Showing papers on "UMTS frequency bands published in 2007"

Reconfigurable Multiband Antenna Designs for Wireless Communication Devices

Abstract: New designs for compact reconfigurable antennas are introduced for mobile communication devices. The uniqueness of the antenna designs are that they allow various groups of their operating frequency bands to be selected electronically. In particular, each group of frequency bands, or mode, can be made to serve several different communication systems simultaneously. These systems may include various combinations of GSM, DCS, PCS, UMTS, Bluetooth, and wireless local-area network (LAN). Therefore, by electronically selecting different antenna modes, a variety of communication systems can be conveniently served by only one antenna. One advantage is that through the different operational modes, the total antenna volume can be reused, and therefore the overall antenna can be made compact. In these designs, the selection of the different modes is achieved by either i) switching different feeding locations of the antenna (switched feed) or ii) switching or breaking of the antenna's connection to the ground (switched ground). This paper demonstrates these two designs. For the first design of switched feed, it can support GSM, DCS, PCS, and UMTS. In the second design, the antenna makes use of a switched-ground technique, which can cover GSM, DCS, PCS, UMTS, Bluetooth, and 2.4 GHz wireless LAN. The designs are investigated when ideal switches and also various realistic active switches based on PIN diodes, GaAs field effect transistor, and MEMs configurations. The designs are verified through both numerical simulations and measurement of an experimental prototype. The results confirm good performance of the two multiband reconfigurable antenna designs.

Long-Term Transmit Beamforming for Wireless Multicasting

Abstract: This paper presents a low-complexity iterative algorithm for long-term transmit beamforming in multicast channels. Since it relies only on antenna correlations at the base station, the algorithm requires only infrequent feedback from the users. Multiantenna receivers are not required, but they are transparently accommodated. Simulation results within the context of the UMTS long-term evolution system indicate that, with half-wavelength antenna spacings and a typical power azimuth spectrum, the performance is close to optimal. The specific gains (in average SINR) then depend on the number of transmit antennas and the number of active users.

Modeling UMTS Power Saving with Bursty Packet Data Traffic

Abstract: The universal mobile telecommunications system (UMTS) utilizes the discontinuous reception (DRX) mechanism to reduce the power consumption of mobile stations (MSs). DRX permits an idle MS to power off the radio receiver for a predefined sleep period and then wake up to receive the next paging message. The sleep/wake-up scheduling of each MS is determined by two DRX parameters: the inactivity timer threshold and the DRX cycle. In the literature, analytic and simulation models have been developed to study the DRX performance mainly for Poisson traffic. In this paper, we propose a novel semi-Markov process to model the UMTS DRX with bursty packet data traffic. The analytic results are validated against simulation experiments. We investigate the effects of the two DRX parameters on output measures including the power saving factor and the mean packet waiting time. Our study provides inactivity timer and DRX cycle value selection guidelines for various packet traffic patterns.

Beyond 3G

Abstract: Beyond 3G is the official IEEE designation for the next stage of wireless technology that some people call 4G or fourth-generation radio. Over the years, every conceptual shift in wireless technology has been characterized as a generational change. Third generation includes wideband mobile multimedia networks and broadband mixed wireless systems. The mobile systems support variable data rates depending on demand and the level of mobility. Typically 144 kb/s is supported for full vehicular mobility and higher bandwidths for pedestrian levels of mobility. Switched packet radio techniques and wideband CDMA-like systems (as the physical channel is) rather than assigned physical channel schemes (referred to as circuit switched) are required to support this bandwidth-on-demand environment. There are two essential concepts beyond 3G. One of these is the provision of data transmission at rates of 100 Mb/s while mobile and 1 Gb/s while stationary. The other concept is that of pervasive networks where a handset supports many access technologies (e.g., cellular, UMTS, and WiFi) perhaps simultaneously and smoothly transitions between them

Handover location accuracy for travel time estimation in GSM and UMTS

Abstract: In this paper, field measurements from the GSM and UMTS networks are analysed in a road traffic information context. The measurements indicate a potentially large improvement using UMTS signalling data compared to GSM. These improvements can be used to generate traffic information with higher quality and extend the geographic usage area for these kinds of systems. Assuming that non-vehicle terminals can be filtered out and that handovers can be predicted correctly, a conclusion from the experiments is that the handover location accuracy in both GSM and UMTS will be sufficient to estimate useful travel times, also in urban environments. For the covering abstract see ITRD E140665.

