CN113347736A - MIMO-based mobile ad hoc network multipoint communication method - Google Patents
MIMO-based mobile ad hoc network multipoint communication method Download PDFInfo
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Abstract
The invention discloses a mobile ad hoc network multipoint communication method based on MIMO, which judges whether to reserve a channel or refresh a NAV value according to different sensed channel states based on the traditional point-to-point information transmission process, and in a sensing range, according to RTS (request to send) of the reserved channeliWhether it is the same target node and maximum RMAXDetermining whether to finish the binary exponential backoff, enter a NAV mechanism or finish the binary exponential backoff and enter a same-node backoff mechanism according to the number; at the moment, the same parallel sub-channel can be reserved for 2 or more, and then waiting time slots T are passed according to different time, different nodes and0and sending CTS-x groups with different x assignments according to the number of the RTS groups, so that the reservation times can be increased under the support of the multi-packet receiving capability of the MIMO system, and the multipoint-to-point communication is realized.
Description
Technical Field
The invention relates to the technical field of wireless mobile ad hoc network communication, in particular to a mobile ad hoc network multipoint communication method based on MIMO.
Background
The mobile Ad Hoc network can also be called an Ad Hoc network, and is a special wireless mobile network without a center, self-organization and multi-hop routing, wherein nodes in the network are connected through wireless, and the positions of the nodes are flat, and fixed communication equipment is not required for connection. The nodes in the network can move everywhere, and can join or quit the network at any time, so that the network topology structure of the network can be changed at any time, and the network topology structure has the characteristics of low deployment cost, easiness in setting and the like. However, it is a hot issue of research at present to realize faster utilization of channel resources, effective data transmission, communication establishment, and network throughput improvement in a mobile ad hoc network, and a medium access control layer protocol for controlling and solving a node access channel plays a critical role, so how to design a new protocol, and the problems of network throughput improvement, wireless channel utilization efficiency, and delay reduction are currently the most concerned.
With the continuous development of Multiple Input Multiple Output (MIMO) technology, combining the mobile ad hoc network technology with the MIMO technology can more flexibly realize network networking. MIMO has space diversity and space multiplexing gain, and can achieve the capability of multi-packet reception in combination with corresponding coding techniques, such as space-time space-frequency coding. In the prior art, the carrier sense multiple access/collision avoidance protocol design of the medium access control layer only allows a single point-to-point communication mode, informs other nodes that the nodes have the right of using the channel reserved by the nodes in a competition mode by sending an RTS packet, when the other nodes receive the RTS packet and detect the duration of a MAC frame header, the back-off is finished and the NAV value is adjusted, and then a CTS is sent to confirm the sending node and send a data packet, and simultaneously informs the nodes in a hidden node: the channel is already occupied; some technologies provide a MAC mechanism (DAP mechanism) based on spatial multiplexing gain for cdma systems, where the mechanism includes several node groups and a single-group network with multiple users, a time axis is divided into consecutive transmission cycles consisting of several time slots, and each time a packet generated in a previous transmission cycle after a single-group network in the system is polled is successfully received, one transmission cycle ends. The existing MAC protocol is designed based on spatial multiplexing and diversity gain of the MIMO technology, so that delay is reduced to the maximum extent and network throughput is improved, however, the problems that conflicts and collisions during communication cannot be solved perfectly and transmission efficiency is low because the conventional MAC layer protocol only supports single point-to-point communication at the same moment cannot be solved.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the problems in the prior art, the invention provides a mobile ad hoc network multipoint communication method based on MIMO, the existing medium access control layer protocol only supports one-to-one node communication in a wireless mobile ad hoc network within the same time, namely point-to-point communication, but the invention utilizes the method of combining the MIMO spatial multiplexing and diversity gain technology with the mobile ad hoc network MAC protocol, is mainly applied to the conditions of researching complex and changeable environments such as emergency rescue and disaster relief, and the like, and focuses on two aspects of point-to-point spatial multiplexing (CSMA/CA) and parallel communication capability (SD-MAC, MIMA-MAC).
