Samsung Electronics Co., Ltd.

The City University of New York

Myung-Jong Lee

Yong Liu

Jong-hun Park

Xu-hui Hu

Chun-hui Zhu

Xuhui Hu

Rakesh Taori

Sung-Won Lee

Ji-Hoon Lee

Chunhui Zhu

Jun-Seo Lee

Jin-Sae Jung

Ji-tae Kim

Yu-jin Lim

Jianliang Zheng

Jian Liang Zheng

Tae-kyung Kwon

A system and method for controlling congestion using Request-to-Send (RTS) and Clear-to-Send (CTS) in a wireless mesh network are provided. A receiver in a congestion state sets a duration field value of congestion control in a CTS frame and transmits the CTS frame to a sender. In response, the sender retransmits an RTS frame to the receiver without transmitting data, after waiting for an RTS retransmission waiting time period corresponding to the duration field value. The congestion state information is broadcast to neighboring nodes. Therefore, the congestion control system using the CTS frame does not use a separate frame for the congestion control. And, all of the neighboring nodes can participate in the congestion control, increasing the network efficiency.

System and method for controlling congestion in wireless mesh networks

A routing method of a wireless communication system is provided implementing advantageous features of both the tree routing and the link state routing. In the routing method, the system generates an adaptive tree table which defines a network in a tree structure of at least one branch with at least one node and each node generates a link state table which includes information on neighbor nodes, such that the packets are routed on the basis of the adaptive tree table and the link state table. Advantageous mechanisms of the tree routing and the link state routing are combined, thereby it is possible to eliminate most single point of failures of conventional tree routing and provide shorter paths compared with conventional tree routing.

Tree-guided distributed link state routing method

A method for relaying a route request RREQ message by an intermediate node which is connected with at least one node using a tree topology in a mobile communication system including a destination node and a source node which sends the RREQ message to the destination node via at least one intermediate node, to thus establish an optimal route for communications. The RREQ message is received along the route other than the tree route, and the first information is updated using its information. The intermediate node relays to a next intermediate node the RREQ message containing the updated first information.

Apparatus and method for setup of optimum route using tree-topology

A method of detecting and solving a network ID conflict is provided. The method of detecting and solving a network ID conflict includes generating and transmitting a personal area network identifier (PAN ID) report command frame that includes an extended PAN ID, and receiving a PAN ID update command frame in response to the transmitted PAN ID report command frame. According to the method, the PAN ID report command and the PAN ID update command are generated and provided by providing an extended PAN ID (EPID), and thus a network ID conflict can be detected and a new PAN ID is provided to solve the network ID conflict.

Method of detecting and solving network ID conflict

A ZigBee network device assigns addresses to its child devices. The ZigBee network device includes a communication section that connects the ZigBee network device to other devices and which communicates with the other devices; a parameter determination section that determines at least one network parameter; a calculation section that calculates addresses for child devices of the ZigBee network device based on a determined network parameter, where each of the child devices is connected to the ZigBee network device via the communication section; and a controller that assigns addresses to the child devices of the ZigBee network device. At least one determined network parameter is at least one of Cm, which indicates a maximum number of the child devices of the ZigBee network device, and Rm, which indicates a maximum number of the child devices of the ZigBee network device which have routing capabilities.

ZigBee network device for separately determining network parameter and assigning addresses, and address assignment method thereof

A method and apparatus is provided for setting multiple paths between wireless nodes of an ad-hoc network including a source node, a relay node and a destination node that receives a message from the source node via the relay node. The multi-path setting method and apparatus includes receiving previous hop address information, and determining whether a wireless node that receives the previous hop address information is included in an insulating region, based on the previous hop address information.

Apparatus and method for setting multi-path

An optimal path routing method is provided for transmitting data from a source node to a destination node. The optimal path setting method includes transmitting a shortcut request (SCRQ) message from the source node to a topology server; determining shortcut information at the topology server based on the SCRQ message; and transmitting a shortcut notification (SCNF) message containing the shortcut information from the topology server to the destination node.

Optimal path routing method in wireless network

An address assigning method in a ZigBee network environment formed of a plurality of devices (or nodes), includes: linking the plurality of nodes in a cluster-tree structure; requesting desirable address blocks from a lowest level to a second highest level of the tree ancestor nodes desirable address blocks, respectively; and assigning the desired address blocks to descendents using a top-down procedure.

