Desarrollo de un simulador celular a nivel de llamada para WCDMA

This article deals with the development of a cell simulator for WCDMA systems. The objective of this tool is to test the results of different algorithms for the cell radius calculation. This simulation tool is conceived on a call/connection level rather than on a packet level. This means that each user connection is considered as a single event independently of the type of service. The article also shows an independent tool for the cell radius calculation which results over different service scenarios are tested with the simulator. Finally the future enhancements of the simulator are presented

Characteristics of narrow bipolar pulses and negative return strokes of vertical electric fields generated by lightning recorded in Malaysia

Lightning that generates electric fields is known to have negative consequences. Therefore, the electric field radiated in microwave and characteristics of different types of lightning activities are studied and analysed to better understand lightning based problems. In this study, two types of lightning electric fields which are Negative Return Strokes (NRS) and Narrow Bipolar Pulses (NBP) are thoroughly analysed. A total of 89 NRS data and 115 NBP data were selected from a set of data recorded during the northeast monsoon period from November to December 2012 in the vicinity of Universiti Teknologi Malaysia (UTM), Johor. For that purpose, flat plate antenna with electronic buffer circuit and a 2.4 GHz monopole antenna were used to measure vertical electric field and microwave radiation. Apart from the electric field characteristics analysis, the measurements of microwave radiation at 2.4 GHz associated with NRS and NBP were also performed and the results are depicted in this study. Nonetheless, the wavelet and the frequency spectrum of both NRS and NBP were examined and the results are discussed inclusively. Furthermore, the number of microwave radiations associated with NBP were notably higher than that of NRS, which indicated that the mechanism of NBP was more distinguished compared to that of NRS. On top of that, the duration of 2.4 GHz emission associated with NBP was discovered to be a factor of a few tens shorter than that of High Frequency (HF) radiation from return strokes. Meanwhile, analysis on the wavelet and frequency spectrum reveals that the energy spectrum for NBP concentrates at high frequency (200 kHz to 500 kHz) with average power spectrum peak of the initial part for NNBP and NPBP to be 76,650 (V/m)2 and 76,309 (V/m)2, respectively. However, the initial part power spectrum peak corresponding to NRS is about 118,931(V/m)2 with lower frequency spectrum (60 kHz). The results suggest that NBP radiates energy at high frequency region compared to NRS. Hence, it can be concluded that electric field pulse for NBP experiences more extensive and rapid ionization process compared to NRS

A study of UMTS terrestrial radio access performance

This thesis considers the performance evaluation of third generation radio networks, in particular UMTS Terrestrial Radio Access (UTRA). First, the performance evaluation methods are presented. The typical capacity of UTRA is estimated using those methods and a few solutions are evaluated to improve the capacity and coverage. The thesis further studies the effect of base station synchronization on the performance of UTRA time division duplex mode. The performance evaluation is based on the combination of theoretical calculations, link and system level simulations, and laboratory and field measurements. It is shown that these different evaluation methods give similar results and – when combined together – they can be used for the radio network development purposes. The simulation results indicate that the typical WCDMA, i.e. UTRA frequency division duplex mode, macro cell capacity is between 600 and 1000 kbps per sector per 5 MHz. The capacity is sensitive to the environment and to the transceiver performance. The results further show that user bit rates up to 2 Mbps can be provided locally for packet data with the basic Rake receiver, but not for full coverage circuit switched connections in macro cells. The following performance enhancement techniques are evaluated in this thesis: soft combining of packet retransmissions, base station multiuser detection and 4-branch base station receiver diversity. The link level simulations show that soft combining can provide a gain up to 2.0 dB, which can be used to increase the capacity up to 60 %. The performance of base station multiuser detection is evaluated with link and system level simulations. It is shown that the studied sub-optimal multiuser detector is able to remove 60-70 % of the intra-cell interference. That gain can be utilized to improve the uplink capacity by 50-100 % or the coverage by 1-2 dB. The performance of 4-branch antenna diversity is evaluated in the simulations and in the field measurements. The results show that the average coverage gain of 4-branch diversity with two separate cross-polarized antennas is 3 dB compared to 2-branch diversity with one cross-polarized antenna. The synchronization requirements of UTRA time division duplex base stations are studied with system simulations. The results show that synchronization is a key requirement for time division duplex operation, especially for the uplink performance. The study indicates that co-location of different operators' base stations is feasible in time division duplex operation only if the two networks are synchronized and if an identical split between uplink and downlink is used.reviewe