The technical scheme is as follows: in order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a mobile ad hoc network multipoint communication method based on MIMO comprises the following steps:
step S1, after the information transmission of the previous frame is completed, initializing the node to be transmitted, and reserving a time slot induction channel; the node monitors the channel state information through the carrier wave and judges whether the channel is idle or not;
step S2, when it is monitored that the channel is in an idle state, the node first enters a binary exponential backoff mechanism, selects a time slot value at that time in the contention window CW, and sets a backoff timer as follows:
backoff timer ═ CW unit time
Where CW ∈ {0,1,2, …,2i+2-1, i is the ith backoff and has a maximum value of 6; the node continuously monitors the channel when the channel is idleIn the state, the timer value is decreased by 1 until the backoff timer first reaches 0; at which point the node sends an RTSiGrouping to reserve a channel;
when the channel is in a busy state, the backoff timer is suspended and is used for refreshing a network allocation vector NAV value according to the duration of the frame header information;
step S3, the node which successfully evades to 0 first sends RTS to the rest nodes in the listening rangei(ii) a And judging whether the rest nodes are the RTSiA target node of the packet; when the rest nodes are not the target nodes of the group, ending binary exponential backoff, suspending a backoff timer, and updating a NAV value;
step S4, when the binary exponential backoff count value of the node is less than 0 and RTS is received during backoffiWhen grouping, judging whether the grouping is consistent with the target node and is less than the maximum receiving antenna number ArWhen the target nodes are consistent and less than ArWhen the binary exponential backoff is finished, entering a co-address backoff mechanism SNB, and randomly generating a corresponding time slot value, wherein the time slot value is less than T 02; when the target node is consistent but larger than ArOr when the target nodes are not consistent, ending binary exponential backoff, entering an NAV mechanism, and updating an NAV value;
step S5, the node which ends the co-address back-off first sends RTSi+1Grouping; target node judgment RTS in interception rangeiWhether the number of the packets reaches RMAX(ii) a Wherein R isMAX＝Ar(ii) a When RTS is usediThe number of the groups is less than RMAXThe target node waits for a time slot T0To receive the remainder (R)MAX-i) RTS packets, when RTSiThe number of packets equals RMAXAccording to different time, different nodes and waiting time slot T0Sending different CTS-x groups in;
the sending of the CTS-x packets in step S6 and step S5 specifically includes:
while waiting for time slot T0In the correct reception of RMAXUpon receipt of a packet, the target node replies to a CTS-T packet, where x assigns a value of T, representing the correct receipt of RMAXA group of the data; while waitingGap T0Internally correct reception of RMAXGrouping and simultaneously receiving RTS grouping sent by nodes which are out of the listening range of the sending node but in the listening range of the target node, replying a CTS-H grouping by the target, wherein x is assigned to H to indicate that R is correctly receivedMAXGrouping and receiving RTS grouping sent by a hidden node;
step S7, the node judges whether the node is out of the interception range of the sending node and in the interception range of the target node according to the different x values of the received CTS-x grouping, when the node is normally sent and the target node normally receives, the node is not hidden, or the sending node and the target node are both in the respective interception ranges, and after waiting for a short interframe space SIFS, the node sends a PACKET to realize communication with the target node; when the node is a hidden node, other nodes which are in the NAV mechanism directly update the NAV value, and the node which sends the RTS packet finishes binary exponential backoff and enters the NAV mechanism;
step S8, when the target node successfully sends the acknowledgement frame ACK, the transmission of the frame is ended; when the target node does not send the acknowledgement frame ACK, the above step S2-7 is repeated to retransmit the frame.
Has the advantages that:
the MIMO-based mobile ad hoc network multipoint communication method modifies the traditional medium access control layer carrier sense multiple access/collision avoidance protocol, combines the MIMO technology multi-packet receiving capability, designs and provides a new flow chart, maximizes the number of data packets capable of simultaneously sending a reservation channel under the condition that the maximum number of receiving antennas is not exceeded, and waits for a time slot T according to different moments, different nodes and the number of waiting time slots0And the number of the RTS groups is used for sending CTS-x groups with different x assignments to judge subsequent data packets or adjust the NAV value of the RTS groups, so that the channel utilization rate and the network throughput are greatly improved. Judging whether to reserve channel or refresh NAV value according to different channel state, and in the interception range, according to RTS received from reserved channeliWhether it is the same target node and maximum RMAXThe number of the binary exponential backoff is determined to end the binary exponential backoff, enter a NAV mechanism or end the binary exponential backoff to enter the same stateNode back-off mechanism, in which the same parallel sub-channel can be reserved for 2 or more, then according to different time, different nodes and waiting time slot T0And sending CTS-x groups with different x assignments according to the number of the RTS groups, so that the reservation times can be increased under the support of the multi-packet receiving capability of the MIMO system, and the multipoint-to-point communication is realized.
