Michel Kadoch

Multicast routing protocols in mobile ad hoc networks: a comparative survey and taxonomy

Multicasting plays a crucial role in many applications of mobile ad hoc networks (MANETs). It can significantly improve the performance of these networks, the channel capacity (in mobile ad hoc networks, especially single-channel ones, capacity is a more appropriate term than bandwidth, capacity is measured in bits/s and bandwidth in Hz) and battery power of which are limited. In the past couple of years, a number of multicast routing protocols have been proposed. In spite of being designed for the same networks, these protocols are based on different design principles and have different functional features when they are applied to the multicast problem. This paper presents a coherent survey of existing multicasting solutions for MANETs. It presents various classifications of the current multicast routing protocols, discusses their operational features, along with their advantages and limitations, and provides a comparison of their characteristics according to several distinct features and performance parameters. Moreover, this paper proposes classifying the existing multicast protocols into three categories according to their layer of operation, namely, the network layer, the application layer, and the MAC layer. It also extends the existing classification system and presents a comparison between them.

Integrating network function virtualization with SDR and SDN for 4G/5G networks

The rapidly diversified market demands have presented a huge challenge to the conventional mobile broadband network architecture. On one hand, the limited machine room space and insufficient power supply make it impossible to accommodate exponentially growing amount of network equipment of operators. On the other hand, net heterogeneity caused by different specifications of wireless access equipment causes costly trouble related to management and optimization. This article, correspondingly, proposes a holistic solution involving different technologies, i.e. network function virtualization (NFV), software defined radio (SDR), and software defined network (SDN). In particular, we investigate both existing standards and possible extensions for 4G/5G mobile networks, followed by a few open issues for future research.

Multipath routing over wireless mesh networks for multiple description video transmission

In the past few years, wireless mesh networks (WMNs) have drawn significant attention from academia and industry as a fast, easy, and inexpensive solution for broadband wireless access. In WMNs, it is important to support video communications in an efficient way. To address this issue, this paper studies the multipath routing for multiple description (MD) video delivery over IEEE 802.11 based WMN. Specifically, we first design a framework to transmit MD video over WMNs through multiple paths; we then investigate the technical challenges encountered. In our proposed framework, multipath routing relies on the maximally disjoint paths to achieve good traffic engineering performance. However, video applications usually have strict delay requirements, which make it difficult to find multiple qualified paths with the least joints. To overcome this problem, we develop an enhanced version of Guaranteed-Rate (GR) packet scheduling algorithm, namely virtual reserved rate GR (VRR-GR), to shorten the packet delay of video communications in multiservice network environment. Simulation study shows that our proposed approach can reduce the latency of video delivery and achieve desirable traffic engineering performance in multipath routing environment.

Multiuser detection based MAC design for Ad Hoc networks

Recent technological advances in code division multiple access (CDMA) with multiuser detection (MUD) allow to consider this technology for future wireless Ad Hoc networks. Due to the fundamentally different physical layer architecture, application of MUD in Ad Hoc networks requires novel approaches for medium access control (MAC) and scheduling mechanisms in order to take advantage of the new features. This paper proposes a new MAC and scheduling paradigm which addresses three design issues: distributed dynamic code assignment that avoids code collision, distributed scheduling scheme that provides fairness among contending nodes, and organization of the data transmission based on multiuser detection. Simulation model is used to verify the performance gains from the increased spectrum reuse due to multiuser reception and from the reduced interference due to multiuser detection. This is done by comparisons with existing MAC paradigms, such as CSMA/CA and parallel CDMA.

