Cooperative spectrum sensing in cognitive radio networks: A survey

This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

The Transmission Control Protocol.

With the rapid deployment of new wireless devices and applications, the last decade has witnessed a growing demand for wireless radio spectrum. However, the fixed spectrum assignment policy becomes a bottleneck for more efficient spectrum utilization, under which a great portion of the licensed spectrum is severely under-utilized. The inefficient usage of the limited spectrum resources urges the spectrum regulatory bodies to review their policy and start to seek for innovative communication technology that can exploit the wireless spectrum in a more intelligent and flexible way. The concept of cognitive radio is proposed to address the issue of spectrum efficiency and has been receiving an increasing attention in recent years, since it equips wireless users the capability to optimally adapt their operating parameters according to the interactions with the surrounding radio environment. There have been many significant developments in the past few years on cognitive radios. This paper surveys recent advances in research related to cognitive radios. The fundamentals of cognitive radio technology, architecture of a cognitive radio network and its applications are first introduced. The existing works in spectrum sensing are reviewed, and important issues in dynamic spectrum allocation and sharing are investigated in detail.

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Advances in cognitive radio networks: A survey

Intelligent reflecting surface (IRS) is an enabling technology to engineer the radio signal propagation in wireless networks. By smartly tuning the signal reflection via a large number of low-cost passive reflecting elements, IRS is capable of dynamically altering wireless channels to enhance the communication performance. It is thus expected that the new IRS-aided hybrid wireless network comprising both active and passive components will be highly promising to achieve a sustainable capacity growth cost-effectively in the future. Despite its great potential, IRS faces new challenges to be efficiently integrated into wireless networks, such as reflection optimization, channel estimation, and deployment from communication design perspectives. In this paper, we provide a tutorial overview of IRS-aided wireless communications to address the above issues, and elaborate its reflection and channel models, hardware architecture and practical constraints, as well as various appealing applications in wireless networks. Moreover, we highlight important directions worthy of further investigation in future work.

Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial

Use of relays is considered one of the most effective ways for capacity enhancement and coverage extension in next-generation broadband wireless access networks (BWAN). The paper investigates the location planning problem in BWANs, aiming at an optimal deployment of relay stations and base stations to enhance capacity. We develop formulations in mixed integer linear programming to effectively capture various planning policies that govern relay and base station placement. Case studies are conducted to verify the effectiveness of the proposed formulations. We show that the same traffic demand can be satisfied with up to 73 % fewer relay stations with a slight (6 %) decrease in the overall network capacity, compared with our benchmark. Based on the developed formulations, we introduce a maximin objective function to properly distribute excess bandwidth to all subscriber stations rather than assigning it to a single one, which surprisingly leads to a significant gain in the rate allocated to each subscriber station.

Optimal location planning of relay-based next generation wireless access networks

The paper proposes a novel distributed control architecture for shared protection with reduced complete routing information, which aims to initiate a graceful compromise between the amount of link-state dissemination and the performance impairment due to the incompleteness of routing information. We first give explicit and comprehensive descriptions on a number of reported routing information dissemination scenarios for shared protection. A novel framework of link-state dissemination for facilitating shared protection, called reduced complete routing scenario, is introduced, in which the singular value decomposition (SVD) transformation is adopted to deal with the information reduction. We show, through simulation, that the proposed scheme can achieve a higher throughput and a better estimation in reconstruction of the spare provision matrix than the other schemes taking the same complexity of link-state dissemination.

A novel distributed control architecture for shared protection

The multi-stage coordinated attack (MSCA) bring many challenges to the security analysts due to their special temporal an spacial characteristics. This paper presents a two-sided model, Janus, to characterize and analyze the the behavior of attacker and defender in MSCA. Their behavior is firstly formulated as Multi-agent Partially Observable Markov Decision Process (MPO-MDP), an ANTS algorithm is then developed from the perspective of attacker to approximately search attack schemes with the minimum cost, and another backward searching algorithm APD-BS is designed from the defender's standpoint to seek the pivots of attack schemes in order to effectively countermine them by removing those key observations associated with the system state estimates. Two case studies are conducted to show the application of our models and algorithms to practical scenarios, some preliminary analysis are also given to validate their performance and advantages.

Janus: a two-sided analytical model for multi-stage coordinated attacks

Optical Burst Switching (OBS) has been proposed as a new paradigm to achieving a practical balance between Optical Circuit Switching (OCS) and Optical Packet Switching (OPS). Hybrid Optical Networks (HON) that combines OCS and OBS has emerged to grant the OBS network the ability to support connection-oriented applications. Although efficient in terms of reducing the burst loss probability as well as improving the overall network performance, it provides a limited degree of Quality of Service (QoS). What we mean by QoS is the capability of a network to provide a guaranteed level of availability while satisfying strict limits on delay. In this paper, we propose new hybrid architecture for OBS networks. The proposed architecture qualifies the OBS network to support different classes of QoS.

A new hybrid architecture for optical burst switching networks

The paper tackles the resource allocation problem for optical networks supporting virtual private networks (O-VPNs), in which working and spare capacities are allocated in the networks for satisfying a series of traffic matrices corresponding to each O-VPN. Based on the (M:N)/sup n/ protection architecture defined in generalized multiprotocol label switching (GMPLS), we propose two novel integer linear program (ILP) models, namely ILP-I and ILP-II, aiming to initiate a graceful compromise between the capacity efficiency and computation time without losing the ability of addressing QoS requirements in each O-VPN. Experiment results show that, in terms of capacity efficiency, a significant improvement is achieved by ILP-I compared to ILP-II at the expense of higher computation time. Although ILP-II is outperformed by ILP-I, it can handle the situation with an arbitrary size of O-VPNs. We conclude that the proposed ILP models yield a scalable solution for capacity planning in survivable optical networks supporting O-VPNs based on the (M:N)/sup n/ protection architecture.

Pin-Han Ho

Papers

Optimal location planning of relay-based next generation wireless access networks

A novel distributed control architecture for shared protection

Janus: a two-sided analytical model for multi-stage coordinated attacks

A new hybrid architecture for optical burst switching networks

Towards a scalable design for survivable optical virtual private networks (O-VPNs)