Abstract:
In a wireless communication system formed of a plurality of nodes, an arbitrary node receives messages broadcasted from neighbor nodes and calculates amounts of changes in receiving times that are differences between receiving times when the messages are currently received and receiving times when the messages are previously received with respect to the neighbor nodes. The node corrects reference time thereof based on the amounts of changes calculated with respect to the neighbor nodes.
Abstract:
A method and apparatus for synchronizing a carrier frequency of a node included in a distributed network are provided. The apparatus includes a frequency offset estimating unit, an offset average value calculating unit, and a frequency adjustment value calculating unit. The method includes receiving preambles from a plurality of nodes adjacent to the node, estimating offsets of the carrier frequencies from the received preambles for each of the plurality of neighbor nodes, calculating an average value of the estimated offsets, calculating an adjustment value of the carrier frequencies with respect to the entirety of the plurality of neighbor nodes by using the average value, and adjusting a carrier frequency of the node on the basis of the adjustment value.
Abstract:
If a target node that enters into a transmission range is sensed, a mesh node of a wireless communication system selects an agent node having itself and a target node as a neighboring node among a plurality of neighboring nodes to form a link with the target node through the agent node. Also, the mesh node deletes the formed link if a target node that is out of a transmission range among a plurality of neighboring nodes is sensed, and forms a substitution path for at least a portion among an entire path of a connection including the deleted link.
Abstract:
A beamforming apparatus and method for expanding coverage of a control channel are provided, by which neighboring communication devices are classified according to the number of beams that they can receive, and therefore the frequency or period of beam transmission is adjusted to transmit a control channel by a beamforming method. Hence, an overhead reduction and an increase in transmission rate can be achieved, and coverage holes can be prevented.
Abstract:
A synchronization group management apparatus of a node recognizes a node belonging to a different group if groups having mobility are moved and located in the same area, and performs an operation of merging the different groups into one group by changing the frame start time and the synchronization reference time of the node.