Mitsubishi Electric Research Laboratories, Inc.

Mitsubishi Electric Research Labs.

Mitsubishi Electric Corporation

Ghulam Bhatti

Yi Huang

Jinyun Zhang

Zafer Sahinoglu

Jianlin Guo

Philip Orlik

Chunjie Duan

Johnas I Cukier

Gaofeng Yue

Anthony Vetro

Koon Hoo Teo

Kieran Parsons

Zhifeng Tao

Fernando Masami Matsubara

Kyeong-Jin Kim

Soichiro Kametani

Frederick J Igo, Jr

Kazuumi Koguchi

Qinghe Du

Chuan Han

Ioannis Avramopoulos

An optical channel data unit (ODU) switch includes a set of two or more client cards, a set of two or more line cards, and a set of two or more switch cards. Each switch card is connected to all client cards, all line cards, and all other switch cards, and each client card, line card and switch card includes control logic for managing an operation of the ODU switch in a distributed manner.

Optical channel data unit switch with distributed control

Interference in a wireless network is detected by first applying during a detection stage a two-sample Kolmogorov-Smirnov (KS) test to samples obtained from a channel in the wireless network to obtain a KS statistic. When the KS statistic is larger than a predetermine threshold, it is determined that the samples include narrowband interference, and wideband otherwise.

Method for detecting, classifying, and reducing interference in wireless networks

Multiple routes from a data source node to multiple data destination nodes in a large scale multi-hop mesh network are discovered. Nodes discover multiple routes to two destinations in an initial discovery phase that includes only two network-wide flooding of packets. The method can also work with one destination. The method can be extended to include more destinations with a proportional increase in the communication overhead. After the completion of the discovery phase, nodes can communicate or forward their own or received data by using any of the available routes.

Method for discovering multiple routes in sensor networks

In a wireless network including a server and clients, network resources, such as time slots and channel frequencies, are managed by having the server define the resources for future use by the clients, while the clients actually allocate the resources for their exclusive use according to performance criteria determined by the clients. The network can be ad-hoc and in industrial environments with low-latency requirements.

Time slot and frequency allocation in wireless communication networks

Broken links in a sensor network are avoided by representing the network as a DODAG. A rank associated with each node defines a position of each node relative to other nodes, and the rank is in a form of a proper fraction, and the rank of each node never increases to enable loop-free routing.

Avoiding broken links in smart meter networks for loop-free routing of packets

An operation channel in a multi-hop network is determined. The network uses a set of channels, and one of the nodes is a network management node. The operation channel is selected in the network management node. Then, the network management node broadcasts a channel information packet including the operation channel using all channels. The channel information packet is received in each of other nodes, either directly from the network management node or from an intermediate node that received and rebroadcasted the channel information packet. Lastly, the operation channel in each node is set according to the channel information packet until the network is formed.

Channel scan for smart meter networks to determine operating channels

A method for transmitting information in a communication network of multiple nodes, in which information transmission is partitioned into successive superframes, and in which each superframe is partitioned into a beacon period followed by a data period, which may consist of a contention free period (CFP), and each beacon period and CFP of the data period is partitioned into timeslots. The method includes allocating to at least a first node of the multiple nodes a designated timeslot in which to transmit data in at least one of a plurality of superframes, and allocating to at least a second node of the multiple nodes the same designated timeslot in which to transmit information during at least one subsequent superframe.

Timeslot sharing protocol for wireless communication networks

A set of routes are discovered in a network including concentrators, smart meters and an imaginary node. Each concentrator node, a source, broadcasts a route request (RREQ) packet to the imaginary destination node. Intermediate nodes store a route as a node list (NL) in the RREQ packet and as a route table (RT) in the node. Then, each smart meter node can select a primary route and a secondary route from the smart meter node to any concentrator from the route table.

Method for discovering and maintaining routes in smart meter networks

A network includes a master and a set of slaves that communicate orthogonal frequency-division multiplexing (OFDM) and time division multiple access (TDMA) symbols on sub-carriers. A master broadcasts 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. Each slave, in response to receiving the downlink polling packet, transmits simultaneously a response packet to the master using uplinks and the assigned sub-carriers. The master then transmits to the set of slave 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 comprise one superframe in one communication cycle, and wherein the broadcasting on the downlinks and the transmitting on the uplinks are disjoint in time.

OFDMA based medium access control and frame structure design for industrial applications

A method localizes a set of nodes in a wireless network that includes a target node having unknown location and a set of anchor nodes having known locations. The set of anchor nodes is partitioned into subsets of anchor nodes, wherein each subset has at least three anchor nodes. A distance from the target node to each of anchor nodes in each subset is measured, to estimate possible locations of the target node. A geometric constraint is applied to each estimated location to determine valid locations, which are then filtered to determine filtered locations. The filtered locations are averaged to determine an initial estimate of the location.

Method for estimating location of nodes in wireless networks

A method and system provide multiple-access control and frequency band allocation, and transmission time sharing among multiple users in orthogonal frequency-division multiple-access (OFDMA) and time-division multiple-access (TDMA) networks. The method can be applied to uplinks and downlinks of multi-user, multi-carrier communication networks. Under a total transmission-power minimization constraint, the method can allocate carriers and transmission time to users optimally, and at the same time, can guarantee a data rate or equivalently a latency requirement of each user.

Joint carrier allocation and time sharing for OFDMA/TDMA networks

A method and system discovers a route in a wireless communications network including multiple nodes. A RREQ frame is broadcast by a first node. The RREQ frame is generated to discover a route. A second node receives the RREQ frame. The second node unicasts a PING frame to the first node to verify an integrity of a wireless communications channel between the first node and the second node. Then, the second node unicasts a RREP frame only if the integrity of the wireless channel is verified.

Method and system for generating antenna selection signals in OFDM transceivers with fewer RF chains than antennas in MIMO wireless networks

A method for multicast communication in a network having plural nodes according to the ZigBee network specification includes creating a multicast group including a subset of the plural nodes and excluding at least one non-member node in the plural nodes. The multicast group has a multicast address. The method also includes transmitting multicast message including the multicast address and receiving the multicast message at each node in the multicast group.

Method, apparatus and system for multicast communication in a wireless multi-hop network

In a wireless network that includes multiple nodes, each periodic announcement cycle of a communication schedule is partitioned into a set of time slots, including a set of management time slots, a set of beacon time slots, and a set of superframe time slots. Management frames are broadcast during the management slot to specify beacons. Beacons are transmitted during the beacon slots to specify when to transmit the superframes during the superframe time slots.

Distributed beacon enabled wireless networks

A method and system access a channel in a wireless network of nodes. A coordinator transmits periodically a beacon, in which time between two consecutive beacons constitute a beacon interval. The coordinator and other nodes transceive a superframe during the beacon interval, in which the superframe begins with an active interval, which is immediately followed by an inactive interval, and in which the active interval begins with a contention free period, which is immediately followed by a contention access period, which is immediately followed by the inactive interval.

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Mansfield, MA, United States of America

Ghulam Bhatti