For higher data rate and attractive price level internet service Very High Data rate Subscriber Line 2 (VDSL2) is a perfect option. VDSL2 is a great achievement in Digital Subscriber Line (DSL) technology. It has a good impact in modern triple play (Voice, Data and Video) Internet service but for modern world applications required more data rate than the VDSL2 system can provide but it should be inexpensive and easy to install. So the desired goal of this thesis work is to achieve higher bitrates for VDSL2 system, by transmitting multiple VDSL2 signal using Plastic Optical Fiber (POF) channel instead of copper channel. POF channel is a suitable solution for high data rate application. Moreover POF is very rugged and suitable for high data rate application because of optical based transmission and it’s also very easy to implement into the interior networking. Moreover POF doesn’t have any impact of Electro Magnetic Interference because of optical transmission. So several VDSL2 signals are amplitude modulated to allocate specific frequency band and combined together which can be called as frequency division multiplexing and POF is used as channel to carry the combined signal which provide much higher bit rate than single signal and efficiently utilize the bandwidth of the channel. Then at the receiver end the combined signals are split and amplitude demodulate at the respective receiver to recover the expected frequency band for the receiver.

According to the combination of video/HDTV, data, and voice on a single medium, dubbed ¡§Triple Play¡¨, requires more sophisticated QoS (Quality of Service) features than are available in either VDSL1 or ADSL. Lastly, Triple Play services, with a minimum of three TV channels, several VoIP connections, and sufficient speed for Internet access, require high data rates of at least 30 ¡V 40 Mbit/s, about twice of what can be achieved under real field conditions with today¡¦s ADSL2+ solutions. VDSL2 was developed and standardized in record time to address the shortcomings of existing access technologies. It serves as the ideal xDSL technology for eliminating last-mile bottlenecks and to enable global mass deployment of advanced Triple Play services.

VDSL2 is the fastest xDSL technology at present. Its data rate is variable depending on the length of wire and generally higher than HDSL and VDSL. VDSL2 uses the original POTS hardware to provide up to 100 Mbps data rate in upstream and downstream. The disadvantage of VDSL2 is that the longer the transmission distance, the lower the data rate. Generally speaking, the transmission distance is typically less than 1200 meters. The VDSL2 modem in this research is based on Infineon chip set composed of PEB83000 and ADM5120 with an operating band up to 30 MHz. The data rate in the different profiles of chip set is compared to find the optimum performance for a certain transmission distance.

