120 results about "Channel contention" patented technology

A method for conveying digitally encoded data within a Wireless Local Area Network (WLAN) using a contention based Media Access Control (MAC) protocol. In the method, a multi-beam access point can transmit a channel contention request and responsively receive channel contention responses. A set of nodes can be determined based upon the channel contention responses. Each node of the determined set can be assigned one beam of the multi-beam access point. The nodes can use the assigned beams to simultaneously communicate with said multi-beam access point in a collision-free fashion along an assigned beam.

Disclosed are an OFDMA contention method and an access point. The present invention relates to the field of computer communications. The OFDMA contention method comprises: an access point receiving, over a subchannel, a contention request frame sent by a station, and determining whether the sum of the number of stations succeeding in a contention in a current channel contention period and the number of stations succeeding in a history contention is smaller than a preset threshold; if yes, triggering the station to enter a next channel contention period, and repeating the step in which an access point receives, over a subchannel, a contention request frame sent by a station, and determines whether the sum of the number of stations succeeding in a contention in a current channel contention period and the number of stations succeeding in a history contention is smaller than a preset threshold, until the number of stations succeeding in a contention is greater than the preset threshold. By means of the OFDMA contention method and the access point, a contention can continue to be triggered when the number of stations initially succeeding in a contention is smaller than a threshold, so as to increase the number of stations succeeding in a contention and further increase the throughput of an OFDMA system.

The embodiment of the invention aims at providing a method for configuring channel access parameters, an access point, a server and a communication system thereof. The invention is characterized in that: user priority of a site is abstained, a channel access configuration strategy corresponding to the user priority is searched for and the channel access configuration strategy is sent down to the site; according to the channel access configuration strategy, the site configures the local channel access parameters. When the site sends the data, a contention channel of the configured channel access parameters can be adopted so as to avoid the problem that when relatively terrible vent resource shortage and congestion exist in the prior art, high priority users can not obtain channel resource priority preferably; besides, the invention realizes that channel contention is carried out according to the level of the users in the site and different QoS are provided for the users with different levels.

A method for accessing a channel under spatial multiplexing and a station, the method including: a monitoring station detects a first radio signal of a third party station and updates local network allocation vector and / or response frame indication deferral access time; if a second radio signal of the third party station is determined to meet the spatial orthogonal condition, a channel competition accessing process is triggered, and subsequent data transmission is completed within the updated time. Under the condition that the network allocation vector or the response frame indication deferral access time is not zero, when the third party station determines that sector transmission in the transmission initiated by the station is orthogonal with own transmission space to be conducted, the third party station ignores or resets the network allocation vector or the response frame indication deferral access time, initiates competition and starts spatial orthogonal transmission within the updated network allocation vector or response frame indication deferral access time. While spatial multiplexing is realized, fairness of channel accessing between stations is ensured; thus, effectiveness of data transmission of stations is ensured.

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 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.

An access point (AP), station (STA) and method of assigning sub-carriers to full-duplex links are generally described. The STAs transmit full-duplex capability to the AP. In response, after winning channel contention, the AP determines communication information including a bandwidth, transmit power and modulation and coding scheme (MCS) for each STA. The bandwidths are independently set by the AP such that a ratio of an expected transmission time of the amount of downlink data using a unit bandwidth to bandwidth is approximately the same for each STA. The AP transmits the communication information to the STAs in a trigger frame. The AP and STAs communicate using Orthogonal Frequency Division Multiple Access (OFDMA) during a full-duplex communication session. The uplink and downlink communications terminate at substantially the same time. Acknowledgement packets are exchanged after the full-duplex communication session.

The invention provides a smart grid MAC layer multi-service performance analysis method based on a Markov model. The method mainly comprises the steps that 1) an EDCA mechanism is realized in the MAC layer on the basis of IEEE802.11s, the new 3D Markov model is provided to analyze the states of service flows of different priorities of the smart grid, and the model includes the whole process from an unsaturated state to a saturated state; 2) in the multi-hop wireless Mesh network, the channel contention performance of services of different priorities in nodes is greatly reduced due to interference of a hidden terminal in the nodes, and thus, the back-off processes of the different service flows in the EDCA mechanism are analyzed by considering the hidden terminal and the QoS requirements of the different service flows in the smart grid comprehensively according to the provided Markov model; and 3) the back-off processes of the different service flows are combined to analyze the MAC-layer performances, as the average throughput and average end-to-end time delay, of the different service flows. The method provided by the invention can provide theoretical guidance for the wireless Mesh network that satisfy different QoS requirements of the smart grid.

