摘要:
There are provided an adaptive collision avoidance apparatus and a method in a channel-hopping based wireless AD-HOC networks. The adaptive collision avoidance apparatus is configured to include a channel quality measuring unit that measures the quality of each channel by using receiving frames; an unavailable channel classifying unit that classifies unavailable channels not to perform communications in the future based on information on the quality of each channel; an unavailable channel propagating unit that transfers a list of unavailable channels classified as unavailable channels to adjacent nodes; and a transceiver that transmits and receives frames through channels not classified as the unavailable channels.
摘要:
A super frame structure supporting a mesh network, and a beacon scheduling method. The super frame structure and the beacon scheduling method may support a mesh topology in a beacon enabled mode, may have an algorithm that is simple and easily realized via beacon scheduling using a distribution method, and may easily adapt to changes in a network environment.
摘要:
Provided is a frame structure designed for distributed access control and OFDMA transmission in a wireless mesh network. Also, a communication method and a network node based on the frame structure are provided. Mesh nodes included in the wireless mesh network may use the frame structure and thus, may have a high prospect of transmitting a network configuration information message and scheduling information for obtaining a resource. Also, a scheduling process of the mesh nodes may be completed within a short period based on the frame structure.
摘要:
A wireless network system using a cyclic frame including a beacon period (BP), a mesh contention access period (MCAP), and a slot period (SP). The cyclic frame has a frame structure that shares a channel hopping sequence of a node, thereby sharing the channel hopping sequence that operates as an existing mesh node without generating an additional channel hopping sequence, and supporting mesh and star type topologies together in order to efficiently operate a network.
摘要:
There are provided an adaptive collision avoidance apparatus and a method in a channel-hopping based wireless AD-HOC networks. The adaptive collision avoidance apparatus is configured to include a channel quality measuring unit that measures the quality of each channel by using receiving frames; an unavailable channel classifying unit that classifies unavailable channels not to perform communications in the future based on information on the quality of each channel; an unavailable channel propagating unit that transfers a list of unavailable channels classified as unavailable channels to adjacent nodes; and a transceiver that transmits and receives frames through channels not classified as the unavailable channels.
摘要:
A distributed channel hopping communication method in a low power wireless ad-hoc network. A beacon transmission and reception scheduling method using a distributed channel hopping method in a wireless ad-hoc network, the method includes: transmitting beacons using channel hopping, before establishing the wireless ad-hoc network including a plurality of nodes having a BP including at least one time slot, and receiving beacons of a plurality of neighboring nodes of each of the plurality of nodes; collecting information about the wireless ad-hoc network and information about the plurality of neighboring nodes from the received beacons; scheduling the receiving of the beacons that are transmitted from the plurality of neighboring nodes in the BP, using TDMA in each of the at least one time slot based on the information about the plurality of neighboring nodes; and scheduling transmitting of a beacon in each of the at least one time slot.
摘要:
Provided is a method of synchronizing time for a multihop sensor network. According to the method, receiving nodes accurately synchronize time by adding a delay transmission time value to a beacon frame in a beacon mode, or by using a time synchronization frame and time synchronization acknowledgement frame containing time information and superframe structure information in a non-beacon mode. Accordingly, a mesh topology is supported, and a media access control (MAC) structure having high reliability and low delay time is provided.
摘要:
In an orthogonal frequency division multiple access (OFDMA)-based wireless mesh network, a communication node receives information regarding a next transmission time of a 1-hop node and a 2-hop node through the 1-hop node, calculates next transmission intervals of the 1-hop node and the 2-hop node, determines a next transmission time of the communication node by using the next transmission intervals of the 1-hop node and the 2-hop node, and then transmits, to an 1-hop node of the communication node, the information of the next transmission time together with the information of the transmission time of the 1-hop node, received from the 1-hop node.
摘要:
In an orthogonal frequency division multiple access (OFDMA)-based wireless mesh network, a communication node receives information regarding a next transmission time of a 1-hop node and a 2-top node through the 1-hop node, calculates next transmission intervals of the 1-hop node and the 2-hop node, determines a next transmission time of the communication node by using the next transmission intervals of the 1-hop node and the 2-hop node, and then transmits, to an 1-hop node of the communication node, the information of the next transmission time together with the information of the transmission time of the 1-hop node, received from the 1-hop node.
摘要:
A method of operating a device capable of periodically hopping a predetermined interval using a channel hopping sequence in order to improve low radio frequency (RF) reliability caused by single frequency based channel access.