About The Development of W-SIM and Jacket The Development Points of W-SIM-using Jacket and The Possibility to Expand Jacket

By Mr. Toshiyuki Fujisawa, Managing Director of Technology of NetIndex Inc.


Mr. Toshiyuki Fujisawa from NetIndex Inc., which is the first to release W-SIM product in the world and is keeping releasing new products corresponding to W-SIM, gave a presentation about the development points of W-SIM style terminals and its expansion possibility in future.

  • Introduction of NetIndex Inc.

    • NetIndex Inc. released the world‘s first 128kbps packet communication card G10 in January 2002. It has also released the world‘s first W-SIM and SIM style in November 2005. The W-OAM correspondent RX420N was released in April 2007. NetIndex Inc. is a leading company in Japanese PHS industry.

  • About the development points of SIM style terminals

    • 1.   About W-SIM and WILLCOM SIM style
    W-SIM is a telecom functional module which concentrates the wireless part of PHS and the function to tackle with base band. As far as we have this, an integrated mobile can be made out only a microphone and a key. Besides, the phone book can be moved with W-SIM, which holds up to 700 records, when it is fitted into a new Jacket.

    There are many merits using W-SIM, and the biggest one is that time for protocol test can be saved for manufacturers. Usually protocol test will cost about 3 months while with W-SIM, the period is shortened to 1 month.


    It is true that more spare parts will be needed for a model with separated W-SIM and Jacket, but the total development period is shortened. Hence, the overall result is favorable. More over, specification can be obtained from WILLCOM Core Module Forum.

    For W-SIM, the important part is the part that fits into antenna. The internal antenna is fitted in the opposite side of a W-SIM terminal. Actually, We installed with substantial care even in case of WS005IN (nico.).

    2.   Development Points
    It is said that the development is possible without understanding wireless technology. Although, you might still need a little bit of professional knowledge.

    Wireless performance is after all wireless efficiency in situation of weak radio wave. That is, it really matters on how the factors that might cause the deteriorated performance of a wireless system can be decreased. The following is a round-up of the development points.

    1.  Conductor around W-SIM
      It is usually considered a good thing to have more grounds, although the common sense doesn't apply to SIM style case. The key lies with how distant it can be kept from a base.


    2.  Human body absorbance
      It is important to bear in mind of the antenna being not covered by hand and its fitted-in position. As long as these two points are solved, it's no exaggeration to say PHS can be made without minding about protocol.


    3.  Communication control of W-SIM
      1)  Respective functional control during communication is not necessary, although state management on W-SIM is demanded.
      2)  WILLCOM specification of mail and browser is needed by the party making the Jacket. Correspondence at certain level is needed.

    Letfs verify the development points with WS005IN (nico.)

    To guarantee the wireless performance, the amount of installed spare parts is reduced at the slot where W-SIM (especially antenna part) is to be fitted in.

    Tuning, that comes after this, will be repeated as the review on deteriorated factor.

    One can understand the topic in more detail by reading the article titled Development Story of SIM Style, which was written Mr. Tsukasa Akiyama from Technical Department at NetIndex, Inc. and was published on the May 2007 Edition of INTERFACE, a monthly-published magazine by CQ Publishing Co,.Ltd.. (http://www.cqpub.co.jp/interface/default.asp)

    Besides, the development and production of W-SIM is carried together with WILLOM, Inc. and its know-how is also sold as a package named W-SIM Interface Appraisal Kit. Please check the information here. (ihttp://www.netindex.co.jp/m/p/a/d/i/87/)

  • The possibility to expand Jacket (The merit of development of Jacket with W-SIM)

    • 1.   The evolvement of PHS/mobile terminals
    Mobile terminals was improved from analog handsets at the beginning to digital handset now. Their functions is also expanded and consolidated from pure voice communication to mail, contents and infra-media Standardization trend is conducted from this flow. It is attractive idea but chaotic situation is also generated.

    But for SIM style, to produce a terminal with personality than with multifunction, that is, to give more terminal choices that match the particular taste of certain users becomes possible, since producing multiple models of little amount becomes easy.

    2.   The merit to use W-SIM
    Since the conventional development process includes the development of the wireless part, which bears the key responsibility for communication, the development cost and time are always big barriers. With W-SIM taking care of the wireless communication function now, the time for development is shortened and the cost is reduced. In another word, by making use of a separate communication function, the multi-model production and small-scale production of terminals become possible.

    3.   Assumed applications in future
    It is presumed that the function can be applied to inventory management, toll collection and consumed figure verification, as communication function can be set into existing vending machines and game machines. In addition, it is assumed that terminals can be designed to adapt in machines with special function, such as those for medical institutions and for the purpose to collect store information.

    In order to expand the sale of W-SIM in future, we tends to release more inexperienced products that correspond to W-SIM.

    (complied by Mr. Jun Okada at NetIndex Inc.)