UMTS network planning, optimization, and inter-operation with GSM

Abstract: UMTS Network Planning, Optimization, and Inter-Operation with GSM is an accessible, one-stop reference to help engineers effectively reduce the time and costs involved in UMTS deployment and optimization. Rahnema includes detailed coverage from both a theoretical and practical perspective on the planning and optimization aspects of UMTS, and a number of other new techniques to help operators get the most out of their networks. Provides an end-to-end perspective, from network design to optimization Incorporates the hands-on experiences of numerous researchers Single authorship allows for strong coherency and accessibility Details the complete iteration cycle of radio link budgeting for coverage planning and dimensioning Rahnema demonstrates detailed formulation of radio capacity and coverage in UMTS, and discusses the tradeoffs involved. He presents complete link budgeting and iterative simulations for capacity and coverage planning, along with practical guidelines. UMTS Network Planning contains seventeen cohesive and well-organized chapters which cover numerous topics, including: Radio channel structures, radio channel models, parameters, model tuning Techniques for capacity and coverage enhancements Complete treatment of power control, handoffs and radio resource practical management processes and parameters Detailed coverage of TCP protocol enhancement for operation over wireless links, particularly UMTS Application of GSM measurements to plan and re-engineer for UMTS radio sites Guidelines for site co-location with GSM, the QOS classes, parameters and inter-workings in UMTS AMR voice codecs and tradeoffs, core and access network design, architectural evolution, and protocols Comprehensive discussion and presentation of practical techniques for radio performance analysis, trending, and troubleshooting Perfect for professionals in the field and researchers specializing in network enhancement. Engineers working on other air interfaces and next generation technologies will find many of the techniques introduced helpful in designing and deploying future wireless networks as well. Students and professionals new to the wireless field will also find this book to be a good foundation in network planning, performance analysis, and optimization.

Random Access Design for UMTS Air-Interface Evolution

Abstract: Comprehensive long term evolution of the Universal Mobile Telecommunications System (UMTS) specifications is currently ongoing to provide significant improvement over the current release. Important goals for the evolved system include significantly improved system capacity and coverage, low latency, reduced operating costs, multi-antenna support, flexible bandwidth operations and seamless integration with existing systems. To ensure low latency, users must be able to establish a connection to the network quickly. This paper provides a preliminary design and procedure for the random access channel used to establish a connection when the mobile is not yet time-synchronized to the network in the uplink.

Dynamic power saving mechanism for 3G UMTS system

Abstract: This paper investigates the power saving mechanism of Universal Mobile Telecommunications System (UMTS). UMTS discontinuous reception (DRX) is exercised between the network and a mobile station (MS) to save the power of the MS. The DRX mechanism is controlled by two parameters: the inactivity timer threshold tI and the DRX cycle tD. Analytic analysis and simulation model are proposed to study the optimal tI and tD selections that maximize the MS power saving under the given mean packet waiting time constraint. We also devise an adaptive algorithm called dynamic DRX (DDRX). This algorithm dynamically adjusts the tI and tD values to enhance the performance of UMTS DRX. Our study quantitatively shows how to select the best inactivity timer and DRX cycle values for various traffic patterns. We also show that DDRX nicely captures the user traffic patterns, and always adjusts the tI and tD close to the optimal values.

