Fujitsu Corporation

Michael John Beems Hart

Yuefeng Zhou

Sunil Keshavji Vadgama

Kevin Power

Mythri Hunukumbure

Chenxi Zhu

Masahiro Watanabe

Makoto Yoshida

Masato Okuda

Michiharu Nakamura

Hiroshi Fujita

Dorin Gheorghe Viorel

Sunil Keshvaji Vadgama

A transmission method for use in a wireless communication system is provided. The system includes a source apparatus, a destination apparatus and an intermediate apparatus, where the source apparatus and destination apparatus are arranged to transmit and receive information via the intermediate apparatus, and where at least the source apparatus is arranged to perform a network entry process in order to connect to the system. The includes, in the intermediate apparatus, determining whether the source apparatus has initiated a network entry process with the intermediate apparatus and if so, notifying the destination apparatus thereof while continuing to conduct the network entry process with the source apparatus. The method also includes, in the destination apparatus, responding to said notification with a return message to the intermediate apparatus, said return message being used to facilitate completion of the network entry process.

Communication systems

A transmission method for use in a multi-hop wireless communication system is provided. The system includes a source apparatus, a destination apparatus and one or more intermediate apparatuses. The system has access to at least one predetermined transmission introduction sequence and also having access to a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval. The method for use in this system includes, when transmitting a message with a preamble in a particular transmission interval, transmitting the preamble in a first transmission window of that transmission interval. The method further includes transmitting the transmission introduction sequence in a second transmission window of that transmission interval other than the first transmission window as control information for use by at least one said intermediate apparatus.

A method for transmission of information about downlink and uplink parameters of a intermediate apparatus link in a multi-hop wireless communication system, the system comprising a first node apparatus, a second node apparatus and one or more intermediate apparatuses, each said apparatus being operable to transmit and receive information along a series of links forming a communication path for downlink and uplink communication, the communication path extending between the first node and second node apparatuses via the or each intermediate apparatus, each link comprising either a first node link between the first node apparatus and a said intermediate apparatus or an intermediate apparatus link between a said intermediate apparatus and a said apparatus which is not the first node apparatus, and the system having access to a minimum allocation unit for allocating time and transmission frequency bandwidth, the method comprising: obtaining values of downlink and uplink parameters for a particular intermediate apparatus link; mapping both values onto a single minimum allocation unit and transmitting them towards the first node apparatus.

System and method for downlink and uplink parameter information transmission in a multi-hop wireless communication system

A transmission method for use in a two-hop wireless communication system is provided. The system includes a source apparatus, a destination apparatus and an intermediate apparatus. The source apparatus is operable to transmit information along two links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus. The intermediate apparatus is operable to receive information from the source apparatus and to transmit the received information to the destination apparatus. The system has access to a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval. Each window occupies a different part of that interval and has a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval. Furthermore, each said window is assignable for such a transmission interval to said source or intermediate apparatus for use in transmission. The transmission method for use in this system includes employing said format to transmit information along the path as two successive transmission signals, link by link, said signals being transmitted using different transmission windows of a particular such transmission interval.

A frame format used in a wireless communication system, more particularly an OFDMA TDD wireless communication system, of the kind that includes a base station and a plurality of fixed or mobile subscriber stations, the base station maintaining connections with each of the subscriber stations by performing wireless communication in units of frames having the frame format, and within each frame, allocating resources for data transmission and signalling. Each frame has a plurality of downlink subframes and a plurality of uplink subframes including, in time order, a first downlink subframe, a first uplink subframe, a final downlink subframe and a final uplink subframe. One or more further downlink subframe/uplink subframe pairs may be interposed between the first and final subframes as desired, and the configuration can be changed dynamically.

Frame structure for a wireless communication system

A timing adjustment method for use in a multi-hop communication system is provided. The system includes a source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit information along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the or each intermediate apparatus, and the or each intermediate apparatus being operable to receive information from a previous apparatus along the path and to transmit the received information to a subsequent apparatus along the path, the system being configured to transmit information in a plurality of consecutive labelled intervals. The method includes transmitting information in a first labelled interval from a first said apparatus along a plurality of consecutive links of said path via one or more said intermediate apparatuses to a second said apparatus, said information including a reference to a particular one of said labelled intervals and the transmission of that information incurring a delay such that the transmitted information, or information derived therefrom, is received by said second apparatus in a second labelled interval a number of such intervals after the first labelled interval. The method also includes adjusting said reference to form an adjusted reference referring to a further labelled interval the or another number of such intervals before or after the particular labelled interval.

Timing adjustment in multi-hop communication system

A wireless communication method in a system in which subscriber stations are each operable for communication with a base station is provided. The base station is capable of performing simultaneous communications with a plurality of the subscriber stations simultaneously by exchange of packets each conforming with a layered protocol of said system. The packets include a first portion for defining physical layer (PHY) parameters and a second portion for defining media access layer (MAC) parameters. Furthermore, communications between the subscriber stations and the base station are performed wholly or partly through at least one relay station. In this system, the method includes, in the relay station, receiving a plurality of packets from the subscriber stations, detecting the second portion of each of the packets, combining the detected second portions to form a second portion of at least one new packet, and transmitting the new packet to the base station.

