Development of a Security-Focused Multi-Channel Communication Protocol and Associated Quality of Secure Service (QoSS) Metrics

The threat of eavesdropping, and the challenge of recognizing and correcting for corrupted or suppressed information in communication systems is a consistent challenge. Effectively managing protection mechanisms requires an ability to accurately gauge the likelihood or severity of a threat, and adapt the security features available in a system to mitigate the threat. This research focuses on the design and development of a security-focused communication protocol at the session-layer based on a re-prioritized communication architecture model and associated metrics. From a probabilistic model that considers data leakage and data corruption as surrogates for breaches of confidentiality and integrity, a set of metrics allows the direct and repeatable quantification of the security available in single- or multi-channel networks. The quantification of security is based directly upon the probabilities that adversarial listeners and malicious disruptors are able to gain access to or change the original message. Fragmenting data across multiple channels demonstrates potential improvements to confidentiality, while duplication improves the integrity of the data against disruptions. Finally, the model and metrics are exercised in simulation. The ultimate goal is to minimize the information available to adversaries

A Survey of Network Coding and Applications

Common networks with source, internal, and destination nodes put data packets in queues for forwarding.Network coding aims to improve network throughput and energy consumption by combining received data packets before forwarding. In this survey, we will explore various network coding schemes, along with the behavior of network coding in applications. Sensor, wireless routing, and distributed storage networks can benefit greatly from network coding implementations. Flooding is a procedure in distributed systems which broadcasts a message to all nodes in the network. NC-Flooding is introduced, which uses network coding to possibly decrease the message complexity and/or time complexity of flooding

COMPASS Final Report: Lunar Communications Terminal (LCT)

The Lunar Communications Terminal (LCT) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session designed a terminal to provide communications between lunar South Pole assets, communications relay to/from these assets through an orbiting Lunar Relay Satellite (LRS) and navigation support. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The Terminal consists of a pallet containing the communications and avionics equipment, surrounded by the thermal control system (radiator), an attached, deployable 10-m tower, upon which were mounted locally broadcasting and receiving modems and a deployable 1 m diameter Ka/S band dish which provides relay communications with the lunar relay satellites and, as a backup, Earth when it is in view. All power was assumed to come from the lunar outpost Habitat. Three LCT design options were explored: a stand-alone LCT servicing the manned outpost, an integrated LCT (into the Habitat or Lunar Lander), and a mini-LCT which provides a reduced level of communication for primarily robotic areas dealing as in situ resource utilization (ISRU) and remote science. Where possible all the designs assumed single fault tolerance. Significant mass savings were found when integrating the LCT into the Habitat or Lander but increases in costs occurred depending upon the level of man rating required for such designs

QoE Driven Multimedia Service Schemes in Wireless Networks Resource Allocation: Evolution from Optimization, Game Theory, to Economics

In order to deal with the Quality of Experience (QoE) improvement issue in the wireless networks services. In this dissertation we first investigated the Device to Device (D2D) relaying approach in the conventional Base Station (BS) to User Equipment (UE) two entities multimedia service system. In this part, the Multiple Input Multiple Output (MIMO) technology will be implemented in the D2D communication. Furthermore, factors such as the multimedia content distribution (i.e., Quad-tree fractal image compression method), the power allocation strategy, and modulation size are jointly considered to improve the QoE performance and energy efficiency. In addition, the emerging Non-Orthogonal Multiple Access (NOMA) transmission method is becoming very popular and being considered as one of the most potential technologies for the next generation of wireless networks. For the purpose of improving the QoE of UE in the wireless multimedia service, the power allocation method and the corresponding limitations are studied in detail in the wireless system where the traditional Orthogonal Multiple Access (OMA) technology and the promising NOMA technology are compared. At last, facing the real business model in the wireless network services, where the Content Provider (CP), Wireless Carrier (WC), and UE are included, we extend on work from the conventional BS-UE two entities research model to the CP-WC-UE three entities model. More specifically, a generalized best response Smart Media Pricing (SMP) method is studied in this dissertation. In our work, the CP and WC are treated as the service provider alliance. The SMP approach and the game theory are utilized to determine the data length of UE and the data price rate determined by the CP-WC union. It is worth pointing out that the concavity of utility function is no longer necessary for seeking the game equilibrium under the proposed best response game solution. Numerical simulation results also validate the system performance improvement of our proposed transmission schemes