The invention discloses a method for contending channels under network coexistence, a reader and an RFID system. The method comprises the following steps: detecting whether an available channel is present in a network; if so, scanning whether the available channel is occupied by other system signals; performing channel contention if the available channel is occupied by the other system signals; occupying the selected available channel, and beginning to read a tag. Therefore, when a plurality of networks are present, the channels can be contended and coordinated with each other so as to avoid collision as possible.

A broadcasting message based wireless sensor network MAC protocol is provided. The protocol uses a cycle working system, and the time length of one working cycle is a fixed value; one working cycle is divided as a synchronizing cycle, a broadcasting cycle and a data cycle based on the timeline; the data cycle is divided into multiple working sections with the same time length; and the achieving procedure of the protocol is: in the synchronizing cycle, through the exchange of the synchronization frame message, node time synchronization in the same virtual cluster is achieved; in the broadcasting cycle, a source node randomly selects the working section in the broadcasting cycle, and completes the data exchange of the related nodes in the corresponding working section using the broadcasting message; and in the data cycle, the related node is waken in the corresponding working section, the source node starts a channel competition, and the source node performs RTS / CTS / DATE / ACK data exchange with a target node after succeeding in accessing the channel. Comparing with the current ADV-MAC protocol and S-MAC protocol, the protocol of the present invention has a better level of network performance in network power consumption, time delay, delivery rate, and the like.

The invention provides a transmission interval configuring method, a device and user equipment (UE), wherein the transmission interval configuring method comprises the steps of acquiring transmissioninterval information in downlink transmission and uplink transmission in an eNB TxOP; and according to the transmission interval information and UE self timing advanced amount, and determining the target time interval in downlink transmission and downlink transmission of the UE in the eNB TxOP. The transmission interval configuring method, the device and the user equipment have advantages of realizing flexible supporting to different time intervals, improving equipment channel competition success rate and reducing interference probability between the equipment.

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.

Systems, apparatus and methods for wireless local area network (WLAN) communication which support real-time application (RTA) packets. The access point (AP) schedules multiple-user (MU) multiple-input-multiple-output (MIMO) transmissions for uplink (UL) or downlink (DL) for RTA packets by allocating resources to packet transmissions before RTA packet arrival. The AP contends for channel access before the expected time of arrival of the RTA packet in the DL or UL direction. The operations reduce RTA packet latency on the WLAN.

The invention provides an implementation method for a high channel utilization H-MAC protocol of a wireless sensor network. The H-MAC protocol takes a longest time TS1 of a continuously sending short preamble of a node as a time interval and divides the time interval into a continuously circulating preamble part and a precontract part. The implementation method has the advantages that the H-MAC protocol adopts a novel channel competition mechanism combining a low-power listening technique (LPL) with a random backoff mechanism to improve the channel utilization; a work schedule of the node is determined through a random wakening mechanism to decrease the probability of data collision; a wakening moment prediction mechanism is adopted to predict a wakening moment of a destination node to decrease the idle listening time of the node.

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.

The invention discloses a data transmission method for a medium access control (MAC) layer in a wireless local area network, which is used for supporting the application of a network coding technology. A transmission flow is applied to a scene that two clients in a basic service set (BSS) in the wireless local area network forward data through an access point (AP); when a source client has data required to be transmitted, the network coding technology can be selected and an application request is sent; if the AP accepts the request for data transmission by using the network coding technology and a receiving client has data to be sent to the source client, the AP can accomplish the data transmission in a specific flow by using the network coding technology; and the AP performs network coding on the received data from the source client and the receiving client, and broadcasts the processed data to the source client and the receiving client. Under the condition of relatively more data directly transmitted by the two clients, channel resources can be fully utilized, time for channel competition is saved, and the service efficiency of resources of the MAC layer is improved.

The invention discloses an unlicensed channel competition parameter generation method and a device. When an LAA base station does not compete a channel at present and has no need to transmit a discovery reference signal, the method and device generate a present competition parameter of the LAA base station by utilizing competition parameters corresponding to to-be-dispatched businesses and weight of the to-be-dispatched businesses. According to the invention, according to comprehensively considering the different competition parameters corresponding to the to-be-dispatched businesses data of LTE on an unlicensed frequency band, the method and the device generates a competition parameter of the base station competing the unlicensed frequency band, on one side, a problem that the LTE always using relatively good competition parameter to compete the channel, which is unfair for other access technologies, is avoided, on the other side, different priority business requirements are considered, so that influence on delay-sensitive business is avoided.