Wireless communication systems

A signalling method for use in a multiple-access communication system, the system comprising a first communication apparatus and a plurality of second communication apparatuses, the second communication apparatuses being operable to communicate with the first communication apparatus using respective parts of a shared communication frame and each using an available service level for such communication, the method comprising: assessing service-level requests from the second communication apparatuses to determine if there is a group of the second communication apparatuses that have corresponding service-level requirements; if it is determined that such a group exists, employing a first control scheme for transmission in the shared communication frame of communication control information for the second communication apparatuses of the group; and for any second communication apparatus not part of the group, employing a further control scheme different from said first control scheme for transmission in the shared communication frame of communication control information for that second communication apparatus, wherein the first and further control schemes are configured such that use of the first control scheme for said group of second communication apparatuses enables communication for more such second communication apparatuses to be supported in said shared communication frame than if such a further control scheme were used for said group of second communication apparatuses.

A signalling mechanism in an OFDMA-based wireless communication system in which the number of bits used to indicate the 2-D resource allocation in each frame are reduced, and optimised for the particular frame configuration. The numbers of bits within the MAP-IEs in at least the DL_MAP and optionally also the UL_MAP of each frame, used to represent the Symbol offset and No. of Symbols, are scaled to the frame duration and the subcarrier allocation scheme used for the zone to which the DL-MAP_IE is associated. Likewise, a variable number of bits is used for the subchannel offset and number of subchannels, which can be optimised based on the selected FFT size and subcarrier allocation scheme. The bit numbers in use can be TLV encoded and transmitted within a downlink channel descriptor following the DL_MAP and UL_MAP. Therefore, in subsequent frames each subscriber station knows the number of bits being used to represent these parameters, and thus the field sizes in the MAP_IEs, until such time as the DCD is updated. In this way, the signalling overhead incurred by the MAP_IEs, which can be very significant for a large number of users and with some frame and FFT sizes, is reduced.

Wireless communication systems and methods and a base station communicating with a plurality of subscriber stations

A wireless communication system in which base stations communicate with subscriber stations by exchange of data packets contained within frames. The frames, which occupy a certain time duration as well as frequency range, each include a downlink subframe from a base station to subscriber stations, and an uplink subframe used by the subscribers to send data to the base station. Each subframe includes a plurality of zones, and each base station maintains a plurality of simultaneous connections with the subscribers by transmitting packets within the zones to the relevant subscriber stations. The zones allow frequency reuse when subscribers are located in different cells served by the same base station. In addition, each connection has an associated service level requiring more or less resources within the system.

A multi-hop wireless communication system, in which packets of data are transmitted over a connection between a base station (MR-BS) and a subscriber station (SS) via at least one relay station (RS), the packets of data being transmitted in accordance with one of a plurality of service classes each having a respective quality-of-service (QoS), and available bandwidth in the system being shared among a plurality of such connections in accordance with their service classes. To decrease the latency of bandwidth allocation in the system, and to support its scheduler algorithm, the RS has to know the QoS demands and the bandwidth allocating requirements of each connection.

A transmission method for use in a multi-hop wireless communication system is provided. The system uses a time-frequency format in assigning available transmission frequency bandwidth during a discrete transmission interval. The format defines transmission windows within an interval, each window occupying a part of that interval and having a frequency bandwidth profile, each said window being assignable for a transmission interval. The transmission windows include an initial control window for control information transmission and a relay window for transmission by a source apparatus to an intermediate apparatus. The relay window is defined as the last window in the discrete transmission interval assignable to the source apparatus for transmission. The method includes employing the format to assign the control window to a source apparatus and to an intermediate apparatus for control information transmission and to assign the relay window to the source apparatus for data transmission to the intermediate apparatus.

Communication system with improved QOS for multihop relay ink

A transmission method for use in a multi-hop wireless communication system is provided. The system includes a base station, a relay station and mobile stations. The method transmits using a downlink transmission frame that has a first zone for transmitting radio signals from the base station to the relay station, a second zone for transmitting radio signals from the relay station to a mobile station, and a third zone provided between the first zone and the second zone for transmitting radio signals from the base station directly to a mobile station.

A timing adjustment method for use in a multi-hop communication system is provided. The method includes transmitting information in a first labelled interval from a first apparatus along a plurality of consecutive links of a path via one or more intermediate apparatuses to a second apparatus, said information including a reference to a particular one of said labelled intervals and the transmission of that information incurring a delay such that the transmitted information, or information derived therefrom, is received by said second apparatus in a second labelled interval a number of such intervals after the first labelled interval. The method also includes adjusting said reference to form an adjusted reference referring to a further labelled interval the or another number of such intervals before or after the particular labelled interval.

A path selection method for use in a communication system is provided. The system includes at least three communication apparatuses, a particular one of said apparatuses being operable to transmit and/or receive a communication signal along at least two different communication paths, each said path being either a single-link path extending from the particular apparatus to another said apparatus directly over a single communication link therebetween, or being a multi-link path extending from the particular apparatus to said other or another said apparatus indirectly via one or more intermediate said apparatuses over a plurality of consecutive such links link-by-link along the path, and at least one said path being such a multi-link path. The method includes, for each link along at least the or one of the multi-link paths, obtaining link-suitability information indicative of the suitability of the link concerned for transmission and/or reception. The method also includes, for at least the or said one of the multi-link paths, combining the link-suitability information for each link of the path concerned so as to generate path-suitability information indicative of the suitability of the path concerned for transmission and/or reception. Furthermore, the method includes selecting one of said paths for transmission and/or reception in dependence upon said path-suitability information.

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London, United Kingdom

Michael John Beems Hart