Sense Multiple Access Protocol Research Articles

Analysis of the Influence of Self-Similar Traffic on Efficiency Multiple Access Protocols

Introduction. Traffic in modern telecommunication radio networks is self-similar, therefore, the use of methods for calculating the parameters of Carrier Sense Multiple Access (CSMA) protocols adopted in the classical theory of teletraffic, based on Poisson distribution models, leads to an underestimation of the load and stability of these protocols. Purpose. Build a mathematical model for the operation of synchronous CSMA protocols with flexible and rigid strategies in conditions of self-shaped traffic. Obtain average transmission rate equations and their comparative analysis of the results of studies of the same protocols for traffic with the Poisson distribution. Methods. The goal is achieved by creating and analyzing a mathematical model for the operation of synchronous CSMA protocols with flexible and rigid strategies under conditions of Pareto-distributing traffic. The model is described by the equations of the average protocol transfer rate, which are a function of traffic intensity and Pareto distribution parameters. Results. It has been proven that self-similar traffic has a significant impact on the stability limit of CSMA protocols and their throughput, which must be taken into account when using these protocols in radio networks with long-term dependence on traffic distribution. At the same time, there is a slight decrease in the maximum average transmission rate of CSMA protocols compared to the traffic model with the Poisson distribution. Conclusions. The proposed mathematical model of CSMA protocols with flexible and rigid strategies makes it possible to calculate the real values of the average speed, stability limit, and throughput of these protocols under conditions of self-similar traffic.

Implementation of Persistent Relay Carrier Sensing Multiple Access Cooperative Communication Protocol for Ad Hoc Network

With the increasing demand for network coverage and congestion-free network traffic, cooperative communication is getting more and more attention from network researchers. Cooperation communication is explored in a number of ways. Such various techniques are studied and one method is discussed in this paper. PRCSMA- Persistent Relay Carrier Sense Multiple Access Protocol is a very efficient protocol that gives good results for cooperative communication. This protocol is implemented using NS2 (Network Simulator). Its analysis is carried out in this paper. This will be useful to compare the advantages of cooperative communication over regular wireless communication.

Optimizing Job Reliability Through Contention-Free, Distributed Checkpoint Scheduling

A datacenter that consists of hundreds or thousands of servers can provide virtualized environments to a large number of cloud applications and jobs that value the requirement of reliability very differently. Checkpointing a virtual machine (VM) is a proven technique to improve reliability. However, existing checkpoint scheduling techniques for enhancing reliability of distributed systems fails to achieve satisfactory results, either because they tend to offer the same, fixed reliability to all jobs, or because their solutions are tied up to specific applications and rely on centralized checkpoint control mechanisms. In this work, we first show that reliability can be significantly improved through contention-free scheduling of checkpoints. Then, inspired by the Carrier Sense Multiple Access (CSMA) protocol in wireless congestion control, we propose a novel framework for distributed and contention-free scheduling of VM checkpointing to provide reliability as a transparent, elastic service. We quantify reliability in closed form by studying system stationary behaviours, and maximize job reliability through utility optimization. Our design is validated via a proof-of-concept prototype that leverages readily available implementations in Xen hypervisors. The proposed checkpoint scheduling is shown to significantly reduce checkpointing interference and improve reliability by as much as one order of magnitude over contention-oblivious checkpoint schemes.

Machine Learning for Medium Access Control Protocol Recognition in Communications Networks

The ability to recognize the medium access control protocol employed by a network can facilitate the incorporation of a cognitive radio into an existing network by elucidating an integral aspect of network behavior. Since the way in which users access the electromagnetic spectrum is one of the most prominent distinctions between reservation based and contention based medium access control protocols, the first part of this work exploits the regular timing of transmissions from networks utilizing reservation based time-division multiple access (TDMA) protocols to differentiate between transmissions governed by TDMA and by contention based carrier sense multiple access (CSMA) protocols. Our approach leverages modular arithmetic to identify periodicity in transmission timings and an unsupervised $k$ -means algorithm to generate distinct TDMA and CSMA clusters. Several supervised machine learning algorithms are explored to build a protocol classifier. We then present a method of distinguishing between transmissions from multi-channel frequency division multiple access (FDMA) based networks and single channel networks. This method uses an automated machine learning clustering algorithm to obtain an estimate of the actual center frequencies of channels utilized by a network. Such information can be used to determine whether the network is employing an FDMA protocol to access the electromagnetic spectrum.

