1x Evolution-Data Optimized Revision A (1xEV-DO Rev. A) is a cellular communications standard that introduces key enhancements to the high data rate packet switched 1xEV-DO Release 0 standard. The enhancements are driven by the increasing demand on some applications that are delay sensitive and require symmetric data rates on the uplink and the downlink. Some examples of such applications being video telephony and voice over internet protocol (VoIP). The handoff operation is critical for delay sensitive applications because the mobile station (MS) is not supposed to lose service for long periods of time. Therefore seamless server selection is used in Rev. A systems. This research analyzes the performance of this handoff technique. A theoretical approach is presented to calculate the slot error probability (SEP). The approach enables evaluating the effects of filtering, hysteresis as well as the system introduced delay to handoff execution. Unlike previous works, the model presented in this thesis considers multiple base stations (BS) and accounts for correlation of shadow fading affecting different signal powers received from different BSs. The theoretical results are then verified over ranges of parameters of practical interest using simulations, which are also used to evaluate the packet error rate (PER) and the number of handoffs per second. Results show that the SEP gives a good indication about the PER. Results also show that when considering practical handoff delays, moderately large filter constants are more efficient than smaller ones.

Radio frequency system optimization and troubleshooting remains one of the most challenging aspects of working in a cellular network. To stay competitive, cellular providers continually monitor the performance of their networks and use this information to determine where to improve or expand services. As a result, operators are saddled with the task of wading through overwhelmingly large amounts of data in order to trouble-shoot system problems. Part of the difficulty of this task is that for many complicated problems such as hand-off failure, clues about the cause of the failure are hidden deep within the statistics of underlying dynamic physical phenomena like fading, shadowing, and interference. In this research we propose that Hidden Markov Models (HMMs) be used as a method to infer signature statistics about the nature and sources of faults in a cellular system by fitting models to various time-series data measured throughout the network. By including HMMs in the network management tool, a provider can explore the statistical relationships between channel dynamics endemic to a cell and its resulting performance. This research effort also includes a new distance measure between a pair of HMMs that approximates the Kullback-Leibler divergence (KLD). Since there is no closed-form solution to calculate the KLD between the HMMs, the proposed analytical expression is very useful in classification and identification problems. A novel HMM based position location technique has been introduced that may be very useful for applications involving cognitive radios. / Ph. D.

The work deals with the developmental stages (Releases) of the third generation UMTS net-works. It explains a partial improvement from Release 99 to Release 5 and Release 6 to im-prove the quality parameters of a mobile data transmission. In the practical part, there are measured qualitative parameters of the third generation networks that are available in the Czech Republic: UMTS, HSDPA, CDMA 1xEV-DO Rev.0 and Rev.A and UMTS-TDD. The measurements give reasonably achievable data rates in both directions (downlink & uplunk), a response time, quality of VoIP calls, a dispersion, a data-loss and an ability to transmit video with different data flows. The other aspects especially an availability of coverage and end-user terminals have been assessed wihin the each network. The work is supplemeted with a laboratory, which is focused on a practical comparison of the basic parameters of data transmissions of 2G and 3G networks.

The interest in the development of wireless high-speed data services is in response to the strong market demand for high-speed wireless Internet access. Current standards aim at delivering a peak data rate greater than 2Mbps on the forward link. Since data services and voice services are fundamentally different, new concepts were introduced in the design of the forward data channel. In addition, methods of evaluating the performance of a cellular CDMA system have to be revisited. This thesis proposes a method which can be used to find the forward link peak and average data rates, throughput and coverage of a cellular CDMA system which is capable of delivering high-speed wireless data. A summary of changes in design philosophy and recent advances in technologies which enable high-speed wireless data delivery are presented. The proposed method takes into account major aspects commonly found in the forward data channel and applies the generalized Shannon capacity formula for multi-element antenna (MEA) systems. The analysis focuses on the physical layer and is flexible enough to be adapted to various propagation environments, antenna configurations, multicode allocations, user distributions and cell site configurations. Sample numerical results for various multicode allocations are shown using a system model with two-tier interfering cells with one transmit antenna and two receive antennas operating under a frequency selective slow fading channel with propagation environment described by the Recommendation ITU-R M. 1225 indoor office, outdoor to indoor and pedestrian and vehicular test environments. Different transmit / receive antenna configurations and multicode allocations and their impact on the average data rate is also explored.

