120 results about "Channel contention" patented technology

The invention discloses a multilink concurrent transmission method suitable for an underwater acoustic sensor network. The method can be divided into a channel competition process and a transmission planning process. The channel competition process is mainly as follows: a plurality of underwater acoustic nodes compete for a channel based on an improved RTS / CTS handshake protocol, transmission conflicts with other nodes in the data transmission process are avoided, and meanwhile nodes of mutually exposed terminals transmit data in a concurrent mode. In the data transmission planning process, when a plurality of sending nodes send data to a receiving node, the receiving node plans when the sending nodes send data, so that transmission conflicts are avoided, and the channel utilization rate is improved. The method aims to improve the network throughput as much as possible while avoiding transmission conflicts through an improved RTS / CTS handshake protocol, a modified back-off algorithm and a transmission planning algorithm. A simulation result in an EXata network simulation environment proves the effectiveness of the method.

A system for managing the simultaneous operation of a plurality of radio modems in a single wireless communication device (WCD). The multiradio control may be integrated into the WCD as a subsystem responsible for scheduling wireless communications by temporarily enabling or disabling the plurality of radio modems within the device. The multiradio control system may comprise a multiradio controller (MRC) and a plurality dedicated radio interfaces. The radio interfaces are dedicated to quickly conveying delay sensitive information to and from the radio modems. The modems may further include control features that take information from the MRC as an input in determining the priority of messages to be sent out to a receiving device. Uplink and / or downlink operations might, for instance, be performed. Instruction that operation can commence prior to an assigned time period might, for example, be provided. Channel contention might, for instance, be initiated in response to the instruction.

Line condition notifying information of a down channel 206)is transmitted as a feedback signal to the destination station while permitting a lowered transmission efficiency of an up channel 202. While the radio line condition of the down channel 206 is poor, the destination station temporarily delays data transmission on receiving the line condition notifying information, thereby preventing unnecessary retransmission and easing channel contention. Data transmission is resumed when the line condition of the transmission line 206 returns to normal.

Provided is a method and apparatus for controlling congestion of a node in an ad-hoc network comprising: classifying a channel state into a busy channel state and an idle channel state and then monitoring the channel state; performing contention for acquiring a channel with neighboring nodes when data to be transmitted is present during the monitoring of the channel state; calculating an available bandwidth on the basis of the channel state when wins the contention; and determining the amount of data to be transmitted on the basis of the available bandwidth. The nodes in the ah-hoc network monitor their own wireless channel state so as to obtain channel contention information, calculate an available bandwidth from the channel contention information, and control a transmission amount on the basis of the available bandwidth. Accordingly, the nodes can avoid excessive traffic which exceeds channel capacity. Channel contention, which is the most immediate and important cause of a decrease in network performance, can be loosened.

The present invention provides a time-space domain multiplexing farmland wireless sensor network frequency spectrum interleaved access method. The method of the present invention is characterized in that in a cluster, a data uploading time slice is distributed for each wireless sensor, namely a node, the nodes upload the data within the corresponding time slices and are located in the dormant states at the other time, thereby reducing the in-cluster channel competition, fully utilizing the frequency spectrum resources, and substantially reducing the power consumption. For each cluster, a cluster head carries out the different node time slice distribution according to the distances between the cluster head and the nodes in the cluster, and the different space domain occupation variation trends, and carries out the space multiplexing to the maximum extent, thereby reducing the mutual interference between the adjacent clusters, at the same time, fully utilizing the frequency spectrum resources. In allusion to the problem that the data uploading process encounters conflict, the method of the present invention designs a channel frequency spectrum conversion access method, enables the channel competition and the waiting time to be reduced and the energy utilization efficiency of the network communication to be improved, and guarantees the accurate, efficient and complete data uploading while prolonging a network life cycle.

The embodiment of the invention provides a channel occupation method, a master device and a slave device. The master device broadcasts a beacon frame carrying a beacon period within a preset range, the beacon period is used for indicating the time the master device occupies the channel, when a message carrying a network allocation vector is received in a waiting time slot of the beacon period, master device broadcasts the beacon frame within the preset range again after waiting for the occupation time of the channel corresponding to the network allocation vector. By sending the low-speed and high-priority beacon frame to participate in the channel contention, when the master device receives the message carrying the network allocation vector in the waiting time slot, the master device broadcasts the beacon frame again after waiting for the occupation time of the channel corresponding to the network allocation vector without randomly evading any time, therefore compared with the method of randomly evading for a period of time in the competition mechanism in the prior art, the method provided by the embodiment of the invention has the advantages of improving the success rate of the master device to occupy the channel, meanwhile reducing the collision probability with the other competing devices and improving the utilization rate of the channel resources.

Disclosed herein is a method of selecting a relay node in a mobile ad-hoc network. The relay node selection method includes updating a neighbor node list based on messages received from one or more other nodes, and selecting a 1-hop neighbor node having a highest Multi-Point Relay (MPR) selector counter (MSC) value, from among one or more 1-hop neighbor nodes included in the updated neighbor node list, as an MPR node. Therefore, the present invention can prevent unnecessary channel competition and conflicts between nodes and improve network performance.

A connection in an optical communication system is routed over a sequence of cross-connects and aggregated links comprising multiple links. A different link selection algorithm is used for service provisioning than is used for restoration, i.e., after a cable cut or other failure or incident has made one or paths in the network suddenly unavailable. In particular, a special link selection algorithm called the Interleave algorithm is used for restoration different from the well known Best-Fit algorithm used for provisioning. The Interleave algorithm substantially reduces the probability of glare while maintaining near-optimum capacity utilization.

The invention discloses a multi-channel multiple access method supporting video data transmission in a wireless ad-hoc network; a source node and a destination node perform channel competition on a common control channel according to the IEEE802.11b standard, after the successful channel competition, if the data to be sent by the source node are video data, the source node forms an identifier in an RTS (request to send) group; then the destination node knows that the data to be received are a video group according to the identifier after the RTS (request to send) group is received, and also forms an identifier in a replied CTS (clear to send) group in the same way; in this way, the adjacent node of the source node and the destination node can remain a section of channel resource after T time of the common control channel according to the received RTS (request to send) or the CTS (clear to send) group. According to the multi-channel multiple access method supporting video data transmission in the wireless ad-hoc network, enough bandwidth and delay guarantee can be provided for the video service.

The embodiment of the invention relates to a wireless local area network communication method and communication equipment, and the method comprises the steps: receiving a data frame; generating a multiplexing frame, the frame type identification carried by the multiplexing frame being a multiplexing frame identification, the multiplexing frame carrying acknowledgement information of the data frame, and the multiplexing frame carrying cache data to be sent; and sending the multiplexing frame. In the embodiment of the invention, the multiplexing frame multiplexes the data frame to be sent, and the function of the ACK message frame can be realized by carrying the acknowledgement information of the received data frame in the multiplexing frame; besides, the multiplexing frame is sent by carrying the cache data to be sent in the multiplexing frame, so that the sending function of the data frame to be sent can be realized on the basis of realizing the ACK message frame function; and the ACKmessage frame does not need to be replied firstly, and then the transmission opportunity is obtained through a channel competition mechanism to send the data frame, so that the spectrum utilization rate is improved, and power saving of equipment is facilitated.