Integration of application layer traffic optimization (ALTO) in software-defined mobile networks could have several benefits for orchestration of endpoint selection for distributed services. ALTO can provide guidance, e.g., in the redirection of end users to appropriate in-network cache, content distribution network server or virtual network function instance during service chaining. ALTO service provides appropriate level of abstraction of network and cost maps, enforcing the policies of mobile network operator and optionally other actors, but keeping the privacy of network topology information. SDN controllers can enforce flow redirection and can dynamically provide abstracted network and cost maps to ALTO server. In this paper we present the operation of ALTO in software-defined networks from the point of view of mobile network operators, and describe our proof-of-concept implementation.
As social networking services are getting more and more common, the need for privacy enhancing options, sophisticated identity management and anonymity emerges. In this paper the authors propose using Role-Based Privacy as a response for these needs and introduce a novel model called Nexus-Identity Network that is capable of describing services extended with such functionality. The concerned principles of Role-Based Privacy are conferred in the paper and criteria are presented for anonymity. Conforming to the criteria the authors suggest storing the profiles of different identities in a tree hierarchy in a user-friendly manner. The analysis of anonymity shows that the network has a structure that can be easily interpreted similarly to graphs representing connections in regular social networks. The ease of profile management and network visualization are advantages of the Nexus-Identity Model which can make a social networking service privacyand user-friendly as well.
In this chapter, we will start by briefly summarizing the history of radio frequency identification systems. After that, we will introduce the components of such systems and classify them based on programmability, data capacity, frequency, and reading distance, as well as power supplement and reply transfer methods. We will describe the various coupling types used in RFID systems, present the common coding schemes and modulations, and give an overview of the standardization efforts. This chapter will focus on collision detection and resolution algorithms and conclude by practical suggestions on RFID system selection for different tasks.
The present research was conducted at the Budapest University of Technology in the field of indoor location using radio waves of Wi-Fi networks with a focus on practical application issues. Our goal was to enhance and combine existing algorithms and create an implementation that is efficient enough to enable real-time operation in 3D space in multi-level office environments while retaining the accuracy of more complex systems and allowing the addition of valuable context-sensitive features.The proposed solution is based on proven empirical propagation models, with the ability to augment and refine with surveyed radio fingerprint data. The results of the location algorithm are combined with heuristic probability distributions layered over the floor plan, thus incorporating available sensor data (accelerometers and magnetometers found in modern devices) and floor plans. The positioning system is used by an indoor navigation software developed for smartphones and complemented by a database of annotated entities (persons, devices, areas and points of interest) to allow the inference of location-dependent, contextsensitive information through an API provided for upper layer applications.This paper primarily focuses on the practical experience accumulated during the development of the positioning algorithm, as well as the possibilities opened by having a dynamic view of all the attributes assigned to persons either directly or indirectly via their locations or other external data sources. The implementation heavily relies on the Spatial extension of the Oracle Database system, which provides geometric data types and operations. The benefits of the employment of such a system are going to be presented in the current article.
Research is conducted at the Budapest University of Technology in the field of indoor positioning using radio waves, with practical application issues in focus. Our goal is to enhance and combine existing algorithms and create an implementation that is efficient enough to enable real-time operation in 3D space in multi-level office environments while retaining the accuracy of more complex systems. The proposed solution is based on proven empirical propagation models (the Motley-Keenan Model and the New Empirical Model of Cheung, Sau and Murch), with the ability to augment and refine with surveyed radio fingerprint data. The propagation model described in this paper can be used to generate estimated signal strength patterns for locations that were left out of the survey; and the values coming from the two different sources can be further handled in a common way. An algorithm is proposed to calculate a probability distribution over the floor plan using these expected values and the positioning-time measurements. The results from this location algorithm are combined with other probability distributions, generated by heuristics such as the distribution of walls, previous walking directions and typical indoor movement patterns, as well as data from G-sensors and digital compasses built into modern handheld devices. Other real-world issues are investigated like reaction to changes in the placement of radio beacons, and the comparability of various devices with different signal characteristics. The proposed algorithm can achieve an average positioning error of 3 metres in a common office environment using fingerprinting data, and errors are only about 50% greater when relying solely on simulated signal strength values.
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