Novel resistance relay network time slot distribution method

Abstract

The invention discloses a novel relay blocking network time slot distribution method, and belongs to the field of mobile ad hoc networks. A reply confirmation time slot related to a data sending time slot is set for a reply confirmation message, and the overall time sequence of the network is replanned: in a relay-resistant network adopting an N-time-slot spatial multiplexing TDMA scheme, a request message and a data packet start from a source node and are diffused outwards hop by hop and time slot by time slot until the request message and the data packet reach a destination node or naturally die; and a reply confirmation message starts from the destination node and is propagated to the source node hop by hop, but due to a reverse link, channel idle time slots exist in the propagation process, and all nodes of the network in some time slots are paused to transmit effective information. According to the method, the transmission time sequence of the reply confirmation message is optimized, a new sending time slot is designed for the packet marked as the reply confirmation message, a forward path for hop-by-hop time slot-by-slot transmission is simulated under the condition of not violating the basic premise of a TDMA protocol, and the utilization rate of resources is improved.

Description

Technical Field

[0001] The invention belongs to the field of mobile ad hoc networks, and mainly relates to a novel relay network time slot allocation method. Background Art

[0002] Mobile ad hoc networks (MANETs) are wireless, multi-hop, self-organizing mobile communication networks that do not rely on fixed infrastructure and can be quickly established at any time and any place. Each node in the network is relatively independent and has the functions of data reception and data transmission; the nodes can move freely, and the network topology changes dynamically; the high degree of collaboration between nodes and the distributed and parallel operation of nodes make the network highly robust and fault-tolerant. Mobile ad hoc networks have many advantages. They were originally used in the military field, and later they were widely used in field communications, rescue and emergency response, wireless sensor networks and other environments that are separated from the backbone network.

[0003] Barrage Relay Networks (BRN) is a new type of self-organizing network technology. Its core features are low latency, low overhead and high reliability. Barrage Relay Networks are a mobile self-organizing network with timely response, strong robustness and high robustness. It adopts the time slot allocation scheme of Time Division Multiple Access (TDMA) technology and has good scalability. It has great potential in improving protocol models and optimizing network performance. Barrage Relay Networks use the blocking function of some nodes to establish a controlled interception area. The controlled interception area is a closed message area. The forwarding of any information in the area will not cross the boundary of the area, ensuring the reliability of the message. The nodes in the controlled interception area are divided into four types: source nodes, destination nodes, relay nodes, and barring nodes. Nodes outside the controlled interception area are called irrelevant nodes because they do not participate in the transmission process of messages. When the source node sends information to the target node, it will first send and receive control messages. The intermediate node receives control messages from the source node and the target node to allocate a time slot for itself to undertake the sending task, determine its position in the network, and then determine its role in this communication task (relay node or blocking node), and finally establish a controlled interception area. After all nodes in the controlled interception area confirm their identities, the processing method for subsequent received messages has been determined, so the corresponding behavioral level processing (forwarding or discarding) can be directly performed on the received messages without submitting them to the upper layer, which effectively improves the communication speed within the controlled interception area. Summary of the invention

[0004] The invention is mainly to solve the problem that a large number of channel idle time slots will be generated and resources will be wasted under the time slot allocation scheme based on TDMA technology in the existing relay network scheme; the invention provides a new relay network time slot allocation method.

[0005] The technical solution of the present invention is a novel relay network time slot allocation method, which includes the following cyclic steps:

[0006] A. Request message stage;

[0007] B. Message confirmation stage;

[0008] C. Data transmission stage;

[0009] The request message stage:

[0010] (A1) Initialize nodes in the network and achieve clock synchronization; the application layer of the node with unicast stream transmission requirements initiates a request to the lower layer to request a single unicast stream transmission; define the network life cycle TTL, the total number of time slots N, and the time slot counter count starts counting;

[0011] (A2) The source node defines its own time slot number T as 0; sends a request message RTS containing time slot T. The RTS message contains: message type declaration, unicast stream source-destination information, local node time slot information, and the number of hops d from the source node. S-X ; Wait for the reply confirmation message to arrive;

[0012] (A3) Ordinary nodes keep listening, unpack the first received request message, allocate their own data transmission time slot, and update the d S-X field, perform +1 operation; broadcast the updated request message when the data transmission time slot arrives, discard the repeated request message; its own time slot is composed of the first received request message d S-X Field determination;

[0013] (A4) The destination node receives the request message for the first time, confirms itself as the destination node of the unicast flow, allocates its own data transmission time slot, and enters the confirmation message phase;

[0014] The confirmation message stage:

[0015] (B1) The destination node generates a reply confirmation message CTS, which contains: message type, unicast stream source-destination information, source-destination node hop distance d S-D , the number of hops from the destination node is d X-D ; Broadcast CTS when the CTS time slot arrives;

[0016] (B2) Ordinary nodes keep listening, unpack the confirmation message received for the first time, confirm their own identity based on the hop count information in the received CTS message, and determine the node that meets the judgment formula as a relay node, and update the d in the message. X-Dfield, perform +1 operation, broadcast CTS message when the next confirmation message slot arrives; nodes that do not meet the conditions are judged as blocking nodes and discard all subsequent packets; nodes that have not received confirmation messages are judged as irrelevant nodes;

