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

Horizontally expanded and vertically stacked optical banyan (HVOB) is a general architecture for constructing banyan-based optical switches. Blocking analysis is an effective approach to studying network performance and finding a graceful compromise among hardware cost, network depth and blocking probability; however, little has been done on analyzing the blocking behavior of general HVOB networks. In this paper, we study the overall blocking behavior of a HVOB network, where an upper bound on the blocking probability of the network is developed. The upper bound depicts accurately the overall performance behavior of a HVOB network as verified by extensive simulation results and it agrees with the strictly nonblocking condition of the network. The derived upper bound is significant because it reveals the inherent relationship among blocking probability, network depth, and network hardware cost, by which a desirable tradeoff can be made among them. In particular, our bound provides network developers an effective tool to estimate the maximum blocking probability of a HVOB network in which different routing algorithms can be applied with a guaranteed performance in terms of blocking probability, hardware cost and network depth. An important conclusion drawn from our work is that the hardware cost of HVOB networks can be reduced dramatically without introducing either significantly high blocking probability or a large network depth.

Blocking probability modeling of distensible optical banyan networks

Network-wide local unambiguous failure localization (NL-UFL) has been demonstrated as an interesting scenario of monitoring trails (m-trails). It attempts to enable every node to autonomously localize any failure event in the network in a distributed and all-optical manner by inspecting a set of m-trails traversing through the node. This paper investigates the m-trail allocation problem under the NL-UFL scenario by taking each link and node failure event into consideration. Bound analysis is performed using combinatorial group testing (CGT) theory and this is followed by the introduction of a novel heuristic on general topologies. Extensive simulation is conducted to examine the proposed heuristic in terms of the required cover length and the number of m-trails to achieve NL-UFL.

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Signaling Free Localization of Node Failures in All-Optical Networks

A vertically stacked optical banyan (VSOB) network is attractive for serving as the optical switch architecture due to its small depth and absolute signal loss uniformity. A plane fixed routing (PFR) algorithm with optimal time complexity was proposed recently for rapid connection setup in a rearrangeable VSOB architecture. In this paper, we conduct the performance analysis of a high-speed PFR-based VSOB network and introduce an analytical model on blocking probability of the network when component failures (link failure and switching element failure) are considered. Simulation is conducted to verify the model, in which the simulation results show that the proposed analytical model can accurately describe the blocking behavior of a high-speed PFR-based VSOB network. The model significantly contributes to the related areas by providing network developers a quantitative guidance to determine the effects of adopting high-speed PFR algorithm, network component failures and workload variation on the blocking behavior of a VSOB network.

Blocking probability of a high-speed optical switching network in presence of component failures

This paper introduces a novel distributed antenna access architecture for achieving a cost-effective solution of 5G indoor service provisioning. The proposed architecture takes advantage of multi-pair local area network (LAN) cables to support simultaneous transmission of multiple baseband and intermediate frequency (IF) signals between the remote radio unit (RRU) and each distributed antenna unit (DAU), so as to meet the massive antenna requirements and overcome the non-line-of-sight nature of the indoor environment with extremely low cost. Two new functional modules, namely Multi-Pair Air-to-Cable (MP-A2C) and DeFEXTer, are defined at the RRU for the purpose of resource mapping between the antenna signals and the LAN cable sub-channels, as well as the mitigation of far end crosstalk (FEXT) due to the signal traversal along the LAN cable. We will discuss in detail the proposed system architecture and enumerate the research issues.

A Novel 5G Indoor Service Provisioning Architecture

Network protection mechanisms are critical in the design of IP-based networks In GMPLS networks, backup path protection and Shared-backup protection have been widely studied More recent protection mechanisms, Self-Protecting Multipath (SPM), can be implemented in GMPLS networks In this paper, we evaluate the traffic provision in SPM GMPLS networks where events of up to two simultaneous link failure can occur We present a mathematical formulation to perform optimal capacity allocation in an SPM network environment Network Service Provider (NSP) could use this mathematical model to design a network with certain availability requirement according to Service Level Agreement(SLA) of each connection requirement in dual link failure scenarios

Pin-Han Ho

Papers

Blocking probability modeling of distensible optical banyan networks

Signaling Free Localization of Node Failures in All-Optical Networks

Blocking probability of a high-speed optical switching network in presence of component failures

A Novel 5G Indoor Service Provisioning Architecture

Availability-aware multiple working-paths capacity provisioning in GMPLS networks