3GPP TSG-T WG2#3
Yokohama, Japan, 19-21 April 1999	TSGT2#3(99)403

Agenda Item:	SWG2

Source:	Mitsubishi Electric Co., NEC, Fujitsu, Toshiba

Title:	Comments on TA-MT Interface

Document for:	Discussion

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TA is, literally, a block which adapts the protocol used in the various kind of application terminal (TE) to the protocol used in the radio link. 
Therefore, it is necessary to prepare different TA for each kind of application terminal.

As for TE, PC is thought to be the major one, so it is natural to secure the easy connection to PC. 
For this purpose, the mobile phone including MT and TA for PC within one body is a useful solution, and user can connect their PC to phone directly. In this case, since TA-MT interface is completely internal, it isn't necessary for this interface to be based on the standards.

Next, let us consider other application terminals, especially, the TE's of which market is not so big, but of which needs from specific people is extremely large, (e.g. medical use, etc.)
From the business point of view, the manufacturers of mobile phones do not want to make TA's for such TE's, in general. But, if the mobile phone supports TA-MT interface and its connector based on a certain standard, TE manufactures or third parties can develop TA's for such TE's. As a result, the demand of mobile phones will expand and it is better for our business.

In ISDN case, there are standards at the reference points of R, S/T, U.
There exist various types of equipment of TA, DSU with TA, TE with TA, etc. in the market, and each category of equipment supplies the best solution for each end user's needs.

As described above, we believe that specifying TA-MT interface in standard does not constrain future evolution but can lead the evolution in new applications and thus create the new markets.
Therefore, we support specifying TA-MT interface in standard.

Of course, it should be written clearly that these specifications are optional.
Manufacturers of mobile phones can implement any physical and logical interface at any reference point as an external interface. Also, they can implement their own interface or mobile phones without the external interface.