Recent advances in wireless communications and networks
Ke Zhang, Hassnaa Moustafa, Sherali Zeadally · Wireless Communications and Mobile Computing · 2009
Welcome to this special issue of the Wiley's Wireless Communications and Mobile Computing Journal. This special issue is devoted to the topic of the latest research and development in the field of wireless communications and networking. With the explosive growth of the ever-increasing users' demands for broadband services, there are a number of emerging wireless technologies, including cognitive radio, wireless sensor networks, WiMAX/LTE, adaptive communications, etc. These technologies have led to significant innovations that enable systems in providing more bandwidth with convenient and inexpensive deployment and mobility. This issue called for papers in various aspects of recent wireless communications and mobile networking. In this special issue, we selected 11 papers to show the recent advances. The papers cover both topical and innovative areas. A detailed overview of the selected works is given below. In 'A Software-Defined Radio Based Cognitive Radio Demonstration over FM Band', R. Zhou et al. present a software-defined radio (SDR) based cognitive radio (CR) implementation and demonstration over the frequency. The authors have proposed, implemented, and demonstrated a frequency hopping scheme over multiple spectrum holes to support multiple secondary users while attaining the minimum interference among the users. In 'A Sensing-Based Cognitive Coexistence Method for Interfering Infrastructure and Ad-Hoc Systems', S. Geirhofer et al. present a novel cognitive coexistence framework, which enables an infrastructure system to reduce interference to ad hoc or peer-to-peer communication links in close proximity. They study how the centralized resource allocation can accommodate the ad hoc links based on sensing and predicting their interference patterns. Results illustrate that utilizing the superior flexibility of the infrastructure links can effectively mitigate interference. In 'Medium Access Control Protocols in Cognitive Radio Networks', J. Xiang et al. make a comprehensive survey of the state-of-the-art MAC and categorize the MAC protocols on the basis of spectrum sharing mechanisms, i.e., overlay and underlay modes. In each mode, they discuss the protocols in both centralized and distributed manners. Finally, they summarize the schemes and identify several open research issues in the realization of cost-efficient MAC protocols. In 'Constructing Secured Cognitive Wireless Networks: Experiences and Challenges', C. Li et al. conduct a high-level survey to review and reflect the state-of-the-art work on the security issues in cognitive radio networks. They focus on analyzing the security system at the macroscopic level, where both protection and detection are considered to be the most essential parts to ensure security in the whole network. Furthermore, they investigate special characteristics of cognitive radio network at different protocol layers, including physical layer, link layer, network layer, transport layer, and application layer. In 'Adaptive Antenna Selection at Mobile Stations for SDMA in WiMAX Networks', Wang et al. present a new antenna selection protocol associated with low signaling and implementation complexity overhead. The protocol has been developed for next-generation IEEE 802.16 mobile stations operating in space division multiple access (SDMA) mode. The authors demonstrate through simulation and analysis that the proposed protocol performs better than traditional IEEE 802.16 terminals that do not have support for antenna selection. The robustness of the protocol is further demonstrated by its capability to adapt different channel conditions. In 'Per-User Service Model for Opportunistic Scheduling Scheme over Fading Channels', Dianati et al. investigated opportunistic scheduling for data transmissions from a single base station to several users. They demonstrate that the received service by a single user can be modeled analytically as a finite-state Markov process under saturated conditions when user queues are heavily loaded. The simulation results obtained closely match those predicted by the proposed analytical model demonstrating the efficacy and accuracy of the model. In 'TinyNET—A Tiny Network framework for TinyOS: Description, Implementation and Experimentation', Castellani et al. present the architecture of an interesting modular network framework that is aimed at speeding up the development and integration of wireless sensor network applications and protocols in TinyOS. By exploiting the framework interfaces, components can be rapidly developed, debugging is made much easier, and software maintenance is simplified because of the in-built modularity. The authors also present a proof-of-concept scenario that explores the proposed framework's basic functionalities and the associated overheads it incurs. The results demonstrate that TinyNET provides significant benefits with no additional complexity and memory costs. In 'Towards Utility-optimal Random Access without Message Passing', Y. Yi et al. study a generalization of CAMA algorithm. In the continuous-time model, a proof is presented of the convergence of these adaptive CSMA algorithms to be arbitrarily close to utility optimality, without assuming that the network dynamics converge to an equilibrium in between consecutive CSMA parameter updates. In the more realistic, slotted-time model, the impact of collisions on the utility achieved is characterized, and the tradeoff between optimality and short-term fairness is quantified. In 'Cross-layer design of joint routing and rate control in ad hoc wireless networks', Ju-Lan et al. present an adaptive modulation coding scheme in multi-hop wireless network in which each node independently selects its cross-layer parameter vector for each packet that it forwards. Furthermore, to enable throughput-effective network operations, a cross-layer scheme is presented under which each node configures its parameter vector by using the link transport capacity measure that it computes as a key metric. The results demonstrate the efficiency of the proposed schemes employing the link transport capacity measure. In 'PC-MAC: Pico Cellular MAC Protocol for Motorway Vehicular Multimedia Communication (extended version)', Bilal et al. presented a detailed analysis of real vehicular traffic data taken from inductive loops on a motorway, and developed their own vehicular simulator to study real-time vehicular traffic scenarios in which a main BS is responsible for multimedia communication. The pico cellular medium access control (PC-MAC) protocol is introduced as a novel MAC protocol combining CSMA and S-TDMA for multimedia communication with optimal utilization for a motorway environment. This proposed protocol was integrated in the simulator to allow managing the access to the base station. In 'Behavior of Clock-Sampling Mutual Network Synchronization in Wireless Sensor Networks: Convergence and Security', MacNeil et al. presented some simulation results that indicate the potential of clock sampling mutual network synchronization algorithm (CS-MNS) to achieve high clock synchronization accuracy in mobile multi-hop wireless networks. It is shown through analysis that in the absence of offset errors the network clocks converge. Finally, a method for adding external reference synchronization that is compatible with a security discussion, given in the paper, is proposed. Finally, we would like to express our gratitude to the Editor-in-Chief, Dr. Mohsen Guizani for his advice, patience, and encouragements since the beginning until the final stage. We thank all anonymous reviewers who spent much of their precious time reviewing all the papers. Their timely reviews and comments greatly helped us select the best papers in this special issue. We also thank all authors who have submitted their papers for consideration for this issue. A special thank goes to Jennifer Chichester Hillier, who made a great effort on the production of this issue within a very tight schedule. We hope you will enjoy reading the great selection of papers in this issue.