Introducing a Novel Minimum Accuracy Concept for Predictive Mobility Management Schemes

In this paper, an analytical model for the minimum required accuracy for predictive methods is derived in terms of both handover (HO) delay and HO signaling cost. After that, the total HO delay and signaling costs are derived for the worst-case scenario (when the predictive process has the same performance as the conventional one), and simulations are conducted using a cellular environment to reveal the importance of the proposed minimum accuracy framework. In addition to this, three different predictors; Markov Chains, Artificial Neural Network (ANN) and an Improved ANN (IANN) are implemented and compared. The results indicate that under certain circumstances, the predictors can occasionally fall below the applicable level. Therefore, the proposed concept of minimum accuracy plays a vital role in determining this corresponding threshold

Application of Location Based Information Services in the Public Bicycle System

Sustav javnih bicikala kao jedan od oblika javnog gradskog prijevoza donosi mnogo prednosti većim gradovima. Iako se taj ekonomski i ekološki prihvatljiv koncept već duže pokušava uvesti u gradove, tek je uvođenjem novih tehnologija uspio postati značajan oblik prometnog povezivanja mnogih svjetskih gradova. Problem dostupnosti i raspodjele bicikala kod modela baziranih na konvencionalnim postajama može se riješiti uvođenjem informacijskih usluga temeljenih na lokaciji koje omogućavaju modeliranje sustava bez biciklističkih postaja. Praćenjem lokacije i kretanja pojedinog bicikla ostvaruje se veća dostupnost usluge javnog biciklističkog sustava. Uvođenjem ovakvih oblika informacijsko komunikacijskih usluga u sustave javnih bicikala mogu se smanjiti troškovi uvođenja i održavanja sustava, te omogućiti cijeli niz indirektnih usluga koje za sve sudionike stvaraju dodatnu vrijednost.The public bicycle system as a form of public transportation brings many advantages for larger cities. Although economically and environmentally acceptable, this concept became relevant mode of transportation only after introduction of new technologies. The problem of the availability and distribution of bicycles in models based on conventional stations can be resolved through the introduction of location based services and by modeling the systems without a bicycle station. By tracking the location and movement of each bicycle it is possible to achieve greater availability of public bicycle system service. The introduction of such forms of information and communication services in public bicycle systems can reduce implementation and maintenance costs, and provide a variety of additional services, thus creating added value for all participants

Application of Location Based Information Services in the Public Bicycle System

Sustav javnih bicikala kao jedan od oblika javnog gradskog prijevoza donosi mnogo prednosti većim gradovima. Iako se taj ekonomski i ekološki prihvatljiv koncept već duže pokušava uvesti u gradove, tek je uvođenjem novih tehnologija uspio postati značajan oblik prometnog povezivanja mnogih svjetskih gradova. Problem dostupnosti i raspodjele bicikala kod modela baziranih na konvencionalnim postajama može se riješiti uvođenjem informacijskih usluga temeljenih na lokaciji koje omogućavaju modeliranje sustava bez biciklističkih postaja. Praćenjem lokacije i kretanja pojedinog bicikla ostvaruje se veća dostupnost usluge javnog biciklističkog sustava. Uvođenjem ovakvih oblika informacijsko komunikacijskih usluga u sustave javnih bicikala mogu se smanjiti troškovi uvođenja i održavanja sustava, te omogućiti cijeli niz indirektnih usluga koje za sve sudionike stvaraju dodatnu vrijednost.The public bicycle system as a form of public transportation brings many advantages for larger cities. Although economically and environmentally acceptable, this concept became relevant mode of transportation only after introduction of new technologies. The problem of the availability and distribution of bicycles in models based on conventional stations can be resolved through the introduction of location based services and by modeling the systems without a bicycle station. By tracking the location and movement of each bicycle it is possible to achieve greater availability of public bicycle system service. The introduction of such forms of information and communication services in public bicycle systems can reduce implementation and maintenance costs, and provide a variety of additional services, thus creating added value for all participants

Traffic pattern prediction in cellular networks.

PhDIncreasing numbers of users together with a more use of high bit-rate services complicate radio resource management in 3G systems. In order to improve the system capacity and guarantee the QoS, a large amount of research had been carried out on radio resource management. One viable approach reported is to use semi-smart antennas to dynamically change the radiation pattern of target cells to reduce congestion. One key factor of the semi-smart antenna techniques is the algorithm to adjust the beam pattern to cooperatively control the size and shape of each radio cell. Methods described in the literature determine the optimum radiation patterns according to the current observed congestion. By using machine learning methods, it is possible to detect the upcoming change of the traffic patterns at an early stage and then carry out beamforming optimization to alleviate the reduction in network performance. Inspired from the research carried out in the vehicle mobility prediction field, this work learns the movement patterns of mobile users with three different learning models by analysing the movement patterns captured locally. Three different mobility models are introduced to mimic the real-life movement of mobile users and provide analysable data for learning. The simulation results shows that the error rates of predictions on the geographic distribution of mobile users are low and it is feasible to use the proposed learning models to predict future traffic patterns. Being able to predict these patterns mean that the optimized beam patterns could be calculated according to the predicted traffic patterns and loaded to the relevant base stations in advance

Security mechanisms for next-generation mobile networks

Basic concepts and definitions -- Motivation and research challenges -- Research objectives -- Mobile value-added service access -- UMTS access security -- DoS attacks in mobile networks -- A lightweight mobile service access based on reusable tickets -- Background work and motivation -- Service access through tickets -- System security analysis -- Comparisons with related work -- Enhancing UMTS AKA with vector combination -- Overview of UMTS AKA -- UMTS AKA weaknesses- -- Vector combination based AKA -- Security analysis of VC-AKA -- Mobility-oriented AKA in UMTS -- Mobility-oriented authentication -- Security analysis of MO-AKA -- A fine-grained puzzle against DOS attacks -- Quasi partial collision -- Fine-grained control over difficulties -- Lightweight to mobile devices -- Against replay attacks -- Confidentiality, integrity and user privacy