Showing papers by "Mehran Abolhasan published in 2011"

A Comprehensive Survey on RAT Selection Algorithms for Heterogeneous Networks

Abstract: Due to the coexistence of different Radio Access Technologies (RATs), Next Generation Wireless Networks (NGWN) are predicted to be heterogeneous in nature. The coexistence of different RATs requires a need for Common Radio Resource Management (CRRM) to support the provision of Quality of Service (QoS) and the efficient utilization of radio resources. RAT selection algorithms are part of the CRRM algorithms. Simply, their role is to verify if an incoming call will be suitable to fit into a heterogeneous wireless network, and to decide which of the available RATs is most suitable to fit the need of the incoming call and admit it. Guaranteeing the requirements of QoS for all accepted calls and at the same time being able to provide the most efficient utilization of the available radio resources is the goal of RAT selection algorithm. The normal call admission control algorithms are designed for homogeneous wireless networks and they do not provide a solution to fit a heterogeneous wireless network which represents the NGWN. Therefore, there is a need to develop RAT selection algorithm for heterogeneous wireless network. In this paper, we propose an approach for RAT selection which includes receiving different criteria, assessing and making decisions, then selecting the most suitable RAT for incoming calls. A comprehensive survey of different RAT selection algorithms for a heterogeneous wireless network is studied. Keywords—Heterogeneous Wireless Network, RAT selection algorithms, Next Generation Wireless Network (NGWN), Beyond 3G Network, Common Radio Resource Management (CRRM).

Boundary node selection algorithms in WSNs

Abstract: Physical damage and/or node power exhaustion may lead to coverage holes in WSNs. Coverage holes can be directly detected by certain proximate nodes known as boundary nodes (B-nodes). Due to the sensor nodes' redundant deployment and autonomous fault detection, holes are surrounded by a margin of B-nodes (MB-nodes). If all B-nodes in the margin take part in the hole recovery processes, either by increasing their transmission power or by relocating towards region of interest (ROI), the probability of collision, interference, disconnection, and isolation may increase affecting the rest of the network's performance and QoS. Thus, distributed boundary node selection algorithms (BNS-Algorithms) are proposed to address these issues. BNS-algorithms allow B-nodes to self-select based on available 1-hop information extracted from nodes' simple geometrical and statistical features. Our results show that the performance of the proposed distributed BNS-algorithms approaches that of their centralized counterparts.

On the Error Exponent of Amplify and Forward Relay Networks

Abstract: In this letter we derive the exact random coding error exponent of a dual hop amplify and forward (AF) relay network with channel state information (CSI) assisted ideal relay gain. Numerical results have been presented, which provide insight about the performance tradeoff between the error exponent and the data rate of the network. Finally we present the capacity analysis of this relay network.

On the Symbol Error Probability of Multihop Parallel Relay Networks

Abstract: In this paper we analyze the symbol error probability (SEP) of a cooperative multihop parallel relay network in Rayleigh fading channels for M-ary Phase-shift keying (M-PSK) modulation. The general closed form expression of the SEP is derived. We present numerical results on the performance of the network.

Hierarchical Collision-free Addressing Protocol(HCAP) for Body Area Networks

Abstract: In Body Area Networks (BANs) the addressing scheme used to address nodes is fundamental to the effective operation of a BAN. This paper proposes a novel BAN addressing scheme called Hierarchical Collision-free Addressing Protocol (HCAP). Proposed scheme is collision free, reduces power consumption and tackles the address wastage problem. Two important scenarios (random location and fixed location) are defined and studied. Through a series of simulation results we show the efficiency and usability of the proposed scheme in Body Area Networks.

Addressing Schemes for Body Area Networks

Abstract: This letter explores address allocation in Body Area Networks (BANs) and proposes two novel schemes - Optimized Prophet Address Allocation (OPAA) and Hierarchical Collision-free Address Protocol (HCAP). The aim of the schemes is to use fewer bits in the address space, solve address wastage problems, reduce collisions and improve power efficiency. The usability and efficiency of the proposed schemes is shown through simulation and analysis.

Optimized prophet address allocation (OPAA) for Body Area Networks

Abstract: Each node in a Body Area Network (BAN) needs to be assigned with a free IP address before it may participate in any sort of communication. This paper evaluates the performance of an IP address allocation scheme, namely Prophet allocation to be used for BANs. This allocation scheme is a fully decentralized addressing scheme which is applicable to BANs as it provides low latency, low communication overhead and low complexity. Relative theoretical analysis and simulation experiments have also been conducted to demonstrate its benefits which also represent the reason for the choice of this allocation scheme. It also solves the issues related to network partition and merger efficiently.