Abstract: A mobile IP communication scheme in which the mobile computer can be operated using the mobile communication protocol such as Mobile IP even in the case where the home network is operated by the dynamic address allocation protocol such as DHCP is disclosed. The current location registration message to be transmitted by the mobile computer from the visited site to the mobile computer management device contains an information indicating that the dynamic address allocation has been received at the home network and an information capable of identifying the mobile computer, and the mobile computer management device carries out exchanges with the dynamic address management server on behalf of the mobile computer, so that the mobile computer which has received the dynamic address allocation at the home network can be operated at the visited site by using the mobile communication protocol.

Abstract: A mobile supporting router device for realizing the handoff control associated with the moving in high speed is forms by at least one first interface connected with radio base stations, each capable of accommodating at least one mobile terminal; at least one second interface connected with a wire network; an information exchanging unit for exchanging a routing protocol on a network layer, through the second interface; a memory unit for storing information regarding a routing on the network layer based on the routing protocol exchanged by the information exchanging unit; a transfer unit for transferring datagram through the first interface according to the information regarding the routing on the network layer stored in the memory unit; a moving detection unit for detecting a moving of the mobile terminal among the radio base stations; and an information updating unit for updating the information regarding the routing on the network layer stored in the memory unit when the moving of the mobile terminal is dete

Abstract: An electronic service system is formed such that the personal authentication information such as user ID and password registered at one site can be utilized in carrying out the electronic commerce or the electronic service at another site, by transferring the user information between a plurality of EC sites safely.

Abstract: In a radio communication system, communication for sending data from a transmitting station to a receiving station and communication for transmitting re-send data from the transmitting station to the receiving station according to the re-send request transmitted from the receiving station to the transmitting station are done on different occasions of communication. Hence, in the applications not requiring real time service, this re-send control method does not spend the power and radio resources wastefully, and by effectively utilizing the system resources and lowering the power consumption, the battery of the terminal may be reduced in size, so that the portability of the terminal may be enhanced.

Abstract: A portable terminal includes a first store for storing a first physical address including a serial number of the terminal, a second store for storing a first logical address including a subscriber's telephone number, a third store for storing a second physical address of a hardware used for computer communication, a fourth store for storing a second logical address corresponding to the second physical address, an interface for radio LAN, and an interface for PHS system. When a call is originated, a first channel is connected by using the first physical address and the first logical address. The second physical address and the second logical address are transmitted to the network from the call originator's terminal through the first channel, thereby setting in a state enabling communication between computers, and necessary data is transmitted to the call originator's terminal through a second channel by communication between computers.

Abstract: An ATM-based radiocommunication system adapted for multimedia communication comprises a repeater for providing communication services over a predetermined service area, first radio terminals for communicating with the repeater by using ATM cells, and a second terminal for communicating with the repeater by using ATM cells and communicating with a backbone network.

Abstract: An ATM-based radiocommunication system adapted for multimedia communication comprises a repeater for providing communication services over a predetermined service area, first radio terminals for communicating with the repeater by using ATM cells, and a second terminal for communicating with the repeater by using ATM cells and communicating with a backbone network.

Abstract: A unit cell switch includes a plurality of input communication routes and output communication routes for transferring data cells therebetween, a plurality of first conversion devices for converting each cell given from these input communication routes into a desired form, a plurality of second conversion devices for converting each data given from the first conversion devices into a suitable form and transferring the resultant data to one of these output communication routes. Cell storing devices respectively receive and temporarily store cells transferred from corresponding first conversion devices based on address information given to the cells.

Abstract: A ATM communication system can satisfy various requests from a node system, a link system, and the like, by performing a self-format transform between a format to be transmitted and a format receiving an ATM switch, and using a cell processing function for performing polishing/shaping, counting of passed cells, counting of discarded cells, drop/insertion of OAM cell, and the like.

Abstract: A preliminary operation system in an ATM network capable of preventing the erroneous cell transmissions due to the header transformation operation during the rewriting of the header transformation table, and recognizing cells of different cell types without using additional hardware components. The system includes a header transformation table for storing a header transformation information including a flag for indicating a preliminary operation mode either in a form of a state of the header transformation table or a type of cell for each cell; and a preliminary operation device for transforming a header of each cell into a format suitable for the ATM cell switch by utilizing the header transformation information stored in the header transformation table, according to the indication of the flag.

Abstract: A buffer device capable of dealing with multiple priority levels in which the efficiency of the memory capacity utilization can be improved such that the priority levels can be handled at the higher efficiency with smaller memory capacities, and which is adaptable to a high speed buffer implementation. The device includes a data register array containing empty data registers and imaginary FIFO queues, and an adminstrative register array comprised of a two port RAM for storing pointer chains specifying the imaginary FIFO queues. The input of data is accompanied by the modification of the pointer chain to extend it, whereas the output of data is accompanied by the modification of the pointer chain to shorten it, so that the imaginary FIFO queues are administered in flexible manner in order to achieve efficient memory capacity utilization. The procedure for controlling the imaginary FIFO queues can be executed in parallel because of the independency of read and write operations in the two port RAM.