Soft handover issues in radio resource management for 3G WCDMA networks

PhDMobile terminals allow users to access services while on the move. This unique feature has driven the rapid growth in the mobile network industry, changing it from a new technology into a massive industry within less than two decades. Handover is the essential functionality for dealing with the mobility of the mobile users. Compared with the conventional hard handover employed in the GSM mobile networks, the soft handover used in IS-95 and being proposed for 3G has better performance on both link and system level. Previous work on soft handover has led to several algorithms being proposed and extensive research has been conducted on the performance analysis and parameters optimisation of these algorithms. Most of the previous analysis focused on the uplink direction. However, in future mobile networks, the downlink is more likely to be the bottleneck of the system capacity because of the asymmetric nature of new services, such as Internet traffic. In this thesis, an in-depth study of the soft handover effects on the downlink direction of WCDMA networks is carried out, leading to a new method of optimising soft handover for maximising the downlink capacity and a new power control approach

Algorithme de transfert intercellulaire vertical pour les réseaux sans fil hétérogènes basé sur le filtrage de Kalman

Les standards de la quatrième génération assurent l'interopérabilité entre différentes technologies d'accès sans fil. Ceci est en partie permis par le transfert intercellulaire vertical (VHO) qui assure une continuité de service lorsqu’on change de technologie d'accès (par exemple à partir d'un réseau local sans fil (WLAN) à un réseau cellulaire (CN) et vice-versa). Dans cet article, nous proposons un algorithme de décision de transfert intercellulaire vertical basée sur le filtrage de Kalman scalaire. Des critères tels que la probabilité de transfert intercellulaire, le nombre de faux transferts intercellulaire et la position des transferts intercellulaires sont utilisés pour évaluer et comparer notre travail avec des algorithmes de transfert intercellulaire basés sur des techniques de filtrage existants. Dans le pire des cas, nous avons démontré que notre algorithme diminue de 40 pour cent la probabilité des faux transferts intercellulaire par rapport à d'autres algorithmes de transfert intercellulaire

Modellierung von Tarifen für digitale Produkte am Beispiel von Mobilfunkverträgen

Mit dieser Arbeit ist gezeigt worden, wie vielfältig die Produkte bzw. Dienste im Mobilfunkbereich sind. Der eigentliche Schwerpunkt lag auf der Fragestellung, wie die Mobilfunk-Dienste im Internet bepreist werden. Die Untersuchung der verschiedenen Mobilfunktarife im Internet hatte das Ziel, die grundlegenden Preisparameter für diese Tarife zu identifizieren, zu diskutieren und zu modellieren. Das oberste Ziel bei der Modellierung war die Erstellung eines flexiblen Tarif- und Abrechnungsmodells. Zu diesem Zweck wurden die Vorteile, die XML-Schema und XML-Netze bieten, zum Ausdruck gebracht. Dabei wurde das methodische Vorgehen in den Vordergrund gestellt und nicht die Abbildung des tatsächlichen Marktgeschehens. Zunächst wurde in dieser Arbeit kurz das Internet und die speziellen Eigenschaften des Internets behandelt. Dabei wurde festgestellt, dass sich das Internet auf Grund seiner Eigenschaften besonderes für digitale Produkte eignet. Die digitalen Produkte und deren Eigenschaften wurden untersucht und daraus ergab sich, dass die digitalen Produkte eine vorteilhafte Kostenstruktur aufweisen; nämlich vernachlässigbar niedrige Reproduktionskosten. Unter anderem ist festgestellt worden, dass für die Nutzung der digitalen Produkte für Konsumenten deren Verbreitungsgrad wichtig ist. Gerade hier kann das Internet dank seiner Eigenschaften diese Anforderung besser als ein anderer Vertriebskanal unterstützen. Schließlich lassen sich aus dem Zusammenspiel der Interneteigenschaften und der Merkmale der digitalen Güter gewisse ökonomische Gesetzmäßigkeiten ableiten. Diese verschaffen einem Unternehmen langfristig Vorteile gegenüber der Konkurrenz. Der Schwerpunkt dieser Arbeit liegt aber bei einer speziellen Gruppe der digitalen Produkte, nämlich der Produkte bzw. Dienste im Mobilfunkbereich. Mobilfunk ist eine wichtige und weitverbreitete Art der Mobilkommunikation. Auf dem deutschen Mobilfunkmarkt wurde gerade die 4. Generation der Mobilfunkstandards – UMTS - eingeführt. Allerdings wird UMTS noch einige Zeit brauchen, um sich auf dem Markt richtig zu etablieren. Damit bleibt der GPRS immer noch der führende Standard auf diesem Markt. Der meist genutzte Dienst im Mobilfunk ist immer noch der „Sprach-Dienst“. Der Mobilfunk bietet neben der „Sprache“ eine ganze Reihe weiterer Dienste an. Durch die neuen Technologien ist der Trend in Richtung Datenübertragung über Mobilfunk stark am Aufholen. Die zur Verfügung stehenden Dienste hängen mit den Mobilfunkstandards zusammen. Daher ist es möglich, dass bei der Änderung der Standards auch die zur Verfügung stehenden Dienste angepasst werden. Ein wichtiger Punkt am Bespiel von Mobilfunk als digitales Produkt bzw. Dienstleistung war die Wahl der richtigen Preisstrategie. Die meisten Netzbetreiber entschieden sich für die Strategie differenzierter Preise. Damit können sie unterschiedliche Zahlungsbereitschaften ihrer Kunden relativ gut ausschöpfen. Hierzu wurden die Vielfältigkeit der Möglichkeiten und die Vorteile, die die Preisdifferenzierungsstrategie anbietet, dargestellt. Der sich anschließende Hauptteil dieser Arbeit ist die Parametrisierung und die Modellierung des Mobilfunktarifs und dessen Abrechnungssystems. Zur Modellierung wurden XML-Schema und XML-Netze gewählt. Das XML-Schema ermöglicht flexible Erstellung, Anpassung und Erweiterung von Tarifelementen. Außerdem ermöglicht XML Datenaustausch über Plattform unabhängige Protokolle. Die XML-Netze bieten durch ihre graphische Darstellung die Visualisierung der Abläufe und der ablaufrelevanten Daten. Die aktuellen Zustände können aufgezeigt, simuliert und analysiert werden. Außerdem ermöglichen sie die gute Umstrukturierung, Anpassung und Erweiterung des Abrechnungsprozesses. Bei der Erstellung des Abrechnungsmodells wurde von den Hauptbestandteilen eines beliebigen Abrechnungsmodells ausgegangen. Anschließend sind diese Bestandteile an die Anforderungen des Abrechnungsmodells für Mobilfunkverträge angepasst worden. Die jeweiligen Abrechnungsparameter wurden, wie z.B. Tarifdaten, mit der modifizierten XMLSchema dargestellt. Die Tarifdaten stellen die Vielfältigkeit der Parameter dar, die die Preise eines Mobilfunktarifes beeinflussen. Die Preisparameter wurden nach eingehender Untersuchung verschiedener Tarife181 der vier Netzbetreiber identifiziert. Dabei fiel auf, dass die Netzbetreiber in der Regel von vergleichsweise ähnlichen Parametern ausgingen. Damit haben auch die Tarife ähnliche Strukturen. Weiterhin führen stark differenziert Preise dazu, dass man nicht vom „schlechtesten“ oder vom „besten“ Tarif sprechen kann. Im Prinzip gibt es nur den „besten“ Tarif für ein bestimmtes Nutzungsverhalten. Außer Sprachkommunikation wurden in der Arbeit auch andere Kommunikationsarten vorgestellt. Dabei wurde eine neue Art des Bepreisens angesprochen, nämlich das Bepreisen nach Dienstqualität. Die darauf basierenden Preisstrukturen werden zukünftig sicherlich eine große Rolle spielen, da sie sich insbesondere für Dienste eignen, die vom UMTS unterstütz werden