Drawings
FIG. 1 is a schematic diagram of node communication transmission provided by the present invention;
FIG. 2 is a flow chart of a MIMO-based mobile ad hoc network multicast communication method provided by the present invention;
fig. 3 is a schematic diagram of signal transmission operation in an implementation case in which the maximum number Ar of receiving antennas is 2 and a plurality of nodes to be transmitted all enter a same-node backoff mechanism according to an embodiment of the present invention;
fig. 4 shows that the maximum number Ar of receiving antennas is 2, and other nodes to be transmitted and RTS transmission are performed according to the embodiment of the present inventioniFrame object inconsistent and correct reception of RMAXA signal transmission working diagram in an implementation case under the condition of the number of frames;
fig. 5 is a schematic diagram of transmission operation of an embodiment of the present invention, in which the maximum number Ar of receiving antennas is 2, the number of RMAX frames is correctly received, and an RTS packet sent by a node outside the sensing range of the sending node and within the sensing range of the target node is received at the same time.
Detailed Description
The present invention will be further described with reference to the accompanying drawings.
The invention provides a mobile ad hoc network multipoint communication method based on MIMO, and a transmission communication process comprises four stages: the first stage is as follows: a contention reservation channel for sending a request to send RTS frame packet; and a second stage: reply to a different channel clear frame packet, i.e., clear to send frame (CTS-x); and a third stage: after receiving the transmission permission frame, transmitting a data packet; a fourth stage: and successfully sending an acknowledgement frame ACK, finishing the transmission communication, and if not, reserving the competition channel again and resending the data packet. The transmission communication flow is shown in fig. 2.
Step S1, after the information transmission of the previous frame is completed, initializing the node to be transmitted, and reserving a time slot induction channel; and the node monitors the channel state information through the carrier wave and judges whether the channel is idle or not.
Step S2, when the monitored channel is in an idle state, first entering a binary exponential backoff mechanism, selecting a certain timeslot value in the contention window CW, and setting a backoff timer as follows:
backoff timer ═ CW unit time
Where CW ∈ {0,1,2, …,2i+2-1}, i is the ith backoff, and the maximum value of backoff timer is 6; the node continuously monitors the channel, and when the channel is in an idle state, the timer value is reduced by 1 until the backoff timer reaches 0 firstly; at which point the node sends an RTSiThe channel is reserved by grouping.
When the channel is in a busy state, the backoff timer is suspended and refreshes the network allocation vector NAV value according to the duration of the frame header information.
Step S3, the node which successfully evades to 0 first sends RTS to the rest nodes in the listening rangei(ii) a Judging whether the rest nodes are the target nodes of the group or not; and when the rest nodes are not the target nodes of the group, ending binary exponential backoff, suspending a backoff timer, and updating the NAV value. If the packet is the destination node, the process proceeds directly to step S5.
Step S4, when the binary exponential backoff count value of the node is less than 0 and RTS is received during backoffiWhen grouping, judging whether the grouping is consistent with the target node and is less than the maximum receiving antenna number ArWhen the target nodes are consistent and less than ArWhen the binary exponential backoff is finished, entering a co-address backoff mechanism SNB, and randomly generating a corresponding time slot value, wherein the time slot value is less than T 02; when the target node is consistent but larger than ArOr when the target nodes are not consistent, ending binary exponential backoff, entering a NAV mechanism, and updating the NAV value.
Step S5, the node which ends the co-address back-off first sends RTSi+1Grouping; target node judgment RTS in interception rangeiWhether the number of the packets reaches RMAX(ii) a Wherein R isMAX＝Ar(ii) a When RTS is usediThe number of the groups is less than RMAXThe target node waits for a time slot T0To receive the remainder (R)MAX-i) RTS packets, when RTSiThe number of packets equals RMAXAccording to different time, different nodes and waiting time slot T0Different CTS-x packets are sent in.