Priority-Mobility Aware Clustering Routing Algorithm for Lifetime Improvement of Dynamic Wireless Sensor Network

Wireless sensor network with mobility is rapidly evolving and increasing in the recent decade. The cluster and hierarchical routing strategy demonstrates major changes in the lifespan of the network and the scalability. The latency, average energy consumption, packet distribution ratio is highly impacted due to a lack of coordination between cluster head and extreme mobile network nodes. Overall efficiency of highly mobile wireless sensor network is reduced by current techniques such as mobility-conscious media access control, sleep/wakeup scheduling and transmission of real-time services in wireless sensor network. This paper proposes a novel Priority-Mobility Aware Clustering Routing algorithm (p-MACRON) for high delivery of packets by assigning fair weightage to each and every packet of node. To automatically decide the scheduling policy, reinforcement learning approach is integrated. The mixed approach of priority and self-learning results into better utilization of energy. The experimental result shows comparisons of slotted sense multiple access protocol, AODV, MEMAC and P-MACRON, in which proposed algorithm delivered better results in terms of interval, packet size and simulation time.

OAM-Based Hybrid-Duplex Cognitive Frequency Hopping

In cognitive radio networks, the jamming attacks, which have the same ability with secondary users (SUs) but access the licensed channels without considering the carrier sense multiple access protocol, can disguise a primary user (PU) or SU to occupy the licensed channels, thus resulting in failing to access the licensed channels for PUs and SUs. Employing full/half duplex cognitive frequency hopping (CFH), where users sense the occupancy of licensed channels and then dynamically adjust the hopping parameters, can mitigate the hostile jamming. However, due to the explosive growth of serves and data traffic, it is very difficult to significantly increase the anti-jamming results and achieve high capacities with full/half duplex CFH for both PUs and SUs in cognitive radio networks. To achieve efficient anti-jamming and high capacities for PUs and SUs, in this paper we propose the orbital angular momentum (OAM)-based hybrid-duplex CFH scheme, which jointly uses the half-duplex cooperative sensing and full-duplex transmission modes for PUs and SUs in cognitive radio networks. Using the OAM-based hybrid-duplex CFH scheme, PUs and SUs can identify the occupancy of licensed channels with half-duplex fashion, thus significantly reducing the probability of signals jammed. Then, based on the sensing results, the signals are allowed to be transmitted and received by the same time-slots, carrier frequencies, and OAM-modes. The average capacities of PUs and SUs are derived, respectively. Extensively numerical results show that our proposed OAM-based hybrid-duplex CFH scheme can significantly increase the capacities of PUs and SUs in cognitive radio networks under hostile jamming attacks.

Hardware implementation and performance analysis of MPTD‐CSMA protocol based on field‐programmable gate array in VANET

Contention-based carrier sense multiple access (CSMA) and contention-free time division multiple access (TDMA) protocol are two typical access protocols of media access control in vehicular ad hoc network (VANET). They all show their unique advantages under specific conditions. TDMA has high transmission reliability, CSMA has a low transmission delay in the communication environment with low packet arrival rate. However, when the arrival rate of information packets increases rapidly, the throughput of CSMA will decrease rapidly and approach zero, which is not suitable for data transmission in the communication environment with a high arrival rate of information packets; while data transmission through a single TDMA protocol will cause high system overhead due to strict synchronous information. Aiming at the defects of the two protocols and the multi-channel communication environment, this study proposes the optimised protocol model multi-priority time division-CSMA (MPTD-CSMA). The optimised protocol model not only ensures the reliability of data communication but also reduces the transmission delay of the system. At the same time, the multi-priority mechanism is added to increase the channel utilisation of the protocol model.

High-Performance Long Range-Based Medium Access Control Layer Protocol

Long Range (LoRa) has become one of the most promising physical layer technologies for the Internet of Things (IoT) ecosystem. Although it manifests low-power consumption and long-distance communication, LoRa encounters a large number of collisions in the IoT environment, which severely affects the system’s throughput and delay performance. In this paper, a code division carrier sense multiple access (CD/CSMA) protocol that resolves the traditional channel collision problem and implements multi-channel transmission is proposed for the LoRa medium access control (MAC) layer. To reduce data transmission delay and maximize the throughput of the system, the adaptive p-persistent CSMA protocol divides the channel load into four states and dynamically adjusts the data transmission probability. Then, to reduce channel collisions significantly, the code division multiple access (CDMA) protocol is performed on different channel states. Moreover, the combination of the proposed adaptive p-persistent CSMA protocol and the CDMA successfully reduces the number of data retransmissions and makes LoRa more stable. The simulation results demonstrate that the proposed adaptive p-persistent CD/CSMA protocol can achieve near-optimal and occasionally even better performance than some conventional MAC protocols, especially in a heavy load channel.

