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3G Mobile Communication Technologies, 2004. 3G 2004. Fifth IEE International Conference on

Date 2004

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Displaying Results 1 - 25 of 153
  • Traffic characteristics of packet-switched streaming services over HSDPA

    Page(s): 574 - 578
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (976 KB)  

    HSDPA (high speed downlink packet access) is an enhancement to WCDMA that delivers a high-performance cellular-data capability. It is introduced into 3GPP as an evolution of WCDMA to handle a wide variety of multimedia services with different QoS requirements. In 3GPP specifications, there are three typical UMTS service classes, streaming, interactive and background, which can be transported over HSDPA. The most popular application of packet-switched streaming services, video streaming, is studied, and the traffic characteristics of such a service transported over HSDPA are analyzed. When a video sequence is coming, NodeB should decide how to choose the HS-DSCH (high-speed downlink shared channel) transport mode, i.e. codes, modulation and transport block size, depending, to some extent, on the traffic characteristics of this service delivered on the selected transport mode. Some answers are proposed, including the principles of choosing TBS, codes and modulation, delay and bandwidth requirement calculation, FER requirement guarantee, and so on. With these analysis results, the comparison of two transmission strategies, i.e. using a guaranteed number of codes and using the maximal number of codes, are presented. The simulations also identify these results and give the suggestion of channel bandwidth redundancy. View full abstract»

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  • MPEG-2 video streaming over IEEE 802.11g WLAN in the presence of Bluetooth interference

    Page(s): 579 - 583
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (940 KB)  

    We investigate the impact of Bluetooth (BT) interference on the performance of MPEG-2 streaming video over the IEEE 802.11g physical layer. Symbol erasures are used to remove the BT interference and restore video quality. A novel perceptual quality metric is used to quantify the optimum number of erasures required to restore video quality as close as possible to its unimpaired level. The results demonstrate that a perceptual video quality metric provides an effective control mechanism as it accounts for both video encoding and transmission impairment attributes. View full abstract»

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  • A novel packetisation scheme for MPEG-4 over 3G wireless systems

    Page(s): 302 - 306
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (991 KB)  

    In this paper, a new packetisation method for MPEG-4 video packets is proposed and analysed. This packetisation method is based on a new header compression scheme to compress headers of MPEG-4 video packets for streaming over UMTS. MPEG-4 header compression not only makes more efficient use of scarce wireless bandwidth but it also improves the perceptual video quality and error robustness. In particular, it makes recovery from errors faster. MPEG-4 video packet headers contribute a significant portion of video packet size, particularly when resynchronisation, header extension code and data partitioning error resilience options are switched on. The new header compression scheme is aimed at reducing the MPEG-4 video packet overheads and optimising the packetisation method for enhanced robustness. Preliminary results obtained from the experiments for this approach show an improvement in objective quality of up to 5 dB, apart from the considerable savings in bandwidth. This paper focuses on the packetisation method for MPEG-4 video packets and features the improvements made for video quality achieved by the defined packetisation scheme. View full abstract»

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  • Calculating uplink Eb/No from uplink SIR measurements

    Page(s): 257 - 261
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (971 KB)  

    Eb/No assumptions form an essential part of 3G radio network planning and system dimensioning. The deployment of 3G networks means that it is now possible to validate theoretical Eb/No assumptions. Network logging tools usually record levels of SIR rather than Eb/No. This paper derives the mathematical relationship between uplink Eb/No and uplink SIR. Example SIR measurements are used to calculate example Eb/No figures. This is done for SIR measurements which have been recorded from a test bed with controlled propagation conditions. View full abstract»

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  • Performance characterisation of WCDMA dedicated traffic channels based on node B transmit power and pilot measurements [UMTS]

    Page(s): 480 - 484
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (985 KB)  

    The task of this paper is to derive some basic relations between pilot measurements and dedicated traffic channel (DTCH) performance. It has been demonstrated that Ec/I0 alone does not provide enough information about the performance of dedicated channels. At least the cell load of the node B, expressed by the transmitted signal strength indicator (TSSI), must also be known. For a target cell load, a certain minimal Ec/I0 is required to provide the quality of service given by the target block error rate (BLER). This value can be derived from the equations stated in the paper and from physical layer simulation results. Also some hints on how this concept can be used in cell planning are given. View full abstract»

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  • Iterative parallel interference cancellation aided CDMA based MPEG-4 video telephony

    Page(s): 307 - 311
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (954 KB)  

    In this contribution we investigate an iterative parallel interference cancellation (PIC) aided CDMA MPEG-4 videotelephony scheme. The number of iterations used by the PIC-based turbo receiver was four. The family of m-sequence based spreading codes having a length of N = 15 chips was employed in our system and the transmission burst length was T = 120 bits. A random channel interleaver having a memory of eight transmission bursts was employed. The system considered supported K = 7 users and communicated over an asynchronous symbol-spaced, equal-weight two-path uncorrelated Rayleigh fading channel. View full abstract»

