Mitsubishi Electric Research Laboratories, Inc.

Mitsubishi Electric Research Labs.

Polytechnic University

Natural Lighting Systems, Inc.

Mitsubishi Electric Corporation

Zhifeng Tao

Jinyun Zhang

Philip Orlik

Andreas F Molisch

Zafer Sahinoglu

Koon Hoo Teo

Toshiyuki Kuze

Daqing Gu

Yu-Jung Chang

Wataru Matsumoto

Neelesh B Mehta

Shivendra S Panwar

Alexander L Cheng

Pei Liu

Shigeru Uchida

Weihuang Fu

Kentarou Sawa

Chunjie Duan

Jianlin Guo

Ye Li

Yukimasa Nagai

Jonathan S Yedidia

Raymond Yim

Ghulam Bhatti

Man-On Pun

Qinghe Du

Amine Maaref

Yi Huang

Jun Ma

Jin Zhang

Di Wang

Xuehong Mao

Tairan Wang

Chun Nie

Philip V Orlik

Neelesh B Metha

A system for self-organizing and auto-configuring mesh networks is disclosed. Special nodes (deemed special for their topological significance) are used as a starting point for forming clusters of fully connected nodes. Here, all nodes can communicate directly with one another and links are scheduled to meet the traffic requirements as indicated by their individual configuration and topological positions. Links that do not interfere with each other are scheduled to operate concurrently, thereby increasing the bandwidth offered by the whole system. When a node leaves or is introduced to the system, the system will adjust with minimum impact on its operation. Once all of the clusters are formed in a system, the clusters are now capable of inter-cluster communications with an increase in bandwidth for such communications.

Self-organizing multi-channel mesh network

The invention provides a data structure embodied in a computer readable media. The data structure is a protocol data packet (PDU) communicated in a mobile multihop network between stations. The data structure includes a relay media access header, a payload and an optional cyclical redundancy checksum for the protocol data unit, and an indication whether the PDU is a relay media access protocol data unit or not.

Protocol data units and header in multihop relay network

A method for facilitating an operation of an ad-hoc energy exchange network is disclosed. The network includes a set of nomadic charging stations (NCSs) and an energy consumer (EC). Upon receiving a request from the EC for an energy exchange, wherein the request includes a current location and a destination location of the EC, an exchange location for performing the energy exchange between a nomadic charging station (NCS) and the EC is determined based on the current location of the EC, the destination location of the EC, and a current location of the NCS. The exchange location is transmitted to the NCS and the EC.

System and method for ad-hoc energy exchange network

A wireless network with a star topology has a first and second central node. The first central node starts up first and initiates the network. The second central node starts up second and synchronizes to the first central node, and wherein one node is in active mode and the other node is in standby mode, and a set of leaf nodes configured to communicate only with the active node.

Wireless star networks with dual adaptive central nodes

A base station transmits a set of sounding requests to a set of mobile station (MS) in a cell, using a set of beams, wherein there is one beam for each sounding request. Qualities of sounding signals transmitted by the set of MSs in response to receiving the sounding request are measured, and the set of MSs are grouped into subsets according to the qualities, wherein there is one subset of MSs associated with each beam.

Analog beamforming to reduce interference in WiMAX networks

Embodiments of the invention disclose a system and a method for determining a rank of a node in a multi-hop wireless network, wherein the network includes a gateway node, client nodes, and relay nodes, wherein a node p(i) is a default parent of the node i having a rank, and the network uses a directed acyclic graph (DAG) topology. The method comprises steps of transmitting at least one data packet from the node to the default parent node over a wireless link; counting a number of successful transmissions of most recent transmissions of data packets; determining an expected transmission time (ETX) for the wireless link based on the number of successful transmissions in the most recent transmissions; and assigning a rank R(i) to the node based on the rank of the parent node and the ETX.

Ranking nodes in networks with topologies arranged as directed acyclic graphs

A wireless network master node periodically broadcasts beacons that specify a structure of a following fixed length superframe. Slave nodes determine a channel condition between each slave and the master. Then, the set of slaves is partitioned into subsets of slaves according to the channel conditions. The master assigns, to each slave, a transmission rate in a low to high order according to the channel conditions, and the slaves transmit data to the master in the low to high order between two consecutive beacons, wherein the subsets of slaves with a higher transmission rate also receive the data from the subsets of slaves with a lower transmission rate, and wherein a slave with a higher transmission rate includes a part of or all the data from a slave with a lower transmission rate.

