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

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.

/pdf/advances-in-cognitive-radio-networks-a-survey-3gp2nvo27m.pdf

Advances in cognitive radio networks: A survey

Bitcoin is a popular cryptocurrency that records all transactions in a distributed append-only public ledger called blockchain . The security of Bitcoin heavily relies on the incentive-compatible proof-of-work (PoW) based distributed consensus protocol, which is run by the network nodes called miners . In exchange for the incentive, the miners are expected to maintain the blockchain honestly. Since its launch in 2009, Bitcoin economy has grown at an enormous rate, and it is now worth about 150 billions of dollars. This exponential growth in the market value of bitcoins motivate adversaries to exploit weaknesses for profit, and researchers to discover new vulnerabilities in the system, propose countermeasures, and predict upcoming trends. In this paper, we present a systematic survey that covers the security and privacy aspects of Bitcoin. We start by giving an overview of the Bitcoin system and its major components along with their functionality and interactions within the system. We review the existing vulnerabilities in Bitcoin and its major underlying technologies such as blockchain and PoW-based consensus protocol. These vulnerabilities lead to the execution of various security threats to the standard functionality of Bitcoin. We then investigate the feasibility and robustness of the state-of-the-art security solutions. Additionally, we discuss the current anonymity considerations in Bitcoin and the privacy-related threats to Bitcoin users along with the analysis of the existing privacy-preserving solutions. Finally, we summarize the critical open challenges, and we suggest directions for future research towards provisioning stringent security and privacy solutions for Bitcoin.

A Survey on Security and Privacy Issues of Bitcoin

The complexity of indoor radio propagation has resulted in location-awareness being derived from empirical fingerprinting techniques, where positioning is performed via a previously-constructed radio map, usually of WiFi signals. The recent introduction of the Bluetooth Low Energy (BLE) radio protocol provides new opportunities for indoor location. It supports portable battery-powered beacons that can be easily distributed at low cost, giving it distinct advantages over WiFi. However, its differing use of the radio band brings new challenges too. In this work, we provide a detailed study of BLE fingerprinting using 19 beacons distributed around a $\sim\! 600\ \mbox{m}^2$ testbed to position a consumer device. We demonstrate the high susceptibility of BLE to fast fading, show how to mitigate this, and quantify the true power cost of continuous BLE scanning. We further investigate the choice of key parameters in a BLE positioning system, including beacon density, transmit power, and transmit frequency. We also provide quantitative comparison with WiFi fingerprinting. Our results show advantages to the use of BLE beacons for positioning. For one-shot (push-to-fix) positioning we achieve $30\ \mbox{m}^2$ ), compared to $100\ \mbox{m}^2$ ) and < 8.5 m for an established WiFi network in the same area.

/pdf/location-fingerprinting-with-bluetooth-low-energy-beacons-23u5zgmm8y.pdf

Location Fingerprinting With Bluetooth Low Energy Beacons

In order to increase accuracy and robustness in state estimation for robotics, a growing number of applications rely on data from multiple complementary sensors. For the best performance in sensor fusion, these different sensors must be spatially and temporally registered with respect to each other. To this end, a number of approaches have been developed to estimate these system parameters in a two stage process, first estimating the time offset and subsequently solving for the spatial transformation between sensors. In this work, we present on a novel framework for jointly estimating the temporal offset between measurements of different sensors and their spatial displacements with respect to each other. The approach is enabled by continuous-time batch estimation and extends previous work by seamlessly incorporating time offsets within the rigorous theoretical framework of maximum likelihood estimation. Experimental results for a camera to inertial measurement unit (IMU) calibration prove the ability of this framework to accurately estimate time offsets up to a fraction of the smallest measurement period.

