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  2. 1G - Wikipedia

    en.wikipedia.org/wiki/1G

    1G refers to the first generation of cellular network (wireless) technology. These are mobile telecommunications standards that were introduced in the 1980s and were superseded by 2G . The main difference between these two mobile cellular generations is that the audio transmissions of 1G networks were analog , while 2G networks were entirely ...

  3. Cellular network - Wikipedia

    en.wikipedia.org/wiki/Cellular_network

    The first commercial cellular network, the 1G generation, was launched in Japan by Nippon Telegraph and Telephone (NTT) in 1979, initially in the metropolitan area of Tokyo. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nationwide 1G network. It was an analog wireless network.

  4. List of wireless network technologies - Wikipedia

    en.wikipedia.org/wiki/List_of_wireless_network...

    1G or (1-G) refers to the first generation of cellular network technology. These are the analog telecommunication standards that were introduced in 1979 and the early to mid-1980s and continued until being replaced by 2G digital telecommunications. The main difference between these two mobile telephone generations is that in 1G systems the ...

  5. Ethernet physical layer - Wikipedia

    en.wikipedia.org/wiki/Ethernet_physical_layer

    The Ethernet physical layer has evolved over its existence starting in 1980 and encompasses multiple physical media interfaces and several orders of magnitude of speed from 1 Mbit/s to 400 Gbit/s. The physical medium ranges from bulky coaxial cable to twisted pair and optical fiber with a standardized reach of up to 80 km.

  6. Insulated-gate bipolar transistor - Wikipedia

    en.wikipedia.org/wiki/Insulated-gate_bipolar...

    Invented. 1959. Electronic symbol. IGBT schematic symbol. An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily forming an electronic switch. It was developed to combine high efficiency with fast switching. It consists of four alternating layers (NPNP) [1][2][3][4][5] that are controlled by a metal ...

  7. Wireless - Wikipedia

    en.wikipedia.org/wiki/Wireless

    Wireless communication (or just wireless, when the context allows) is the transfer of information (telecommunication) between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most common wireless technologies use radio waves. With radio waves, intended distances ...

  8. Third-generation photovoltaic cell - Wikipedia

    en.wikipedia.org/wiki/Third-generation...

    Third-generation photovoltaic cell. Third-generation photovoltaic cells are solar cells that are potentially able to overcome the Shockley–Queisser limit of 31–41% power efficiency for single bandgap solar cells. This includes a range of alternatives to cells made of semiconducting p-n junctions ("first generation") and thin film cells ...

  9. Communications satellite - Wikipedia

    en.wikipedia.org/wiki/Communications_satellite

    v. t. e. A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military ...