DATA COMMUNICATION SYSTEM AND NETWORK INTERFACE UNIT USED FOR THE SYSTEM

摘要

PROBLEM TO BE SOLVED: To shorten negotiation time and to reduce connecting charge by providing NIU(a network interface unit) which can be directly connected to a digital mobile communication network in a data controller and also using only the digital mobile communication network. SOLUTION: A personal computer 51 is connected to a host computer 59 with a digital portable telephone 53 and NIU 61 and only with the digital communication network. In order to connect the personal computer of the host computer 59 with NIU 61, the personal computer 51 originates a call with the digital portable telephone by the prescribed telephone number of a digital portable telephone network which is assignee to NIU 61. By the call originating, NIU 61 is called from the base station 62 of the digital portable telephone network and NIU 61 responds to the call so that a line between the personal computer 1 and the host computer 59 is set. At this time, an analog communication network and MODEMs 56 and 58 are not used and negotiation time is shortened to be a degree of one-fifth in comparison with conventional technique.