Competitive Selection of Ephemeral Relays in Wireless Networks

International audienceWe consider an opportunistic wireless communication setting, in which two nodes (referred to as forwarders) compete to choose a relay node from a set of relays, as they ephemerally become available (e.g., wake up from a sleep state). Each relay, when it becomes available (or arrives), offers a (possibly different) " reward " to each forwarder. Each forwarder's objective is to minimize a combination of the delay incurred in choosing a relay and the reward offered by the chosen relay. As an example, we develop the reward structure for the specific problem of geographical forwarding over a common set of sleep-wake cycling relays. In general, our model can be considered as a game theoretic variant of the asset selling problem studied in the operations research literature. We study two variants of the generic relay selection problem, namely, the completely observable (CO) and the partially observable (PO) cases. These cases are based on whether a forwarder (in addition to observing its reward) can also observe the reward offered to the other forwarder. Formulating both problems as a two person stochastic game, we characterize the solutions in terms of Nash Equilibrium Policy Pairs (NEPPs). For the CO case we provide a general structure of the NEPPs. For the PO case we prove that there exists an NEPP within the class of threshold policy pairs. Through numerical work, for a one-hop forwarding example we compare the cost performance of various NEPPs with a simple forwarding (SF) policy which causes each forwarder to act as if the other is not present. We find that if the forwarders are not very close then the SF policy suffices. Insights gained from this numerical work are then used in an end-to-end simulation of geographical forwarding in a large network, in which we are concerned with delivery of packets from a tagged source to a sink, in the presence of competition from other packet flows destined to the same sink

Data management for cloud supported cooperative driving

Tese de mestrado, Engenharia Informática (Arquitetura, Sistemas e Redes de Computadores) Universidade de Lisboa, Faculdade de Ciências, 2020The increasing number of technologies inserted into vehicles, allowed the common user to have access to a broad number of utilities that allows driving to be easier, safer and more economical. ABS, GPS, Bluetooth and onboard computer are some of the technologies associated with a recent vehicle. On more experimental ones there is obstacle detection, automatic braking and self-driving technologies, which can be supported by a wireless network connection to further improve their capabilities. That connection allows the transformation of each independent vehicle into nodes in an ad-hoc network. The current challenge is to connect all those vehicles and be able to provide the data needed for their correct functioning in a timely manner. That is the challenge this dissertation will seek to analyse: the possibility to create a reliable vehicular information system for cooperative driving based on the cloud. Cloud-based storage can support an ever changing number of vehicles while still satisfying scalability requirements and maintaining ease of access without the need to maintain a physical infrastructure, as that responsibility is laid upon the provider. To understand which service is the best to host the vehicular information system it was analyzed three services from Amazon Web Services (AWS): S3, EC2 and DynamoDB. Ease of utility, latency, scalability and cost were the main requirements tested as they are the most important aspects for a real-time vehicular information system for autonomous vehicles. After deciding which cloud service would be the most appropriate to implement the vehicular information system, two client models were created that fulfilled a set of requirements. They were based in an already existing algorithm named Two-Step Full Replication which utilizes a group of Key-Value Stores services from various clouds to simulate a shared-memory based on multi-writer, multi-reader (MWMR) registers. This algorithm tolerates Byzantine faults by using Byzantine quorum techniques and integrity and authenticity checks. It was defined and implemented the necessary changes on the algorithm to create usable a client for a vehicular information system. The first model called ”Atomic Snapshot Client”, uses the modified Two-Step Full Replication interface with the Atomic Snapshot algorithm. This model guarantees that the read of the system (snapshot) is done atomically without being adulterated by concurrent writes, sacrificing execution latency. The second model is a faster version of the first one with the objective of obtaining faster responses from the system without overly sacrificing data consistency, which is called ”Fast Snapshot Client”. The main change from the first one is the reduction of the guarantees of the atomic registers to regular ones making the reads (scan) and writes (update) simpler and faster, although removing the atomic snapshot feature. With the analysis of the data collected from experiments performed with this model it was possible to observe a relation between the increase of the scan latency time and the total time spent on the execution of the read and write operations on an application with various clients. To solve this problem a simple garbage collector was implemented, which cleans each register when the number of outdated writes that it contains goes over a specified threshold. This solution, although simple, proved to be effective to reduce each scan time. Finally, a vehicular information system based on the AWS S3 service was implemented. It is composed by two types of clients based on the Fast Snapshot Client, named vehicular client and calculator client. The two types of client work together, where the vehicular clients trade information with the calculator. The calculator client scans the registers of the vehicle clients and writes on its registers the processed data for each vehicular client. The vehicle clients need to write all the relevant data they gather and read the register of their respective calculator client and act according to the data read. Each of the clients was tested separately and analysed in order to discuss the viability of this system in a real-world application as well as possible changes to further improve it

TorSH: Obfuscating consumer Internet-of-Things traffic with a collaborative smart-home router network

When consumers install Internet-connected smart devices in their homes, metadata arising from the communications between these devices and their cloud-based service providers enables adversaries privy to this traffic to profile users, even when adequate encryption is used. Internet service providers (ISPs) are one potential adversary privy to users’ incom- ing and outgoing Internet traffic and either currently use this insight to assemble and sell consumer advertising profiles or may in the future do so. With existing defenses against such profiling falling short of meeting user preferences and abilities, there is a need for a novel solution that empowers consumers to defend themselves against profiling by ISP-like actors and that is more in tune with their wishes. In this thesis, we present The Onion Router for Smart Homes (TorSH), a network of smart-home routers working collaboratively to defend smart-device traffic from analysis by ISP-like adversaries. We demonstrate that TorSH succeeds in deterring such profiling while preserving smart-device experiences and without encumbering latency-sensitive, non-smart-device experiences like web browsing