Experimental Evaluation of UMTS and Wireless LAN for Inter-Vehicle Communication

Abstract: The rapid development of mobile communication technologies in recent years allows their application for inter-vehicle communication (IVC). In this paper, we evaluate the suitability of two wireless technologies for IVC, namely Universal Mobile Telecommunication System (UMTS) and IEEE 802.11 Wireless Local Area Network (WLAN). We analyze the communication properties of these technologies and point out the requirements of applications for IVC. We present a series of practical experiments to evaluate the eligibility of each technology for applications of IVC. To obtain comparable results, we performed measurements based on IP-unicast communication, since the lower layers of the two communication technologies differ drastically. Based on the recorded data of radio coverage, latency and throughput, we draw conclusions on currently feasible and infeasible applications for each technology.

Wireless communication method and system for performing handover between two radio access technologies

Abstract: The present invention relates to a method and apparatus for performing handover between a universal mobile telecommunication system (UMTS) terrestrial radio access network (UTRAN), and an evolved-UTRAN (E-UTRAN) based system. The wireless communication system includes a UTRAN, an E-UTRAN, a 2G/3G core network, and long term evolution (LTE) core network, and at least one wireless transmit/receive unit (WTRU) including an LTE element and ad 2G/3G element. According to the present invention the WTRU shall be able to handover a call initiated on the UTRAN to the E-UTRAN, and visa versa. The 2G/3G core network and the LTE core network are linked by a Gn interface.

Seamless Handoff Scheme Based on Pre-registration and Pre-authentication for UMTS-WLAN Interworking

Abstract: Interworking issues between Universal Mobile Telecommunication System (UMTS) and Wireless Local Area Network (WLAN) have become a great matter of interest as an increasing number of mobile internet users require broadband wireless access to IP services in the wide area. In this paper, we present a practical UMTS---WLAN interworking architecture based on 3GPP standards and propose a seamless handoff scheme that guarantees low delay and low packet loss during UMTS---WLAN handoff. For low handoff delay, the proposed handoff scheme performs pre-registration and pre-authentication processes before layer 2 handoff. Moreover, it uses packet buffering and forwarding functions in order to reduce packet loss during the handoff period. On the above basis, detailed signaling procedures are presented, together with system requirements when a mobile terminal moves from UMTS to WLAN and vice-versa. Numerical results show that the proposed scheme performs well with respect to signaling cost, handoff delay, and packet loss compared with conventional schemes.

Packet scheduling in 3.5G high-speed downlink packet access networks: breadth and depth

Abstract: Forecasts for emerging mobile device markets anticipate that bandwidth will be squeezed by demanding applications like multimedia on demand. This will spur the need for data rates beyond what the upcoming 3G wireless cellular systems such as UMTS can offer. To boost the support for such high data rates, HSDPA, labeled as a 3.5G wireless system, has been introduced in Release 5 of UMTS technical specifications. HSDPA is a definite step toward meeting the "anywhere, anytime, and in any form" 4G communication concept. HSDPA promises a peak data rate of up to 10 Mb/s, five times larger than the data rate offered by 3G systems. In order to support such high data rates, HSDPA relies on many new technologies, among which is packet scheduling. In this article we provide breadth and depth related issues of packet scheduling in HSDPA, discuss state-of-the-art HSDPA scheduling algorithms in terms of their objectives, advantages, and limitations, and suggest further research issues that need to be addressed. In addition, we propose a packet scheduling algorithm for data traffic in HSDPA. Simulation results demonstrate the effectiveness of the proposed algorithm

A Four-Element Antenna System for Mobile Phones

Abstract: In this letter, a multiantenna system with four printed monopoles is presented. The monopoles that occupy relatively small area are positioned at the four corners of a printed circuit board, so that the four-element antenna system can be equipped on the lid of a folder-type mobile phone, leaving enough space for the circuits and reducing the effect of human hands. Based on simulation, a prototype for the Universal Mobile Telecommunications System (UMTS) operation has been constructed and tested. The measured -10-dB impedance bandwidths of the four elements are larger than 320 MHz with higher than 11.5-dB isolation. Moreover, the proposed antenna can provide spatial and pattern diversity in a diversity/multiple-input-multiple-output (MIMO) system.