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  • Synchronous H-ARQ with energy reduction (ER-HARQ) retransmissions

    Page(s): 227 - 229
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (859 KB)  

    An H-ARQ scheme with energy reduction transmission for the retransmitted subpackets termed energy reduction H-ARQ (ER-HARQ) is proposed and adopted in the Revision D of cdma2000. Compared to the conventional H-ARQ, ER-HARQ offers higher H-ARQ gain and less transmission time. In this paper we describe the ER-HARQ and show the performance gain by simulation with respect to the average number of subpacket transmissions and required Eb/Nt to achieve a given target performance. View full abstract»

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  • Novel admission control algorithm for GPRS/EGPRS based on fuzzy logic

    Page(s): 342 - 346
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1023 KB)  

    As users in a GPRS/EGPRS network have different quality of service (QoS) demands, the network aims to satisfy their demands while maximizing the utilization of the existing resources. A crucial aspect of the resource allocation problem in cellular data networks is the admission control (AC). We propose a new session admission control algorithm that overcomes most of the difficulties encountered by the existing AC algorithms. The novelty of our approach is the use of fuzzy logic (fuzzy inference) for the AC. We demonstrate the efficiency of our AC algorithm by simulations. View full abstract»

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  • Experience of Linux and GTK+2 Smartphone

    Page(s): 267 - 270
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (991 KB)  

    A smartphone is a newcomer that has the ability of personal digital assistants (PDA) with the small appearance of cellular telephones. Although a PDA phone, which is a PDA with a CDMA or GSM module, has bigger appearance, a smartphone is a small device, which looks like a cellular telephone with PDA ability. Most smartphones have adopted Smartphone2002, Smartphone2003 or embedded Linux. Smartphone2002 and Smartphone2003 made by Microsoft have great capability, performance and conveniences. But they are not license-free. Embedded Linux is license-free and gives good opportunity for users and developers to modify it. But most smartphones adopting embedded Linux have PDA appearance. In addition, the graphical user interface (GUI) such as GTK is not proper for the cellular telephone size. In this paper, a smartphone system based on Linux and GTK+2 is proposed. The smartphone system is license-free and small like cellular telephone systems. It supports one-handed operation using keys or touch screen. To adopt Linux as the OS of the smartphone, ETRI's QPlus-P kernel is used. To adopt GTK+2 as the GUI system of the smartphone, GTK+2 is modified to support one-handed operation without touch screen or stylus. View full abstract»

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  • UE receive diversity as a performance enhancement to 3GPP Rel99, Rel5 and Rel6 radio features

    Page(s): 39 - 43
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1000 KB)  

    This paper discusses the radio performance improvements that handsets with two-antenna receive diversity can bring about to 3GPP Rel99, Rel5 and Rel6 WCDMA systems. The scope of this study is to offer a comprehensive picture of the UE receive diversity gains when dual antenna reception is used along with Rel99 radio features, e.g. soft handover, Rel5 HSDPA functionality, e.g. hybrid automatic repeat request (H-ARQ), and Rel6 MBMS radio features, e.g. longer interleaving time. The receive diversity gains have been investigated with the use of 3GPP compliant link level simulators and through analytical calculations to evaluate the system capacity and coverage enhancements. The results of this investigation show that UE receive diversity with 0.5 antenna correlation can increase Rel99 system capacity by around 85%, Rel5 HSDPA cell throughput by 40% and can reduce by 60% the NodeB transmission power for Rel6 MBMS 64 kbit/s user data services. View full abstract»

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  • Uplink and downlink simulations of a WCDMA network in the presence of hot-spots traffic

    Page(s): 564 - 568
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (960 KB)  

    The paper presents a simulator built to evaluate the uplink and downlink capacity of a WCDMA network in the presence of hot-spots traffic. As the traffic is no longer distributed uniformly, some typical assumptions and approximations used in conventional network simulators become invalid. A new iterative approach to address the problem is proposed and explained. Uplink capacity simulations are performed and the results of the new uplink approach and the conventional one are also compared. This has shown that when performing uplink simulations of WCDMA networks with hot-spots traffic, extra care has to be taken for obtaining accurate results. View full abstract»

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  • A new mobility management scheme for mobile IP-based wireless networks

    Page(s): 669 - 673
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (985 KB)  

