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    TransferJet(Close-Proximity Wireless Transfer)

    TransferJet is a close-proximity wireless transfer technology developed by Sony. A consortium of companies is currently creating standards for the new technology, which allows data to be transferred at speeds of up to 560 Mbps simply by touching the transmitting device directly to the receiving device. TransferJet eliminates complex and troublesome configuration and settings typically associated with conventional wireless technology. For example, if you wish to enjoy video content residing in their smart phones on larger screens, you can simply touch their smartphone to the tablet PC and immediately enjoy playback on their tablet screen. In the near future, anyone will be able to instantly and conveniently download/transfer content anywhere. For example, rail commuters will be able to drop by a retail kiosk at any train station and simply touch their smartphone to an electronic terminal to instantly download free (ad-supported) newspapers and magazines. In the summer of 2011, the basic TransferJet specifications were approved and published as Ecma standards (ECMA-398 and ECMA-399). In the spring of 2012, the same specifications were ratified by ISO/IEC as international standards (ISO/IEC 17568 and ISO/IEC 17569).

    Wireless Technology with a few cm Range

    Your TV responds when you push the button on your remote, and your mobile phone will always connect to a base station when you turn on the power. Everyone from the young to senior citizens can easily use these wireless technologies without thinking. Yet before any wireless system can be used, it is necessary to select the receiving device, and this action requires complex settings.

    The aim of TransferJet is to create a simple wireless technology that anyone can use. By reducing the range to less than a few cm, Sony was able to create an intuitive interface that simply requires two devices be brought into contact. This eliminates the need for complex initial setup and configuration with the other devices, such as access points.

    As shown in the video, TransferJet enables users to sample music for a specified period and, if they like it, purchase an entire song right there, simply by touching their mobile terminal to the target point on the signage. Because TransferJet has a range of only a few centimeters, there can be different music content offered from multiple target points arranged side-by-side.

    The TransferJet Coupler
    --- A New Communications Technology Based on Electric Induction

    Instead of a traditional wireless antenna, which employs electromagnetic radiation, Sony has developed a new antenna element designed to work with longitudinal electric induction fields. Known as the "TransferJet Coupler," it consists of a coupling electrode, a resonant stub, and ground. When a signal is applied to the stub, charge accumulates in the coupling electrode, and a inverse image charge of opposite polarity is generated beneath the ground plane. The ultra-low-power vertical dipole structure formed by these charges is the basis of the TransferJet Coupler system.
    • Figure 1: Structure and Operating Principle of the TransferJet Coupler Longitudinal Wave Emitted in
      Figure 1: Structure and Operating Principle of the TransferJet Coupler
      Longitudinal Wave Emitted in Forward Direction (Z Axis)


    Compared to a conventional antenna, the gain of the TransferJet Coupler is high at short distances but decreases rapidly as distance increases. Because communication takes place only when devices are placed in close proximity (and breaks when they are moved apart), the system is extremely easy for users to understand and operate, and there is no uncertainty about whether or not the wireless connection is working.

    High-speed, Ultra-low-power Wireless Communication System

    With a physical layer transmission rate of 560 Mbps, the TransferJet Coupler can achieve an effective data throughput of 375 Mbps, after taking into account error correction and other protocol overhead. At the same time, Sony also succeeded in minimizing transmission power. In fact, the TransferJet system uses 1/700 as much power as ultra-wide-band (UWB) technology (which is already known for low power operation). TransferJet complies with the Japanese standard for low-intensity wireless stations and can be used indoors, outdoors as well as in vehicles throughout Japan. Also, because TransferJet is an ultra-low-power wireless transfer system designed to operate at very close range, there is almost no interference with other wireless systems. This means the TransferJet system will not cause problems with wireless LAN or Bluetooth since these operate on different frequencies.
    Center frequency 4.48 GHz
    Transmission
    power    		 -70 dBm/MHz or lower (average power) Complies with low-intensity wireless station standard in Japan, and with local radio wave regulations in other countries.
    Maximum Transmission rate 560 Mbps (max.)/ 375Mbps (effective throughput) . Capable of
    selecting optimal transmission rate
    Transmission
    distance    		 Approximately a few cm (nominal)
    Table 1: Summary of TransferJet Specifications

    How TransferJet Differs from Wi-Fi

    Because Wi-Fi only has a few available channels and the standard allocates equal access to all devices connected, the more devices connected to the Wi-Fi network at any given time, the slower the transfer rate. TransferJet, on the other hand, is not affected by the number of individual simultaneously communications since the connections are always one-on-one. Therefore, if a customer were to purchase an e-book at a store offering such content or a high-volume content from a train station retail kiosk, TransferJet would enable the customer to download the purchased content some 10 to 100 times faster than Wi-Fi. This is especially true outdoors since TransferJet is much more stable than Wi-Fi in open environments.
    • TransferJet
      *Transfer rates for a 112 MB file---TransferJet versus Wi-Fi (actual measured results)
      With TransferJet, multiple device pairs can be supported simultaneously without affecting the transfer rate. However, with Wi-Fi, when six devices are supported simultaneously, the transfer rate decreases to less than one-fourth compared to the case of supporting just one device.

      Wi-Fi experiment:
      112 MB file simultaneously transferred from access point to each device (2m)
      802.11n 2.4GHz 150 Mbps mode. Measurements repeated several times and results have been averaged.


    Future of the Technology

    In 2012, the TransferJet Consortium added a new suite of specifications to the TransferJet standard including support for data transfer between IP-based home networks and specifications to support the handling of commercial, protected content. The Consortium has been working on expanding the initial set of technical specifications and the first installment has been completed. They consist of four sets of specifications at the protocol conversion later (PCL), allowing mapping of the TransferJet link layer data to Serial, SD over SCSI, PTP/MTP and IP protocols. Additional means of enhancing speed are currently being explored.

    TransferJet shows promise in many areas. Among new potential fields being explored, new services combining the advantages of TransferJet with Near Field Communication (NFC) --- a technology currently entering mass-deployment phase --- is one of many possible options.

    Related Press Release




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