Node-blockage reduction and removal of hidden-terminal problem of CSMA/CA MAC protocol

2012 ◽  
Author(s):  
Milan Kumar Dholey ◽  
G. P. Biswas
Keyword(s):  
Mac Protocol ◽  
Hidden Terminal

An Asynchronous Multi-Channel MAC Protocol Based on Cooperation Mechanism in Vehicular AdHoc Network

2015 ◽  
Vol 713-715 ◽  
pp. 1294-1298
Author(s):  
Xin Yun Li ◽  
Lun Tang
Keyword(s):  
Network Reliability ◽  
Mac Protocol ◽  
High Mobility ◽  
Collision Probability ◽  
Delivery Ratio ◽  
Adhoc Network ◽  
Cooperation Mechanism ◽  
Hidden Terminals ◽  
Hidden Terminal ◽  
Channel Environment

To solve the problem of vehicle adhoc network reliability is not high and multi-channel hidden terminals, we propose a multi-channel MAC protocol CAMP(cooperation-based asynchronous multi-channel MAC protocol) based mechanism for asynchronous cooperation in VANET. CAMP add to cooperation mechanisms in asynchronous multi-channel environment, the proposed scheme nodes cooperation in order to obtain the channel state information and status information to other nodes, thus a good solution to the hidden terminal problem multichannel transmission process, to achieve high mobility environment under the reliable transmission of data. The simulation results show that CAMP has better performance than IEEE 1609.4 standard, AMCP protocol, AMCMAC protocol on collision probability of SCH, safety messages delivery ratio.

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 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 CU-MAC: A Duty-Cycle MAC Protocol for Internet of Things in Wireless Sensor Networks

2018 ◽  
Vol 16 (2) ◽  
pp. 30-43
Author(s):  
Tanapoom Danmanee ◽  
Kulit Na Nakorn ◽  
Kultida Rojviboonchai
Keyword(s):  
Internet Of Things ◽  
Duty Cycle ◽  
Data Transfer ◽  
Mac Protocol ◽  
Sensor Data ◽  
Wireless Sensor ◽  
Local Network ◽  
The Internet ◽  
Delivery Ratio ◽  
Hidden Terminal

Nowadays “Internet of Things” or IoT becomes the most popular technology in the Internet system. Types of devices and sensors have been connected as a network of devices and sensors. While a wireless sensor network is a traditional network of sensors that can be considered as a beginning point of IoT systems. Currently, these sensor data are not only exchanged within a local network but also are delivered to other devices in the Internet. Consequently, well-known organizations such as IEEE, IETF, ITU-T and ISO/IET are trying to set standards for wireless sensor devices in IoT systems. The recommended standard utilizes many of internet stack standards such as CoAP, UDP and IP. However, the traditional design of WSNs is to avoid using internet protocol in the system to reduce transmission overhead and power consumption due to resource limitation. Fortunately, the current technology in both hardware and software allow the internet standard to sufficiently operate in a small sensor.  In this paper, we propose a MAC protocol named CU-MAC to efficiently support IoT standard that need request-respond communication or bi-direction communication. CU-MAC uses multi-channel communication to perform continuous and bi-directional data transfer at low duty-cycle. It also has a mechanism to overcome the hidden terminal problem. We evaluated the performance of CU-MAC on both simulation and real testbed based on Contiki OS. The result shows that CU-MAC outperforms other existing MAC protocols in term of packet delivery ratio at 98.7% and requires lower duty-cycle than others to operate in the high traffic environment.

scholarly journals Design and Analysis of an Efficient and Reliable Mac Protocol for Vanets

2021 ◽  
Author(s):  
Khalid Abdel Hafeez
Keyword(s):  
High Stability ◽  
Mac Protocol ◽  
Network Capacity ◽  
Wireless Channel ◽  
Propagation Model ◽  
Ieee 802.11P ◽  
Inference System ◽  
Hidden Terminal ◽  
On The Road ◽  
The Impact