Steps S1-S5 are the first stage, each node continuously monitors the channel, determines whether to send RTS packet to reserve the competition channel or enter the NAV mechanism according to the idle state of the channel, and refreshes the NAV value; in waiting time slot T0If the target node does not receive the packet larger than or equal to the RMAX, other nodes of the same target node in the interception range enter a same-node back-off mechanism after receiving the RTSi, so that the condition that the T is within the interception range can be ensured0Receiving enough RTS reservation channels to improve the network throughput greatly;
the sending of the CTS-x packets in step S6 and step S5 specifically includes:
while waiting for time slot T0In the correct reception of RMAXUpon receipt of a packet, the target node replies to a CTS-T packet, where x assigns a value of T, representing the correct receipt of RMAXA group of the data; while waiting for time slot T0Internally correct reception of RMAXGrouping and simultaneously receiving RTS grouping sent by nodes which are out of the listening range of the sending node but in the listening range of the target node, replying a CTS-H grouping by the target, wherein x is assigned to H to indicate that R is correctly receivedMAXAnd receives an RTS packet sent by the hidden node.
Step S6 is the second stage, according to different time, different nodes and waiting time slot T0Different CTS-x packets are sent in.
Step S7, the node judges whether the node is out of the interception range of the sending node and in the interception range of the target node according to the different x values of the received CTS-x grouping, when the node is normally sent and the target node normally receives, namely the node is not hidden, or the sending node and the target node are both in the respective interception ranges, and sends PACKET after waiting for SIFS; when the node is a hidden node, other nodes in the NAV mechanism directly update the NAV value or the node sending the RTS packet finishes binary exponential backoff and enters the NAV mechanism.
Step S7 is the third phase, preparing to send data packet or refreshing NAV value
Step S8, when the target node successfully sends the acknowledgement frame ACK, the transmission of the frame is ended; when the target node does not send the acknowledgement frame ACK, the above step S2-7 is repeated to retransmit the frame.
Step S8 is the fourth stage, the target node sends successful ACK to inform each node channel to be in idle state, and reservation competition can be carried out; and if unsuccessful, retransmitting.
The network is assumed to be in an ideal state, and due to the characteristics of the mobile ad hoc network nodes of moving along with Time and moving along with Time, the Time points of the nodes reaching the Slot Time Slot of the induction channel are inconsistent. First, a new frame is transmitted, a node which reaches the time slot first senses that the channel is in an idle state and enters binary exponential backoff first, and at this time, a plurality of nodes may be in the backoff mechanism, for example, a backoff timer of the node a randomly reaches 6 (CW ∈ unit time) (CW ∈ {0,1,2, …,2 ∈ unit time) due to the inconsistency of randomly selected counter values of the backoff algorithmi+2-1, i is the ith backoff, if transmission fails, i is increased by 1, and if transmission succeeds, 1 is recovered, with a maximum of 6 being defined. After the backoff time is selected, the node listens to the detection channel once every time it passes a slot: if the channel is detected to be idle, the counter value is decreased by one; if the channel is detected to be busy, suspending the counter value, adjusting the NAV value, waiting for the channel to be idle again, and continuing to count down from the last remaining time after the DISF. The node that finishes the backoff first sends RTSiFrame grouping, nodes in the listening range are subjected to RTSiFrame grouping and information reading, the target node will receive the first RTSiWaiting time slot T after frame grouping0And the other sending nodes in the band will make the following judgments: if the target nodes are consistent and less than Ar (maximum number of receiving antennas), ending the binary backoff, entering SNB backoff, and sending the rest when which node ends first(RMAX-i) The RTS frame groups still receive the residual RTS frame groups at other nodes of SNB back-off, judge whether the residual RTS frame groups are smaller than Ar again, and continue SNB back-off if the residual RTS frame groups are smaller than Ar; if the channel is larger than or equal to the preset channel, entering a NAV mechanism and waiting for the channel to be idle; if the binary system is started to retreat and receives RTS frame grouping, the node is judged to be inconsistent or the node is always larger than Ar, then a NAV mechanism is entered, and the channel is waited to be idle. If in the waiting time slot T0In the correct reception of RMAXUpon receipt of the CTS-T packet, the destination node replies with a CTS-T packet, where the x value assigned T indicates correct reception of RMAXA group of the data; if in the waiting time slot T0Internally correct reception of RMAXIf a packet is received and a node outside the listening range of the sending node and within the listening range of the target node also sends an RTS packet, a CTS-H packet is replied, wherein x is assigned H to represent that R is correctly receivedMAXGrouping and receiving RTS grouping sent by a hidden node; and then sending a data packet reply acknowledgement frame ACK to finish the whole transmission communication. The method has the advantages that the MIMO technology can be fully utilized to realize the improvement of a plurality of pairs of nodes of the mobile ad hoc network on the utilization rate of the channel and the great increase of the network throughput.
In the following, 3 embodiments are sequentially provided with reference to fig. 3 to 5, and the multicast method provided by the present invention is specifically explained.
Example 1:
referring to fig. 3, a node A, C, D (a node ABCD represents any node in the nodes that may perform transmission communication, which is only one possible case in this embodiment) passes through a DIFS after a last frame is transmitted or a NAV value is finished, and a channel is still in an idle state, then a node a and a node D first enter a binary exponential backoff stage and randomly select a certain time slot in a Contention Window (Contention Window) according to a rule, and then a backoff timer (backoff timer) value is set at the time slot position, at this time, the backoff timer value of the node a is 7, the backoff timer value of the node D is 5, both nodes that are in backoff will continuously monitor the channel, and if the channel is idle, the counter value is decremented by 1; when the node A and the node D are in the backoff process, the node C detects that the channel is in an idle state after the DIFS, and then the node C is added in the backoff process and setsBackoff timer value 4; at this time, three nodes continuously contend for backoff in the contention channel process until the node D which finishes backoff first sends RTS1Frame grouping and broadcasting to all nodes in the listening area, at which point the target node B receives the RTS1After frame grouping, setting the maximum RTS grouping number R of the frame according to the maximum receiving antenna number of 2MAXIs 2 and starts waiting for a waiting time slot T0Time to receive the remainder (R)MAX-i) RTSs. Node A and node C receive RTS1After grouping, reading the target node information in the frame header and judging whether the target node information is consistent with the target node of the target node: when the node A and the node C both judge that the node D is consistent with the target node, the node A and the node C immediately finish binary exponential backoff, enter a same-node backoff mechanism, randomly select a corresponding time slot value according to a rule and then perform a same-node backoff reciprocal process, and the node A which firstly finishes the same-node backoff sends RTS2Grouping frames and broadcasting the frames to all nodes in the interception range, wherein the node C which does not finish backoff of the same node at the moment receives RTS2After frame grouping, according to R set by receiving nodeMAXValue to determine that it has been unable to send an RTS frame packet any more, it is due to receiving an RTS2And the frame grouping is finished, the same node retreats and refreshes the NAV value, and the channel is waited to be idle again. In the passing of waiting time slot T0The target node B then receives the correct number of RTS' siAnd sending a CTS-T frame group after the number of the frames, and successfully finishing the transmission process of the frame after the node A and the node D receive the channel clearing confirmation frame CTS-T, send a data packet and receive an ACK confirmation frame sent by the target node D again.
Example 2
Referring to fig. 4, when a node A, B, D (node ABCD represents any node in the node that may perform transmission communication, which is only one possible case in this embodiment) passes through DIFS after the last frame is transmitted, and the channel is still in an idle state, node a, node B, and node D enter a binary exponential backoff stage and randomly select a time slot in a Contention Window (Contention Window) according to a rule, and then set a backoff timer (backoff timer) value at the time slot position, where the backoff timer value of node a is 7, and the node a is a node that may perform transmission communicationThe value of a point B backoff timer is 5, the value of a node D backoff timer is 7, three nodes in backoff continuously monitor the channel, and if the channel is idle, the value of a counter is reduced by 1; node B, which first completes backoff, sends RTS1Frame grouping and broadcasting to all nodes in the listening area, at which point the target node C receives the RTS1After frame grouping, setting the maximum RTS grouping number R of the frame according to the maximum receiving antenna number of 2MAXIs 2 and starts waiting for a waiting time slot T0Time to receive the remainder (R)MAX-i) RTSs. Node A and node D receive RTS1After grouping, reading the target node information in the frame header and judging whether the target node information is consistent with the target node of the target node: if the node A judges that the time slot value is consistent with the target node, the node A immediately finishes binary exponential backoff, enters a same-node backoff mechanism, randomly selects a corresponding time slot value according to a rule, performs a same-node backoff reciprocal number process, and receives RTS at the same time1If the node D of the frame grouping judges that the node D is inconsistent with the target node of the node D, the node D of the frame grouping receives RTS1The frame packet immediately ends the binary exponential backoff, suspends the backoff timer value and refreshes the NAV value. Node A sends RTS after finishing same node back-off2The frame is grouped and broadcast to the rest of nodes in the listening range, and node D receives RTS2The frame packet continues to refresh the NAV value and waits for the channel to be idle again. Passing through waiting time slot T0After time, node C correctly receives RMAXAnd sending a CTS-T channel clear acknowledgement frame packet to the nodes in the listening range to allow the node A and the node B to send data packets until the target node sends an acknowledgement frame ACK and the node A, B receives the ACK, and then finishing the transmission process of the frame.
