Hitachi, Ltd.

Fujitsu Corporation

Tsinghua University

Alcatel Lucent

Zhisheng Niu

Sheng Zhou

Peng Yang

Mika Mizutani

Chunguang Liu

Jie Gong

Lu Geng

Takashi Yano

Lei Li

Satoshi Tamaki

Kenzaburo Fujishima

Jing Zhu

Shunji Abe

Masashi Yano

Hideya Yoshiuchi

Akinori Iwakawa

Lan Jun Wang

Xiaolei Wang

Yunjian Jia

Hui Deng

Yuanchen Ma

Tao Zhao

Zhi Zheng

Ling Qian

Miao Jiang

Zexi Yang

Yanan Bao

Dongheon Lee

Dongxu Cao

Meng Zheng

Shiro Tanabe

Lei Wang

A synchronization apparatus in a control base station is disclosed. A GNSS synchronization unit receives a GNSS signal through a GNSS antenna to obtain time information. A clock generation unit adjusts a clock of the control base station based on the time information provided by the GNSS synchronization unit. A traffic base station synchronization unit transmits and receives information with a traffic base station through a wired connection. A user data sample generation unit generates data required by a mobile user including network time information, and transmits the data to the mobile user equipment through a control base station antenna.

Cellular network synchronization methods and apparatus under separation architecture

It is provided a dynamic association control apparatus comprising: an information acquisition part configured to acquire information related to an object relay node and to candidate base stations to be associated; a blocking probability calculation part configured to calculate respectively a candidate blocking probability in a case where the object relay node performs association with each of the candidate base stations to be associated according to the acquired information; and an association control part configured to select an object blocking probability from the calculated candidate blocking probabilities, and use a base station corresponding to the selected object blocking probability as an object base station to which the association is transferred, so that the object relay node changes to be associated with the object base station to which the association is transferred.

Wireless communication system and method, and dynamic association control apparatus and method

It is provided are a server including: a storage module for storing original files and characteristics of the original files; an encoding module for encoding the original files stored in the storage module to generate encoded symbols; an information acquisition module for communicating with at least one transmission node and acquiring state information from the at least one transmission node; a control module for calculating a number of the encoded symbols to be sent to the at least one transmission node for caching based on the characteristics of the original files stored in the storage module and the state information of the at least one transmission node acquired by the information acquisition module; and a communication module for sending the encoded symbols to the at least one transmission node based on the number of the encoded symbols calculated by the control module.

Server, data caching method, and communication system

The base station includes: a determination unit for comparing states of traffic currently provided by the base station and other neighboring base stations and determining whether the base station has the lowest traffic; an information transmission unit for sending a sleep request and a handover request for handing over the user terminal associated with the base station to one of the neighboring base stations in case where the determination unit determines that the traffic currently provided by the base station is lowest; a receiving unit for receiving feedback information sent from the one of the neighboring base stations after admission control; and an executing unit for executing sleep decision after receiving handover request permitting information from the neighboring base station.

Base station in cellular network system and sleep control method for base station

It is provided a renewable energy base station, which is used in a wireless cellular system, including: an adjustment request determining part for determining whether an adjustment to a coverage area is required; an adjustment request transceiver in case where it is determined that the adjustment to the coverage area is required, sending a coverage area adjustment request to neighboring base stations in the wireless cellular system, and receiving an adjustment request response from the neighboring base stations; an adjustment request responding part for determining whether the coverage area adjustment request from the one of the neighboring base stations is allowed in case where receiving the coverage area adjustment request from one of the neighboring base stations; and a response transmitter for sending the adjustment request response to the neighboring base stations based on a result of the determination made by the adjustment request responding part.

Renewable energy base station and coverage adjustment method therefor, and wireless cellular system

Provided is a micro base station to be used in a heterogeneous cellular network. The micro base station has resources including frequency bands and time slots and being available for a user to use. The heterogeneous cellular network includes a plurality of base stations including a macro base station and the micro base station. The micro base station includes: an information acquiring part configured to acquire configuration information and load information of the micro base station, and to acquire configuration information and load information of a neighboring base station adjacent to the micro base station from the neighboring base station; and a resource selection part configured to select a part of the resources from the resources to provide the selected part of the resources to the user based on the configuration information and the load information of the micro base station and the neighboring base station.

Heterogeneous cellular network

A method of sending data from a source node in a wireless communications network is provided. In an example, the method includes selecting one of a plurality of available routing paths, from the source node to a destination node, on which to send data based on routing criteria specified by the source node.