H ∞ filtering for multi‐rate multi‐sensor systems with randomly occurring sensor saturations under the p ‐persistent CSMA protocol

In this study, the $H_{\infty }$H∞ filtering problem is studied for a class of discrete networked multi-rate multi-sensor systems with randomly occurring sensor saturations under the p-persistent carrier sense multiple access (CSMA) protocol. A set of mutually independent Bernoulli distributed white sequences is introduced to characterise the random occurrence of the sensor saturations. The p-persistent CSMA protocol is employed to decide which sensor is allowed to transmit its measurement to the filter at a certain time instant. By using the lifting technique, the multi-rate system is converted to a single-rate one for convenient analysis. The main purpose of the addressed problem is to design an $H_{\infty }$H∞ filter such that the filtering error dynamics is exponentially mean-square stable and the $H_{\infty }$H∞ performance requirement is satisfied simultaneously. Sufficient conditions are established on the existence of the desired $H_{\infty }$H∞ filters and the corresponding filter gains are then characterised by resorting to the feasibility of certain matrix inequalities. Finally, a numerical example is given to illustrate the effectiveness of the proposed filtering scheme.

A two-channel slotted sense multiple access protocol for timely and reliable data transmission in industrial wireless sensor networks

In designing a real-time MAC protocol for wireless sensor networks, it is desirable to shorten the data acquisition cycle time to satisfy more applications with a tighter time constraint in data collection. To achieve this, one often tries to improve throughput by employing a slot reuse technique. Meanwhile, the slotted sense multiple access protocol that uses a sharable slot was proven to be advantageous for timely and reliable data delivery. However, since the nodes at lower tree levels process more packets or bigger packets with data aggregation, they need a bigger sharable slot. Thus, it is not easy to employ a slot reuse technique due to the size variation of sharable slots. To tackle this problem, we try to reduce the size of an aggregated packet by limiting the number of packets for aggregation using two channels. If every node is allowed to send a single packet during data acquisition cycle time, an equal-sized sharable slot can be allocated to every tree level. It is shown that the proposed approach can reduce data acquisition cycle time significantly while maintaining good reliability in data transmission compared with slotted sense multiple access and also reduce energy consumption greatly compared with another multi-channel MAC protocol.

Parameters of the Сarrier Sense Multiple Access Protocol with Conflicts Resolving at the Physical Layer

At present, the global growth of communication needs makes us more efficient in using of the frequency spectrum. The development of communication systems requires an increase of throughputs, but the frequency spectrum is limited, which will not allow to increase the channel width or the number of channels. Assuming that at one frequency there is an opportunity to transmit several mutual interference signals at one time, the problem of the separation of these signals arises. But, complexity of demodulation procedures has significantly increased compared to the classical. It is necessary, therefore, to determine whether this complexity increasing will be justified. To answer this question, it is necessary to find out how the throughput of the random multiple access system increases, where the frequency resource multiple reusing is possible. For research was chosen the carrier sense multiple access protocol, which have become widespread in packet networks for their successful combination of relative simplicity of access algorithms and fairly high efficiency. The purpose of the research is to determine the main characteristics of the various carrier sense multiple access protocols with collision detection and with additional assumption about conflicts resolving at the physical layer. The parameters of the carrier sense multiple access protocols with collision detection and with additional assumption about conflicts resolving at the physical layer are obtained. It is shown that in comparison with the classical protocol, the assumption about paired conflicts resolving at the physical layer gives the significant increasing of the throughput in the communication systems with such access protocols. The comparison results are given. The obtained results allow to confirm the expediency of implementation in demodulators of the perspective receiving devices algorithms of conflicts resolving at the physical layer as being characterized by relatively small complexity.