Unified temporal and spatial calibration for multi-sensor systems

The Network Time Protocol (NTP) is widely used to synchronize computer
clocks in the Internet. This document describes NTP version 4 (NTPv4),
which is backwards compatible with NTP version 3 (NTPv3), described in
RFC 1305, as well as previous versions of the protocol. NTPv4 includes
a modified protocol header to accommodate the Internet Protocol
version 6 address family. NTPv4 includes fundamental improvements in
the mitigation and discipline algorithms that extend the potential
accuracy to the tens of microseconds with modern workstations and fast
LANs. It includes a dynamic server discovery scheme, so that in many
cases, specific server configuration is not required. It corrects
certain errors in the NTPv3 design and implementation and includes an
optional extension mechanism. [STANDARDS-TRACK]

Network Time Protocol Version 4: Protocol and Algorithms Specification

Mobile ad hoc networks (MANETs) are considered by many as fundamental to realizing the global information grid (GIG) and the vision of network-centric warfare. Indeed, a fully realized MANET would be powerful in enabling highly mobile, highly responsive, and quickly deployable tactical forces. However, significant technical challenges remain before this realization is viable. Addressing these deficiencies is a significant task that will require the invention and adoption of new technology. The goal of this article is not to declare these capabilities impossible to achieve. Rather, it is to manage the expectation of the capabilities achievable in the foreseeable future through edification on the technical difficulties standing between current technology and the desired capabilities. This article provides an overview of the military MANET problem space, describing the ideal military MANET solution. Several deficiencies are highlighted that exist between MANET technologies and the desired capability. Identified technical issues include system-level architecture, routing (both interior and exterior), management, security, and medium access control (MAC), with an emphasis on the former two areas

Key Challenges of Military Tactical Networking and the Elusive Promise of MANET Technology

This paper discusses the topic of wireless security in cognitive radio networks, delineating the key challenges in this area. With the ever-increasing scarcity of spectrum, cognitive radios are expected to become an increasingly important part of the overall wireless networking landscape. However, there is an important technical area that has received little attention to date in the cognitive radio paradigm: wireless security. The cognitive radio paradigm introduces entirely new classes of security threats and challenges, and providing strong security may prove to be the most difficult aspect of making cognitive radio a long-term commercially-viable concept. This paper delineates the key challenges in providing security in cognitive networks, discusses the current security posture of the emerging IEEE 802.22 cognitive radio standard, and identifies potential vulnerabilities along with potential mitigation approaches.

/pdf/security-in-cognitive-radio-networks-the-required-evolution-rwwfi4fhh0.pdf

Security in Cognitive Radio Networks: The Required Evolution in Approaches to Wireless Network Security

This paper discusses the emerging IEEE 802.16 broadband wireless technologies and potential applicability to military networks. Interest continues to grow in the military network design community, for leveraging commercial technologies for use in the global information grid (GIG). This is also true in the design of tactical edge networks where there is growing interest in leveraging commercial wireless networking technologies such as the IEEE 802.11 wireless local area network (WLAN) technology family. An emerging commercial capability is in the area of wireless metropolitan area networks (WMA Ns). The emerging IEEE 802.16 broadband wireless access standards aim to provide high data rates over wide geographic ranges. There is also ongoing standardization effort of the eventual IEEE 802.20 mobile broadband wireless solution. This paper provides an overview of IEEE 802.16, then presents a high-level military applicability analysis, identify any technical deficiencies that may require military-specific enhancements. This analysis focuses on the areas of achievable coverage, supportable mobility, quality-of-service (QoS), and security

IEEE 802.16 broadband wireless technology and its application to the military problem space

This book focuses on providing a detailed and practical explanation of key existing and emerging wireless networking technologies and trends,while minimizing the amount of theoretical background information. The book also goes beyond simply presenting what the technology is, but also examines why the technology is the way it is, the history of its development, standardization, and deployment. The book also describes how each technology is used, what problems it was designed to solve, what problems it was not designed to solve., how it relates to other technologies in the marketplace, and internetworking challenges faced withing the context of the Internet, as well as providing deployment trends and standardization trends. Finally, this book decomposes evolving wireless technologies to identify key technical and usage trends in order to discuss the likely characteristics of future wireless networks.

Jack L. Burbank

Papers

Network Time Protocol Version 4: Protocol and Algorithms Specification

Key Challenges of Military Tactical Networking and the Elusive Promise of MANET Technology

Security in Cognitive Radio Networks: The Required Evolution in Approaches to Wireless Network Security

IEEE 802.16 broadband wireless technology and its application to the military problem space

Wireless Networking: Understanding Internetworking Challenges