Method for operating enhanced rlc entity and rnc entity for wcdma and system thereof

Abstract: A method for operating an RLC entity and a MAC entity in a Universal Mobile Telecommunications System (UMTS), the European IMT-2000 system. A format of a MAC-hs PDU is optimized in a MAC-hs entity, so that a large number of users can be supported with using less resources when a VoIP service is provided in one cell.

Uplink Control Channel Design for 3GPP LTE

Abstract: Long term evolution (LTE) of the UMTS Terrestrial Radio Access and Radio Access Network is aimed for commercial deployment in 2010. Goals for the evolved system include support for improved system capacity and coverage, high peak data rates, low latency, reduced operating costs, multi-antenna support, flexible bandwidth operations and seamless integration with existing systems. To reach these goals, a new design for the air interface is currently being specified in the 3GPP standards body. The Uplink (UL) for LTE is based on Single Carrier Frequency Division Multiple Access. The UL control channel carries non-data associated control signaling like CQI, ACK/NACK, Scheduling request etc. To maintain the low PA power de-rating, the single carrier property of the UL has to be maintained. As such, special consideration should be given to the UL control channel design. This paper discusses in detail the LTE UL control channel design and its performance.

Hepta-Band Internal Antenna for Personal Communication Handsets

Abstract: Modern personal communication handsets are shrinking in size and are required to operate at multiple frequency bands for enhanced functionality and performance. This poses an important challenge for antenna designers to build multiband antennas within the limited allowable space. In this paper, an internal antenna covering seven frequency bands is presented for personal communication handsets. The proposed antenna operates at GSM (880-960 MHz), DCS (1710-1880 MHz), PCS (1880-1990 MHz), UMTS (1900-2170 MHz), WiBro (2300-2390 MHz), Bluetooth (2.4-2.48 GHz), and WLAN (5.0-5.5 GHz) frequency bands. Measured input return loss of the antenna is better than dB at all the frequency bands with reasonable radiation performance. Antenna volume is 30 mm times15 mm times 4.0 mm (1.8 cm) that makes it attractive for modern multiband and multifunctional slim handsets.

UMTS base station location planning: A mathematical model and heuristic optimisation algorithms

Abstract: Radio networks of universal mobile telecommunication system (UMTS) need accurate planning and optimisation, and many factors not seen in second generation (2G) networks must be considered. However, planning and optimisation of UMTS radio networks are often carried out with static simulations, for efficiency and to save time. To obtain a good trade-off between accuracy and computational load, link-level performance factors need to be taken into account. The authors propose a mathematical model for UMTS radio network planning taking into consideration fast power control, soft handover and pilot signal power in both uplink and downlink. Optimisation strategies are investigated based on three meta-heuristics: genetic algorithm, simulated annealing (SA) and evolutionary-SA. The base station location problem is modelled as a simplified p-median problem, and parameter tuning of these meta-heuristics are presented. Extensive experimental results are used to compare the performance of different algorithms in terms of statistical measurements.

On PHY and MAC Performance of 3G-LTE in a Multi-Hop Cellular Environment

Abstract: Next generation cellular radio systems will exceed the limitations of UMTS. The convergence of data and voice traffic will be supported by a flexible OFDM-based PHY layer and an OFDMA-capable MAC layer. The long term evolution (LTE) successor of the 3G systems incorporates this. But problems concerning coverage and capacity at the cell border still remain for the classical cellular layout. Relaying or Multihop operation is an option to massively improve the coverage as well as the capacity issue at low cost, without the need of a cable or fibre access. For the performance analysis of such cellular systems models for ISO-OSI layers 1+2 (PHY+MAC) are needed. In this paper an analytic modelling framework and results are presented for the cellular LTE performance in two multihop scenarios.

