387 results about "Multi hop relay" patented technology

A Point to Multipoint (PMP) multi-hop relay network includes a base station, one or more relay stations and one or more subscriber stations. Active service flows in a PMP multi-hop relay network have a 16-bit connection identifier (CID). A CID defines the connection that a packet is servicing. Before traffic can be transmitted, the path through the network, and the association of CIDs with respective hops needs to be established. The CID mapping relationship from the ingress air link to the egress air link at each relay station is first set up, which is then followed by a traffic phase where the CID mapping relationship is used to route traffic from a base station to a subscriber station.

Methods, protocols and systems for communicating in a multi-hop wireless mesh network may include explicitly providing information relating to backhaul wireless link qualities in multi-hop wireless mesh network to next generation subscriber stations in a first mode. In a second mode, embodiments are configured to implicitly provide indicia of multi-hop wireless link qualities to legacy subscriber stations by adjusting a transmit power of frames sent to the legacy subscriber stations. Other embodiments and variations are described in the detailed description.

Provided is an apparatus and method for communicating a frame in a multi-hop relay cellular communication system. When communicating at a Relay Station (RS), a Downlink (DL) signal is received from a Base Station (BS) and the received DL signal is reconfigured during a first section of a frame. The reconfigured DL signal is transmitted to a Mobile Station (MS) during a second section of the frame. During a third section of the frame, a UL signal is received from the MS and is reconfigured. The reconfigured UL signal is transmitted to the BS during a fourth section of the frame. The RS recovers data from the BS to retransmit only specific data corresponding to the BS. Accordingly, unnecessary retransmission can be prevented and thus resources can be used efficiently.

A wireless relaying network having a number of network nodes including a designated originating node, at least one relaying node, and at least two receiving nodes. The designated originating node transmits a pilot signal, and the relaying node(s) receives and forwards the pilot signal to the receiving nodes, each of which measures channel quality based on the received pilot signal. At least part of the receiving nodes feed information on the measured channel quality all the way back to the designated originating node, and the originating node then schedules data for transmission to at least one selected node of the receiving nodes based on the received channel quality information. Subsequently, the designated originating node transmits data to the selected receiving node(s) via the same relaying node(s) that forwarded the pilot signal. In this way, multi-user diversity scheduling is introduced to relaying networks that provides significant data rate enhancements.

An apparatus and method of processing handover of a mobile relay station (MRS) in a cellular communication system using a multihop relay scheme is provided. The handover processing method includes transmitting, by the MRS, a handover request message containing child node information to a serving BS when handover is required; making, by the serving BS, an adjacent node list by collecting handover-related information from adjacent nodes to which the MRS is able to be handed over when the handover request message is received; transmitting, by the serving BS, a handover response message containing the adjacent node list to the MRS; and determining, by the MRS, a handover target node based on information contained in the handover response message and transmitting a handover indication message containing the target node to the serving BS. By suggesting the handover method of the MRS in the multihop relay system, it is possible to provide uninterrupted communication to the MRS and its child node in the service area of the MRS.

The embodiments balance wireless communication bandwidth capacity in a channel one or more cascading wireless communication links in a wireless communication cell, and manage the wireless communication bandwidth capacity in the channel across two or more virtual cells within the wireless communication cell.

A method communicates packets in a relay network. The packets are communicated from a set of mobile stations to a relay station using a set of connections, there being one connection between each mobile station and the relay station. The packets are communicated between the relay station and a base station using a relay tunnel connection, between the relay station and its adjacent relay station the packets are communicated using the relay tunnel connection.

An apparatus and a method for supporting an MS-initiated handover in a multi-hop relay BWA communication system are provided. An MS determines whether a handover is required by measuring the strengths of signals received from neighbor BSs and neighbor RSs. If the handover is required, the MS sends to a serving station a handover request message including MS-recommended target neighbor node list information, and receives from the serving station a handover response message including serving station-recommended target neighbor node list information.

The present invention provides a handover control method in a wireless access system, a relay station and a base station for performing handover control in a mobile multi-hop relay wireless access system such that the wireless access system is enabled to cover a wider area. To achieve the above object, the present invention provides a handover control method in a wireless access system, wherein the wireless access system comprises a mobile station and a base station, which receive and send message via a wireless channel, and further comprises a relay station for forwarding message from the mobile station and the base station under control of the base station, characterized in that the method comprising a relay station measure and arbitration step in which the relay station measures the message and arbitrates whether to relay the message, and a base station measure and handover step in which the base station measures the message and arbitrates whether to perform handover.

An apparatus and a method for mitigating interference of a neighbor cell in a multihop relay wireless communication system are provided. The method includes constituting a subframe for a link affected by interference of a neighbor cell over a first frequency band of the frame, and constituting a subframe for a link causing interference to a neighbor cell over a second frequency band of the frame. Therefore, the interference between the neighbor cells can be reduced and the amount of the resources allocated to the links can be freely adjusted.