Example 3
Referring to fig. 5, node A, B, C (node ABCD represents any node in the node that may perform transmission communication, but this embodiment is only one possible scenario) passes through DIFS after the last frame is transmitted or the NAV value is ended, and the channel is still in an idle state, so that node a and node B first enter a binary exponential backoff stage and randomly select a certain time slot in a Contention Window (Contention Window) according to a rule, and then at that timeSetting a backoff timer value at the slot position, setting the backoff timer value of the node A to be 5 and the backoff timer value of the node B to be 7, then starting to continuously monitor the channel state to compete for the reserved channel by the two nodes, and subtracting 1 from the backoff timer value if the channel is monitored to be in an idle state. And in the back-off process of the node A and the node B, after the node C passes the DIFS, the random binary exponential back-off is started and a timer value of 6 is selected. Firstly, the node A finishing binary exponential backoff sends RTS to the interception range1Frame grouping, at which point the target node D receives RTS1After frame grouping, setting the maximum RTS grouping number R of the frame according to the maximum receiving antenna number of 2MAXIs 2 and starts waiting for a waiting time slot T0Time to receive the remainder (R)MAX-i) RTS, and node B receives RTS1After the frame is grouped, the header frame information is read, then the target node is judged to be consistent with the target node, then the target node immediately finishes the binary exponential backoff, enters a same-node backoff mechanism, selects a corresponding time slot according to a rule and starts the backoff, and sends RTS after the backoff is finished2And (5) grouping frames. Node C is out of sensing range of the sending node A, B and does not receive RTS1、RTS2Frame grouping, the binary exponential backoff is continued and RTS is sent after finishing3And (5) grouping frames. Passing through waiting time slot T0Thereafter, the target node correctly receives RMAXOne packet but simultaneously accepts RTS in the sensing range of the target node outside the sensing range of the transmitting node3The target node sends a CTS-H frame packet to inform the transmitting node that it is allowed to receive the previous RMAXThe node sends data packet, and sends RTS after the node is out of the monitoring range of the sending node and in the monitoring range of the target node3The node of (b) refreshes the NAV value and waits for the channel to be idle again due to the reception of the CTS-H packet. And the node A and the node B send data packets after receiving the CTS-H group, and finish the transmission process of the frame after correctly sending the data packets and receiving an acknowledgement frame ACK.
The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.
Claims (1)
1. A mobile ad hoc network multipoint communication method based on MIMO is characterized by comprising the following steps:
step S1, after the information transmission of the previous frame is completed, initializing the node to be transmitted, and reserving a time slot induction channel; the node monitors the channel state information through the carrier wave and judges whether the channel is idle or not;
step S2, when it is monitored that the channel is in an idle state, the node first enters a binary exponential backoff mechanism, selects a time slot value at that time in the contention window CW, and sets a backoff timer as follows:
backoff timer ═ CW unit time
Where CW ∈ {0,1,2, …,2i+2-1, i is the ith backoff and has a maximum value of 6; the node continuously monitors the channel, and when the channel is in an idle state, the timer value is reduced by 1 until the backoff timer reaches 0 firstly; at which point the node sends an RTSiGrouping to reserve a channel;
when the channel is in a busy state, the backoff timer is suspended and is used for refreshing a network allocation vector NAV value according to the duration of the frame header information;
step S3, the node which successfully evades to 0 first sends RTS to the rest nodes in the listening rangei(ii) a And judging whether the rest nodes are the RTSiA target node of the packet; when the rest nodes are not the target nodes of the group, ending binary exponential backoff, suspending a backoff timer, and updating a NAV value;
