Ntt Docomo, Inc.

Yugo Watanabe

Masami Yabusaki

Masumi Fujiwara

Shoichi Hirata

Satoshi Hiyama

Masahiro Sawada

Kouji Sasada

Ken Igarashi

Koji Sasada

Masashi Yamashita

The object is to prevent occurrence of packet loss in Cellular IP and a drop of TCP throughput due to duplication of packets. On the occasion of relaying a packet from correspondent, a relay router multicasts a router advertisement to access routers forming respective cells into which a target mobile terminal might move. The mobile terminal receives the router advertisements from the neighbor access routers, calculates a difference between reception times of the packets from the respective access routers, and specifies a relay router to perform multicasting. Then the mobile terminal transmits delay information of a delay to be added to each path in multicasting by the relay router, to the relay router thus specified. The relay router adds the delay to each path in multicasting on the basis of the delay information.

Packet transmission method and communication system

A mobile communications control method of this invention controls mobile communication by a mobile terminal in a network in which a plurality of wireless systems are available. In the mobile communications control method, the mobile terminal performs location registration with a wireless system selected from among the wireless systems, based on at least one of a status of the network, a status of the mobile terminal, location information of the mobile terminal, a frequency of incoming call reception of the mobile terminal, and service area information of the wireless systems.

Mobile communications control method, control system and mobile terminal

Mobile terminal status information is sent from a mobile terminal to the communication network after predetermined period advertised from outside, and settings related with a location area for the mobile terminal are made based on the mobile terminal status information at a node in the communication network. In this manner, for example, the optimal location area may be set up in a way to follow changes in the mobile terminal property information, and location control may be performed efficiently even when the mobile terminal does not detect a change of location area, such as when a terminal moving at a high speed slows down it moving speed.

Location registration system, mobile terminal, control equipment, methods of location registration in the location registration system

The presence area information of the moving portable communication terminals accompanied by a moving object is changed according to the scheduled path of the moving object and the scheduled time in the movement of the moving object by using a presence area unit which stores the presence area information indicating the presence area of each portable communication terminal and a moving schedule storage unit which stores the scheduled path information indicating the scheduled path of the moving object (a train, etc.) accompanied by at least one portable communication terminal and the scheduled time information indicating the scheduled time of the movement of the moving object.

Location registration apparatus, location registration method, and mobile communication network

A mobile terminal calling apparatus for calling a mobile terminal existing in a location area constituted by a plurality of cells to corresponding to a plurality of wireless base stations comprises a determination unit and a control unit. When there is a calling request for the mobile terminal, the determination unit determines the kind of the calling request. According to the kind of the calling request determined by the determination unit, the control unit decides a sequence of calling for the plurality of cells constituting the location area.

Mobile terminal calling apparatus, mobile terminal calling method, exchange apparatus, and mobile communication system

A mobile communication network system is provided in which when a radio system is selected from plural types of radio systems as a radio system for use in paging, the optimum radio system for the mobile terminal to be paged can be selected. When it is selected, traffic does not concentrate on a specific radio system, or no excess delay occurs when the mobile terminal starts communications. When the mobile communications network system performs paging as a paging notification to a mobile terminal through any one of various radio systems under a communications environment in which radio waves of various radio systems having different communication systems are used, a radio system is selected from a plurality of radio systems depending on the application used in the communications of the paging requested mobile terminal and a paging operation is performed through the selected radio system when a paging request is issued.

Mobile communications network system, mobile terminal, and paging method

One piece of information used in setting up the optimum location registration area is an area of a peripheral cell. However, in the current system, the area of a cell is set up by the predicted number of subscribers in the area, and therefore, depends on the location. Therefore, when a mobile communication terminal computes the optimum location registration area, it is necessary to obtain the size information about the peripheral cell, which can cause the problem of traffic. The mobile communication terminal in a cell signals a plurality of paging point nodes of mobility and traffic characteristic. Then, the plurality of paging point nodes sets up a location registration area of the mobile communication terminal according to the above mentioned information and network information. Thus, the location management of the mobile communication terminal can be efficiently realized, thereby reducing the traffic.

Method of location registration, location registration system, mobile communication terminal equipment for setting up location registration area, and program for setting up location registration area

A relay device installed in a moving unit can, by notifying an own identification number to a mobile communication network along with identification numbers of all mobile communication terminals subordinate to itself, perform en bloc updating of location registration area information of these mobile communication terminals. This relay device can receive an en bloc paging request wherein paging requests to plural subordinate mobile communication terminals are aggregated, reconstruct the received en bloc paging request, and transmit the paging requests to each of the mobile communication terminals subordinate to itself.

Method of registering position of mobile communication terminal, general calling method for mobile communication terminal and mobile communication system

Location registration method for mobile communication terminals, en bloc paging method for mobile communication terminals, and mobile communication system

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Yokohama, Japan

Yugo Watanabe