Research on MAC Protocols in Cluster-Based Ad Hoc Networks

Mobile ad hoc networks can be widely used in many scenes, for example, military communication, emergency communication, and 5G wide area coverage as well as ultradense network scenes. A cluster-based network can decrease network overhead effectively and then constitute a large-scale network through extending network scale by clustering and cascading. In view of multiservice simultaneous transmission demand for small-scale dense networking scene and large-scale extended networking scene, a MAC protocol based on scheduling of cluster head is proposed, which can avoid collision and retransmission between nodes effectively, and then the network synchronizing in intercluster and intracluster as well as the time-slot scheduling is solved fast and efficiently. A network synchronization algorithm based on clock spread of the sponsorship node is proposed to achieve network self-synchronizing, and a modified schedule-tree algorithm based on cluster head and exactly sponsorship node is proposed to decrease network overhead and to increase network fairness, then MAC protocol based on scheduling of cluster head is verified by simulated analysis. Finally, a dynamic gateway selection algorithm based on link stability is proposed in this paper to decrease intercluster communication control overhead and improve intercluster communication reliability.

Download Full-text

Autonomous Clustering Scheme for Removing the Effects of Heterogeneous Node Degrees in Ad Hoc Networks

Image Processing & Communications ◽

10.1515/ipc-2016-0010 ◽

2016 ◽

Vol 21 (2) ◽

pp. 43-54

Author(s):

Ryosuke Morita ◽

Chisa Takano ◽

Masaki Aida

Keyword(s):

Ad Hoc Networks ◽

Large Scale ◽

Ad Hoc ◽

Cluster Head ◽

Node Degree ◽

Hierarchical Routing ◽

Mobile Ad Hoc ◽

The Difference ◽

Hoc Networks ◽

Heterogeneous Node

Abstract In large scale mobile ad hoc networks (MANETs), it is effective to reduce the load of routing by introducing hierarchical routing, and it is conducted by clustering of nodes. A clustering mechanism based on the diffusion equation is a typical autonomous clustering in MANETs, and gives appropriate clustering if all the node degrees are uniform. However, node degrees in MANETs are heterogeneous in general, the fact causes the difference in the strength of diffusion effect. This difference causes that the position of cluster head tends to be around the boundary of networks and degrade battery efficiency of nodes. In this paper, by introducing an asymmetric diffusion depending on node degree, we propose a new clustering method independent of heterogeneity of node degrees. We show that the proposed method has efficient characteristics for battery consumption. In addition, we show the comparison of the proposed method with the conventional method with respect to the efficiency of routing.

Download Full-text

Extensions to the IEEE 802.11 TSF for Efficient and Reliable Network Synchronization in Large Scale MANETs

African Journal of Information & Communication Technology ◽

10.5130/ajict.v2i2.233 ◽

2006 ◽

Vol 2 (2) ◽

pp. 110

Author(s):

Peter Rauschert ◽

Arasch Honarbacht ◽

Anton Kummert

Keyword(s):

Ad Hoc Networks ◽

Ieee 802.11 ◽

Large Scale ◽

Ad Hoc ◽

Small Scale ◽

Distributed Coordination ◽

Self Organized ◽

Mobile Stations ◽

Hoc Networks ◽

Coordination Function

Designing new protocols for Mobile Ad hoc Networks (MANETs) is a great challenge due to their distributed and self organized nature. Though, aspects of approved algorithms for hierarchical topographies may be carried over to these flat networks. The IEEE 802.11 protocol supports ad hoc networks in small scale applications, but its performance in large scale environments is still under investigation. Besides the Distributed Coordination Function (DCF), the Timer Synchronization Function (TSF) can be significantly improved in order to increase the performance in large scale multihop networks. This article presents systematic extensions to the TSF that allow increasing the overall reliability and disburdening the network at the same time. The presented scheme may be tailored to specific applications and even supports mobile stations and herewith MANETs.

Download Full-text