Showing papers by "Mehran Abolhasan published in 2012"

Energy efficient thermal and power aware (ETPA) routing in Body Area Networks

Abstract: Research on routing in a network of intelligent, lightweight, micro and nano-technology sensors deployed in or around the body, namely Body Area Network (BAN), has gained great interest in the recent years. In this paper, we present an energy efficient, thermal and power aware routing algorithm for BANs named Energy Efficient Thermal and Power Aware routing (ETPA). ETPA considers a node's temperature, energy level and received power from adjacent nodes in the cost function calculation. An optimization problem is also defined in order to minimize average temperature rise in the network. Our analysis demonstrates that ETPA can significantly decrease temperature rise and power consumption as well as providing a more efficient usage of the available resources compared to the most efficient routing protocol proposed so far in BANs, namely PRPLC. Also, ETPA has a considerably higher depletion time that guarantees a longer lasting communication among nodes.

Wireless technologies for Body Area Networks: Characteristics and challenges

Abstract: Body Area Networks (BANs) are an exciting new networking technology expected to cause a dramatic shift on the way people think and manage their health and the way they benefit from information technology and advancements in a wide range of medical and non-medical applications. Since BANs are in the early stages of their development, a number of fundamental features and challenges need to be investigated to overcome the stringent requirements tied with this technology. Also the choice of an appropriate wireless technology is required to enable BAN systems to communicate physiological data. This paper provides an overview of existing wireless technologies applicable to BANs. The specific features of each wireless technology is described along with their major advantages, drawbacks and most appropriate application in BANs. Comparison of the described technologies are provided from different aspects of frequency range, data rate, coverage area, modulation technique and network topology.

Studying the Impact of the CORNER Propagation Model on VANET Routing in Urban Environments

Abstract: Accurate modelling of the radio channel is often the most difficult aspect of a Vehicular Ad Hoc Network (VANET) simulation due to the large variability present in vehicular terrain CORNER is a propagation model that calculates path-loss in an urban terrain with a large concentration of buildings, based on the position of the transmitter and receiver on a street map This paper proposes additions to the CORNER propagation model to take selective multi-path fading into account and investigates the performance of the GPSR routing protocol under the CORNER propagation model in a realistic city environment

A power efficient RAT selection algorithm for heterogeneous wireless networks

Abstract: The Fourth Generation of wireless network (4G) is a heterogeneous network where different Radio Access Technologies (RATs) are integrated. This requires a need for Common Radio Resource Management (CRRM) to support efficient utilization of radio resources and to provide the required Quality of Service (QoS) for allocated calls. RAT selection algorithms are an important part of CRRM. This paper proposes an intelligent hybrid power efficient RAT selection algorithm (patent pending1). It is a battery power saver algorithm which includes sorting available RATs, collecting information on each RAT using the IEEE P1900.4 Protocol, and making decisions for selecting the most suitable RAT for incoming calls. The proposed power efficient algorithm is compared to centralized and distributed algorithms in terms of new call blocking and Vertical Handover (VHO) call dropping probabilities. Users' satisfactions probability and saving battery power percentage are also compared. Simulation results show that the proposed algorithm performs better than the centralized and distributed algorithms in terms of blocking, dropping and users' satisfactions probabilities. The proposed and the distributed algorithms have similar performance in term of saving battery power, and both perform better than the centralized algorithm.

WSNs Coverage Hole Partial Recovery by Nodes' Constrained and Autonomous Movements Using Virtual alpha-chords

Abstract: —In WSNs, in order to recover from coverage holesand to mitigate their indirect/direct effects on networks’ perfor-mance, different recovery strategies such as increasing proximatenodes’ transmission range and/or relocation of nodes towardscoverage holes seem to be appropriate solutions. Since the major-ity of a mobile node’s energy is consumed by movement and sincenodes’ residual energy may be affected by damage events, nodemovements should be performed sparingly. Conventional nodes’information exchange in real-time applications with security andinterference concerns are neither practical nor secure. Therefore,for the aforementioned scenarios, at the price of possible node col-lisions, disconnections, and reasonable compromises, promisingdistributed and autonomous node movement algorithms based onlimited 1-hop neighbour knowledge are proposed. Our proposedautonomous and constrained node movement model based on anode’s 1-hop perception provides a feasible and rapid recoverymechanism for large scale coverage holes in real-time and harshenvironments. Our model not only maintains moving nodes’connectivity to the rest of network to some extent, but also offersemergent cooperative recovery behaviour among autonomousmoving nodes. Our movement model based on virtual chordsformed by nodes and their real and virtual 1-hop neighbours,not only confines node movement range, but also takes the issueof moving nodes’ connectivity into account. Suitable performancemetrics for partial recovery via constrained movement are intro-duced to compare the performance and efficiency of our modelwith conventional Voronoi-based movement algorithms. Resultsshow that our proposed model’s performance is comparable withVoronoi-based movement algorithms.Index Terms—Coverage holes; autonomous and constrainedmovements; Wireless sensor networks; virtual chord.

