Osamah S. Badarneh

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.

Opportunistic medium access control for maximizing packet delivery rate in dynamic access networks

One of the key challenges to enabling efficient cognitive radio (CR) communications is how to perform opportunistic medium access control (MAC) that maximizes spectrum efficiency. Several CRN MAC protocols have been designed assuming relatively static primary radio (PR) channels with average idle durations largely exceed CR transmission times. For such CR environment, typical multichannel MAC protocols, which select the best quality channel, perform reasonably well. However, when such mechanism is employed in a CRN that coexists with highly dynamic licensed PR networks (PRNs), where PR channel idle durations are comparable to CR transmission times, the forced-termination rate for CR transmission can significantly increase, leading to a reduction in network throughput. To reduce the forced-termination rate, many MAC protocols have been proposed to account for the dynamic time-varying nature of PR channels by requiring communicating CR users to consistently perform channel switching according to PR activities. However, such channel-switching strategy introduces significant overhead and latency, which negatively affect network throughput. Hence, in this paper, we propose a probabilistic channel quality- and availability-aware CRN MAC. Our protocol uses a novel channel assignment mechanism that attempts at maximizing the packet success probability of each transmission and hence avoids the significant overhead and latency of channel switching. Simulation results show that by being quality- and availability-aware, our protocol provides better spectrum utilization by decreasing the forced-termination rate and improving network throughput.

Performance Analysis of Spatial Modulation and Space-Shift Keying With Imperfect Channel Estimation Over Generalized

Novel performance analysis of spatial modulation (SM) and space-shift keying (SSK) over generalized η-μ fading channels in the presence of Gaussian imperfect channel estimation at the receiver is presented in this paper. A general expression for the pairwise error probability (PEP) is derived along with an asymptotic expression at high signal-to-noise ratio (SNR). The η-μ fading channel has Nakagami-m, Rayleigh, one-sided Gaussian, and Nakagami-q (Hoyt) channels as special cases. The derived expression for the PEP is valid for integer and noninteger values of the fading parameter μ. The impact of channel estimation errors with different η and μ values is investigated. Analytical results are sustained through Monte Carlo simulation results, and a close match is reported for a wide range of SNR and for different system parameters.

\eta{-}\mu

In this paper, we introduce a probabilistic routing metric that considers the peculiar characteristics of the operating environment of cognitive radio networks (CRNs). This metric captures the dynamic changes in channel availabilities due to the randomness of primary users activity and the rich channel diversity due to the fact that a CRN is expected to operate over highly separated frequency channels with different propagation characteristics. Our metric, Probability of Success (PoS), statistically quantifies the chances of a successful cognitive radio (CR) packet transmission over a given channel. Based on the PoS metric, we propose a joint probabilistic routing and channel assignment protocol for multi-hop CRNs that attempts at selecting the path with the maximum probability of success among all possible paths for a given CR source-destination pair. Selecting such a path results in minimizing the number of disruptions to CR packet transmissions, which consequently improves network throughput. Simulation results verify the significant throughput improvement achieved by our protocol compared to reference CRN routing protocols.

Fading Channels

This paper analyzes and evaluates the performance of digital communication systems that operate over the α-η-μ fading channels. More specifically, we derived novel, unified, and exact closed-form analytical expressions for the cumulative density function (CDF), the moment-generating function (MGF), the average channel capacity, and the average symbol error probability (SEP) for several coherent and non-coherent modulation schemes. Note that the derived expressions are valid for arbitrary values of the fading parameters. The derived expressions are then used to study the implication of the fading parameters on system performance. In addition, the performance over other well-known fading channels, such as η-μ and α-μ, as well as their inclusive special cases, can be analyzed using our results. To validate the correctness of our derivations, the numerical results are compared with Monte Carlo simulation results. Both results are in perfect agreement over a wide range of average signal-to-noise ratio (SNR) and different values of the fading parameters.