Design and analysis of scheduling algorithms for next generation broadband wireless access systems

Efficient utilization of network resources is a key goal for emerging Broadband Wireless Access Systems (BWAS). This is a complex goal to achieve due to the heterogeneous service nature and diverse Quality of Service (QoS) requirements of various applications that BWAS support. Packet scheduling is an important activity that affects BWAS QoS outcomes. This thesis proposes a new packet scheduling mechanism that improves QoS in mobile wireless networks which exploit IP as a transport technology for data transfer between BWAS base stations and mobile users at the radio transmission layer. In order to improve BWAS QoS the new packet algorithm makes changes at both the IP and the radio layers. The new packet scheduling algorithm exploits handoff priority scheduling principles and takes into account buffer occupancy and channel conditions. The packet scheduling mechanism also incorporates the concept of fairness. The algorithm also offers an opportunity to maximize the carriers’ revenue at various traffic situations. Performance results were obtained by computer simulation and compared to the well-known algorithms. Results show that by exploiting the new packet scheduling algorithm, the transport system is able to provide a low handoff packet drop rate, low packet forwarding rate, low packet delay, ensure fairness amongst the users of different services and generates higher revenue for the telecom carriers. Furthermore this research proposes a new and novel measure named “satisfaction factor to measure the efficacy of various scheduling schemes and finally this s research also proposes four performance measurements metric for NodeB’s of Next Generation Wireless Network

Convergence of packet communications over the evolved mobile networks; signal processing and protocol performance

