| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the waste of carrying a PHS and a portable telephone and paying basic charges for the two. SOLUTION: This super PHS is made by unifying a PHS and a portable telephone. There were difficulties in unifying them both in terms of a technique and in terms of a system. Technical difficulties are miniaturization and compatibility in the common use of the PHS and the portable telephone. Also, PHS radio waves are automatically and preferentially sensed and transmitted at the time of trnasmission and changeover is manually performed by the judgement of a user as well. Difficulties in terms of the system is an adoption of a method of sending the PHS radio waves to a terminal first at the time of the transmission and immediately switching to the radio waves of the portable telephone when no reception is performed. It is similar to roaming at the time of calling the outside of an area. The super PHS can receive the radio waves of both PHS and portable telephone at all times. By the super PHS, the enlargement of the area and low charge communication are made possible. |