The interest in the development of wireless high-speed data services is in response to the strong market demand for high-speed wireless Internet access. Current standards aim at delivering a peak data rate greater than 2Mbps on the forward link. Since data services and voice services are fundamentally different, new concepts were introduced in the design of the forward data channel. In addition, methods of evaluating the performance of a cellular CDMA system have to be revisited. This thesis proposes a method which can be used to find the forward link peak and average data rates, throughput and coverage of a cellular CDMA system which is capable of delivering high-speed wireless data. A summary of changes in design philosophy and recent advances in technologies which enable high-speed wireless data delivery are presented. The proposed method takes into account major aspects commonly found in the forward data channel and applies the generalized Shannon capacity formula for multi-element antenna (MEA) systems. The analysis focuses on the physical layer and is flexible enough to be adapted to various propagation environments, antenna configurations, multicode allocations, user distributions and cell site configurations. Sample numerical results for various multicode allocations are shown using a system model with two-tier interfering cells with one transmit antenna and two receive antennas operating under a frequency selective slow fading channel with propagation environment described by the Recommendation ITU-R M. 1225 indoor office, outdoor to indoor and pedestrian and vehicular test environments. Different transmit / receive antenna configurations and multicode allocations and their impact on the average data rate is also explored.

Orientador: Shusaburo Motoyama / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-06T08:13:44Z (GMT). No. of bitstreams: 1 Bassi_TaniaAidaGarcia_M.pdf: 1045495 bytes, checksum: a7f5a1d48c5810466fa34b39df1b4d0b (MD5) Previous issue date: 2006 / Resumo: Neste estudo, o desempenho do enlace direto do sistema I xEV -DV é analisado através de simulações e o tempo médio de atraso dos pacotes. a vazão de dados e a utilização de enlace são avaliados em função do carregamento de tráfego do sistema. Para a realização das simulações foi desenvolvido. na ferramenta de software /v/atlab, um modelo que representa o processamento e escalonamento da estação rádIo base do sistema IxEV-DV. antes da transmissão na interface aérea. bem como os modelos baseados em tráfego real de dados WAP, HTTP e FTP. O enlace direto do sistema I xEV -DV é analisado em cenários que consideram o escalonamento FIFO e o escalonamento baseado em prioridade de taxas, mostrando a redução do tempo médio de atraso dos pacotes no sistema com prioridade. Além disto. é possível verificar e quantificar a eficiência da 1111plementação da multiplexação por divisão em código (COM) além da multiplexação por divisão no tempo (TOM) no enlace direto. Os resultados do sistema 1 xEV -DV com tráfego W AP, HTTP e FTP são também comparados aos resultados obtidos com tráfego poissoniano, mostrando as diferenças e a importância da utilização de modelos de tráfego de dados reais / Abstract: In this study, the forward link performance 01' the I xEV -DV system is analyzed through simulations. and the average packet delay, the data throughput and the link utilization are evaluated in function of the system traffic load. For the simulations, it was developed in Matlab software tool, a model that represents the I xEV -DV radio base station processing and scheduling, before the aerial interfaee transmission. and the mode1s based in real data traffic WAP, HTTP and FTP. The forward link 01' the I xEV -DV system is analyzed in scenarios that consider FIFO scheduling and data rate priority scheduling, showing the average packet delay reduction in the system with priority. Besides, it is possible to verify and quantify the efficiency of the code division multiplexing (CDM) implementation besides the time division muItiplexing (TDM) in the forward link. The results of IxEV-OV system with WAP, HTTP and FTP traffic are also compared with the results obtained with Poisson traffic, showing the differences and the importance of the real data traffic models utilization / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica