Nec Corporation

Koichi Ebata

Hiroshi Furukawa

Kenji Takeda

Morihisa Momona

Kazuhiro Okanoue

Akira Miyashita

A case search system for searching for a case that serves as a reference in a design or operation of a wireless network. The case search system includes a case database in which, for a case of design or operation of a wireless network, environment information that determines environmental characteristics of a wireless network in an area associated with the case is registered, and a case search unit that searches the case database for a case which serves as a reference using, as a search key, environment information that determines environmental characteristics of a wireless network in a target area which is a subject matter of the design or operation of the wireless network.

Case search system, case database, case search apparatus, case search method, and program

A system is connected to an access point via a network, receives packet transmission information held by the access point, and extracts an address having a transfer destination which is radio interface from the packet transmission information. It is assumed that the terminal of the extracted address exists under the access point holing the packet transmission information. Thus, it is possible to realize connection relationship between a terminal and an access point at low cost and not depending on the vendor.

Radio network monitor device and monitor system

An area to be estimated is sectioned to minute sections, the received signal qualities from a plurality of installed base stations () are found, respectively in each of the minute sections, a difference between the received signal quality of each minute section and the received signal quality of a minute section adjacent to the above minute section is referred to as well as a change point at which a difference between a received signal quality used as a hand-over condition and the above received signal quality changes is detected so that an area in which a hand-over occurs can be accurately estimated. With this manner, there can be obtained a received signal quality estimation method capable of estimating an area in which a hand-over occurs very accurately in a mobile communication system.

Method of and apparatus for estimating received quality of communication area and program

A reception quality estimating method estimates reception quality of a wireless communication area for estimating success or failure of handover processing occurring in a service area of a wireless communication system including a plurality of base stations. The method includes a first step and a second step. In the first step, the reception qualities of radio waves from the plurality of base stations are grasped at a given location within the service area. In the second step, the start point and end point of the handover processing are estimated by referring to time required for the handover processing, moving speed of a mobile terminal, which are previously input, and the reception qualities, and then success or failure of the handover processing is estimated by referring to the reception qualities of radio waves from the base stations at the start point and end point of the handover processing.

Method for estimating reception quality of communication area, apparatus thereof, and program thereof

In a network connecting apparatus, relations of targets and attributions of the targets are registered in a attribution table and relations of the attributions and available connection settings are registered in a connection setting table. An attribution determining section is configured to specify a target when detecting a request of a wireless communication associated with the target, and refer to the attribution table to determine the attribution of the target. A connection setting section is configured to change a connection setting based on the target attribution by referring to the connection setting table. A connecting section is configured to execute a connecting process for the wireless communication based on the connection setting.

Network connecting apparatus and connection setup method

The above base-station cell design method is for sequentially adding base stations, and a technique of which throughput is few is employed for a radio-wave propagation characteristic evaluation to be made in this addition, and a technique of which the throughput is much, but which is of high-precision, more specifically, a technique such as the ray tracing is applied for the radio-wave propagation characteristic evaluation to be made after addition. The result of the high-precision radio-wave propagation characteristic evaluation to be made after this addition is put to practical use for estimating an interference quantity in selecting the arrangement location of the base station to be added newly. This allows the quantity of the radio wave analytic processing, which accounts for a large majority of the base-station cell design processing, to be reduced, thus enabling a fast base-station cell design.

Base-station cell design method and base-station cell design apparatus, and program thereof in mobile communication system

A control packet is broadcast over a route, containing first and second metric values of different transmission characteristics of the route. At a local node, control packets from multiple nodes are received and examined for their source. If the packets are received from upstream nodes, the metrics of the received packets are updated, the second metric is weighted and summed with the first metric to produce a number of combined metrics and a minimum value of the combined metrics is detected. One of the routes having the detected value is selected as a route to an upstream node. If the control packets are received from downstream nodes, the second metric is weighted and summed with the first metric to produce a number of combined metrics and a smaller values of combined metrics are detected corresponding in number to usable antennas and routes of the detected values are selected.

Route selection in a communications network using combined values of metrics of different characteristics

A managing serverand a propagation characteristic computing servergrasp a load situation for each cell that is a coverage range of each of a plurality of APsto, calculate an evaluation value defined for evaluating the load situation, and take a control of the load situation of each cell so that this evaluation value is minimized. The control of load situation is a control for altering a shape (including size) of each cell, and further, specifically, a control for making a cell alteration so that the above-mentioned evaluation value is minimized, by performing processes such as regulation of the transmission power of the AP, alteration of the installation position of the AP and addition of the AP. This allows the load of each cell (AP) to be regulated most suitably.

Management method, system, and management apparatus of radio communication system

A radio network can select a route of minimum path loss among entire relay routes and can set the relay route so as to satisfactorily resist interference. The radio network has a core node connected to a wired network, relay nodes each relaying at least one of a down-link data packet transmitted from the core node and an up-link data packet directed toward the core node, and a terminal station capable of transmission and reception of data packets with both the core node and the relay node. The relay node has total path loss optimized to be minimum between relay nodes included in a relay route of the data packet or between the relay node and the core node or both.

Radio network, relay node, core node, relay transmission method used in the same and program thereof

An operation management system in a radio communication system, including a plurality of wireless base stations, includes: a cell determining means for determining a boundary of a cell by: collecting power transmitted, and antenna gain, from each wireless base station, computing a propagation loss from each of the wireless base stations at an arbitrary observation point, using a statistical technique employing an estimation model in which a radio wave damps depending upon distance or by use of a ray-tracing method, computing power received from each wireless base station at the observation point, deciding that the wireless base station that achieves maximum received power at the observation point is a connection base station at the observation point, and determining the space between points in which connection base stations differ as cell boundaries.

Operation management system of radio communication system and method thereof, and operation management apparatus and program to be employed for it

When locating base stations which are wirelessly coupled with each other and establish one or more inter-cell wireless relay routes in a mobile communications system, the heights of directional antennas to be installed at the base stations are determined so as to be different, which base stations are adjacent with each other in a given inter-cell wireless relay route.

Method and computer program for use in locating wireless base stations in a mobile communications system

In a source node of a multi-hop network is provided with a route table in which a number of routes from the node to all destinations are mapped to hop count numbers. In response to a request for transmission of data, the node determines a hop count number from the route table corresponding to a route indicated in the request and segments the data into a number of data segments according to the hop count number. The data segments are converted into packets and transmitted. In a transit node, the packets are placed into one of a set of queuing buffers that corresponds to the hop count number of the packets. The stored packets are scheduled for transmission according to their hop count number.

Multi-hop network for transmission of packets whose size is determined by hop count number

A task is to automatically carry out directional control of an antenna in parallel with routing in a radio network. In the event that a radio transmission apparatus, which is a node configuring the radio network, received a routing packetfrom the node over the radio network, it acquires and records a received direction of the routing packet, an identifier of a transmission source node, metric information indicating a route cost, and an identifier of a route destination node, and in the event that the route destination node is not its own node, the radio transmission apparatustakes control so as to match a direction of an antenna systemto the received direction of the node having minimum metric information out of the recorded metric information.

Radio transmission apparatus, routing method, and routing program of radio network

A data transfer system allowing high-quality transfer of streaming data through a network having a relatively large delay variation in data delivery is disclosed. When transferring streaming data in packets from a server computer to a client computer through a repeater provided in the network, the repeater buffers a streaming packet for a set time period before forwarding it to the client computer. The set time period is determined so that a receiving time interval of packets at the client computer is substantially equal to a sending time interval of packets at the server computer.

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Tokyo, Japan

Koichi Ebata