Provided is an apparatus and method for constructing a frame for transmitting a direct link and a multi-hop relay link signal in one frame in a multi-hop relay cellular network. The signals are multiplexed on a time-division multiplexing basis and a base station downlink and relay station uplink subframe are located in a conventional downlink subframe. Accordingly, the overhead for a relay station receive transition gap in the downlink subframe and a relay station transmit transition gap in the conventional uplink subframe are eliminated.

An apparatus and method for configuring a subframe to support a relay service in a multi-hop relay BWA communication system are provided. The apparatus includes at least one of a BS-MS link subframe, a primary RS-MS link subframe, and a BS-secondary RS link subframe are configured in a first period of the subframe, and at least one of a BS-primary RS link subframe, an RS-RS link subframe, and a secondary RS-MS link subframe is configured in a second period of the subframe.

This invention discloses a multi-hop relay method including: data are interacted and transferred between a base station and relays or among relays by relay sub-frames and terminals of the base station, relays or their administrative regions interact service data by terminal sub-frames. This invention also discloses a multi-hop relay system.

Provided is an apparatus and method for relaying Ranging messages in a multi-hop relay BWA system. A RS receives a Ranging Request message from an MS, reconfigures the received Ranging Request message into a Relay Ranging Request message, and transmits the Relay Ranging Request message to a serving BS. Thereafter, the RS receives a Relay Ranging Response message from the serving BS, reconfigures the Relay Ranging Response message into a Ranging Response message, and transmits the Ranging Response message to the MS.

Provided are an apparatus and a method for handling a handover in multi-hop relay Broadband Wireless Access (BWA) system. In a communication method of a Relay Station (RS) in a multi-hop relay BWA system, a handover request message including a candidate node list is received from a Base Station (BS), the handover request message is sent to a Mobile Station (MS), and a handover indication message is received from the MS, the handover indication message indicating whether to perform a handover. Communication persistence can be provided for the MS having mobile characteristics, and cell load management and RS configuration / arrangement can be easily accomplished.

Provided is an apparatus and method for determining a data transmission rate in consideration of the queue length of a Relay Station RS in a multi-hop relay system. A Base Station BS apparatus of the multi-hop relay system includes a receiver and a calculator. The receiver receives channel condition information and queue length information for a Mobile Station MS from an RS. The calculator of the BS apparatus determines a data transmission rate between the BS and the RS for data of the MS using the channel condition information and the queue length information.

A method for selecting a relay mode depending on channel status of relay links in a multihop relay broadband wireless communication system and a Relay Station (RS) apparatus for supporting the method. When signals are received from a Base Station (BS) and a Mobile Station (MS), channel status values (e.g., eigenvalue, mutual information, and probability error) of relay links (BS-RS link and RS-MS link) are estimated using the received signals. The estimated channel status values are compared with a preset reference value. According to a result of the comparison, the relay mode for relaying the received signals is selected. Accordingly, the reliability of the relayed signal can be enhanced and the capacity of the signal link can be increased.

A framing method of fixing a training signal and a control channel for multi-link (direct link and relay link) synchronization in a multi-hop relay cellular network, and a transmitting / receiving apparatus for supporting the framing method. A base station (BS) transmits BS downlink (DL) subframe sequentially including a preamble, control information, and a DL burst to a relay station (RS) or a first mobile station (MS) connected to the BS by direct link. The RS transmits an RS DL subframe sequentially including a DL burst, a postamble, and control information to a second MS connected to the BS by relay link. Therefore, difficulties of initial synchronization, handoff, and cell search can be removed from MSs. Furthermore, multi-link bursts can be located between the preamble and the postamble by Time Division Multiplexing (TDM) or Frequency Division Multiplexing (FDM).

A system and method for managing a multihop relay station in a wireless wide-area communication network includes determining whether any mobile stations are being served by the relay station. If not, inactivating the relay station by; inactivating transmitted signals from the relay station, leaving a receiver active, and monitoring signals on the active receiver. Whereafter, estimating a channel quality of at least one mobile station from the monitored signals by the inactive relay station, and activating the relay station in response to the monitored signals indicating that a channel quality of the mobile station will improve when being served by the relay station.

Provided are a method and apparatus for using and relaying multi-hop frames over mobile multi-hop relay (MMR) systems. According to the present invention, a base station in a MMR network determines the number and temporal length of unit frames to be included in a super frame, allocates channel periods for transmitting data having a communication request to uplink and downlink data channels of each unit frame, generates frame control information to be the same for each unit frame and transmits each piece of the frame control information for each unit frame together with downlink data to be transmitted. A relay station according to the present invention recognizes frame control information of a received unit frame, reorganizes the frame control information of the received unit frame in order to allow a base station and neighboring relay stations to transmit the same frame control information from a subsequent unit frame, transmits the reorganized frame control information through the subsequent unit frame to the neighboring relay stations, thereby preventing interference between the base station and the relay stations and waste of channels of the unit frame which is caused by retransmitting the frame control information.

