Eavesdropping on GSM: state-of-affairs

In the almost 20 years since GSM was deployed several security problems have been found, both in the protocols and in the - originally secret - cryptography. However, practical exploits of these weaknesses are complicated because of all the signal processing involved and have not been seen much outside of their use by law enforcement agencies. This could change due to recently developed open-source equipment and software that can capture and digitize signals from the GSM frequencies. This might make practical attacks against GSM much simpler to perform. Indeed, several claims have recently appeared in the media on successfully eavesdropping on GSM. When looking at these claims in depth the conclusion is often that more is claimed than what they are actually capable of. However, it is undeniable that these claims herald the possibilities to eavesdrop on GSM using publicly available equipment. This paper evaluates the claims and practical possibilities when it comes to eavesdropping on GSM, using relatively cheap hardware and open source initiatives which have generated many headlines over the past year. The basis of the paper is extensive experiments with the USRP (Universal Software Radio Peripheral) and software projects for this hardware.Comment: 5th Benelux Workshop on Information and System Security (WISSec 2010), November 201

Optimization Algorithms for Large-Scale Real-World Instances of the Frequency Assignment Problem

Nowadays, mobile communications are experiencing a strong growth, being more and more indispensable. One of the key issues in the design of mobile networks is the Frequency Assignment Problem (FAP). This problem is crucial at present and will remain important in the foreseeable future. Real world instances of FAP typically involve very large networks, which can only be handled by heuristic methods. In the present work, we are interested in optimizing frequency assignments for problems described in a mathematical formalism that incorporates actual interference information, measured directly on the field, as is done in current GSM networks. To achieve this goal, a range of metaheuristics have been designed, adapted, and rigourously compared on two actual GSM networks modeled according to the latter formalism. In order to generate quickly and reliably high quality solutions, all metaheuristics combine their global search capabilities with a local-search method specially tailored for this domain. The experiments and statistical tests show that in general, all metaheuristics are able to improve upon results published in previous studies, but two of the metaheuristics emerge as the best performers: a population-based algorithm (Scatter Search) and a trajectory based (1+1) Evolutionary Algorithm. Finally, the analysis of the frequency plans obtained offers insight about how the interference cost is reduced in the optimal plans.Publicad

Nine Regimes of Radio Spectrum Management: A 4-Step Decision Guide

Diverse radio spectrum management regimes are defined according to 4 levels of options: - Should frequencies be allocated according to a harmonised plan? - Should the technologies allowed be standardised? - Should spectrum usage rights be exclusive, eased, or collective? - Should usage rights be assigned through market mechanisms (auctions and trading), administrative procedures, or hybrid procedures? These guidelines propose a balanced set of decision criteria, thus allowing the completion of rigorous impact assessments. It describes the possible regimes resulting from the combined choices. The taxonomy illustrates the possible rationales for a diversity of regimes broader than the usually exposed standard trilogy of Command and Control, Market and Commons: This includes Harmonised neutrality, Administered neutrality, Technology neutrality in Command and Control context, Harmonised neutrality Plus, Private Commons and California Dream. The nine regimes described can also be considered as a map with which to navigate in order to accommodate institutional and technological transitions over time. This allows decision-makers to come-up with informed choices using all the technical information available, and based on definite criteria and a rigorous methodology.radio spectrum;spectrum policy; telecom regulation; spectrum regimes

A Case for Time Slotted Channel Hopping for ICN in the IoT

Recent proposals to simplify the operation of the IoT include the use of Information Centric Networking (ICN) paradigms. While this is promising, several challenges remain. In this paper, our core contributions (a) leverage ICN communication patterns to dynamically optimize the use of TSCH (Time Slotted Channel Hopping), a wireless link layer technology increasingly popular in the IoT, and (b) make IoT-style routing adaptive to names, resources, and traffic patterns throughout the network--both without cross-layering. Through a series of experiments on the FIT IoT-LAB interconnecting typical IoT hardware, we find that our approach is fully robust against wireless interference, and almost halves the energy consumed for transmission when compared to CSMA. Most importantly, our adaptive scheduling prevents the time-slotted MAC layer from sacrificing throughput and delay

Revisiting the Evolution and Application of Assignment Problem: A Brief Overview

The assignment problem (AP) is incredibly challenging that can model many real-life problems. This paper provides a limited review of the recent developments that have appeared in the literature, meaning of assignment problem as well as solving techniques and will provide a review on   a lot of research studies on different types of assignment problem taking place in present day real life situation in order to capture the variations in different types of assignment techniques. Keywords: Assignment problem, Quadratic Assignment, Vehicle Routing, Exact Algorithm, Bound, Heuristic etc

Tragedy of the Regulatory Commons: LightSquared and the Missing Spectrum Rights

The endemic underuse of radio spectrum constitutes a tragedy of the regulatory commons. Like other common interest tragedies, the outcome results from a legal or market structure that prevents economic actors from executing socially efficient bargains. In wireless markets, innovative applications often provoke claims by incumbent radio users that the new traffic will interfere with existing services. Sometimes these concerns are mitigated via market transactions, a la “Coasian bargaining.” Other times, however, solutions cannot be found even when social gains dominate the cost of spillovers. In the recent “LightSquared debacle,” such spectrum allocation failure played out. GPS interests that access frequencies adjacent to the band hosting LightSquared’s new nationwide mobile network complained that the wireless entrant would harm the operation of locational devices. Based on these complaints, regulators then killed LightSquared’s planned 4G network. Conservative estimates placed the prospective 4G consumer gains at least an order of magnitude above GPS losses. “Win win” bargains were theoretically available, fixing GPS vulnerabilities while welcoming the highly valuable wireless innovation. Yet transaction costs—largely caused by policy choices to issue limited and highly fragmented spectrum usage rights (here in the GPS band)—proved prohibitive. This episode provides a template for understanding market and non-market failure in radio spectrum allocation

NASA's mobile satellite development program

A Mobile Satellite System (MSS) will provide data and voice communications over a vast geographical area to a large population of mobile users. A technical overview is given of the extensive research and development studies and development performed under NASA's mobile satellite program (MSAT-X) in support of the introduction of a U.S. MSS. The critical technologies necessary to enable such a system are emphasized: vehicle antennas, modulation and coding, speech coders, networking and propagation characterization. Also proposed is a first, and future generation MSS architecture based upon realized ground segment equipment and advanced space segment studies