The invention discloses a design method of a CSMA / CA (carrier sense multiple access / collision avoidance) protocol for a M2M network, and the method is characterized in that energy consumption of a node with high energy consumption is reduced in the M2M network, and the transmission reliability of data in the M2M network can be ensured when the life cycle of the mentioned node is prolonged, thus the method can be applied to the CSMA / CA protocol of the M2M network. The method comprises steps of: step 1: assigning permission to the monitoring point in the M2M network; step 2: periodically detecting the operation status of the monitoring node in the M2M network, performing step 3 under the idle state of the monitoring node, and performing step 4 under the to-be-transmitted data state of the monitoring node; step 3: performing dormancy operation to the monitoring node, and performing the step 2 after some interval of time; step 4: performing signal channel contention operation to the M2M network, acquiring signal channel use right by the monitoring node, and performing step 5; step 5: uploading the data to the monitoring node, and performing the step 2 after uploading the data.

The invention discloses a device, method and system for measuring the throughput of wireless air interfaces of wireless local area network (WLAN) terminal devices. The device comprises a wireless comprehensive test instrument, a software control platform and a microwave shielding dark room. At least one to-be-measured WLAN terminal device is placed into the microwave shielding dark room; the wireless comprehensive test instrument and the to-be-measured WLAN terminal devices are in communication connection by means of radio-frequency signals; the to-be-measured WLAN terminal devices send uplink data frames to the wireless comprehensive test instrument through a distributed contention channel access mechanism, and meanwhile, the wireless comprehensive test instrument participates in channel contention through a contention channel access protocol and sends downlink data frames to all the to-be-measured WLAN terminal devices; and the wireless comprehensive test instrument is connected with the software control platform through a communication cable, so as to calculate the data throughput of the wireless air interfaces. The device, method and system can be used for measuring the throughput of the air interfaces of one or two or more to-be-measured devices simultaneously, the measuring method is high in efficiency, and the measuring process is short in consumed time.

The invention discloses a network concurrent competition channel and arbitration method based on power distribution. The network concurrent competition channel and arbitration method comprises implementation steps as follows: a neighbor node information table is established when each node in a network is started; each node distributes power of a concurrent competition channel for a neighbor node with a recursion method, the neighbor node information table is input and a distribution result set is output in the method, and one that accommodates the most nodes in the result set is selected as a final distribution result; when nodes send data, channel competition is performed according to the power distributed to the nodes by target nodes; a receiving party decodes a signal of a competition party according to a capturing effect and assigns the nodes allowed to send data and transmission time length. By using the capturing effect and the power distribution, the number of nodes participating in concurrent transmission is adjusted, the capture success rate is increased, and the utilization rate and the network throughput of channels are increased.

A method, system and computer program product for maximizing throughput by assigning nodes to the states of a given back-off level non-uniformly when experiencing channel contention. The back-off-state assignment process of the present invention can provide a novel and non-obvious assignment method, system and apparatus for assigning a node at back-off state s(i, k) in order to ensure fairness among nodes and to reduce channel contention. To achieve the foregoing effect, the back-off state assignment process of the present invention can set a back-off counter value for a given node to a randomly selected higher value with a greater probability.

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.

The embodiment of the invention discloses a data transmission method and device, a storage medium and a wireless node, and belongs to the field of wireless communication. The method comprises the following steps: in an idle state, updating a sending waiting time length and the number of data frames to be sent; if the duration value of updating, sending and waiting is greater than or equal to the duration threshold value or the number of the data frames to be sent is greater than or equal to the first aggregation number threshold value, executing a channel competition process; if the channel competition is successful, determining a starting moment and an ending moment of a TXOP period; sending the cached data frames in an aggregation mode in the TXOP period; if the data transmission is successful or partially successful, continuing to update the transmission waiting duration and the number of the data frames to be transmitted in an idle state; if the upper limit of the TXOP period is not reached, updating the number of the data frames to be sent, if the number of the data frames to be sent is larger than or equal to the second aggregation number threshold value, sending the cached data frames in the TXOP period. The purposes of controlling data transmission time delay and improving transmission efficiency can be achieved.