The present invention relates to a selection method of a user resident mechanism pf a wireless multi-hop relay network and synergy relay nodes centralizedly controlled by the base station. The present invention provides a user resident mechanism, uses thefriendly relay nodes relay and control the signaling transmission to complete; at the same time provides a relay node selection method of carrying out the centralized control and management to the entire relay node selection process by the base station, which is carried in synergies through potential relay nodes and the target terminal. The identification and selection of the relay node are divided into two steps: the first step is to identify the appropriate relay nodes, to constitute an alternative assembly; and the second step is to select a relay nodes subset to tansmit the carrying business from the alternative assembly according to the multi-optimization objective selection algorithm, and contemporarily completing the business carrying configuration of the relay nodes in the subset based on the business properties, as well as the hollow characteristics. The method not only focuses on a two-hop wireless relay network, but also can extend to the multi-hop wireless relay networks, or even extends to a wireless Mesh network and a wireless sensor network.

A packet buffering apparatus and method in a multi-hop relay system supporting hop-by-hop retransmission are provided. In the buffering apparatus and method, a first buffer buffers a user packet until the user packet is successfully transmitted to a next node, and a second buffer buffers the user packet until the user packet is successfully transmitted to an MS, after the user packet is successfully transmitted to the next node. Accordingly, time delays and transmission costs are reduced.

An apparatus and method for providing relay link zone information in a multi-hop relay BWA communication system, where a BS performs a network entry procedure with an RS during an initial access of the RS to the BS, generates a message including relay link zone information regarding a relay link zone in which the BS communicates with the RS, processes the message in a physical layer, and transmits the processed message to the RS.

In a wireless multi-hop relay network arranged in a tree topology, the base station and one or more relay stations are associated as a virtual base station (VBS). The base station and each relay station have a unique virtual base station identifier (VBS-ID) associated with the path defined by the base station and the one or more relay stations. a relay station in the branch uses its VBS-ID for communicating with an attached subscriber station (e.g. a mobile station) such that communications between the base station and subscriber station occur via the VBS. Subscriber station data communications are relayed between the base station and the one or more relay stations over the VBS via a tunnel connection. The VBS is autoconfigurable. Mobility for subscriber stations and relay stations is provided through reconfiguration of VBS's.

An apparatus and method for selecting an RS using an RS preamble signal in a multi-hop relay BWA communication system are provided, in which a BS sends preamble channel allocation information to at least one RS, the at least one RS sends a preamble to an MS according to the preamble channel allocation information, the MS measures the signal strength level of the preamble received from the at least one RS and reports the signal strength level to the BS, and the BS selects an RS for providing a relay service to the MS according to the signal strength level.

Provided is an apparatus and method for constructing a subframe to support a multi link in a multi-hop relay cellular network. In a first section of a subframe, a subframe for communication with a mobile station (MS) is constructed, and in a next second section of the subframe, a subframe for communication with a relay station (RS) is constructed. Therefore, resources can be efficiently used without interference between subframes, pilots can be flexibly used, advanced technologies can be easily applied, and overhead due to RS switching gaps can be reduced.

A method of forming a frame in a Mobile Multi-hop Relay (MMR) system, and a system for implementing the method are provided. In a multi-hop relay system, when a relay station of a specific layer receives data, the relay station receives data from both a higher layer and a lower layer. When the relay station transmits data, the relay station transmits data to both the higher layer and the lower layer. By doing so, data reception and data transmission are exclusively performed without interfering with each other, and the method and the system are easily applied to the multi-hop MMR system.

The present invention relates to a method, a system and an apparatus for implementing bandwidth allocation and scheduling management based on a relay station. A mapping information unit for controlling a RS (MAPRS) is set in a frame structure of the physical layer of a BS and an extended frame structure of the physical layer of a BS is constructed in a frame structure of the BS physical layer. The BS constructs a mapping information message MAPRS for controlling the relay station RS base on the extended frame structure of the BS physical layer, and performs bandwidth allocation and scheduling management of a communication channel of the RS by the RS according to the MAPRS message. Through the present invention, a bandwidth allocation is implemented mainly at the BS, and a service scheduling is implemented mainly at the BS. The RS only performs an uplink or downlink scheduling of the RS passively. The complexity of the RS reduced effectively. The Multi-hop relay problem is solved using a bandwidth request relay and a bandwidth allocation relay, without introducing any complex technologies and procedures of the bandwidth request, the bandwidth allocation and the scheduling management. The complexity of the BWA relay network is simplified.

An apparatus and a method for supporting multiple links in a multi-hop relay cellular network using at least two frequency bands are provided. A subframe for a link on which a Mobile Station (MS) or a Relay Station (RS) communicates with a Base Station (BS) is configured in a first frequency band, and a subframe for a link on which the BS or the RS communicates with the MS is configured in a second frequency band.

An apparatus and method for communicating control information in a Broadband Wireless Access (BWA) system using a multi-hop relay scheme is provided. A method of transmitting control information includes generating scheduling information by performing scheduling for a Relay Station (RS); determining a valid duration for the scheduling information; generating a resource allocation message containing the scheduling information and the valid duration information; and processing the resource allocation message in a physical layer and for transmitting the resource allocation message to the RS.