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Internet e Televisão de nova Geração em Portugal

Discussão em 'Dúvidas e Suporte—Internet, Redes, Segurança' iniciada por boot, 9 de Janeiro de 2009. (Respostas: 2; Visualizações: 751)

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  1. boot

    boot Power Member

    Rede CABO: The latest version of EuroDOCSIS -version 3.0- is a breakthrough technology for European cable operators and consumers. It already allow data speeds of 160 Mbps downstream and 120 Mbps.

    Most remarkable about EuroDOCSIS 3.0 is that it bundles minimum 4 frequency channels of the cable network together whereas previous versions of EuroDOCSIS used only one frequency channel. This makes EuroDOCSIS 3.0 at least 4 times faster than the previous EuroDOCSIS version. As EuroDOCSIS 3.0 has no limit in how many channels it can bundle, the speed for data communications via cable will progressively increase to a multitude of 160Mbps/120Mbps.

    EuroDOCSIS 3.0 also responds to the increased demand for IP addresses by integrating the new Internet Protocol version 6 (IP vs6). The demand for more IP addresses is generated by an array of new Internet enabled devices (laptops, PVRs, mobile phones, etc.).

    Em uso pela ZON

    O cabo que chegas às casas continua a ser COAXIAL, contudo os Modems podem vir a ser trocados (Modems mais recentes apenas precisam de uma actualização de FIRMWARE)


    Rede Fixa: VDSL2 (Very High Speed Digital Subscriber Line 2) is an access technology that exploits the existing infrastructure of copper wires that were originally deployed for POTS services. It can be deployed from central offices, from fibre-fed cabinets located near the customer premises, or within buildings.
    VDSL2 is the newest and most advanced standard of DSL broadband wireline communications. Designed to support the wide deployment of Triple Play services such as voice, video, data, high definition television (HDTV) and interactive gaming, VDSL2 enables operators and carriers to gradually, flexibly, and cost efficiently upgrade existing xDSL-infrastructure.
    It has been standardized as ITU G.993.2.
    ITU-T G.993.2 (VDSL2) is an enhancement to G.993.1 (VDSL) that permits the transmission of asymmetric and symmetric (Full-Duplex) aggregate data rates up to 200 *****/s on twisted pairs using a bandwidth up to 30 MHz.
    VDSL2 deteriorates quickly from a theoretical maximum of 250 *****/s at 'source' to 100 *****/s at 0.5 km (1640 ft) and 50 *****/s at 1 km (3280 ft), but degrades at a much slower rate from there, and still outperforms VDSL. Starting from 1.6 km (1 mile) its performance is equal to ADSL2+.
    ADSL-like long reach performance is one of the key advantages of VDSL2. LR-VDSL2 enabled systems are capable of supporting speeds of around 1-4 *****/s (downstream) over distances of 4 to 5 km (2 ½ to 3 miles), gradually increasing the bit rate up to symmetric 100 *****/s as loop-length shortens. This means that VDSL2-based systems, unlike VDSL1 systems, are not limited to short local loops or MTU/MDUs only, but can also be used for medium range applications.

    Em uso pela PT e Clix (In Portugal, Clix (ISP) and Portugal Telecom is planning to provide VDSL2 + FTTH in 2008 end, new technology of PTInovação (PT Labs) called mediaDSLAM can provide 100 *****/s in a long range, 4/5 km of main "source", against 0.5 km.)

    Não é fibra optica que vai chegar às vossas casas mas sim POTS (Plain Old Telephone System).


    TDT(Televisão Digital Terrestre) : DVB-T is an abbreviation for Digital Video Broadcasting – Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television. This system transmits compressed digital audio, video and other data in an MPEG transport stream, using COFDM modulation.

    The DVB-T Standard is published as EN 300 744, Framing structure, channel coding and modulation for digital terrestrial television. This is available from the ETSI website, as is ETSI TS 101 154, Specification for the use of Video and Audio Coding in Broadcasting Applications based on the MPEG-2 Transport Stream, which gives details of the DVB use of source coding methods for MPEG-2 and, more recently, H.264/MPEG-4 AVC as well as audio encoding systems. Many countries that have adopted DVB-T have published standards for their implementation

    In Portugal (experimental, uses MPEG-4 video)

    Em uso por todos os operadores que já transmitam canais HD e operação atraves de IPTV (Requer equipamento : Set-top-box Digital).


    Apois do Governo:
    Têm por objectivo aumentar a capacidade das redes do Governo;
    Comprir as metas da EU no que toca a Televisão Digital (ínicio em 2009 e fecho do analogico em 2011);
    Melhorar a qualidade de serviço a empresas/privados.
    Última edição: 9 de Janeiro de 2009

    RAPMAD Power Member

    É bom poder aproveitar e melhorar o que já existe. Mas venha é a fibra :009:
  3. amjpereira

    amjpereira Folding Member

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