An efficient management algorithm for clustering in mobile ad hoc network

Clustering of mobile nodes among separate domains has been proposed as an efficient approach to mimic the operation of the fixed infrastructure and manage the resources in multi-hop networks. In this work, we propose a new clustering algorithm, namely Efficient Management Algorithm for Clustering (EMAC) based on weighting parameters. The goals are yielding low number of clusters, maintaining stable clusters, minimizing the number of invocations for the algorithm and maximizing lifetime of mobile nodes in the system. Through simulations we have compared the performance of our algorithm with that of WCA in terms of the number of clusters formed and number of states transitions on each clusterhead. The results demonstrate the superior performance of the proposed algorithm

A Flexible Weight Based Clustering Algorithm in Mobile Ad hoc Networks

Clustering has been proven to be a promising approach for mimicking the operation of the fixed infrastructure and managing the resources in multi-hop networks. In order to achieve good performance, the formation and maintenance procedure of clusters should operate with minimum overhead, allowing mobile nodes to join and leave without perturbing the membership of the cluster and preserving current cluster structure as much as possible. In this paper, we propose a Flexible Weight Based Clustering Algorithm (FWCA) in Mobile Ad hoc Networks. The goals are yielding low number of clusters, maintaining stable clusters, minimizing the number of invocations for the algorithm and maximizing lifetime of mobile nodes in the system. Through simulations we have compared the performance of our algorithm with that of WCA in terms of the number of clusters formed, number of re-affiliations, number of states transitions on each clusterhead and number of clusterheads changes. The results demonstrate the superior performance of the proposed algorithm.

Virtual backbone based on MCDS for topology control in wireless ad hoc networks

This paper proposes to utilize virtual backbone to handle control messages in ad hoc networks. The virtual backbone is built by using the Minimum Connected Dominating Set (MCDS) on a graph. The first part of this paper presents a new algorithm to construct the MCDS. The construction of the MCDS is formulated using the linear programming approach. We compared the performance of this procedure with those other previous approaches, and we find that our approach is less complex and gives the nearest solution to the optimal one. The second part of this paper presents different techniques of diffusion in ad hoc networks such as flooding, clustering, MP relay, and backbone based on MCDS, etc. The flooding technique is simple and efficient, but it is expensive in term of bandwidth, and causes excessive flows of message etc. Simulation results show that the approach of virtual backbone based MCDS outperforms flooding and MP relay.

ATM signalling: a tutorial

Asynchronous transfer mode is used as a transport mechanism for B-ISDN. Being a connection oriented link, a connection control mechanism must be established to set up virtual circuits. This is the outcome of the work performed in standard organisations of which the main issues are highlighted.

Multiuser detection based MAC design for ad hoc networks

In general, the performance and radio resource utilization of Ad Hoc networks are limited by half-duplex operation and possible collisions. In this paper, we propose a novel approach for MAC design that practically eliminates collisions and significantly increases the bandwidth utilization. The key element of this approach is the CDMA multiuser detection technology that allows receiving several signals in parallel without inflicting self-interference. These features give a promise of significant performance improvements. The main goal of this paper is to assess the range of this gain when compared to other existing alternatives. In particular, we compare the performance of the proposed multiuser detection based MAC design with MAC design based on IEEE 802.11 concept and with MAC design based on multi-code CDMA with one signal reception by one user at a time.

Inter-cell handoff performance improvement in LTE-a multi-hop relay networks

Multi-hop relay technology is one of the most promising candidate technologies to overcome the coverage and capacity problem in LTE-Advanced networks. Currently 3GPP is considering the incorporation of multi-hop relays into Release 12 of LTE-A standards. However, many issues remain to be resolved due to the complexity of multi-hop relaying paradigm, specifically resource allocation and mobility management. In this work we focus on the relay selection problem, where a user may have in his range several relay nodes to choose. The conventional selection scheme is based on the channel condition between the relay and the user, such that the user will achieve a high level of throughput. Alternatively we propose in this paper a novel relay selection strategy taking handoff into account over LTE-A multi-hop relay networks. Our goal is to achieve significant performance improvement against legacy centralized resource allocation and handoff algorithms such as disjoint path relay selection. Simulation results show that our design has the advantage of reducing inter-cell handoff frequency and lowering handoff failure ratio.