Distributed Energy Efficient Channel Allocation

Design of energy efficient protocols for modern wireless systems has become an important area of research. In this paper, we propose a distributed optimization algorithm for the channel assignment problem for multiple interfering transceiver pairs that cannot communicate with each other. We first modify the auction algorithm for maximal energy efficiency and show that the problem can be solved without explicit message passing using the carrier sense multiple access (CSMA) protocol. We then develop a novel scheme by converting the channel assignment problem into perfect matchings on bipartite graphs. The proposed scheme improves the energy efficiency and does not require any explicit message passing or a shared memory between the users. We derive bounds on the convergence rate and show that the proposed algorithm converges faster than the distributed auction algorithm and achieves near-optimal performance under Rayleigh fading channels. We also present an asymptotic performance analysis of the fast matching algorithm for energy efficient resource allocation and prove the optimality for a large enough number of users and number of channels. Finally, we provide numerical assessments that confirm the faster convergence of the proposed algorithm compared to the distributed auction algorithm.

Design of Dual Priority Persistent CSMA Protocol Based on FPGA

In order to study the MAC layer protocol in the wireless sensor network under the actual channel condition, the field programmable gate array (FPGA) hardware circuit is used to provide a dual-priority implementation scheme for the persistence carrier sense multiple access (CSMA) protocol. According to the characteristics of each node in the network, analyzes the system throughput and energy consumption, and the FPGA is used to overcome the shortcomings of the existing implementation scheme and the article combines the actual application, changes the single channel mode, and realizes the dual channel data transmission. Finally, the simulation tests the correctness of the design.

To overlap or not to overlap: Enabling channel bonding in high-density WLANs

Wireless local area networks (WLANs) are the most popular kind of wireless Internet connection because of their simplicity of deployment and operation. As a result, the number of devices accessing the Internet through WLANs such as laptops, smartphones, or wearables, is increasing drastically at the same time that applications’ throughput requirements do. To cope with these challenges, channel bonding (CB) techniques are used for enabling higher data rates by transmitting in wider channels, thus increasing spectrum efficiency. However, important issues like higher potential co-channel and adjacent channel interference arise when bonding channels. This may harm the performance of the carrier sense multiple access (CSMA) protocol because of recurrent backoff freezing, while making nodes more sensitive to hidden node effects. In this paper, we address the following point at issue: is it convenient for high-density (HD) WLANs to use wider channels and potentially overlap in the spectrum? First, we highlight key aspects of DCB in toy scenarios through a continuous time Markov network (CTMN) model. Then, by means of extensive simulations covering a wide range of traffic loads and access point (AP) densities, we show that dynamic channel bonding (DCB) – which adapts the channel bandwidth on a per-packet transmission – significantly outperforms traditional single-channel on average. Nevertheless, results also corroborate that DCB is more prone to generate unfair situations where WLANs may starve. Contrary to most of the current thoughts pushing towards non-overlapping channels in HD deployments, we highlight the benefits of allocating channels as wider as possible to WLANs altogether with implementing adaptive access policies to cope with the unfairness situations that may appear.

SSCSMA-based random relay selection scheme for large-scale relay networks

Effective relay selection is a way to achieve considerable performance gains in cooperative communication. However, in practice, the best relay may not always be selected due to the difficulty in collecting accurate network information when the network scale is very large or when the channel information is time-varying. In this paper, we propose a suboptimal relay selection scheme where the only information available to the source is the destination location. The proposed scheme consists of three phases. During the first phase, the area of relay selection is narrowed down based on the outage probability and target transmission rate. In the second phase, a node within this region is selected using the Successive Slotted Carrier Sense Multiple Access (SSCSMA) protocol. In the third and last phase, data is transmitted from the source via the relay to the destination. We present a detailed analysis of the transmission rate and the outage probability. Simulation results have shown that our method using SSCSMA outperforms Random Access based Blind Relay Selection (RABRS) in terms of transmission rate. The results have also indicated that both the outage probability constraint and the source-destination distance affect the transmission rate.

A Hybrid TDMA/CSMA-Based Wireless Sensor and Data Transmission Network for ORS Intra-Microsatellite Applications.

To achieve launch-on-demand for Operationally Responsive Space (ORS) missions, in this article, an intra-satellite wireless network (ISWN) is presented. It provides a wireless and modularized scheme for intra-spacecraft sensing and data buses. By removing the wired data bus, the commercial off-the-shelf (COTS) based wireless modular architecture will reduce both the volume and weight of the satellite platform, thus achieving rapid design and cost savings in development and launching. Based on the on-orbit data demand analysis, a hybrid time division multiple access/carrier sense multiple access (TDMA/CSMA) protocol is proposed. It includes an improved clear channel assessment (CCA) mechanism and a traffic adaptive slot allocation method. To analyze the access process, a Markov model is constructed. Then a detailed calculation is given in which the unsaturated cases are considered. Through simulations, the proposed protocol is proved to commendably satisfy the demands and performs better than existing schemes. It helps to build a full-wireless satellite instead of the current wired ones, and will contribute to provide dynamic space capabilities for ORS missions.

