scholarly journals Highly Reliable MAC Protocol Based on Associative Acknowledgement for Vehicular Network

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 382
Author(s):  
Odilbek Urmonov ◽  
HyungWon Kim
Keyword(s):  
Multiple Access ◽  
Mac Protocol ◽  
High Reliability ◽  
Medium Access ◽  
Safety Message ◽  
Hidden Terminal ◽  
Channel Resource ◽  
Multiple Vehicles ◽  
Average Transmission ◽  
Short Time

IEEE 1609/802.11p standard obligates each vehicle to broadcast a periodic basic safety message (BSM). The BSM message comprises a positional and kinematic information of a transmitting vehicle. It also contains emergency information that is to be delivered to all the target receivers. In broadcast communication, however, existing carrier sense multiple access (CSMA) medium access control (MAC) protocol cannot guarantee a high reliability as it suffers from two chronic problems, namely, access collision and hidden terminal interference. To resolve these problems of CSMA MAC, we propose a novel enhancement algorithm called a neighbor association-based MAC (NA-MAC) protocol. NA-MAC utilizes a time division multiple access (TDMA) to distribute channel resource into short time-intervals called slots. Each slot is further divided into three parts to conduct channel sensing, slot acquisition, and data transmission. To avoid a duplicate slot allocation among multiple vehicles, NA-MAC introduces a three-way handshake process during slot acquisition. Our simulation results revealed that NA-MAC improved packet reception ratio (PRR) by 19% and successful transmission by 30% over the reference protocols. In addition, NA-MAC reduced the packet collisions by a factor of 4. Using the real on-board units (OBUs), we conducted an experiment where our protocol outperformed in terms of PRR and average transmission interval by 82% and 49%, respectively.

scholarly journals Collision-Free Advertisement Scheduling for IEEE 802.15.4-TSCH Networks

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1789 ◽  
Author(s):  
Apostolos Karalis ◽  
Dimitrios Zorbas ◽  
Christos Douligeris
Keyword(s):  
Power Consumption ◽  
Ieee 802.15.4 ◽  
Mac Protocol ◽  
High Reliability ◽  
Mobile Nodes ◽  
Medium Access ◽  
Worst Case ◽  
Channel Hopping ◽  
Transmission Schedule ◽  
Scheduling Method

IEEE802.15.4-time slotted channel hopping (TSCH) is a medium access control (MAC) protocol designed to support wireless device networking, offering high reliability and low power consumption, two features that are desirable in the industrial internet of things (IIoT). The formation of an IEEE802.15.4-TSCH network relies on the periodic transmissions of network advertising frames called enhanced beacons (EB). The scheduling of EB transmissions plays a crucial role both in the joining time and in the power consumption of the nodes. The existence of collisions between EB is an important factor that negatively affects the performance. In the worst case, all the neighboring EB transmissions of a node may collide, a phenomenon which we call a full collision. Most of the EB scheduling methods that have been proposed in the literature are fully or partially based on randomness in order to create the EB transmission schedule. In this paper, we initially show that the randomness can lead to a considerable probability of collisions, and, especially, of full collisions. Subsequently, we propose a novel autonomous EB scheduling method that eliminates collisions using a simple technique that does not increase the power consumption. To the best of our knowledge, our proposed method is the first non-centralized EB scheduling method that fully eliminates collisions, and this is guaranteed even if there are mobile nodes. To evaluate our method, we compare our proposal with recent and state-of-the-art non-centralized network-advertisement scheduling methods. Our evaluation does not consider only fixed topology networks, but also networks with mobile nodes, a scenario which has not been examined before. The results of our simulations demonstrate the superiority of our method in terms of joining time and energy consumption.

