Design of the intelligent network segment of future mobile communication systems

Future mobile communcation systems will have to provide sophisticated services at quality levels comparable with those provided by fixed systems. An additional requirement is that these systems should be deployed by minimally impacting the existing infrastructures. In this respect an important component of future mobile communication systems is their intelligent network segment, which contains the logic of the services provided and the relevant data required for providing these services. In the context of this paper we study the problem of designing this segment. Our reference system is UMTS, but the practices presented herein may be applied to other systems as well. We identify two major problems, the first at the Mobility and Services Control Point (MSCP) level and the second at the Mobility and Services Data Point (MSDP) level. Our aim in this paper is the following. First, the overall design process is decomposed into a sequence of well-defined problems. Second, the problems are formally stated and theoretically formulated. Third, owing to the computational complexity associated with the theoretical formulations, we take the first steps towards the design of approximate (heuristic) algorithms. Finally we provide results and draw subsequent conclusions. © 1998 John Wiley & Sons, Ltd.     

Power control in CDMA networks based on soft computing methods

Power control is a fundamental procedure for CDMA mobile radio communication systems. In multiservice CDMA systems, power control should be used to minimise the transmission power of each connection, in order to limit the multiple access interference, while obtaining the desirable SIR levels. This paper starts from a transmitted-power allocation algorithm (TPAA) that considers a set of uplink transmissions, which should be supported by the system. In the sequel, the TPAA algorithm is used for training an Elman neural network, which, due to its internal characteristics, is applicable in the time critical context of power control. Simulations and numerical results are analysed for obtaining a solid basis for employing our scheme in the power control of CDMA systems.     

Design of the Access Network Segment of Future Mobile Communications Systems

An important component of future mobile communications systems is their access network segment that enables interworking between the mobile unit and the fixed network. In this paper we define and solve two important problems, related to the design of this segment. First, the efficient utilisation of the available radio spectrum. In this context we present a scheme that may be used for reconfiguring the frequency allocation, therefore, improving the spectrum utilisation. The second problem that we address is that of deploying Cell Site Switches (CSSs), and Local Exchanges (LEs). Our aim in this paper is the following. First, to formally define and optimally formulate these problems. Second, to solve them resorting also to computationally efficient heuristic algorithms. Finally, to provide results and draw subsequent conclusions.     

Network Load Predictions Based on Big Data and the Utilization of Self-Organizing Maps

The pervasiveness of computers in everyday life has already increased and keeps increasing the available digital data both in volume and variety/disparity. This large and dynamic availability of digital data is referred to as Big Data and is very promising in bringing forward new insights and knowledge. For obtaining these insights, the proper combination and processing of the data is required. However, the dynamicity and the increasing size of data start making their handling impossible for analysts and raise many concerns on the manner in which data will be processed from now on. Towards this direction, this paper proposes a tool that processes and combines disparate data in order to create insights regarding a future network load. In particular, the tool (based on the unsupervised machine learning technique of Self-Organizing Maps) builds knowledge on the network load that is encountered with respect to the date of interest, the location, the weather, and the features of the day (e.g., weekend, bank holiday, etc.). The obtained results reveal that the tool is capable of learning the traffic pattern and thus predicting the network load that will be encountered in the near or distant future given information for the above presented parameters with small deviations (up to 0.000553 in terms of Mean Square Error). Moreover, the tool maintains only the most representative data instances and thus reduces the data storage requirements with no loss of information.     

Management of the power control operation in HIPERLAN/2 networks

BRAN/WLAN systems, e.g., HIPERLAN/2, IEEE 802.11a, etc., are seen as a promising solution for covering residential, business, transport, tourism, etc., environments, and generally areas of high demand, characterized as “hot spots”. This paper presents management functionality for augmenting the potential exploitation of one of these systems, HIPERLAN/2, by making feasible their (loose or tight) integration in a composite radio (CR) context. The approach will be the following. The first point will be to revisit the main features of a HIPERLAN/2 system. Next, the architecture of a general Service and Network Management System (SNMS), which has been developed for assisting wireless systems in their operation in a CR context, will be briefly presented. The next main point will be the presentation of the functionality of the SNMS component that is tailored to the managed HIPERLAN/2 technology and specifically to the configuration of the Power Control (PC) functionality. An algorithm for configuring the PC operation, based on a greedy algorithm and a neural network, will be presented. A relevant resource management problem, which should be efficiently solved for exploiting HIPERLAN/2 networks, will be addressed. Numerical results will be presented. Acknowledgment This work was partially funded by the Commission of the European Communities, under the Fifth Framework Program, within the IST project MONASIDRE (IST-2000-26144: Management of Networks and Services in Diversified Radio Environment).