The thesis focuses on the area of copper twisted pair based wireline communications. As one of the most widely deployed communication media, the copper twisted pair cable plays an important role in the communication network cabling infrastructure. This thesis looks to exploit diversity to improve twisted pair channels for data communications in two common application areas, namely Ethernet over Twisted Paris and digital subscriber line over twisted pair based telephone network. The first part of the thesis addresses new approaches to next generation Ethernet over twisted pair cable. The coming challenge for Ethernet over twisted pair cable is to realise a higher data rate beyond the 25/40GBASE-T standard, in relatively short reach scenarios. The straight-forward approaches, such as improving cable quality and extending frequency bandwidth, are unlikely to provide significant improvement in terms of data rate. However, other system diversities, such as spectrum utilization are yet to be fully exploited, so as to meet the desired data rate performance. The current balanced transmission over the structured twisted pair cable and its parallel single-in-single-out channel model is revisited and formulated as a full-duplex multiple-in-multiple-out (MIMO) channel model. With a common ground (provided by the cable shield), the balanced transmission is converted into unbalanced transmission, by replacing the differential-mode excitation with single-ended excitation. In this way, MIMO adoption may offer spectrum utilization advantages due to the doubled number of the channels. The S-parameters of the proposed MIMO channel model is obtained through the full wave electromagnetic simulation of a short CAT7A cable. The channel models are constructed from the resulting S-parameters, also the corresponding theoretical capacity is evaluated by exploiting different diversity scenarios. With higher spectrum efficiency, the orthogonal-frequency-division-multiplexing (OFDM) modulation can significantly improve the theoretical capacity compared with single-carrier modulation, where the channel frequency selectivity is aided. The MIMO can further enhance the capacity by minimising the impact of the crosstalk. When the crosstalk is properly handled under the unbalanced transmission, this thesis shows that the theoretical capacity of the EoTP cable can reach nearly 200GBit/s. In order to further extend the bandwidth capability of twisted pair cables, Phantom Mode transmission is studied, aiming at creating more channels under balanced transmission operation. The second part of the thesis focuses on the research of advanced scheduling algorithms for VDSL2 QoS enhancement. For VDSL2 broadband access networks, multi-user optimisation techniques have been developed, so as to improve the basic data rate performance. Spectrum balancing improves the network performance by optimising users transmit power spectra as the resource allocation, to mitigate the impact from the crosstalk. Aiming at enhancing the performance for the upstream VDSL2 service, where the users QoS demand is not known by all other users, a set of autonomous spectrum balancing algorithms is proposed. These optimise users transmit power spectra locally with only direct channel state information. To prevent selfish behaviour, the concept of a virtual user is introduced to represent the impact on both crosstalk interference and queueing status of other users. Moreover, novel algorithms are developed to determine the parameters and the weight of the virtual user. Another type of resource allocation in the VDSL2 network is crosstalk cancellation by centralised signal coordination. The history of the data queue is considered as a time series, on which different smooth filter characteristics are investigated in order to investigate further performance improvement. The use of filter techniques accounts for both the instantaneous queue length and also the previous data to determine the most efficient dynamic resource allocation. With the help of this smoothed dynamic resource allocation, the network will benefit from both reduced signalling communication and improved delay performance. The proposed algorithms are verified by numerical experiments.

This diploma thesis focuses on G.fast and VDSL2 technologies and their comparison. G.fast has the prerequisites for replacing VDSL2 for short distances. This work describes in detail the modulation techniques of both DSL technologies - DMT modulation used by both technologies. The aim of this work is to create a software for comparing the transfer rates of all profiles of both technologies, including the effects of far-end crosstalk. This is performed in the Matlab environment. This work describes how the program works and how to run the simulations. The results of selected simulations and their charts are enclosed in this work.

Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-07-31T13:19:37Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_SimulacaoAvaliacaoTecnologias.pdf: 1013915 bytes, checksum: da3b515d7ab4934a83707693639a07ea (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-09-05T12:15:02Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_SimulacaoAvaliacaoTecnologias.pdf: 1013915 bytes, checksum: da3b515d7ab4934a83707693639a07ea (MD5) / Made available in DSpace on 2014-09-05T12:15:02Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_SimulacaoAvaliacaoTecnologias.pdf: 1013915 bytes, checksum: da3b515d7ab4934a83707693639a07ea (MD5) Previous issue date: 2013 / A crescente demanda por capacidade vem levando os padrões de comunicação sem-fio a prover suporte para a coexistência de macro e pico células. O backhaul, conexão entre a rede de acesso e o núcleo da rede, é de grande interesse neste contexto devido aos diversos desafios técnicos e financeiros envolvidos ao tentar satisfazer o crescente tráfego dos usuários. Fibra óptica e micro-ondas com linha de visada são as opções mais amplamente adotadas para o backhaul de macro-células. Contudo, em muitas situações de interesse prático, estas não são factíveis devido aos altos custos e logística envolvidos. Este trabalho avalia o backhaul de pico-células, focando primeiramente na utilização de cobre como backhaul. O simulador OPNET foi utilizado para avaliar os requerimentos de backhaul para redes móveis em cenários específicos considerando garantir qualidade de serviço para os diversos tipos de tráfego envolvidos. Assumindo demandas de tráfego para LTE e LTE-Advanced, as tecnologias VDSL2 e G.fast são avaliadas e os resultados mostram que mesmo com uma grande demanda de aplicações de vídeo de alta definição, estas tecnologias podem acomodar o tráfego no backhaul de pico-células. VDSL2 é capaz de prover as taxas requeridas para cenários de pico-células LTE, mas não é capaz de acomodar tráfego LTE-Advanced típico. Por outro lado, considerando as taxas atingidas com a tecnologia G.fast, o tráfego backhaul para pico-células LTE-Advanced pode ainda ser entregue com garantias de qualidade de serviço. Neste trabalho também é proposta uma solução para simulação de cenários contendo redes de acesso heterogêneas considerando backhaul LTE sem linha de visada. São demonstrados também os resultados de simulações no OPNET com o backhaul LTE proposto para validar a solução proposta como capaz de caracterizar o tráfego de ambas as tecnologias WiFi e LTE na rede de acesso de acordo com o tipo de serviço. / The increasing demand for capacity has been driving the wireless communication standards to provide support to the coexistence of macro and small cells. The backhaul, which is the link between the radio access network and the backbone, is of particular interest due to the many involved technical challenges on keeping up with the user demand for bandwidth. Line-of-sight microwave radio and optical fiber are the preferred choices and widely adopted for the mobile backhaul (MBH) of macrocells. However, in many situations of practical interest, both options are not feasible due to cost and logistics. This work evaluates the backhaul of small cells, focusing on the adoption of copper pairs. Opnet was also used to evaluate copper MBH requirements in specific scenarios taking into consideration QoS provisioning. Assuming traffic demands for LTE and LTE-Advanced, VDSL2 and G.fast technologies are evaluated and the results show that even with a heavy load of video, these technologies can accommodate the small cell MBH traffic. VDSL2 is capable of delivering the required data rates for LTE small cell scenarios but not if considered LTE-Advanced traffic. Otherwise, if considered G.fast data rates, backhaul traffic for LTE-Advanced small cells can still be delivered by xDSL technology with QoS guaranteed. Also, this work enables the implementation of heterogeneous access networks scenarios considering LTE NLOS out-of-band backhaul. A solution of LTE backhaul implementation in OPNET is proposed and simulations are performed to validate such solution as a QoS-aware LTE Backhaul for WiFi and LTE radio access technologies.

This semester work focuses on the basic characteristics of the VDSl2 and G.fast technologies that allow to transfer data using old telephone lines. The theoretical part of the work describes the main parameters of all currently known profiles for VDSL and G.fast. There is also a description of DMT modulation, used in both types of DSL connections. Moreover, the theoretical part presents a vectoring technique that helps to increase the data transfer rate using a twisted pair. The work also provides methods for testing networks using the recommendations of RFC 2455, ITU-T Y.1564 and RFC6349. The practical part of this thesis contains all conducted tests and measuring, which were described in detail. The results od these tests were presented in the format of graphs and tables.

The thesis concerns the problem of interference modelling for xDSL technologies and Ethernet. The introduction describes the origin of crosstalk, that arise during the operation of the systems and the physical properties of the lines, therefore, the next section describes the properties of the primary and secondary parameters of the homogenous line and their modelling. In order to achieve higher data rates on the metallic line, systems with larger frequency spectrum are applied, resulting in a greater attenuation of the line. This issue and the characteristics determination of the transmission systems are subjects of the mathematical models, which are divided according to the modelling of primary or secondary parameters. The main goal of this work is to describe the effects which influence the performance of data transfer via xDSL and Ethernet technology focusing on internal and external disturbances acting on the cable lines. This is the crosstalk at the near and far end, adaptive white noise, radio frequency interference RFI and impulse noise. Following part of the thesis deals with the properties of xDSL technologies, specifically ADSL2+ and VDSL2 and Ethernet. Another aim is to design applications which enable to test the performance of xDSL and Ethernet transmission systems with its own award simulations interference. The conclusion describes the design and implementation of laboratory experiments for measuring of the efficiency and spectral properties of xDSL. The proposed laboratory protocols are annexed to this thesis, including the measured waveforms.