A Slotted Multichannel MAC Protocol for Fair Resource Allocation in VANET

2018 ◽  
Vol 9 (3) ◽  
pp. 45-59 ◽  
Author(s):  
Pant Varun Prakash ◽  
Saumya Tripathi ◽  
Raghavendra Pal ◽  
Arun Prakash
Keyword(s):  
Mac Protocol ◽  
Cluster Head ◽  
Ieee 802.11P ◽  
Medium Access ◽  
Service Channel ◽  
Packet Delivery ◽  
Vehicle Density ◽  
Hidden Terminal ◽  
Future Data ◽  
Multichannel Mac

This article proposes a slotted multichannel medium access control (SMMAC) protocol for VANETs to reduce CCH congestion, decrease RSU dependency, increase safety and data packet's reliability and improve fairness among vehicles. The main entity is the cluster head that not only notifies all the vehicles under the same cluster about the present state of service channel and future data transmissions but also imposes a condition on the maximum number of vehicles allowed inside a cluster. Controlled vehicle density reduces CCH collisions and as a result, it makes the protocol better in terms of packet delivery. To eliminate the inter-cluster hidden terminal problem, in the proposed algorithm, each cluster uses a service channel different from its neighboring cluster. Analyzing the system for both dense and sparse scenario it can be seen through simulation results that the proposed protocol performs much better in comparison to IEEE 802.11p with respect to Throughput, PDR and Delay.

scholarly journals Vehicle Density Based Forwarding Protocol for Safety Message Broadcast in VANET

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jiawei Huang ◽  
Yi Huang ◽  
Jianxin Wang
Keyword(s):  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Mac Protocol ◽  
Medium Access ◽  
Safety Message ◽  
Vehicle Density ◽  
Multihop Broadcast ◽  
Hoc Networks ◽  
Time Critical ◽  
Safety Applications

In vehicular ad hoc networks (VANETs), the medium access control (MAC) protocol is of great importance to provide time-critical safety applications. Contemporary multihop broadcast protocols in VANETs usually choose the farthest node in broadcast range as the forwarder to reduce the number of forwarding hops. However, in this paper, we demonstrate that the farthest forwarder may experience large contention delay in case of high vehicle density. We propose an IEEE 802.11-based multihop broadcast protocol VDF to address the issue of emergency message dissemination. To achieve the tradeoff between contention delay and forwarding hops, VDF adaptably chooses the forwarder according to the vehicle density. Simulation results show that, due to its ability to decrease the transmission collisions, the proposed protocol can provide significantly lower broadcast delay.

scholarly journals Medium access control protocol design for wireless communications and networks review

2022 ◽  
Vol 12 (2) ◽  
pp. 1711
Author(s):  
Zaid Hashim Jaber ◽  
Dheyaa Jasim Kadhim ◽  
Ahmed Sabah Al-Araji
Keyword(s):  
Wireless Networks ◽  
Wireless Communications ◽  
Access Control ◽  
Medium Access Control ◽  
Spectral Efficiency ◽  
Research Method ◽  
Multiple Access ◽  
Mac Protocol ◽  
Protocol Design ◽  
Medium Access

<p><span>Medium access control (MAC) protocol design plays a crucial role to increase the performance of wireless communications and networks. The channel access mechanism is provided by MAC layer to share the medium by multiple stations. Different types of wireless networks have different design requirements such as throughput, delay, power consumption, fairness, reliability, and network density, therefore, MAC protocol for these networks must satisfy their requirements. In this work, we proposed two multiplexing methods for modern wireless networks: Massive multiple-input-multiple-output (MIMO) and power domain non-orthogonal multiple access (PD-NOMA). The first research method namely Massive MIMO uses a massive number of antenna elements to improve both spectral efficiency and energy efficiency. On the other hand, the second research method (PD-NOMA) allows multiple non-orthogonal signals to share the same orthogonal resources by allocating different power level for each station. PD-NOMA has a better spectral efficiency over the orthogonal multiple access methods. A review of previous works regarding the MAC design for different wireless networks is classified based on different categories. The main contribution of this research work is to show the importance of the MAC design with added optimal functionalities to improve the spectral and energy efficiencies of the wireless networks.</span></p>

A Low Power IoT Medium Access Control for Receiver-Assigned CDMA

2019 ◽  
Vol 11 (2) ◽  
pp. 24-41 ◽  
Author(s):  
Eric E. Petrosky ◽  
Alan J. Michaels ◽  
Joseph M. Ernst
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Access Control ◽  
Low Power ◽  
Medium Access Control ◽  
Multiple Access ◽  
Mac Protocol ◽  
Wireless Sensor ◽  
Medium Access ◽  
Cdma Networks