In this thesis, the convergence of packet communications over the evolved mobile networks is studied. The Long Term Evolution (LTE) process is dominating the Third Generation Partnership Project (3GPP) in order to bring technologies to the markets in the spirit of continuous innovation. The global markets of mobile information services are growing towards the Mobile Information Society. The thesis begins with the principles and theories of the multiple-access transmission schemes, transmitter receiver techniques and signal processing algorithms. Next, packet communications and Internet protocols are referred from the IETF standards with the characteristics of mobile communications in the focus. The mobile network architecture and protocols bind together the evolved packet system of Internet communications to the radio access network technologies. Specifics of the traffic models are shortly visited for their statistical meaning in the radio performance analysis. Radio resource management algorithms and protocols, also procedures, are covered addressing their relevance for the system performance. Throughout these Chapters, the commonalities and differentiators of the WCDMA, WCDMA/HSPA and LTE are covered. The main outcome of the thesis is the performance analysis of the LTE technology beginning from the early discoveries to the analysis of various system features and finally converging to an extensive system analysis campaign. The system performance is analysed with the characteristics of voice over the Internet and best effort traffic of the Internet. These traffic classes represent the majority of the mobile traffic in the converged packet networks, and yet they are simple enough for a fair and generic analysis of technologies. The thesis consists of publications and inventions created by the author that proposed several improvements to the 3G technologies towards the LTE. In the system analysis, the LTE showed by the factor of at least 2.5 to 3 times higher system measures compared to the WCDMA/HSPA reference. The WCDMA/HSPA networks are currently available with over 400 million subscribers and showing increasing growth, in the meanwhile the first LTE roll-outs are scheduled to begin in 2010. Sophisticated 3G LTE mobile devices are expected to appear fluently for all consumer segments in the following years

Mpa: A Network-centric Architecture For Micro-mobility Support In Ip And Mpls Networks

Micro-mobility protocols aim to improve localized mobility by reducing the handover overheads. In this paper we present the Mobility Plane Architecture (MPA). This architecture was designed to support micro-mobility in standard IP or MPLS/GMPLS networks in a network-centric way, that is, the burden demanded by micro-mobility is placed on the network, not on the mobile nodes. The main advantages of this architecture are its independence of IPv6 and the absence of new protocols for supporting L3 mobility. © 2008 IEEE.609616R. Aggarwal, D. Papadimitriou, and S. Yasukawa. Extensions to Resource Reservation Protocol - Traffic Engineering (RSVP-TE) for Point-to-Multipoint TE Label Switched Paths (LSPs). RFC 4875, The Internet Engineering Task Force (IETF), May 2007D. Awduche, L. Berger, D. Gan, T. Li, V. Srinivasan, and G. Swallow. RSVP-TE: Extensions to RSVP for LSP Tunnels. RFC 3209, The Internet Engineering Task Force (IETF), December 2001Chiussi, F.M., Khotimsky, D.A., Krishnan, S., A Network Architecture for MPLS-Based Micro-Mobility (2002) IEEE Wireless Communications and Networking ConferenceJohnson, D., Perkins, C., Arkko, J., Mobility support in IPv6. RFC 3775, The Internet Engineering Task Force (IETF) (2004), JuneDroms, R., (1997) Dynamic Host Configuration Protocol. RFC 2131, The Internet Engineering Task Force (IETF), , MarchR. Droms, J. Bound, B. Volz, T. Lemon, C. Perkins, and M. Carney. Dynamic Host Configuration Protocol for IPv6 (DHCPv6). RFC 3315, The Internet Engineering Task Force (IETF), July 2003Farinacci, D., Li, T., Hanks, S., Meyer, D., Traina, P., (2000) Generic Routing Encapsulation (GRE). RFC 2784, The Internet Engineering Task Force (IETF), , MarchKoodli, R., Fast Handovers for Mobile IPv6. RFC 4068, The Internet Engineering Task Force (IETF) (2005), JulyLangar, R., Tohme, S., Micro mobile MPLS protocol in next generation wireless access networks (2004) 9th CDMA International Conference (CIC), , OctoberMontavont, N., Noël, T., Handover management for mobile nodes in IPv6 networks (2002) IEEE Communications Magazine, pp. 38-43. , AugustMoskowitz, R., Nikander, P., Host Identity Protocol (HIP) Architecture. RFC 4423, The Internet Engineering Task Force (IETF) (2006), MayRamjee, R., Porta, T.L., Thuel, S., Varadhan, K., Wang, S., HAWAII: A Domain-based Approach for Supporting Mobility in Wide-area Wireless Network (1999) Proc. IEEE Intl. Conf. Network ProtocolsH. Soliman, C. Castelluccia, K. E. Malki, and L. Bellier. Hierarchical Mobile IPv6 Mobility Management (HMIPv6). RFC 4140, The Internet Engineering Task Force (IETF), August 2005Valko, A.G., Cellular IP: A New Approach to Internet Host Mobility (1999) ACM Comp. Commun. Rev, , JanuaryJ. O. Vatn. An experimental study of IEEE 802.11b2b handover performance and its effect on voice traffic. TRITATRITAIMIT-TSLAB R 03:01, Telecommunication Systems Laboratory, Department of Microelectronics and Information Technology, KTH, Royal Institute of Technology, Stockholm, Sweden, July 200