Method and network for transmitting data in a wireless network with fixed transmission intervals

A method optimizes a performance of a multi-cell orthogonal frequency-division multiple access (OFDMA) network that includes a set of base stations (BSs) located in a cell, and each BS transmits data on downlink channels to a set of mobile stations (MSs) in the cell. Each BS acquires channel state information (CSI) and inter-cell interference information (ICI) for each downlink channel to each MS in the cell. Each BS selects a power level and a modulation coding scheme level (MCS) for transmitting the data to each MS on the downlink channels based on the CSI and ICI, such that a bit rate is maximized and the ICI is minimized. Then, time and frequency resource are allocated for transmitting the data on the downlink channels to the set of MSs, such that the allocated resources are minimized to optimize the performance of the network.

Method for optimizing performance in multi-cell OFDMA networks

A network includes a master node (master) and a set of slave nodes (slaves). The network uses orthogonal frequency-division multiplexing (OFDM) and time division multiple access (TDMA) symbols on sub-carriers. During a first downlink transmission from the master to the set of slaves using downlinks and all of the sub-carriers, a broadcast polling packet including data packets for each slave and sub-carrier assignments for the slaves is broadcast. Each slave transmits simultaneously to the master using uplinks and the assigned sub-carriers, a first response packet after receiving the broadcast polling packet. The master then broadcasts using the downlinks and all of the sub-carriers, a group acknowledgement packet, wherein the broadcast polling packet, the response packet, and the group acknowledgement packet include one superframe in one communication cycle, and wherein the broadcasting on the downlinks and the transmitting on the uplinks are disjoint in time.

Cooperative ultra-reliable wireless communications

A method transmits a sequence of symbols in a multiple-input multiple-output (MIMO) network including a transmitter having a set of transmit antennas and a receiver having a set of receive antennas. The sequence of symbols is represented by a vector S=[SSSS]of individual symbols, where T is a transpose operator. The individual symbols are transmitted as a transmit matrix where * is a complex conjugate, and wherein each column of the matrix S represents the symbols transmitted at each transmission interval, and subscripts index the set of transmit antennas.

Coding for large antenna arrays in MIMO networks

When it is advantageous to do so, a wireless LAN station sends data packets to a destination station via an intermediate station, instead of to the destination station directly. That is, the intermediate station, which serves as a helper to the source, forwards packets received from the source station to the intended destination station. This cooperative data transmission approach can result in system performance improvement, as long as the total time consumed by two-hop transmission (i.e., transmission via the helper station) is less than direct transmission. Such a determination may be made using rate information stored at each station. Specifically, using the rate information, signaling needed to set up a transmission, the amount of data to be transmitted, etc., transmitting the data directly and via a help station may be compared.

Cooperative wireless communications

A method allocates resources in an orthogonal frequency-division multiple access (OFDMA) network including a set of base stations (BSs), and a set of mobile stations (MSs) for each BS. Each cell includes a center and edge zone. A node weighted constraint graph is constructed for the network. Maximal independent sets in the graph are searched as sub-channels are allocated to the MSs in edge zones. Remaining bandwidth is allocated to the MSs in the center zones. Power is assigned to the sub-channels so that inter-cell interference is minimized and traffic load is maximized.

Dynamic fractional frequency reuse in OFDMA networks

A method allocates bandwidth from a radio frequency spectrum in a cellular network including a set of cells. Each cell includes a base station for serving a set of mobile stations in the cell. An area around each base station is partitioned into a center region and an edge region. In each base station, cell-center bandwidth for use by the mobile stations in the center region is reserved according to an inter-cell interference coordination (ICIC) protocol, and cell-edge bandwidth for use by the mobile stations in the edge region is reserved according to the ICIC protocol. The bandwidth can be fixed or adaptive to reduce the signaling overhead. The adaptive bandwidth can be further partitioned into reserved and the free bands. Mobile stations are classified as primary and secondary users, depending on whether they use or are assigned the fixed or adaptive band radio resources.

Method for allocating resources in cell-edge bands of OFDMA networks

The invention provides a data structure embodied in a computer readable media. The data structure is a protocol data packet (PDU) communicated in a mobile multihop network between stations. The data structure includes a relay media access header, a payload and an optional cyclical redundancy checksum for the protocol data unit; and an indication whether the PDU is a relay media access protocol data unit or not.

A method communicates packets in a relay network. Multiple packets are communicated between a set of mobile stations and a relay station using a set of connections. There is one connection between each mobile station and the relay station. The multiple packets are aggregated on single connection between the relay station and a base station.

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Allston, MA, United States of America

Zhifeng Tao