A Slotted Sense Multiple Access Protocol for Timely and Reliable Data Transmission in Dynamic Wireless Sensor Networks

A wireless medium access control protocol that uses a topology-dependent slot schedule is vulnerable to link failures. This becomes severer in industrial fields due to node mobility and various obstructions unfriendly to wireless communication. The proposed protocol allocates a big sharable slot (SS) to each tree level, producing a topology-independent schedule that makes the protocol highly responsive to the changes of topology. Then, the nodes at the same level use carrier sense multiple access (CSMA)/CA for data transmission and channel hopping to cope with the varying condition of a channel. The use of CSMA/CA and channel hoping makes data transmission reliable against internal and external interferences. Another feature is that every node gets its SS using a slot generation function independently of other nodes. Simulations and experiments verify that the proposed protocol achieves good performance in terms of packet delivery ratio and energy efficiency against the variation of multipath fading, various external sources of interference, and node mobility.

A Sensor Redeployment Algorithm Based on Virtual Forces for Underwater Sensor Networks

Practical underwater sensor networks redeployment algorithm needs to fully consider limited node resources, node move time and other characteristics in real environment. A Redeployment based on virtual forces (RBVF) algorithm is proposed. The non-persistent carrier sense multiple access protocol is introduced to solve communication conflicts between nodes during redeployment process. Based on existing study on three-dimensional space node deployment, the threshold value is determined to divide the attractive and repulsion forces. The speed of the node is considered. Simulation results indicate that the RBVF algorithm can achieve better coverage and less total move distance when moving nodes are not considered in virtual forces calculation. Water flow force is introduced, and a Virtual forces redeployment based on energy consuming (VFRBEC) algorithm is proposed, where different energy consumptions in different directions are used to modify node displacement. Simulation results indicate that the VFRBEC algorithmcan achieve the same coverage performance with the RBVF algorithm with less energy and is better than the redeployment based on combined virtual forces algorithm in terms of both coverage and energy consumption performances.

Performance Comparison of RIPv2 and DSR Protocols in Customized Zigbee Stack with 5 Nodes and 1HOP

Wireless sensor network (WSN) is a collection of different sensor nodes communicating with each other in a mesh network to improve reliability and prevent link failures. WSN is suffering with scarcity of resources like memory, data rates, throughput and others. WSN integrated with IP can lead to many applications and enables any electronic device to access different networks and use the commonly shared resources. IP stack is not suitable to be ported into the memory of WSN node as it occupies more memory and causes more overhead to WSN. In order to realise such a challenging concept, an experiment is carried out such that a new stack is proposed with middleware, by incorporating different protocol sets in network layer and medium access control (MAC) layers of Zigbee stack. Routing Information Protocol (RIP) and Dynamic Source Routing (DSR) protocols are ported in the network layer of Zigbee stack and Carrier Sense Multiple Access (CSMA) protocol ported in the MAC layer of Zigbee stack while keeping the other layers of the Zigbee stack unchanged. Experimentation results of RIP–CSMA and DSR–CSMA protocol sets are compared and published in this paper.

Constructing an optimally balanced tree to maximize data throughput with multiple channels

It is critical to improve throughput in real-time wireless sensor networks in order to reduce delay in data gathering and satisfy more real-time applications with tighter deadlines. One approach to achieving this is to construct a tree, such that the sizes of sub-trees of a root are well balanced, and to then assign a unique channel to each sub-tree. However, it is not easy to construct a balanced tree, because each node has to know the current connectivity status of other nodes in the network, which is not reasonable due to the increase in control overhead. We prove that building an optimal balanced tree is NP-Complete. Thus, we devise a heuristic algorithm to efficiently construct a balanced tree that is almost comparable to an optimally balanced tree. Furthermore, we suggest a way that each sub-tree is constructed to increase parallel transmission within itself. We apply the slotted sense multiple access (SSMA) protocol to each sub-tree, and evaluate the new approach with SSMA using a single channel and multi-channel lightweight medium access control. According to simulation results, SSMA using a balanced tree significantly outperforms other protocols in terms of packet delivery ratio and energy consumption.