Design Solutions For Modular Satellite Architectures

The cost-effective access to space envisaged by ESA would open a wide range of new opportunities and markets, but is still many years ahead. There is still a lack of devices, circuits, systems which make possible to develop satellites, ground stations and related services at costs compatible with the budget of academic institutions and small and medium enterprises (SMEs). As soon as the development time and cost of small satellites will fall below a certain threshold (e.g. 100,000 to 500,000 €), appropriate business models will likely develop to ensure a cost-effective and pervasive access to space, and related infrastructures and services. These considerations spurred the activity described in this paper, which is aimed at: - proving the feasibility of low-cost satellites using COTS (Commercial Off The Shelf) devices. This is a new trend in the space industry, which is not yet fully exploited due to the belief that COTS devices are not reliable enough for this kind of applications; - developing a flight model of a flexible and reliable nano-satellite with less than 25,000€; - training students in the field of avionics space systems: the design here described is developed by a team including undergraduate students working towards their graduation work. The educational aspects include the development of specific new university courses; - developing expertise in the field of low-cost avionic systems, both internally (university staff) and externally (graduated students will bring their expertise in their future work activity); - gather and cluster expertise and resources available inside the university around a common high-tech project; - creating a working group composed of both University and SMEs devoted to the application of commercially available technology to space environment. The first step in this direction was the development of a small low cost nano-satellite, started in the year 2004: the name of this project was PiCPoT (Piccolo Cubo del Politecnico di Torino, Small Cube of Politecnico di Torino). The project was carried out by some departments of the Politecnico, in particular Electronics and Aerospace. The main goal of the project was to evaluate the feasibility of using COTS components in a space project in order to greatly reduce costs; the design exploited internal subsystems modularity to allow reuse and further cost reduction for future missions. Starting from the PiCPoT experience, in 2006 we began a new project called ARaMiS (Speretta et al., 2007) which is the Italian acronym for Modular Architecture for Satellites. This work describes how the architecture of the ARaMiS satellite has been obtained from the lesson learned from our former experience. Moreover we describe satellite operations, giving some details of the major subsystems. This work is composed of two parts. The first one describes the design methodology, solutions and techniques that we used to develop the PiCPoT satellite; it gives an overview of its operations, with some details of the major subsystems. Details on the specifications can also be found in (Del Corso et al., 2007; Passerone et al, 2008). The second part, indeed exploits the experience achieved during the PiCPoT development and describes a proposal for a low-cost modular architecture for satellite

An architecture for an ATM network continuous media server exploiting temporal locality of access

With the continuing drop in the price of memory, Video-on-Demand (VoD) solutions that have so far focused on maximising the throughput of disk units with a minimal use of physical memory may now employ significant amounts of cache memory. The subject of this thesis is the study of a technique to best utilise a memory buffer within such a VoD solution. In particular, knowledge of the streams active on the server is used to allocate cache memory. Stream optimised caching exploits reuse of data among streams that are temporally close to each other within the same clip; the data fetched on behalf of the leading stream may be cached and reused by the following streams. Therefore, only the leading stream requires access to the physical disk and the potential level of service provision allowed by the server may be increased. The use of stream optimised caching may consequently be limited to environments where reuse of data is significant. As such, the technique examined within this thesis focuses on a classroom environment where user progress is generally linear and all users progress at approximately the same rate for such an environment, reuse of data is guaranteed. The analysis of stream optimised caching begins with a detailed theoretical discussion of the technique and suggests possible implementations. Later chapters describe both the design and construction of a prototype server that employs the caching technique, and experiments that use of the prototype to assess the effectiveness of the technique for the chosen environment using `emulated' users. The conclusions of these experiments indicate that stream optimised caching may be applicable to larger scale VoD systems than small scale teaching environments. Future development of stream optimised caching is considered

Tactical Satellite (TacSat) feasibility study a scenario driven approach

The objective of this project was to examine the feasibility of developing a tactically controlled, operationally responsive satellite system. A specific mission scenario, the Philippine Sea Scenario, was chosen to guide and bound the analysis. Within the bounds of this scenario, this high level space systems engineering exercise provided insights into operations and military utility as well as enough granularity to estimate costs for such a system. The operational approach and high level design concept is based on the Space Mission Analysis and Design (SMAD) process authored by Wiley J. Larson and Kames R. Wertz. The study shows that there are tactical scenarios in which space capabilities provide military utility and cost effectiveness above what is provided by traditional tactical assets such as UAVs. This is particularly true when large operational areas are involved and long periods of service are required.http://archive.org/details/tacticalsatellit109456927N