Low power, low cost, and security-conscious wireless sensor networks are becoming increasingly pervasive in the internet of things (IoT). In these networks, receiver-assigned code division multiple access (RA-CDMA) offers benefits over existing multiple access techniques. RA-CDMA networks are asynchronous, robust against multipath interference, and offer resilience against collision. A lightweight medium access control (MAC) protocol is needed to facilitate communication in RA-CDMA networks between low power sensor nodes and access points. This article provides an overview of RA-CDMA and proposes elements of a new MAC protocol that could improve performance of certain wireless sensor networks. Key features of the proposed MAC design are introduced and compared to those of existing protocols, highlighting its simple and lightweight design. Through its compatibility with RA-CDMA, the MAC design eliminates significant overhead and complexity while meeting requirements for low power networks, which enables the implementation of dense IoT sensor networks.

scholarly journals The Impact of Dynamic RTS Threshold Adjustment for IEEE 802.11 MAC Protocol

2009 ◽  
Vol 5 (1) ◽  
pp. 5-20 ◽  
Author(s):  
Mostafa Mjidi ◽  
Debasish Chakraborty ◽  
Naoki Nakamura ◽  
Norio Shiratori
Keyword(s):  
Ieee 802.11 ◽  
Data Transmission ◽  
Mac Protocol ◽  
Threshold Value ◽  
Local Area ◽  
Wireless Channel ◽  
Main Element ◽  
Medium Access ◽  
Hidden Terminal ◽  
The Impact

In recent years, wireless technologies and application received great attention. The Medium Access Control (MAC) protocol is the main element that determines the efficiency in sharing the limited communication bandwidth of the wireless channel in wireless local area networks (WLANs). IEEE 802.11 introduced the optional RTS/CTS handshaking mechanism to address the hidden terminal problem as well as to reduces the chance of collision in case of higher node density and traffic. RTS Threshold (RT) determines when RTS/CTS mechanism should be used and proved to be an important parameter for performance characteristics in data transmission. We first investigate to find a meaningful threshold value according to the network situation and determine the impact of using or disengaging the RTS/CTS optional mechanism and dynamically adjust the RTS Threshold to maximize data transmission. The results show a significant improvement over existing CSMA/CA and RTS/CTS schemes. Our adaptive scheme performed even better when data rate increases. We verify our proposed scheme both analytically and with extensive network simulation using ns-2.

scholarly journals A hybrid access method for broadcasting of safety messages in IEEE 802.11p VANETs

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiaoying Lei ◽  
Xiangjin Chen ◽  
Seung Hyong Rhee
Keyword(s):  
Access Control ◽  
Multiple Access ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Mac Protocol ◽  
Ieee 802.11P ◽  
Media Access Control ◽  
Access Method ◽  
Safety Message ◽  
Hybrid Access

AbstractVehicular Ad-hoc Networks (VANETs) can improve the road safety by transmitting safety-critical messages such as beacons and emergency messages. IEEE 802.11p VANETs have adopted the carrier sense multiple access with collision avoidance (CSMA/CA) mechanism for the multiple access control. The 802.11p media access control (MAC) protocol, however, can not guarantee the reliability of broadcasting data, since the reception of transmitted messages are not acknowledged. Moreover, the backoff scheme of the 802.11p MAC utilizes a fixed-size contention window for safety message broadcasting, which causes high collision probabilities especially in dense environments. In order to improve such drawbacks, we propose a hybrid access method as follows: Nodes are equipped to reserve time slots for the next round of broadcasting, while unoccupied time slots are preserved for those which have emergency needs. In addition, implicit feedbacks are enabled for detecting collisions incurred during random channel accesses in preserved time slots. We devise a mathematical model which optimally controls the parameters of our scheme while minimizes the cost caused by idle channels and collisions. Extensive simulations show that our mechanism can remarkably improve the performance of VANETs in broadcasting of the safety messages.