[0017] (B3) The source node receives the reply confirmation message for the first time, and considers that the controlled interception area in this unicast stream transmission is successfully established, and the unicast stream data transmission can be carried out; and enters the data transmission stage;

[0018] The data transmission phase:

[0019] (C1) If the node is a source node, it is ready to send a data packet and sends a data packet broadcast when its own sending time slot arrives, that is, when T=count%N is satisfied;

[0020] (C2) If the node is a relay node and receives this data packet for the first time, it will forward the data packet when its own transmission time slot arrives, that is, when T=count%N is satisfied; if a duplicate data packet is received, it will be discarded;

[0021] (C3) If the node is a blocking node, the node will directly discard the data packet after receiving it without any forwarding;

[0022] (C4) If the time slot count count is less than the network life cycle TTL, repeat steps C1, C2, and C3; if the time slot count count is greater than or equal to the network life cycle TTL, proceed to step C5;

[0023] (C5) All node types are changed to ordinary nodes, the time slot count is reset to zero, and the request message phase is waiting for arrival.

[0024] 1) Further, the calculation method of the sending time slot in step A3 is:

[0025] 2) T = (d s-x +1)%N

[0026] 3) Where % means remainder.

[0027] Furthermore, the CTS time slot in step B1 is calculated by the following formula:

[0028] 4) T CTS =(N+M-1-T)%N

[0029] Where M is any non-negative integer.

[0030] Furthermore, the decision formula in step B2 is:

[0031] 5)d S-X +d X-D ≤d S-D .

[0032] In the present invention, by setting a reply confirmation time slot related to the data transmission time slot for the reply confirmation message, the overall timing of the network is replanned: in a relay network using a TDMA scheme with N time slot space multiplexing, both the request message and the data packet start from the source node and spread outward hop by hop and time slot by time slot until they reach the destination node or die naturally; while the reply confirmation message starts from the destination node and propagates to the source node hop by hop, but because it is a reverse link, there are channel idle time slots during the propagation process, which is manifested as all network nodes "pausing" in certain time slots to transmit effective information. The present invention optimizes the transmission timing of the reply confirmation message, and by designing a new transmission time slot for the packet marked as the reply confirmation message, a forward path of hop by hop and time slot transmission is simulated without violating the basic premise of the TDMA protocol, thereby improving resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a timing diagram of the six-node chain network of this scheme. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical methods and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the implementation modes and the accompanying drawings.

[0035] like Figure 1 As shown, there are 6 nodes in the ad hoc network. The nodes in the mobile ad hoc network are time synchronized by default, and the time slot count is cleared after a network life cycle is completed.

[0036] The request message stage:

[0037] (A1) Initialize nodes in the network and achieve clock synchronization; the application layer of the node with unicast stream transmission requirements initiates a request to the lower layer to request a single unicast stream transmission; define the network life cycle TTL, the total number of time slots N = 3, the non-negative integer M = 0, and the time slot count count starts;

[0038] (A2) The source node defines its own time slot number T as 0; sends a request message (RTS) containing time slot T. The RTS message contains: message type declaration, unicast stream source-destination information, local node time slot information, and the number of hops d from the source node. S-X ; Wait for the reply confirmation message to arrive;

[0039] (A3) Ordinary nodes keep listening, unpack the first received request message, allocate their own data transmission time slot, and update the d S-X field, perform +1 operation; broadcast the updated request message when the data transmission time slot arrives, discard the repeated request message; its own time slot is composed of the first received request message d S-X The field is determined, and the allocation algorithm is as follows: where % means remainder;

[0040] 6) T = (d s-x +1)%N

[0041] (A4) The destination node receives the request message for the first time, confirms itself as the destination node of the unicast flow, allocates its own data transmission time slot, and enters the confirmation message phase;

[0042] The confirmation message stage:

[0043] (B1) The destination node generates a reply confirmation message (CTS), which contains: message type, unicast source-destination information, source-destination node hop distance d S-D , the number of hops from the destination node is d X-D ; Broadcast the confirmation message when the confirmation message time slot arrives; allocate ordinary nodes and wait for time slot allocation; The confirmation message time slot is defined by the allocated time slot:

[0044] (B2)T CTS =(N+M-1-T)%N

[0045] (B3) The ordinary node keeps listening, unpacks the confirmation message received for the first time, and confirms its own identity based on the hop count information in the received control message. The judgment formula is:

[0046] 7)d S-X +d X-D ≤d S-D

[0047] The node that meets the conditions is judged as a relay node and updates the d in the message. X-D field, perform the +1 operation, and broadcast the CTS message when the next confirmation message time slot arrives; the node that does not meet the conditions is determined to be a blocking node and discards all subsequent packets; the node that has not received the confirmation message is an irrelevant node that is irrelevant to this unicast stream transmission.