    This paper introduces two new approaches, co-operated with the mobile routing table (MRT), for optimizing the routing path such that the triangular routing problem is avoided. The first approach combines an ICMP network-mask query and directed broadcast mechanism to find the routers. The other approach uses a tracking mechanism, similar to traceroute, to find all the MRT routers on the path from home agent to corresponding node. We analyze and compare both the standard mobile IP (MIP) and the proposed scheme. It is clear that the proposed scheme acts like the MIP in the worst case, and like the MIP-route optimization in the best case. View full abstract»

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  • On the uplink performance of band-limited DS-CDMA systems using RAKE-receiver over Nakagami-m channels

    Page(s): 312 - 316
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (964 KB)  

    In this paper, we investigated the BER performance of DS-CDMA using various chip-waveforms, which include three time-limited chip-waveforms and two bandlimited chip-waveforms. Closed-form formulae were derived for evaluating the achievable bit-error rate performance with the aid of the standard Gaussian approximation. View full abstract»

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  • Network composition: a step towards pervasive computing

    Page(s): 198 - 202
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1008 KB)  

    Pervasive computing is the next generation computing paradigm, which not only enables users to compute "everywhere, all the time", but also distinguishes itself from mobile computing and distributed computing in terms of invisibility, heterogeneity, smartness and scalability. How to implement pervasive computing is a challenging task. In this paper, we propose to use the concepts of "ambient networks" and "network composition" as a potential solution to some of the problems in pervasive computing. An entire set of mechanisms related to network composition is described. We further explain how pervasive computing can be facilitated with the help of these concepts. View full abstract»

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  • WCDMA evolved - high-speed data access

    Page(s): 212 - 216
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1030 KB)  

    To meet future demands for improved uplink packet data performance, WCDMA is continuously evolving. In Rel5, HSDPA was introduced, providing substantial downlink improvements, and in Rel6, the enhanced uplink will be an integral part of the specifications. The paper describes the principles behind HSDPA and enhanced uplink and how they are integrated into WCDMA. Simulation results exemplify the performance gains possible. View full abstract»

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  • Low complexity basis selection algorithm for per-common basis rate control

    Page(s): 230 - 234
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1015 KB)  

    Considering per-common basis modulation and coding scheme at the transmitter and successive interference cancellation at the receiver, the active basis subset and the corresponding decoding order are determined where equal powers are allocated to the active bases. We first take into account a maximum likelihood decision strategy in which the optimal active basis subset and its decoding order are jointly determined such that the system capacity is maximized among all possible decoding orders over all possible basis subsets. We then propose a serial decision procedure consisting of a successive process that tests whether basis selection gain exists or not when the basis with the lowest post-processing SINR is discarded at each stage. The serial decision procedure that simply drops the worst basis at each stage leads to the globally optimal solution with considerably reduced complexity. Numerical results show that the proposed serial decision procedure induces no capacity loss compared with the maximum likelihood decision strategy. View full abstract»

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  • On the nature of UMTS circuit-switched capacity figures obtained through Monte Carlo system-level simulations

    Page(s): 524 - 528
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1002 KB)  

    Sophisticated dimensioning exercises for CDMA-based systems (such as UMTS) involve Monte Carlo-based system-level simulations. In the absence of any hardware limitations, it is common practice to further apply Erlang B to the capacity numbers obtained through such simulations. While the application of Erlang B to TDMA/FDMA-based systems is acceptable, similar practice for UMTS will result in highly pessimistic capacity numbers under certain conditions. This paper proposes a methodology that can be incorporated in Monte Carlo-based UMTS system-level simulators to derive directly the supported traffic intensity. Using such a method, simulation results are presented supporting the Erlang nature of the DL/UL capacity numbers generated by a UMTS Monte Carlo-based system-level simulator. View full abstract»

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  • Vertical handover between HIPERLAN/2 and UMTS cellular system

    Page(s): 69 - 72
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (908 KB)  

    HIPERLAN/2 (H/2) is a WLAN technology which could be used to complement 3G (UMTS) in hotspot areas, i.e. places where there will be an extraordinary demand for network capacity and bandwidth. WLAN is a relatively inexpensive and uncomplicated technology; hence it is a good investment. Integrating HIPERLAN/2 infrastructure in the 3G network should be taken by the operator as a good opportunity to provide high data rates to customers. WLAN technology will never be an alternative, but rather a complement, to UMTS. The paper presents the packet loss caused by the handover procedure to and from UMTS and HIPERLAN/2 systems in a tight interworking architecture under different link latencies and application data rates. It is shown that the handover latency from UMTS to H/2 is greater than that of H/2 to UMTS handover, where this has a direct influence on the number of data packets that do not get transmitted to the mobile user's node. View full abstract»

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  • MIMO capacity limits in a 3G WCDMA multi-access cell

    Page(s): 98 - 102
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1023 KB)  