Spatial Outage Probability for Cellular Networks

Abstract: In this paper, we propose a new framework for the study of cellular networks called the fluid model and we derive from this model analytical formulas for interference, outage probability, and spatial outage probability. The key idea of the fluid model is to consider the discrete base stations (BS) entities as a continuum of transmitters which are spatially distributed in the network. This allows us to obtain simple analytical expressions of the main characteristics of the network. In this paper, we focus on the downlink other-cell interference factor, f, which is defined here as the ratio of outer cell received power to the inner cell received power. Although this factor has been firstly defined for CDMA networks (in particular UMTS and HSDPA), the analysis presented hereafter is still valid for other systems using frequency reuse 1, like OFDMA (WiMAX), TDMA (GSM with frequency hopping), or even ad hoc networks. A closed- form formula of f is provided in this paper. From f, we are able to derive the global outage probability and the spatial outage probability, which depends on the location of a mobile station (MS) initiating a new call. All results are compared to Monte Carlo simulations performed in a traditional hexagonal network.

Mobile radio communication system, communication apparatus applied in mobile radio communication system, and mobile radio communication method

Abstract: In the mobile radio communication system where the UMTS and an another system coexist an idle slot for observing the frequency component of another system is inserted in one superframe of UMTS. The duration of this idle slot is at most half of the duration of one frame that form the superframe and it is inserted at an interval of a specified number of frames. Therefore, the frequency component of the another system can be observed securely from the UMTS. Further, deterioration of interleaving performance of the compressed mode frames during such observation can be suppressed.

The long term evolution towards a new 3GPP ∗ air interface standard

Abstract: The performance targets for the long term evolution (LTE) of the Universal Mobile Telecommunication System (UMTS) into a 4th generation system have been chosen to be very ambitious. While all of these targets may not be achievable in practice, they have served to motivate the decisions for a particular LTE design. Specifically, we discuss the choice of the multiple access scheme for LTE, provide details on the uplink and downlink transmission formats, analyze the benefits of multiple input multiple output (MIMO), and outline approaches for intercell interference mitigation. The trade-off between usage of MIMO spatial multiplexing and beamforming is shown for a practical system. The required signaling overhead is weighed against the performance improvements available from the additional information. Finally, some examples for the achievable physical layer performance are given. © 2007 Alcatel-Lucent.

The sandbridge SB3011 platform

Abstract: This paper describes the Sandbridge Sandblaster real-time software-defined radio platform. Specifically, we describe the SB3011 system-on-a-chip multiprocessor. We describe the software development system that enables real-time execution of communications and multimedia applications. We provide results for a number of interesting communications and multimedia systems including UMTS, DVB-H, WiMAX, WiFi, and NTSC video decoding. Each processor core achieves 600MHz at 0.9V operation while typically dissipating 75mW in 90nm technology. The entire chip typically dissipates less than 500mW at 0.9V.

The common RRM approach to admission control for converged heterogeneous wireless networks

Abstract: As the wireless environment becomes ever more populated and complex, individual networks offering single or restricted services will become ever more uncompetitive. Common radio resource management algorithms and strategies are used in heterogeneous or converged wireless networks to integrate multiple physical radio interfaces to support different levels of data rates, mobility, and traffic. Admission control in a common RRM environment is used to select the most appropriate wireless access based on service type, user preference, and network load. This is used to provide a balance between real-time and non-real-time traffic across the available access technologies. The development of common radio resource management strategies requires a suitable platform of coupled access networks and is the motivation behind the development of a converged wireless test platform. The tightly coupled platform supports voice and data call setup and delivery over UMTS and WLAN

Network-Based Access Selection in Composite Radio Environments

Abstract: In this paper, we introduce a network-based approach for access and interface selection (AIS) in the context of resource management in heterogeneous wireless environments (UMTS, WLAN and DVB-T). We focus on the optimization of the resource utilization, while ensuring acceptable QoS provision to the end users. Our objective is to optimally manage the overall system resources and minimize the possibility of QoS handovers (non-mobility handovers). The adopted architecture applies to typical heterogeneous environments and network entities (access routers) are enhanced with extra functionalities. We propose an AIS algorithm that exploits the multihoming concept and globally manages network resources at both radio access and IP backbone networks. The algorithm can estimate near optimal solutions in real time and we also introduce a novel triggering policy. We present simulation results that demonstrate the advantages of our approach. System performance metrics, derived from the simulations, show minimum degradations in high load and congestion situations.