The protection of sports events in the EU: Property, intellectual property, unfair competition and special forms of protection

This article analyses some of the legal tools available to organisers of sporting events under EU law and the law of EU Member States. The focus is on remedies based on property rights and contracts, as well as on intellectual property, unfair competition rules and so called “special” forms of protection. As it is well known, in fact, following the ECJ ruling in Premier League v. QC Leisure, sporting events as such do not qualify as works under EU copyright law. Nevertheless, the article shows that remedies based on both traditional and new forms of property, IP and cognate rights can still offer adequate protection to sports organisers. First, many sports events take place in dedicated venues on which sports organisers can claim exclusive use rights and thereupon develop conditional access agreements (i.e. “house right”). Second, the recording and broadcast of sporting events may give rise to a variety of intellectual property rights, especially in the field of copyright and related rights. Third, unfair competition rules, and in particular misappropriation doctrines, have been invoked to protect sporting activities from unauthorised copying. Fourth, special forms of protection have recently been devised at the national level in order to offer an additional layer of rights protecting sports organisers. The article argues that even in the absence of a dedicated EU harmonised right tailored to sports events, the current legal framework is well equipped to offer protection to the investments that the sport industry is making in this sector. The article also argues that national initiatives in the field have so far proven of little practical relevance and, as a matter of fact, have the potential to clash with the general EU legal framework. There is only one area that escapes this rule: a right to use sporting events data to organise betting activities, or in other words, a right to consent to bets. The article concludes that if such a right is to be recognised, it is not the field of intellectual property, nor even property in general, the most appropriate area of law at which to look

ROUTING IN MOBILE AD-HOC NETWORKS: SCALABILITY AND EFFICIENCY

Mobile Ad-hoc Networks (MANETs) have received considerable research interest in recent years. Because of dynamic topology and limited resources, it is challenging to design routing protocols for MANETs. In this dissertation, we focus on the scalability and efficiency problems in designing routing protocols for MANETs. We design the Way Point Routing (WPR) model for medium to large networks. WPR selects a number of nodes on a route as waypoints and divides the route into segments at the waypoints. Waypoint nodes run a high-level inter-segment routing protocol, and nodes on each segment run a low-level intra-segment routing protocol. We use DSR and AODV as the inter-segment and the intra-segment routing protocols, respectively. We term this instantiation the DSR Over AODV (DOA) routing protocol. We develop Salvaging Route Reply (SRR) to salvage undeliverable route reply (RREP) messages. We propose two SRR schemes: SRR1 and SRR2. In SRR1, a salvor actively broadcasts a one-hop salvage request to find an alternative path to the source. In SRR2, nodes passively learn an alternative path from duplicate route request (RREQ) packets. A salvor uses the alternative path to forward a RREP when the original path is broken. We propose Multiple-Target Route Discovery (MTRD) to aggregate multiple route requests into one RREQ message and to discover multiple targets simultaneously. When a source initiates a route discovery, it first tries to attach its request to existing RREQ packets that it relays. MTRD improves routing performance by reducing the number of regular route discoveries. We develop a new scheme called Bilateral Route Discovery (BRD), in which both source and destination actively participate in a route discovery process. BRD consists of two halves: a source route discovery and a destination route discovery, each searching for the other. BRD has the potential to reduce control overhead by one half. We propose an efficient and generalized approach called Accumulated Path Metric (APM) to support High-Throughput Metrics (HTMs). APM finds the shortest path without collecting topology information and without running a shortest-path algorithm. Moreover, we develop the Broadcast Ordering (BO) technique to suppress unnecessary RREQ transmissions

Web Radio Blueprint

The Internet is one of the most significant technological developments in our lifetime, and its impact affects many established technologies and media. Radio is one of the established media revolutionized by the Internet because of the expanding multi-media capabilities, leading the way to a more focused medium when compared to traditional terrestrial radio broadcasting. Radio transmissions over the Internet (Web Radio) offers the opportunity to provide content focused to a “niche” audience, while providing an opportunity for broader operator participation than terrestrial radio. Web Radio is an Information Technology that offers a viable alternative to commercial radio, which has become increasingly consolidated since the Passage of the Telecommunications Act of 1996. Commercial radio consolidation into ten major owners has resulted in less localism, diversity, and competition in radio. Web Radio can restore these elements to the radio industry, assuming policies implemented support the goals of localism, diversity, competition, and interaction. Web Radio is at a critical stage in its development as an Internet supported information technology. Web Radio content providers are facing several significant issues in the economic and regulatory components of their businesses. Web Radio represents a unique opportunity for entrepreneurs and producers to establish viable conduits for the content that they are able to create. It is critical that policies concerning the technical, legal, and operational issues be determined in a way that does not cripple the development of the industry. This thesis provides a blueprint for individuals or organizations that are new to the technology of Web Radio, or would like to review the current state of affairs in the technical and legal components of webcasting. This “Web Radio Blueprint” will assist individuals or organizations with the implementation of webcasting as a way to communicate their music or message to an interested listener. It provides a blueprint for an organization attempting to become an Internet Broadcaster, or add an Internet Broadcasting function to an e-commerce site, by presenting three key areas that should be considered in the organization\u27s plan. These areas include infrastructure technologies used in webcasting, legal obstacles imposed by the 1998 “Digital Millennium Copyright Act” and other rulings, and operational concerns that an e-commerce organization should address