Waheb A. Jabbar

Power-efficient routing schemes for MANETs: a survey and open issues

Ubiquitous smart devices with embedded sensors are paving the way for mobile ad hoc networks (MANETs) that enable users to communicate directly, thereby playing a key role in Smart City and Internet of Things applications. In such smart environments, people with smart devices (nodes) can freely self-organize and form self-configuring MANETs to send and forward data packets to a destination over multiple hops via intermediate nodes. However, the energy consumption during routing remains a challenge in such ensemble mobile environments due to the limited battery capacity of mobile devices. This challenging issue has received substantial research attention, necessitating an exhaustive literature search over the variety of academic fields addressing this topic. The main motivation of this paper is to review various power-efficient routing schemes in MANETs that have recently been proposed to reduce the energy consumed when transmitting and receiving packets during active communication. Accordingly, these protocols are classified into six categories: (1) link state-based, (2) source-initiated-based, (3) transmission power control-based, (4) load-balancing-based, (5) location-based and (6) multicast-based routing approaches. The review covers various state-of-the-art protocols for each category and highlights their operation concepts, design challenges and key features. In addition, the various protocols are compared with emphasis on the merits and drawbacks as well as the considered metrics of each scheme. Finally, we provide a conclusion and suggest potential directions for future research in the field.

Performance Evaluation of MBA-OLSR Routing Protocol for MANETs

This paper proposes a multipath battery aware routing protocol, namely, MBA-OLSR, based on OLSRv2 and its multipath extension. The proposed approach considers the remaining battery energy of the nodes for calculating the initial cost of the multiple links between source-destination pairs. The MBA-OLSR aims to construct energy efficient routes and extend the network lifetime to avoid network failure due to battery exhaustion. The protocol performance is evaluated in different simulation scenarios of wireless mobile ad hoc networks (MANETs) environment. The simulation results demonstrate that our approach can achieve longer network lifetime and lower energy cost per packet. In addition, the results show improvement in terms of packet delivery ratio and end-to-end delay.

On the Performance of the Current MANET Routing Protocols for VoIP, HTTP, and FTP Applications

The recent advances of ensemble mobile environment of smart devices with embedded sensors have enabled the MANET to play a key role in the smart cities as well as WSN and WMN. However, these smart devices are still limited in terms of energy, processor, and memory. Moreover, the efficient routing for reliable network connectivity at anytime, anywhere, and about everything is still a challenge in multihop wireless networks. This paper evaluates the QoS and energy efficiency of three active routing protocols: (i) OLSRv2, a successor to OLSR, (ii) DYMO, a successor to both DSR and AODV, and (iii) MP-OLSR multipath extension to OLSRv2. In contrast to the related previous works which focused only on CBR traffic without considering the influence of specific traffic types on the performance of routing protocols, this work focused on this area from a different perspective. It evaluates the performance of three internet-based traffic types that can be used in the smart city applications: VoIP, HTTP, and FTP using different simulation models. The impact of the network density, load traffic, and nodes mobility on the considered protocols was evaluated by considering particular performance metrics for each traffic application. Based on the results, the study concludes by presenting useful recommendations for future work.

Peer-to-peer communication on android-based mobile devices: Middleware and protocols

There has been an increasing interest of a wide number of scholars and researchers in promoting the applications for Peer-to-Peer (P2P) communication in Androidbased smartphones as ubiquitous. Such increasing interest has been attributed to their increasing perception of these devices. There is a wide use of many P2P applications in mobile devices. These applications include IM, VoIP, file sharing, social networks, and video streaming. This paper describes a proposed Android-based middleware acts as the interface point between mobile nodes and higher application layers for mobile ubiquitous computing. The middleware mainly aims at supporting and enhancing the protocols for direct P2P communication among users in the ensemble mobile environment. Moreover, the paper presents a discussion of the available P2P middleware for the mobile environment along with its applications. Furthermore, the paper moves on to providing the mobile devices limitations and the challenges encountered in the adoption of the P2P communication technology in the mobile environment. Finally, the paper is concluded by presenting the directions for future research as to develop a middleware with necessary APIs and implement an enhanced P2P protocol in the proposed middleware on Android-Based mobile devices.

Evaluation of energy consumption in multipath OLSR routing in Smart City applications

The current advances of smart devices embedded with sensors have led to catalyzing the mobile ad hoc networks (MANET) in the Smart Cities. However, the energy consumption during routing are still challenging in such ensemble mobile environments. In this study, we compare and analyze the energy consumption of the Multi-Path-Optimized Link State Routing (MP-OLSR) and the Dynamic MANET On-demand (DYMO). The simulation involves Internet-based traffic for the Internet of Things (IoT) and Smart City applications using different simulation models. Particular performance metrics were selected to assess the effect of the network size and load traffic on the considered protocols. It was found that the MP-OLSR protocol consumed lower energy compared to DYMO when transmitting and receiving packets by taking advantage of its multiple paths policy. However, during idle mode, the DYMO protocol can perform better, especially in the low traffic scenarios.