Wireless communication method and system for performing dual mode paging

Abstract: A wireless communication method and system for performing dual mode paging over a wireless communication network having both a second-generation/third-generation (2G/3G) radio access network (RAN) and an evolved-universal mobile telecommunication system (UMTS) terrestrial radio access network (E-UTRAN). When a wireless transmit/receive unit (WTRU) registers or originates traffic with an evolved network, no additional signaling is required Otherwise, the WTRU is paged via both of the 2G/3G RAN and the E-UTRAN, depending on the response from the WTRU, data is forwarded to the WTRU via the 2G/3G RAN or the E-UTRAN.

Efficient two-port antenna system for GSM=DCS=UMTS multimode mobile phones

Abstract: The design of several two-port antenna systems for mobile phones is presented. All these structures are made up of two planar inverted-F antennas closely positioned on a small ground plane and radiating in the GSM900/DCS1800 and UMTS frequency bands. First, the antennas are simply associated at the top edge of the same printed circuit board. Thus, to improve their isolation and their total efficiency, a neutralisation effect is created by means of an optimised suspended line, which links the feeding strips of the radiators. The performance of these systems is measured and compared with theoretical results.

Adaptive discontinuous reception mechanism for power saving in UMTS

Abstract: We propose the ADRX (adaptive discontinuous reception) mechanism with the EPI (extended paging indicator) for power saving in the UMTS (Universal Mobile Telecommunications System). In the proposed mechanism, DRX period for each UE (user equipment) is individually and adaptively controlled by the EPI which is decided by node B considering the current traffic situation of each UE. Simulation results show significant improvement of power saving performance by the proposed mechanism as compared to the conventional fixed DRX

A 3GPP-IMS Based Approach for Converging Next Generation Mobile Data Networks

Abstract: This paper presents a promising architecture for converging third-generation (3G) cellular data networks and wireless local area networks (WLANs) by using the IP multimedia subsystem (IMS), proposed by the 3G Partnership Project (3GPP), as an arbitrator. The IMS provides real-time session management, and unified session control. Within the scope of the presented framework, terminal and session handoffs are investigated for two different roaming scenarios. The first scenario investigates handoff from UMTS to WLAN and the second scenario investigates handoff from WLAN to UMTS. The paper concludes by presenting some simulation results obtained for these handoff scenarios using an OPNET based simulation model.

HANDOVER BETWEEN AN IEEE 802.16 WiBro NETWORK AND A UMTS NETWORK USING MEDIA INDEPENDENT HANDOVER FUNCTION

Abstract: A wireless transmit/receive unit (WTRU) may include an IEEE 802.16 modem, a universal mobile telecommunication system (UMTS) modem and a media independent handover (MIH) entity. Software application programming interfaces provide the MIH entity with mechanisms to receive information about IEEE 802.16 and UMTS links, control IEEE 802.16 and UMTS modems for handover, discover an MIH server and IP multimedia system nodes, trigger mobile IP handover, etc. If an IEEE 802.16 link has been successfully established, the MIH entity starts an MIH session. When the IEEE 802.16 modem indicates that a connection is going to be terminated, the MIH entity activates the UMTS modem for handover. If the IEEE 802.16 modem indicates that a link parameter has crossed a threshold, the MIH entity sends IEEE 802.16 and WCDMA signal measurements to an MIH server. After receiving an MIH switch request, the MIH entity initiates handover to the UMTS network.