The increase number of vehicles on roads and the immense number of fatal accidents they cause have driven the research and development of new generation technologies to help drivers travel more safely. One major cause of traffic accidents is that drivers cannot consistently respond to the changing road conditions appropriately. In fact, most accidents could be avoided if drivers could obtain and use relevant information of the traffic that is beyond their vision using wireless communications technology. Recently, the IEEE community adopted the IEEE 802.11p standard as a main technology for VANETs. To test the feasibility of this technology, most researchers use simulations to evaluate its new applications and protocols due to the prohibitive cost of implementing real VANET setup. Therefore, we first analyze VANET’s wireless channel analytically and by simulations to predict its most appropriate propagation model and the communication range that minimizes the impact of the hidden terminal problem. Second, we derive a new mobility model that takes into account the vehicle’s follow-on safety rule, to accurately derive the relationship between vehicle’s speed and network density. It is expected that broadcasting and multi hop communications will be dominant in VANETs safety applications and protocols. Therefore, a Network Topology p-Persistence (NTPP) scheme is proposed to alleviate the impact of the broadcast storm problem. NTPP is based on vehicles’ knowledge of their neighbors in their range and traffic parameters to reduce the channel contention, redundant re-broadcasts and message travel time and to increase the emergency message reception rate. We analyze the reliability of the IEEE 802.11p in VANETs safety and warning applications scope taking into consideration different factors. It is shown analytically and by extensive simulations that the current DSRC specifications may lead to undesirable performance under harsh vehicular environments. Therefore, a novel Distributed Multichannel and Mobility Aware Cluster-based MAC Protocol (DMCMAC) is proposed to alleviate the impact of the hidden terminal problem, increase the network capacity and reliability. Cluster heads in DMCMAC are elected and re-elected in a distributed manner according to their relative speed and distance from their cluster members. The high stability of DMCMAC results from its adaptability to drivers’ behavior on the road and its learning process to predict the future speed and position of all cluster members using the fuzzy logic inference system. The reliability of DMCMAC is analyzed and compared with other protocols. It is shown by simulations that DMCMAC has high stability, its performance exceeds other protocols and can achieve a timely and reliable delivery of emergency messages to their intended recipients which make it more suitable for VANETs. iv

A MAC protocol for directional hidden terminal and minor lobe problems

2008 ◽  
Author(s):  
Yuya Takatsuka ◽  
Masanori Takata ◽  
Masaki Bandai ◽  
Takashi Watanabe
Keyword(s):  
Mac Protocol ◽  
Hidden Terminal

scholarly journals CUMAC-CAM: a channel allocation aware MAC protocol for addressing triple hidden terminal problems in multi-channel UWSNs

2019 ◽  
Vol 1 (7) ◽  
Author(s):  
Purobi Rahman ◽  
Amit Karmaker ◽  
Mohammad Shah Alam ◽  
Mohammad Asadul Hoque ◽  
William L. Lambert
Keyword(s):  
Channel Allocation ◽  
Mac Protocol ◽  
Hidden Terminal

scholarly journals Design and Analysis of an Efficient and Reliable Mac Protocol for Vanets

2021 ◽  
Author(s):  
Khalid Abdel Hafeez
Keyword(s):  
High Stability ◽  
Mac Protocol ◽  
Network Capacity ◽  
Wireless Channel ◽  
Propagation Model ◽  
Ieee 802.11P ◽  
Inference System ◽  
Hidden Terminal ◽  
On The Road ◽  
The Impact

The increase number of vehicles on roads and the immense number of fatal accidents they cause have driven the research and development of new generation technologies to help drivers travel more safely. One major cause of traffic accidents is that drivers cannot consistently respond to the changing road conditions appropriately. In fact, most accidents could be avoided if drivers could obtain and use relevant information of the traffic that is beyond their vision using wireless communications technology. Recently, the IEEE community adopted the IEEE 802.11p standard as a main technology for VANETs. To test the feasibility of this technology, most researchers use simulations to evaluate its new applications and protocols due to the prohibitive cost of implementing real VANET setup. Therefore, we first analyze VANET’s wireless channel analytically and by simulations to predict its most appropriate propagation model and the communication range that minimizes the impact of the hidden terminal problem. Second, we derive a new mobility model that takes into account the vehicle’s follow-on safety rule, to accurately derive the relationship between vehicle’s speed and network density. It is expected that broadcasting and multi hop communications will be dominant in VANETs safety applications and protocols. Therefore, a Network Topology p-Persistence (NTPP) scheme is proposed to alleviate the impact of the broadcast storm problem. NTPP is based on vehicles’ knowledge of their neighbors in their range and traffic parameters to reduce the channel contention, redundant re-broadcasts and message travel time and to increase the emergency message reception rate. We analyze the reliability of the IEEE 802.11p in VANETs safety and warning applications scope taking into consideration different factors. It is shown analytically and by extensive simulations that the current DSRC specifications may lead to undesirable performance under harsh vehicular environments. Therefore, a novel Distributed Multichannel and Mobility Aware Cluster-based MAC Protocol (DMCMAC) is proposed to alleviate the impact of the hidden terminal problem, increase the network capacity and reliability. Cluster heads in DMCMAC are elected and re-elected in a distributed manner according to their relative speed and distance from their cluster members. The high stability of DMCMAC results from its adaptability to drivers’ behavior on the road and its learning process to predict the future speed and position of all cluster members using the fuzzy logic inference system. The reliability of DMCMAC is analyzed and compared with other protocols. It is shown by simulations that DMCMAC has high stability, its performance exceeds other protocols and can achieve a timely and reliable delivery of emergency messages to their intended recipients which make it more suitable for VANETs. iv

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