Performance evaluation of PAPR in OFDM for UMTS-LTE system

Next generation mobile telecommunication networks will provide high data rates needed for multimedia rich applications as the demand in mobile broadband services is expected to increase in the coming years. Orthogonal Frequency Division Multiplexing (OFDM) technique has been increasing its popularity as a transmission scheme for several radio technologies. One of the challenging issues in OFDM technique is its high peak-to-average power ratio (PAPR). This paper studies the performance of PAPR in long term evolution (LTE) of universal mobile telecommunications system (UMTS). The implementation will be based on specifications and protocols from 3rd Generation Partnership Project (3GPP) work groups. The simulator used to simulate UMTS-LTE environment has been developed in Matlab which follows the standard according to UMTS-LTE physical layer transmission scheme. Evaluation results show that reduction of PAPR can be seen in UMTS-LTE model compared to conventional OFDM model.

Traffic load-based analysis of MBQA-OLSR routing protocol in wireless ad hoc networks

In wireless Ad hoc networks, congestion occurs frequently at intermediate nodes when forwarding data packets between source-destination pairs. This traffic incurs higher packet loss, longer transmission delay, and faster energy resources depletion, thus degrades the performance of the network. This paper analyzes the performance of our hybrid Multipath Battery and Queue-Aware OLSR routing protocol (MBQA-OLSR), which is an adaptation of MP-OLSRv2, for congestion avoidance, load balancing and energy-efficient routing in wireless ad hoc networks. The MBQA-OLSR considers multiple metrics, namely, residual energy, nodes lifetime, nodes idle time, and length of traffic queue for route computation and also selects Multipoint Relays (MPR) using an enhanced mechanism, Energy-Aware MPR (EA-MPR), thereby prolonging network lifetime, reducing the overhead involved and improving the QoS while maintaining connectivity of the network. The proposed scheme avoids the selection of congested and low battery level nodes for forwarding data packets and/or flooding topological information. The performance characteristics of the MBQA-OLSR protocol are evaluated through simulations by comparing it to the conventional routing protocols, namely the: MP-OLSRv2 and MPQ-OLSRv2. It emerges that MBQA-OLSR performs well under various traffic load scenarios and it significantly improves QoS metrics, reduces energy cost per packet, and extends the network lifetime.

Energy and mobility conscious multipath routing scheme for route stability and load balancing in MANETs

Abstract Mobility and limited energy resources of nodes are the most critical attributes of Mobile Ad hoc Networks (MANETs). The mobility of the nodes changes the networks topology in an unpredictable manner, which in turn, affects the stability of connected paths. In addition, it causes an excessive overhead traffic that leads to a higher energy consumption and degrades the performance of routing protocols. Therefore, a routing scheme in MANETs should comprise techniques that cope with challenges incurred by both the energy failures and nodes mobility. In this paper, we proposed Multipath Battery and Mobility-Aware routing scheme (MBMA-OLSR) based on MP-OLSRv2. Specifically, the study exploits a Multi-Criteria Node Rank (MCNR) metric that comprises the residual battery energy and the speed of nodes. It aims to rank the stability of the links using a link assessment function and to select the most efficient and stable paths to the destination. Moreover, an Energy and Mobility Aware Multi-Point Relay (EMA-MPR) selection mechanism is introduced and utilized by the MBMA-OLSR to set the willingness of nodes to contribute as MPRs, for flooding topological information. We implemented the proposed scheme as an extension to the EXata network simulator. Benefits of the innovative scheme have been demonstrated and validated under various simulation scenarios based on different mobility parameters. The simulation results provided evidence of the effectiveness of our scheme, especially during the high mobility scenarios with heavy traffic load where it outperformed the conventional MP-OLSRv2 routing protocol in terms of QoS and energy related metrics.

Downlink performance of a relay-enhanced mobile WiMAX networks

Mobile WiMAX is based on IEEE 802.16e standard to provide fixed and mobile broadband wireless access from anywhere within the metropolitan area network (MAN). Multi-hop relaying is a cost-effective approach to significantly extend the coverage and enhance the throughput and capacity of the WiMAX networks. In this paper, we evaluate the downlink (DL) performance of a relay-enhanced WiMAX networks. The effect of the number of implemented relay stations (RSs) on the performance of the mobile WiMAX networks is studied and evaluated. The performance evaluation is carried out using a system-level simulation developed in MATLAB software. The performance evaluation metrics are the average DL carrier-to-interference-and-noise ratio (CINR) and the average DL spectral efficiency. Evaluation results show that as the number of RSs is increased, the performance of the mobile WiMAX is significantly improved. However, in the scenario in which 4 RSs are deployed, the maximum achieved average DL CINR and the average DL spectral efficiency gains are 11.58 dB and 115.44%, respectively, compared to the scenario without RS.