scholarly journals IEEE 802.11 based Medium Access Design for Wireless IoT-Blockchain Networks

2020 ◽  
Author(s):  
Arezou Zamanyzadeh Abyaneh ◽  
Nizar Zorba
Keyword(s):  
Access Control ◽  
Collision Avoidance ◽  
Ieee 802.11 ◽  
Multiple Access ◽  
Wireless Channels ◽  
Performance Metrics ◽  
Mac Protocol ◽  
Carrier Sense Multiple Access ◽  
Medium Access ◽  
Carrier Sense

Communication is a very basic essence of the blockchain network and must be carefully planned while integrating with IoT, where an extremely large number of devices are interconnected. In this work, blockchain nodes are assumed to use wireless channels to communicate among themselves and other elements of the IoT setup. These communications can be in unicast and broadcast manner where transmission latency and throughput are significant metrics that might jeopardize the overall system. This work is proposing a Medium Access Control (MAC) mechanism addressing these performance metrics and best suitable for wireless IoT-Blockchain system. The proposed MAC protocol is based on the widely used IEEE 802.11 protocol, Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) basic access.

scholarly journals Analysis of IEEE 802.15.4 Beacon-Enabled MAC Protocol

2016 ◽  
Vol 6 (3) ◽  
pp. 1122
Author(s):  
Nga Dinh ◽  
Sangsoon Lim
Keyword(s):  
Power Consumption ◽  
Power Efficiency ◽  
Multiple Access ◽  
Ieee 802.15.4 ◽  
Mac Protocol ◽  
Carrier Sense Multiple Access ◽  
Data Frame ◽  
Medium Access ◽  
Access Delay ◽  
Mathematical Expressions

This paper aims to develop several mathematical models to study medium access control (MAC) protocol in the IEEE 802.15.4 beacon-enabled mode with star topology. In particular, the MAC protocol which employs a slotted carrier-sense multiple access with collision avoidance (CSMA/CA) algorithm used in the contention access period (CAP) of a superframe is modelled. The analysis studies the effectiveness of the CSMA/CA algorithm and provides explicit mathematical expressions for power consumption, access delay, and data frame drop probability. The proposed models precisely follow CSMA/CA algorithm in MAC protocol of beacon-enabled mode and differ from those previously published in the literature as 1) they are derived based on data frame generation rate of end devices, 2) they provide a completed expression for frame access delay, and 3) lowpower states of end devices are considered for power efficiency evaluations. The paper shows how power consumption of end devices is improved on the balance with data frame delay. The validity of the proposed models is confirmed and complemented by extensive simulations.

scholarly journals MAC Protocol for Ad Hoc Networks Using a Genetic Algorithm

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Omar Elizarraras ◽  
Marco Panduro ◽  
Aldo L. Méndez ◽  
Alberto Reyna
Keyword(s):  
Genetic Algorithm ◽  
Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Multiple Access ◽  
Ad Hoc ◽  
Transmission Rate ◽  
Mac Protocol ◽  
Medium Access ◽  
Hoc Networks ◽  
Code Division Multiple

The problem of obtaining the transmission rate in an ad hoc network consists in adjusting the power of each node to ensure the signal to interference ratio (SIR) and the energy required to transmit from one node to another is obtained at the same time. Therefore, an optimal transmission rate for each node in a medium access control (MAC) protocol based on CSMA-CDMA (carrier sense multiple access-code division multiple access) for ad hoc networks can be obtained using evolutionary optimization. This work proposes a genetic algorithm for the transmission rate election considering a perfect power control, and our proposition achieves improvement of 10% compared with the scheme that handles the handshaking phase to adjust the transmission rate. Furthermore, this paper proposes a genetic algorithm that solves the problem of power combining, interference, data rate, and energy ensuring the signal to interference ratio in an ad hoc network. The result of the proposed genetic algorithm has a better performance (15%) compared to the CSMA-CDMA protocol without optimizing. Therefore, we show by simulation the effectiveness of the proposed protocol in terms of the throughput.

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