[0048] (B4) The source node receives the reply confirmation message for the first time, and considers that the controlled interception area in this unicast stream transmission is successfully established, and the unicast stream data transmission can be carried out; and enters the data transmission stage;

[0049] The data transmission phase:

[0050] (C1) If the node is a source node, it is ready to send a data packet and sends a data packet broadcast when its own sending time slot arrives, that is, when T=count%3 is satisfied;

[0051] (C2) If the node is a relay node and receives this data packet for the first time, it will forward the data packet when its own transmission time slot arrives, that is, when T=count%3 is satisfied; if a duplicate data packet is received, it will be discarded;

[0052] (C3) If the node is a blocking node, the node will directly discard the data packet after receiving it without any forwarding;

[0053] (C4) If the timeslot count is less than the network lifecycle TTL, repeat steps C1, C2, and C3; if the timeslot count is greater than or equal to the network lifecycle TTL, proceed to step C5

[0054] (C5) If all node types are changed to ordinary nodes, the time slot count is reset to zero and the waiting request message phase arrives.

[0055] The invention is characterized in that:

[0056] Based on the TDMA technology, a time slot allocation algorithm for spatial multiplexing of time slots is implemented, so that nodes can fully utilize channel resources to send data without causing competition for channel resources between nodes, thereby improving network transmission efficiency.

[0057] In the request message stage, each node is assigned a time slot number that is allowed to be sent. Based on this, in the confirmation message stage, a link timing of slot-by-slot and hop-by-hop transmission is simulated and planned. Through a more efficient request-confirmation interaction process, a link for message transmission is quickly established, overcoming the potential conflict and congestion effects of high node density on broadcasting.

[0058] The time slot allocation scheme of the present invention solves the topology change problem caused by node movement and dynamic joining and leaving in the self-organizing network by periodizing the three stages.

Claims

1. A novel relay network time slot allocation method, the method comprising the following cyclic steps: A. Request message stage; B. Message confirmation stage; C. Data transmission stage; The request message stage: (A1) Initialize nodes in the network and achieve clock synchronization; the application layer of the node with unicast stream transmission requirements initiates a request to the lower layer to request a single unicast stream transmission; define the network life cycle TTL, the total number of time slots N, and the time slot counter count starts counting; (A2) The source node defines its own time slot number T as 0; sends a request message RTS containing time slot T. The RTS message contains: message type declaration, unicast stream source-destination information, local node time slot information, and the number of hops d from the source node. S-X ; Wait for the reply confirmation message to arrive; (A3) Ordinary nodes keep listening, unpack the first received request message, allocate their own data transmission time slot, and update the d S-X field, perform +1 operation; broadcast the updated request message when the data transmission time slot arrives, discard the repeated request message; its own time slot is composed of the first received request message d S-X Field determination; (A4) The destination node receives the request message for the first time, confirms itself as the destination node of the unicast flow, allocates its own data transmission time slot, and enters the confirmation message phase; The confirmation message stage: (B1) The destination node generates a reply confirmation message CTS, which contains: message type, unicast stream source-destination information, source-destination node hop distance d S-D , the number of hops from the destination node is d X-D ; Broadcast CTS when the CTS time slot arrives; (B2) Ordinary nodes keep listening, unpack the confirmation message received for the first time, confirm their own identity based on the hop count information in the received CTS message, and determine the node that meets the judgment formula as a relay node, and update the d in the message. X-D field, perform +1 operation, and broadcast CTS message when the next confirmation message slot arrives; nodes that do not meet the conditions are judged as blocking nodes and discard all subsequent packets; Nodes that have not received confirmation messages are judged as irrelevant nodes; (B3) The source node receives the reply confirmation message for the first time, and considers that the controlled interception area in this unicast stream transmission is successfully established, and the unicast stream data transmission can be carried out; and enters the data transmission phase; The data transmission phase: (C1) If the node is a source node, it is ready to send a data packet, and when its own sending time slot arrives, that is, when T=count%N is satisfied, it sends a data packet broadcast; (C2) If the node is a relay node and receives this data packet for the first time, it will forward the data packet when its own transmission time slot arrives, that is, when T=count%N is satisfied; if a duplicate data packet is received, it will be discarded; (C3) If the node is a blocking node, the node will directly discard the data packet after receiving it without any forwarding; (C4) If the time slot count count is less than the network life cycle TTL, repeat steps C1, C2, and C3; if the time slot count count is greater than or equal to the network life cycle TTL, proceed to step C5; (C5) All node types are changed to ordinary nodes, the time slot count is reset to zero, and the request message phase is waiting for arrival.

2. A novel relay network time slot allocation method as claimed in claim 1, characterized in that: The calculation method of the sending time slot in step A3 is: T=(d s-x +1)%N Where % means remainder.

3. A novel relay network time slot allocation method as claimed in claim 1, characterized in that: The CTS time slot in step B1 is calculated by the following formula: T CTS =(N+M-1-T)%N Where M is any non-negative integer.

4. A novel relay network time slot allocation method as claimed in claim 1, characterized in that: The decision formula in step B2 is: 1)d S-X +d X-D ≤d S-D 。

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