistent CSMA Systems

This letter investigates the stability region of $p$ -persistent carrier sense multiple access systems with $N$ users, where each user has an unlimited length of queue, its own arrival rate, and (re)transmission probability. To do this, we apply Foster–Lyapunov stability theorem and show the necessary and sufficient condition of the system stability in terms of the existence of queue-stabilizing (re)transmission probability. Then, using a multiobjective optimization problem, we characterize the boundary of the stability region.

Analysis of carrier sense multiple access protocols for channels supporting multi‐packet reception

Exact throughput analysis of unslotted carrier sense multiple access (CSMA) protocols for channels supporting multi-packet reception (MPR) is carried out. The protocols considered include (i) non-persistent and (ii) 1-persistent CSMA. An adaptive non-persistent CSMA protocol for channels supporting MPR has been proposed and evaluated. A Markov chain model with states representing the transmission period of the 1-persistent CSMA is used in the analysis. Analytical results are validated using simulation. The authors show that for CSMA protocols supporting MPR the throughput is crucially dependent on the carrier sensing delay.

Stability Analysis of <inline-formula> <tex-math notation="TeX">$p$</tex-math></inline-formula>-Persistent Slotted CSMA Systems With Finite Population

When multiple users are communicating with an access point based on a random access, the stability region is known as all possible combinations of the mean packet arrival rates to keep their queue lengths bounded. This paper investigates the stability region of $p$ -persistent carrier sense multiple access (CSMA) systems, where two users have different mean packet arrival rates and (re)transmission probabilities. We then extend our results to $p$ -persistent CSMA systems with $N$ users and discuss applicability of our results to IEEE 802.11 systems with the basic and request-to-send/clear-to-send access mechanisms. In numerical studies, we show the stability region by varying system parameters such as packet arrival rates, (re)transmission probabilities, and radio channel errors, and how the stability region of $p$ -persistent CSMA systems gets close to that of a time-sharing system.

Impact of Interfering Bluetooth Piconets on a Collocated $p$-Persistent CSMA-Based WLAN

In this paper, the effect of cochanneled Bluetooth (BT) piconets on a carrier-sense multiple-access (CSMA)-based wireless local area network (WLAN) is investigated. Specifically, the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -persistent CSMA protocol is considered for WLANs, and the probability of error of a WLAN packet is calculated in the presence of interfering BT packets of different lengths and variable piconet traffic loads and as a function of the BT's frequency-hopping guard time. The probability derivation is then used in conjunction with the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -persistent CSMA throughput and delay formulations to examine its net performance in the presence of BT interference. Simulations have been used to corroborate the analytical results, which indicate that the presence of just one fully loaded interfering BT piconet reduces the peak CSMA throughput by 42%. Furthermore, we show that under fully loaded BT traffic conditions, the effect of more shorter BT packet transmissions on the CSMA delay performance can outweigh the interference impact of a higher number of BT piconets with longer packet transmissions.

Unslotted 1- and p/sub i/-persistent CSMA-CD protocols for fiber optic bus networks

Analyzes the performance of the unslotted 1-persistent carrier sense multiple access with collision detection (CSMA-CD) protocol for fiber optic bus networks with a finite number of stations M, each of which has an infinite storage buffer for storing packets with its length fixed or exponentially distributed. Treating the bus network as an M-class priority queueing system with a preemptive repeat-identical retransmission strategy, the authors show numerically that this 1-persistent retransmission strategy provides better delay-throughput performance than the non-persistent one. To satisfy the fairness of equal delays among stations in the bus network, the authors next present the unslotted p/sub i/-persistent CSMA-CD protocol. Under this protocol, the first packet arriving at station i is forced to enter into the backoff procedure with the probability of (1/spl minus/p/sub i/). After backoffs, transmission begins until the station becomes empty. The authors determine the persistent probability p/sub i/ and show that the delay-throughput performance of the p/sub i/-persistent strategy is better than that of the 1-persistent one, and further it is robust for any packet lengths. Simulation results are presented to verify the analytical results.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Unslotted CSMA-CD protocols with combined retransmission strategy for fiber optic bus and ring networks

We present an unslotted 1-persistent carrier sense multiple access with collision detection (CSMA-CD) protocol with the combined preemptive-resume/-repeat-identical retransmission strategy for fiber optic bus and ring networks. Under this protocol, if the information field of a packet is preempted by upstream packets, its remaining portion is retransmitted with the identical header. However, when the header field of a packet is preempted, the packet is retransmitted from its beginning. Treating the bus and ring networks with M stations as an M -class priority queueing system and a two-class priority queueing system with the combined retransmision strategy, respectively, we show numerically that this protocol provides better delay-throughout performance than the unslotted CSMA-CD protocol in both networks, and it solves the instability problem of the unslotted CSMA-CD protocol in the ring network. To satisfy the fairness of equal delays among stations in the bus network, we next present the unslotted p i -persistent CSMA-CD protocol with the combined retransmision strategy, and determine the persistent probability p i and its delay performance. Simulation results are present to verify the analytical results.

1-persistent carrier sense multiple access in radio channels with imperfect carrier sensing

A comprehensive analysis of a 1-persistent carrier-sense multi-access (CSMA) system using a radio channel with imperfect carrier sensing is presented and discussed. It is shown that a careful optimization of the channel state detector parameters must be performed in order to get good system performance. If the threshold of the detector is too high, the system will tend to behave like an unslotted ALOHA; if the threshold is too low, the system throughput will be zero. It is also shown that for the larger average packet rate G the system throughput is decreased. This is because for the same probability of correct channel sensing, the probability of incorrect transmissions from the waiting mode is increased.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Queueing Analysis For Buffered Persistent Csma Local Networks

We develop a joint probability generating function for the message queue lengths in a slotted persistent CSMA (Carrier-Sense Multiple-Access) system with afinitepopulation of buffered users. Each user is assumed to have an independent and identical process of packet generation and an infinite buffer for storing outstanding packets. A closed form formula is obtained for the generating function in case of a two user system.

Throughput Analysis for Persistent CSMA Systems

The channel throughput for a finite number of packet broadcasting users is analyzed for random access protocols, including slotted persistent carrier sense multiple access (CSMA) with and without collision detection and unslotted persistent CSMA with and without collision detection. We consider both <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</tex> - and 1-persistent CSMA. Our results can be extended to infinite population cases (by taking the proper limit), where they agree with the known throughput expressions when available.