Zigbee network device for assigning addresses to child nodes after constructing cluster-tree structure, address assigning method and routing method

A routing requesting method to transmit data to a device of a different piconets in a scatternet including at least two piconets which have a master device and at least one slave device controlled by the master device. A source device generates as a single packet an information inquiring a first radio resource used in each device of the piconet and an information requesting the routing. The source device broadcasts the packet to adjacent devices. The adjacent device, which receives the generated packet, sends the packet to a destination device by repeating the above process. The destination device assigns itself the master device, generates a RREP message including a clock information, and sends the generated RREP message to an adjacent device. The source device becomes aware of devices along the route using the information contained in the RREP message.

Routing system and method in scatternet

A route recovery method in a wireless network of a tree topology, in which a second node, which is a lower node of a first node and is disconnected from the first node, recovers the route in the network. The route recovery method includes the second node broadcasting a local repair request (LREQ) packet, each node receiving the LREQ packet sending a local repair reply (LREP) packet to the second node to act as a relay node for the route recovery, the second node selecting the relay node from among the nodes sending the LREP packet, and sending a local repair confirm (LCON) packet from the second node to the relay node, and establishing the route between the second node and the first node by the relay node sending a local repair inform (LINF) packet to the first node.

Method for route recovery in wireless network of tree topology

A method to manage nodes in a ZigBee network. In a ZigBee network including a plurality of nodes, a multicast group is generated including at least two nodes among the plurality of the nodes. A multicast group coordinator (GC) which manages the multicast group is set among the nodes forming the multicast group. The multicast group includes the GC, a multicast group member (GM) requesting to join the multicast group, and/or a multicast router (MR) which links GMs to each other or links the GC and the GC. Accordingly, since the GC manages the multicast group, the load is decreased and the packet data transmission rate is enhanced.

Multicast method in zigbee network

A routing method comprising receiving a first packet, the first packet being broadcast for discovery of a route. A first backoff of the first packet is calculated based on a route cost of the first packet. The first packet is rebroadcast if a second packet is not received within the first backoff, the second packet being a duplicate of the first packet. A second backoff of the second packet is calculated based on a route cost of the second packet if the second packet is received within the first backoff. One of the first and the second packets is rebroadcast as a result of comparing the first backoff and the second backoff.

Cost-based routing using backoff scheme

A system and method for selecting a starting point to transmit a beacon (BTSP) from a coordinator and a first node in a communication system. The communication system includes the coordinator, a first node group with at least one node having the first node which receives the beacon from the coordinator, and a second node group with at least one node having a second node which receives the beacon from the first node. The coordinator determines a beacon window size for the beacon transmission, selects the BTSP within the beacon window size, and transmits at the BTSP, the beacon containing information on the beacon window size and the BTSP. The first node selects its BTSP within the beacon window size so as not to overlap with the BTSP of the received beacon.

System and method for selecting beacon transmission starting point in communication system

A broadcast method in a wireless network and a communication apparatus using the same. The broadcast method determines whether the broadcast packet is first received upon receiving a broadcast packet. If a determination reveals that the packet is first received, the broadcast packet is stored and rebroadcast to neighbor nodes. Subsequently, a node, among the neighbor nodes, from which the broadcast packet is received, is marked as 'relayed'. The broadcast packet is rebroadcast when all of the neighbor nodes from which the broadcast packet is received are not marked as 'relayed'. When all of the neighbor nodes from which the broadcast packet is received are marked as &#x2018;relayed&#x2019;, the broadcast packet is destroyed. Accordingly, an efficient link-based broadcast method is provided.

Broadcast method in wireless network and communication apparatus using the same

A method for packet re-flooding in a wireless ad hoc network for transmitting a broadcast packet from a source node to a destination node. In order to determine the respective nodes received with the broadcast packet from the source node into a certain number of power levels in accordance with the receiving power of the signal carrying the received packet, the packet re-flooding method includes the steps of setting a power level reference by which the power level increases as the receiving power increases, obtaining the receiving power of the signal carrying the packet received from the respective nodes but not the source node, determining power levels based on the power level reference and the obtained receiving power, calculating a back-off delay time in accordance with the power levels of the respective nodes but not the source node, and re-flooding the received packet when the calculated back-off delay time of the respective nodes excluding the source node expires and when the received packet is the first packet that is received. Accordingly, the possibility of having collisions due to re-flooding of the respective nodes is reduced, and also, overall power consumption of the network decreases.

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New York, NY, United States of America

Myung-Jong Lee