Hitachi, Ltd.

Hitachi Communication Technologies, Ltd.

Daigo Takayanagi

Shiro Mazawa

Yosuke Takahashi

Akihiko Yoshida

Kiyoshi Kawamoto

Shigeyasu Kubo

Rintaro Katayama

Toshiyuki Saito

A radio communication method in which, when hand-off of the down direction is performed while a radio mobile device subjects one application packet of the up direction to fragmentation to divide the one application packet into a plurality of radio packets and transmits the plurality of radio packets, sequence numbers of radio packets managed by a first radio base station to the plurality of fragmented radio packets of the one application packet even after the hand-off of the down direction is performed and to apply sequence numbers of radio packets managed by a second radio base station to fragmented radio packets of the application packet transmitted subsequently after completion of transmission of the plurality of fragmented radio packets of the one application packet; and making a radio base station accommodation apparatus identify a radio base station and restore data for each radio base station.

Radio communication method, radio mobile device and radio base station accomodation apparatus

A method for, in a radio communication system having at least a content server, plurality of base stations, and plurality of radio terminals, enabling two or more base stations among the plurality of base stations to broadcast or multicast data delivered from the content server to the radio terminals, the method includes: providing a Broadcast Multicast Service (BCMCS) Serving Node between the content server and two or more base stations; the BCMCS Serving Node includes a period number and sequence number into data delivered from the content server and transmits data including the period number and sequence number to the two or more base stations; in case that a synchronization is deviated or data is lost during data delivery from the base stations to the radio terminals, the base stations perform re-synchronization on a basis of the period number and sequence number included in data received from the BCMCS Serving Node.

Synchronous delivery method

An information transmitting method including; determining, on a basis of a packet error rate from a master station to slave stations, a number of times of multicast transmission in accordance with an expected value of a number of slave stations that transmit a retransmission request, an expected value of a number of retransmitted packets responding to the retransmission request, or a probability that the slave stations receive all packets forming information; notifying determined number of times of multicast transmission to the slave stations; and transmitting, to plural slave stations in multicast, same information formed of plural packets the determined times of multicast transmission.

Information transmitting method and information transmitting system

In order to narrow down base stations within the tracking-area-based paging area to ones within a smaller area where the mobile unit may exist in a mobile communication system performing the paging on the tracking-area basis, the mobile communication system has a location registration information database memorizing tracking area information, a last location registration information and a N-th (N is an integer of one or more) location registration information from the last for each mobile unit, calculates statistical data on a movement distance for each mobile unit based on the location registration information memorized in the location registration information database, and performs the paging via base stations included both within an area whose radius is equal to the calculated statistical data on the movement distance and within the tracking area.

Paging-area determination method and call-processing control apparatus in mobile communication system

A decryption key for decrypting data from an access node is distributed to an access terminal intending to receive the data. An authentication unit receives a message for terminal authentication including a terminal identifier from the terminal and authenticates the terminal. The authentication unit refers to a content registration table having stored in advance the content type of a content which the terminal can receive, in association with the terminal identifier, according to the received terminal identifier to obtain a corresponding content type. The authentication unit refers to a decryption data base having stored in advance a decryption key and its valid period in association with a content type, according to the obtained content type to obtain a corresponding decryption key and valid period. The authentication unit sends an authentication result and the decryption key and valid period to the terminal or to a packet control unit.

Decryption-key distribution method and authentication apparatus

A radio communication system of an HARQ method that makes an HARQ transmission interval of subpackets appropriate and reduces data transmission delay resulting from subpacket retransmission. In the radio communication system in which a packet is transmitted and receives with the HARQ method between a base station and multiple radio mobile stations, each of the base station and the multiple radio mobile stations has: a packet transmission circuit for transmitting subpackets in predetermined intervals; a packet reception circuit for repeating decoding processing by combining a newly received subpacket and a previously received former subpacket until an original packet is successfully decoded; and a HARQ control equipped with a function of, for packet communication whose data length is short, transmitting a subpacket or response from the packet transmission circuit in an HARQ transmission interval that is shortened from the HARQ transmission interval of the normal mode.

Radio communication system, mobile station, and radio base station

An aggregation device performs a synchronous processing so that a synchronous delivery may be made from a plurality of base stations through a broadcasting channel. A BSN () gives, when it sends broadcasting data for the synchronous delivery to an AN () and an AN (), a period number and a sequence number are added to the broadcasting data so that the data to be sent from the AN () and the AN (can be synchronously delivered.

A wireless communication system including a wireless terminal, a plurality of base stations and a call processing control unit is disclosed. The wireless terminal, upon reception of the notification information from any of the base stations, judges whether the area included in the notification information is contained in the location registration area list stored in a storage unit, and in the case where the particular area is not so contained, sends a location registration request to the call processing control unit. On the other hand, the call processing control unit creates a new location registration area list based on the area included in the notification information and the neighboring areas, and sends the location registration area list to the wireless terminal.

Wireless communication system

A call processing control apparatus automatically detects that a lot of handover and location registration simultaneously occur, and notifies a monitor control server. The monitor control server receiving the notification from the call processing control apparatus transmits a TAI change request to a base station so that a tracking area identity (TAI) of a movement destination cell where congestion occurs and a tracking area identity of a movement origin cell have the same value. The base station receiving the TAI change request message from the monitor control server changes its own TAI value. After that, all mobile devices perform only handover when they move between the cells where the TAI values are changed, and does not perform location registration.

Location registration area assigning method and wireless communication system

A transmission area is specified flexibly in accordance with the contents of a flow. An area identification number (SHOG) is specified for each interlaced stream of wireless base stations. The same flow is sent at the same timing (or substantially at the same timing) in the interlaced stream specified for the same SHOG. A wireless terminal determines a neighbor sector or a neighbor wireless base station sending the same flow, in accordance with information given from the wireless base stations, and receives and combines the flows.

Area management system

Information transmitting arrangements for transmitting information through a plurality of base stations from a master station to a plurality of slave stations which communicate with the base stations.

A slave station which transmits/receives signals to/from a master station, the slave station includes: a transmitting unit and receiving unit for transmitting/receiving signals regarding the master station; a storing unit; an input unit; wherein under a control by a control unit, the transmitting unit transmits a transmission request for transmitting multicast data to the master station in accordance with a timing of power-on or an input by the input unit; the receiving unit receives information of a number of times of transmission for requested multicast data from the master station and stores the number in the storing unit; and after receiving the multicast data the number of times of transmission stored in the storing unit, the control unit determines presence of absence of lacking data which have not been received and, transmits a retransmission request for requesting the lacking data in a case of presence the lacking data.

Admission control wireless resources including abase station which obtains a down wireless resource available rate based on a down QoS requested bandwidth Brequested by a terminal i during QoS communication and a data rate Rwhich the terminal can receive. A down wireless resource usage rate is obtained by dividing a down QoS requested bandwidth B requested by the terminal trying to perform QoS communication by the data rate R which the terminal can receive. An up wireless resource available rate is obtained based on ROT of an up channel and a threshold value Tindicating an allowable upper limit of the ROT. The QoS communication is performed on the terminal in which the up and down wireless resource available rates are respectively equal to or more than the up and down wireless resource usage rates.

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Yokohama, Japan

Daigo Takayanagi