Method of sending data

Disclosed are a communication control device, a communication control method and the system thereof, which provide efficient multi-base station joint services in a mobile communication system using dynamic clustering. Optimal base station clustering is chosen according to the communication state between a terminal and each base station. The communication control device connects with multiple base stations through a network, and clusters the multiple base stations dynamically so that the clustered multiple base stations can provide services for the mobile terminal in union. The communication control device comprises: an interface, connecting with multiple base stations, receiving channel state information related to the mobile terminal from each base station; a memory unit, storing the channel state information of the mobile terminal received from the interface; a control unit, clustering each base station dynamically according to the channel state information of the mobile terminal stored in the memory unit.

Device and method for base stations dynamic clustering in mobile communication

A subchannel scheduling method in a multi-user MIMO-OFDM environment modifies proportional fairness scheduling specifications and maximizes a system throughput under conditions that a minimum data transmission rate required by a multimedia user be ensured. In a method for allocating subchannels in a wireless network, plural users are subscribed in the wireless network, a base station has Ntransmission antennas, a user i has Nreception antennas, a network capacity determined by the Ntransmission antennas and K subcarrier groups is divided into K transmission subchannel groups, and a network bandwidth determined by the Ntransmission antennas is divided into the K subchannel groups. The base station sequentially allocates channels to the users on the basis of a proportional value of a data transmission rate supported to each user and an average throughput of each user in a predetermined time and a service quality required by each user.

Method for allocating subchannel in wireless network

A handoff method of wireless LAN comprises the steps of: 1) immediately starting by a mobile terminal to count time from a time point of entering the wireless LAN or building the new association, that is, when building association with a certain access point; 2) always tracking a signal-to-noise ratio (SNR) of the old access point by the mobile terminal, and once the mobile terminal starts getting weak, starting to search for a near access point and making a preparation for handoff, and issuing a probe request signal to a new access point, and always responding to a probe response message by the new access point after receiving the probe request signal; and 3) judging by the mobile terminal whether or not to associate the new access point according to a signal strength and an association time of each of the access points, and if a judging result is yes, issuing the reassociation request signal to the new access point. Accordingly, the new access point issues a reassociation response message to build the new association.

Handoff method of wireless local area network (LAN)

A method of retransmitting of a lost packet in a mobile communication system in which multiple copies plus delays occur i.e. after a transmitter has received from a receiver a negative acknowledgement (NACK) signal, which points to a specific data packet, multiple copies of the specific data packet are retransmitted with a delay, which is inserted between two consecutive copies. The number of multiple copies can be acquired by a linear or exponential calculation according to the current number of retransmission. The specific retransmission method may be the interleaving transmission method, which transmits a retransmission queue in the interleaving retransmission interval; or the multiple queues polling transmission method, which transmits the retransmission queue by copy queues sequence. In the correlated fading channels, the method of the present invention can decrease the number of retransmissions, and at the same time it can increase efficiency of each retransmission.

Method for retransmission of lost packet in fading channels

The present invention relates to a local retransmission scheme, which uses Transport Control Protocol (TCP) in an unreliable network. It provides reliable transmission for out-of-order TCP data packet in an unreliable link. It recovers non-congestion loss packets. It avoids incorrect adjustment of window size in TCP source end. It applies TCP local retransmission scheme, which checks together a link layer transfer sequence and a TCP source delivery sequence. With inserting timestamp of local sequence number, which is in TCP data packet and TCP acknowledgement packet, together with acknowledgement number AN, it is defined whether a data packet is lost and retransmitted. Then, with explicit retransmission ERN feedback, a TCP source false action is avoided. Therefore TCP performance of a wireless network is greatly improved.

TCP aware local retransmissioner scheme for unreliable transmission network

A designing and managing system for a communications network having a physical network and a logical network includes a designing system adaptable to a traffic fluctuation through a simple procedure, and a managing system for quickly selecting a suitable communications path in response to a path connection request and a path capacity change request. The designing system has units for respectively determining the topologies of the physical network and the logical network independently of traffic conditions, and units for setting the path capacities of the physical network and the logical network, respectively, based upon a long-term traffic demand and an actual request. The managing system includes a unit for registering the limited number of detour path candidates, a unit for determining the existence of a detour path in response to a virtual path connection request, and a unit, provided in a start point node of a communications path, for determining the acceptability of a change in the capacity of a path based on a value of a size of each link forming part of the communications path.

Growing community of inventors

Beijing, China

Zhisheng Niu