Probabilistic quality-aware routing in cognitive radio networks under dynamically varying spectrum opportunities

In this paper, we present a comprehensive framework for quadrature spatial modulation (QSM) in generalized fading channels. In particular, the performance analysis of QSM systems in the presence of imperfect channel knowledge and under correlated fading channels is presented. A simple and closed-form expression for the pairwise error probability (PEP) is provided. Based on the obtained PEP, a closed-form upper bound expression for the average bit error probability (BEP) is obtained. The analysis is unified in the sense that it is applicable for any fading channel once its envelope and phase distributions are available. As such, different generalized fading distribution models, namely, η-μ, κ-μ, and α-μ distributions, are considered. The obtained results clearly show the influence of the fading parameters on the average BEP. In the case of the α-μ fading channels, increasing α has larger negative impact on the average BEP compared with increasing μ. For the κ-μ channels, increasing μ results in increasing the average BEP dramatically when compared with increasing κ. In the same context, in η-μ fading channels, as μ increases the average BEP degrades whereas increasing η slightly improves the average BEP. In addition, it is demonstrated that transmit-antenna correlation significantly deteriorate the average BEP when compared with receive-antenna correlation.

Performance Analysis of Digital Communication Systems Over

This letter considers the average symbol error rate (SER) of M-ary phase shift keying (M-PSK) over the α-η-μ fading channels subject to additive Laplacian noise. Specifically, novel unified closed-form expressions for the average SER are derived and evaluated. The derived expressions include other wellknown general fading channels such as η-μ, α-μ, and their inclusive ones as special cases. Numerical results are presented to study the influence of the fading parameters on the average SER. In addition, simulation results are provided to prove the correctness of the analytical results.

\alpha{-}\eta{-}\mu

The performance of spectrum-sensing based energy-detection (ED) in cognitive radio networks (CRNs) over the extended generalized-K (EGK) fading channels is analyzed. More specifically, exact and accurate analytical expressions for the average detection probability under different detection scenarios, such as, single channel (no diversity), diversity reception, and cooperative spectrum sensing, are derived and evaluated. The derived analytical framework can be used for both integer and non-integer values of the fading/shadowing parameters. The impact of the fading/shadowing parameters on the performance of energy detectors is studied in terms of receiver operating characteristics (ROC) curves. To verify the correctness of our analysis, the derived analytical expressions are corroborated via Monte-Carlo simulation results.

Fading Channels

Dual-hop transmission systems employing decodeand-forward relay are studied in this paper. The examination has been done for independent, but not necessarily identical Extended Generalized-K fading channels. New, exact, closedform expressions are derived for the outage probability, the nth moments of the end-to-end signal-to-noise ratio (SNR), and the ergodic capacity. Moreover, the average symbol error probability (ASEP) for coherent and non-coherent modulation schemes is derived. Analytical results along with simulation results are obtained with excellent agreement.

A Comprehensive Framework for Quadrature Spatial Modulation in Generalized Fading Scenarios

The end-to-end performance of cooperative beamforming in dual-hop relaying systems operating over η - μ fading channels is investigated. In the analysis, the source-destination node pair is equipped with multiple antennas, whereas the fixedgain relay has a single antenna. The η - μ fading channel has Nakagami-m, Rayleigh, one-sided Gaussian, and Nakagami-q (Hoyt) channels as special cases. In this paper, novel statistical expressions for the generalized moments of the end-to-end signal- to-noise ratio (SNR), cumulative density function (cdf), probability density function (pdf), and moment-generating function (mgf) are derived and evaluated. Furthermore, the obtained results are used to derive new and simple expressions for the pdf, the outage probability, and the mgf of the end-to-end SNR over Nakagami-m fading channels. In addition, we show that the derived expression for parameter C over the Nakagami-m fading channel is incorrect, and hence, it leads to inaccurate results. Also, we study the impact of the fading parameters η and μ on the end-to-end system performance. Simulation results show that, in contrast to the fading parameter η, μ has a significant impact on the system performance.