step S4, when the binary exponential backoff count value of the node is less than 0 and RTS is received during backoffiWhen grouping, judging whether the grouping is consistent with the target node and is less than the maximum receiving antenna number ArWhen the target nodes are consistent and less than ArWhen the binary exponential backoff is finished, entering a co-address backoff mechanism SNB, and randomly generating a corresponding time slot value, wherein the time slot value is less than T02; when the target node is consistent but larger than ArOr when the target nodes are not consistent, ending binary exponential backoff andentering a NAV mechanism and updating a NAV value;
step S5, the node which ends the co-address back-off first sends RTSi+1Grouping; target node judgment RTS in interception rangeiWhether the number of the packets reaches RMAX(ii) a Wherein R isMAX＝Ar(ii) a When RTS is usediThe number of the groups is less than RMAXThe target node waits for a time slot T0To receive the remainder (R)MAX-i) RTS packets, when RTSiThe number of packets equals RMAXAccording to different time, different nodes and waiting time slot T0Sending different CTS-x groups in;
the sending of the CTS-x packets in step S6 and step S5 specifically includes:
while waiting for time slot T0In the correct reception of RMAXUpon receipt of a packet, the target node replies to a CTS-T packet, where x assigns a value of T, representing the correct receipt of RMAXA group of the data; while waiting for time slot T0Internally correct reception of RMAXGrouping and simultaneously receiving RTS grouping sent by nodes which are out of the listening range of the sending node but in the listening range of the target node, replying a CTS-H grouping by the target, wherein x is assigned to H to indicate that R is correctly receivedMAXGrouping and receiving RTS grouping sent by a hidden node;
step S7, the node judges whether the node is out of the interception range of the sending node and in the interception range of the target node according to the different x values of the received CTS-x grouping, when the node is normally sent and the target node normally receives, the node is not hidden, or the sending node and the target node are both in the respective interception ranges, and after waiting for a short interframe space SIFS, the node sends a PACKET to realize communication with the target node; when the node is a hidden node, other nodes which are in the NAV mechanism directly update the NAV value, and the node which sends the RTS packet finishes binary exponential backoff and enters the NAV mechanism;
step S8, when the target node successfully sends the acknowledgement frame ACK, the transmission of the frame is ended; when the target node does not send the acknowledgement frame ACK, the above step S2-7 is repeated to retransmit the frame.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104703288A (en) * | 2013-12-05 | 2015-06-10 | 上海无线通信研究中心 | Transmission method based on quasi-random back-off strategy in wireless distributed network |
| CN105101453A (en) * | 2015-07-13 | 2015-11-25 | 西北工业大学 | Carrier sensing method based on dynamic idle channel assessment threshold |
| CN106572499A (en) * | 2016-11-07 | 2017-04-19 | 西北工业大学 | Chanel access method based on decimal backoff |
| CN106973442A (en) * | 2017-05-09 | 2017-07-21 | 北京科技大学 | The self-adapting regulation method and device of a kind of contention window minimum |
| CN109714807A (en) * | 2019-01-16 | 2019-05-03 | 南京航空航天大学 | A kind of cognition wireless network cut-in method based on common control channel |
| CN112188565A (en) * | 2020-09-24 | 2021-01-05 | 江苏中利电子信息科技有限公司 | Mobile ad hoc network multi-user cooperative transmission method based on network allocation vector |
-
2021
- 2021-07-06 CN CN202110762539.0A patent/CN113347736B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104703288A (en) * | 2013-12-05 | 2015-06-10 | 上海无线通信研究中心 | Transmission method based on quasi-random back-off strategy in wireless distributed network |
| CN105101453A (en) * | 2015-07-13 | 2015-11-25 | 西北工业大学 | Carrier sensing method based on dynamic idle channel assessment threshold |
| CN106572499A (en) * | 2016-11-07 | 2017-04-19 | 西北工业大学 | Chanel access method based on decimal backoff |
| CN106973442A (en) * | 2017-05-09 | 2017-07-21 | 北京科技大学 | The self-adapting regulation method and device of a kind of contention window minimum |
| CN109714807A (en) * | 2019-01-16 | 2019-05-03 | 南京航空航天大学 | A kind of cognition wireless network cut-in method based on common control channel |
| CN112188565A (en) * | 2020-09-24 | 2021-01-05 | 江苏中利电子信息科技有限公司 | Mobile ad hoc network multi-user cooperative transmission method based on network allocation vector |
Non-Patent Citations (2)
| Title |
|---|
| 唐铁斌等: "一种无线局域网络信道接入自适应退避算法", 《海南大学学报(自然科学版)》 * |
| 姚志强等: "利用MIMO系统多包接收能力的Ad hoc网络MAC协议", 《华南理工大学学报(自然科学版)》 * |
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