    MIMO capacity limits for interference limited WCDMA systems are estimated using practical channel data. Uplink and downlink capacity limits for STBC and code multiplexing MIMO schemes are presented, highlighting the impacts of interference mitigation, code rate, transmitter/receiver ratio and code orthogonality. View full abstract»

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  • Performance analysis of a compact robotic tele-echography E-health system over terrestrial and mobile communication links

    Page(s): 118 - 122
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (961 KB)  

    In this work, we present a comparative performance analysis of an end-to-end robotic tele-echography system using two means of communication links; satellite and mobile (GPRS and UMTS) links. The functional modalities of the system in terms of the delay, total throughput and the jitter has been investigated, showing the capabilities and limitations of each communication link. The effect of concurrent and asynchronous system data transmission have been studied. The transmission of still and stream of ultrasound images investigated under different network conditions, has been simulated and studied on a real network. The limitation of the GPRS network with respect to the other communication links options, has been verified and analysed. The outcome of the study shows that the UMTS network is a promising communication link for the OTELO system. View full abstract»

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  • Performance evaluation of smart antenna concepts and shared channel transmission in 3G mobile communication systems

    Page(s): 271 - 275
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (971 KB)  

    In this work we investigate the influence of smart antenna concepts in the downlink of third generation mobile communication systems (3G) like UMTS (Universal Mobile Telecommunication System) when packet scheduled transmission over downlink shared channels (DSCH) is carried out. We consider hexagonal site structures that are subdivided in three or six subsectors or cells. For the three sector case we investigate smart antenna concepts that use antenna arrays of two and four antenna elements. We illuminate beampointing and fixed beam switching and assume transmission of delay tolerant data such as E-mail or download applications utilising shared channels. Users are scheduled to shared code resources in a time multiplexed manner, where proportional fair and throughput fair scheduling algorithms are investigated. Results are presented in terms of average user throughput figures obtained from system level simulations. A significant increase in system packet data throughput shows when smart antenna concepts with four antenna elements are applied. View full abstract»

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  • An analysis of delay of small IP packets in cellular data networks

    Page(s): 347 - 351
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (964 KB)  

    The delay characteristics of small IP packets in cellular data networks is investigated through the analysis of the SR-ARQ mechanism. The delay of the radio link controller is taken as the primary delay in the radio access network and all core networking delays are neglected. Results indicate that the average delay may be a misleading measure of system performance for conversational traffic such as voice over IP packets. View full abstract»

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  • Service level agreement and global QoS index for 3G networks

    Page(s): 683 - 687
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (962 KB)  

    In addition to discussion of the emergence of service level agreement (SLA) studies for 3G networks, the paper concerns three issues: design of a global SLA index for interconnection regulation on the basis of the "gold-silver-bronze" approach; developing an approach to choose a subset of informative quality indicators; and a compensation and penalty scheme. As a "best practice" the 30-year long Verizon NY experience on QoS regulation is discussed. View full abstract»

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  • A dynamic resource allocation method for HSDPA in WCDMA system

    Page(s): 569 - 573
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (948 KB)  

    HSDPA (high-speed downlink packet access) users are not only time multiplexing in a given channelisation code but also code multiplexing during a given TTI (time transmission interval). The fast scheduling technology in HSDPA should provide a flexible method to allocate both the time domain and code domain resources to all users. Conventional scheduling methods, C/I (maximum carrier/interference ratio), PF (proportional fairness) and RR (round robin), only permit a single user to transmit per TTI, which cannot effectively use the code resources when the channel condition of the selected user is bad. A dynamic fast scheduling (DFS) method is proposed. Instead of serving only one user at each TTI, it selects multiple users to share the code domain resources at each TTI. Both the instantaneous channel condition and average throughput of each user are the scheduling criteria, and, therefore, the served users at each TTI dynamically change accordingly. The simulation results show that the proposed scheduling method increases the overall cell throughput and, at the same time, has quite a good fairness performance. View full abstract»

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  • Space-time spreading assisted adaptive QAM aided multicarrier DS-CDMA video telephony

    Page(s): 148 - 152
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (945 KB)  

    A space-time spreading (STS) assisted near-instantaneously adaptive quadrature amplitude modulated (AQAM) multi-carrier CDMA (MC-DSCDMA) video transceiver is proposed and investigated. When the STS scheme is invoked for spreading the signal of each sub-carrier to multiple transmit antennas, the effects of channel-induced fading are substantially mitigated. Furthermore, turbo convolutional coding is invoked for enhancing the achievable BER versus SNR performance. The AQAM-aided STS MC-CDMA system was capable of maintaining a near-constant target BER and hence a near-constant video PSNR across a wide range of channel qualities, requiring a signal-to-noise ratio (SNR) as low as 7dB for achieving a perceptually pleasing video quality. View full abstract»

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