Improving Fairness in IEEE 802.11 EDCA Ad Hoc Networks Based on Fuzzy Logic

2020 ◽  
Vol 24 (5) ◽  
pp. 615-620
Author(s):  
Luong Duy Hieu ◽  
Bui The Tung ◽  
Pham Thanh Giang ◽  
Thai Quang Vinh ◽  
Le Nam ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Ieee 802.11 ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Distributed Network ◽  
Medium Access ◽  
Fairness Index ◽  
Data Flows ◽  
Hoc Networks ◽  
Logic System

Wireless ad hoc network is a self-configurable and dynamically distributed network in which stations can move freely. In the ad hoc network, some flows have difficulty in accessing the channel due to contention at both the medium-access control (MAC) and link layers. The IEEE 802.11 protocol is currently the de facto standard for wireless networks. It uses enhanced distributed channel access (EDCA) method to access the transmission environment of each type of data flow. The size of the contention window (CW) in EDCA is related to the probability of accessing the channel of each flow. In our approach, useful information is obtained from the physical, MAC, and link layers. A fuzzy logic system is then used to adjust the size of CW to rely on such value, thereby improving the fairness index of data flows (voice, video, best effort) in IEEE 802.11 EDCA. The simulation results show that the proposed method can improve the throughput and fairness index of data flows.

scholarly journals An Efficient Routing Protocol Using an Improved Distance-Based Broadcasting and Fuzzy Logic System for VANET

2020 ◽  
Vol 13 (6) ◽  
pp. 81-93
Author(s):  
Khalid Kandali ◽  
◽  
Hamid Bennis ◽  
Keyword(s):  
Fuzzy Logic ◽  
Routing Protocol ◽  
Data Transmission ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Network Routing ◽  
Fuzzy Logic System ◽  
Network Bandwidth ◽  
Logic System

The high mobility and frequent changes in the network topology remain a great divergence between Vehicular Ad-hoc Network (VANET) and Mobile Ad-hoc Network (MANET). This makes existing routing protocols for MANET imperfect for a VANET environment. In order to ensure good data transmission between vehicles, it is mandatory to improve these protocols to this new environment. Ad-hoc On-demand Distance Vector (AODV) is one of the most proposed reactive protocols in the literature for MANET, but its direct application in VANET returns poor performance results. In this paper, we propose an Efficient Routing Protocol using an improved Distance-Based Broadcasting and Fuzzy Logic System (ERPFL), which is an extension of the AODV routing protocol. In the first, the proposed scheme uses an improved Distance-Based Broadcasting method in route discovery process. Each vehicle selects the most suitable neighbours to send a route request, using different mobility parameters such as distance, velocity and direction. Then, the destination vehicle selects the best route from the most reliable routes received, using the Fuzzy Logic System. Link Expiration Time and Link Reliability Model are considered input metrics for this system. The simulation results show that ERPFL saves network bandwidth resources which contributes to a higher data transmission ratio. In addition, our proposed protocol efficiently distributes data packets, decreases the hop count and reduces network routing time.

Throughput Analysis of IEEE 802.11 DCF with Modified Binary Exponential Backoff in Mobile Ad Hoc Networks

2010 ◽  
Vol 2 (3) ◽  
pp. 61-70
Author(s):  
Rishipal Singh ◽  
D. K. Lobiyal
Keyword(s):  
Wireless Networks ◽  
Ieee 802.11 ◽  
Spread Spectrum ◽  
Ad Hoc ◽  
Distributed Coordination ◽  
Medium Access ◽  
Binary Exponential Backoff ◽  
802.11 Dcf ◽  
Hoc Networks ◽  
Coordination Function

In the design of wireless networks, the medium access protocols have a very large impact on the performance of the network. The IEEE 802.11 is widely accepted technology for the Wireless LANs and is used by wireless networks. This paper presents an analysis of the performance of Distributed Coordination Function (DCF) for IEEE 802.11 under modified Binary Exponential Backoff (BEB) Algorithm using Frequency Hoping Spread Spectrum (FHSS). In the modified algorithm, the size of Contention Window (CW) has been changed with the factor of for the first four collisions and the size becomes double thereafter in each subsequent collision. This paper also covers the effects of various parameters in modified BEB Algorithm.

ABCR-STC: An Improved Adaptive Backoff Algorithm for MAC Protocol in Ad Hoc Networks

2010 ◽  
Vol 40-41 ◽  
pp. 462-468 ◽  
Author(s):  
Xiao Yun Chen ◽  
Sha Liu ◽  
Long Jie Li
Keyword(s):  
Ad Hoc Networks ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Mac Protocol ◽  
Network Environment ◽  
Medium Access ◽  
Backoff Algorithm ◽  
Access Protocols ◽  
Medium Access Protocols ◽  
Hoc Networks

The performance of backoff algorithm plays an important role in designing efficient Medium Access Protocols for Ad hoc networks. In this paper, we propose three backoff algorithms for Ad hoc networks. The first algorithm aims at higher fairness, and the second aims at stronger adaptivity. Then, we combine the first two algorithms to propose an optimized backoff algorithm. We use NS2 to simulate Ad hoc network environment to evaluate the performance of our improved backoff algorithms. The results show that our algorithms exhibit a significant improvement in throughput and fairness with the existing BEB and AASC algorithm.

scholarly journals Enhancing the Selection of Backoff Interval Using Fuzzy Logic over Wireless Ad Hoc Networks

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Radha Ranganathan ◽  
Kathiravan Kannan
Keyword(s):  
Fuzzy Logic ◽  
Ieee 802.11 ◽  
Ad Hoc ◽  
Distributed Coordination ◽  
Medium Access ◽  
Ieee 802.11 Dcf ◽  
802.11 Dcf ◽  
Effective Manner ◽  
Distributed Coordination Function ◽  
Coordination Function

IEEE 802.11 is the de facto standard for medium access over wireless ad hoc network. The collision avoidance mechanism (i.e., random binary exponential backoff—BEB) of IEEE 802.11 DCF (distributed coordination function) is inefficient and unfair especially under heavy load. In the literature, many algorithms have been proposed to tune the contention window (CW) size. However, these algorithms make every node select its backoff interval between [0, CW] in a random and uniform manner. This randomness is incorporated to avoid collisions among the nodes. But this random backoff interval can change the optimal order and frequency of channel access among competing nodes which results in unfairness and increased delay. In this paper, we propose an algorithm that schedules the medium access in a fair and effective manner. This algorithm enhances IEEE 802.11 DCF with additional level of contention resolution that prioritizes the contending nodes according to its queue length and waiting time. Each node computes its unique backoff interval using fuzzy logic based on the input parameters collected from contending nodes through overhearing. We evaluate our algorithm against IEEE 802.11, GDCF (gentle distributed coordination function) protocols using ns-2.35 simulator and show that our algorithm achieves good performance.

Estimating the Available Medium Access Bandwidth of IEEE 802.11 Ad Hoc Networks With Concurrent Transmissions

2015 ◽  
Vol 64 (2) ◽  
pp. 689-701 ◽  
Author(s):  
Lei Lei ◽  
Ting Zhang ◽  
Liang Zhou ◽  
Xiaoming Chen ◽  
Chenfei Zhang ◽  
...  
Keyword(s):  
Ad Hoc Networks ◽  
Ieee 802.11 ◽  
Ad Hoc ◽  
Medium Access ◽  
Hoc Networks
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