A fuzzy logic node relocation model in WSNs

Abstract: Hostile and harsh environments may preclude the possibility of manual redeployment of new sensor nodes, especially in the areas suffering from widespread damage and unbalanced node deployments. Distributed local relocations of currently deployed nodes is one promising solution to this problem. By using expected global node density and force-based movement algorithms inspired by the laws of nature, it is possible to address the aforementioned challenge. Force-based movement algorithms steer nodes towards their new locations based on the aggregation of exerted virtual forces on the node from their neighborhood. Some implicit assumptions about nodes' global status such as expected global node density are not realistic in dynamic and harsh environments. Thus, to conform to the uncertain nature and local interactions of nodes, a combination of radial-angular force fuzzy movement algorithms is suggested. The performance of the proposed model in terms of percentage of coverage, uniformity and average movement under three different boundary conditions are evaluated and compared with distributed self-spreading algorithms (DSSA). The results show that the simple fuzzy movement algorithm either outperforms or matches DSSA even if nodes don't benefit from expected global node density as in DSSA.

A mobility optimization CRRM approach for Next Generation Wireless Networks

Abstract: Next Generation Wireless Networks (NGWN) are predicted to be heterogeneous in nature This is achieved through the integration of different Radio Access Technologies (RATs) over a common platform Common Radio Resource Management (CRRM) was proposed to manage radio resource utilization in heterogeneous wireless networks and to provide required Quality of Service (QoS) for allocated calls RAT selection algorithms are an integral part of the CRRM algorithms Their role is to decide, when a new or Vertical Handover (VHO) call is requested, which of the available RATs is most suitable to fit the need of the incoming call and when to admit them In this paper, we propose an intelligent hybrid RAT selection approach for mobility optimization (patent pending 1) which includes sorting available RATs, collecting information on each RAT using the IEEE P19004 Protocol, and making decisions for selecting the most suitable RAT for incoming calls A comparison for the performance of centralized load-balancing, distributed and the proposed mobility optimization algorithms is presented in terms of new calls blocking probability, VHO calls dropping probability and satisfactions probability Simulation results show that the proposed algorithm performs better than the centralized load-balancing and distributed algorithms in terms of blocking, dropping and satisfactions probabilities

Outage Probability Analysis of Dual Hop Relay Networks in Presence of Interference

Abstract: Cooperative relaying improves the performance of wireless networks by forming a network of multiple independent virtual sources transmitting the same information as the source node. However, interference induced in the network reduces the performance of cooperative communications. In this work the statistical properties, the cumulative distribut ion function (CDF) and the probability density function (PDF) for a basic dual hop cooperative relay network with an arbitrary number of interferers over Rayleigh fading channels are derived. Two system models are considered: in the first system model, the interferers are only at the relay node; and in the second s ystem model, interferers are both at the relay and the destination. This work is further extended to Nakagami-m faded interfering channels. Simulation results are presented on outage probability performance to verify the theoretical analysis.

Location-Based Utilization for Unidirectional Links in MANETs

Abstract: Heterogeneous Mobile Ad hoc Network(HMANET) comprises different nodes with different capabilities. Hence, transmission and receiving capabilities are different. This causes unidirectionality problem. Avoidances is the most used strategy in researches to route data, e.g., Blacklist. In this paper, we proposed a strategy for on-demand routing protocols to detect unidirectional link and resolve it in timely fashion. This strategy is based on utilizing locations of nodes to filter and cache incoming RREQ packets to find reliable path to destination in the existence of unidirectional links. Simulation results show that our strategy outperforms Blacklist strategy in homogeneous and heterogeneous MANET. Keywords-MANET; routing protocol; unidirectional link; AODV;

NFMIC Cooperative Communication Methods for Body Area Networks

Abstract: To achieve higher data rate or to extend the coverage range of a wireless communication system, cooperative relay has been seen as a promising solution. This concept has been integrated in many traditional wireless communication networks. However, it has not been extensively examined for near field magnetic induction communication (NFMIC) systems. This paper aims to apply cooperative relay to NFMIC in a sense that is applicable to body area networking, since NFMIC is stated to be a suitable physical layer for body area networks. We have shown that using idle NFMIC nodes as relaying terminals, the system performance will be enhanced, as compared to a point to point communication system. In this context we have proposed three relaying methods to enhance the data rate and the received signal power in a personal area network. The relaying strategies are denoted as MI-Relay, MAMI Relay1 and MAMI Relay2. In this paper, using theoretical studies and simulation results, we have compared the performance of the three strategies and we have shown that higher data rates can be achieved through MAMI Relay1. However, we have discussed that the separation distance between relaying nodes and the source or destination can be a key factor for relay node selection.

On the impact of RD link in resource allocation for multi-cell OFDMA cooperative relay networks with partial CSI

Abstract: This paper investigates the impact of the relay-to-destination channel gain on subcarrier allocation for uplink OFDMA based cooperative relay networks using multiple amplify-and- forward (AF) relaying protocols. The closed form outage probability is derived for the system under partial channel state information (PCSI) and considering the presence of intercell interference (ICI). The results show that the impact of the link between the relay station and the destination is very low when the ICI is high. Hence, under this condition, the channel information of this link can be ignored during the resource allocation which significantly reduces the complexity of the resource allocation processes. Furthermore, this paper quantifies the level of interference at which the RD link can be ignored.