CN104009913A - Broadcast Method Based on Distance and Energy Balance in Mobile Ad Hoc Networks - Google Patents

Abstract

The invention discloses a broadcasting method based on distance and energy balance in a mobile Ad Hoc network. A node obtains information of neighbor nodes according to groupings received from the neighbor nodes, determines the distance between itself and the neighbor nodes, and builds or updates a neighbor information table; forwarding priorities are determined according to the distance between the node and the neighbor nodes and the residual energy of the node, the node carries out time-sharing forwarding according to the forwarding priorities, and channel competition and grouping collision are reduced. A lost packet retransmission mechanism is included in the method, whether broadcasting groupings are sent successfully or not is judged according to the fact whether the same broadcasting grouping forwarded by the neighbor nodes is received or not, and the broadcasting reliability is further improved. The method can well restrain the broadcasting storm, and the broadcasting reliability is improved; meanwhile, the time delay is small, and the requirement of QoS application can be better met; the method can further balance the energy consumption of the nodes in the network better, and the service life of the network is prolonged.

Description

Broadcast Method Based on Distance and Energy Balance in Mobile Ad Hoc Networks

technical field

The present invention relates to the field of wireless communication technology, in particular to a mobile Ad Hoc network based on a mobile Ad Hoc network that can effectively suppress broadcast storms, improve broadcast reliability, balance the energy of nodes in the network, and have a higher arrival rate and lower delay. Broadcast methods for distance and energy balance. the

Background technique

Mobile Ad Hoc networks usually have the characteristics of self-organization, multi-hop routing, limited wireless transmission coverage, limited link bandwidth, dynamic network topology changes, limited energy supply, etc., especially the broadcast characteristics of wireless channels and hidden node problems, making Compared with broadcasts in wireless networks and wired networks with infrastructure, the broadcasting of mobile Ad Hoc networks is prone to broadcast storms, and the probability of collisions is also higher. Especially for a single-channel mobile Ad Hoc network, since the sending and receiving of data between nodes are carried out on the same channel, the probability of collision between broadcast packets is greatly increased. It can be seen that broadcasting will introduce a large part of the network load, seriously affecting the network throughput and QoS (Quality of Service) performance, so broadcasting has become one of the bottlenecks hindering the development of mobile Ad Hoc networks. the

In the mobile Ad Hoc network, the simplest broadcasting method is flooding broadcasting, and many improvement methods are also proposed based on the flooding method. In flood broadcasting, all nodes pass the broadcast packet on to their neighbors whenever they receive a broadcast packet for the first time. Generally speaking, the flooding algorithm is relatively simple and can obtain greater network coverage, but blind flooding in a network with dense mobile nodes will cause a large number of repeated messages and consume a large amount of network resources. To sum up, the main problems of flooding broadcast are broadcast storm and broadcast unreliability, which are mainly manifested as information redundancy, channel contention and signal collision. the

Compared with broadcast storms, there are less researches on unreliable broadcasts. Unreliable broadcasts will cause certain routes to fail to be established and routing information to be inconsistent. The research schemes on unreliable broadcast include flooding-based schemes, minimum spanning tree-based schemes and hybrid schemes. The method based on flooding is relatively simple and has relatively high reliability, but it will bring broadcast storm problem. In the scheme based on the minimum spanning tree, the calculation of constructing the minimum spanning tree is relatively large, and it is difficult to realize it in a distributed manner. the

For example, Abdalla et al. proposed a hybrid scheme based on probability and neighbor information: dynamic probabilistic broadcasting method DP (Dynamic Probabilistic broadcasting algorithms). The DP scheme adjusts the rebroadcast probability so that in areas with high node density, the broadcast probability is small, and in areas with sparse node density, the rebroadcast probability is high, which can effectively reduce the redundancy of broadcast information. However, the DP method needs to periodically send HELLO messages to the surrounding nodes to exchange topology information, and the node that receives the HELLO information needs to reply to the received information in addition to sending the HELLO message to the neighbor nodes. It causes the consumption of resources and node energy in the network. the

Chinese patent publication number: CN101170560A discloses a broadcast protocol in an ad hoc network. Including the maintenance of the information of the 2-hop neighbor nodes, node data packet processing and selection of BRG (the node that receives the data packet and broadcasts the data packet again) set three parts, specifically: among the neighbor nodes, select the only and two-hop The one-hop node connected to the node is used as the forwarding node; among the one-hop nodes, the node with the highest priority among the priority is selected, and the selection of the priority is determined by the remaining energy and the degree of the node. Priority = node degree × N, 10≤N≤100, when the remaining energy of the node is less than 10% of the original energy, priority = node degree × M, 2≤M≤N, when the remaining energy of the node is less than 10% of the original energy When the energy is less than 10%, priority = node degree; forwarding nodes are selected through priority selection until all nodes within the two-hop range are covered. The method of this invention prolongs the life cycle of the network by balancing the energy between nodes. The disadvantage is that the remaining energy is divided into three levels, and the energy consumption cannot be well balanced; in the same energy level, only nodes are considered The degree of the node is selected as the forwarding priority, which cannot suppress the broadcast storm well, because although some nodes have a high degree, but the distance between the neighbor node and itself is very close, then if its neighbor nodes forward again, they will get additional coverage The range is very small; and, the invention does not consider the reliability of the broadcast. the

Contents of the invention

The purpose of the present invention is to overcome the problems of broadcast storm, low reliability and unbalanced energy consumption, and provide a mobile Ad Hoc network based Broadcast methods for distance and energy balance. the

In order to achieve the above object, the present invention adopts the following technical solutions:

A broadcast method based on distance and energy balance in a mobile Ad Hoc network, comprising the steps:

(1-1) Establish a neighbor information table:

Any node J in the mobile Ad Hoc network receives a packet from any of its neighbor nodes H, node J obtains the address of H from the broadcast packet, and calculates the distance between J and H;

If node J receives a packet from node H for the first time, node J establishes a neighbor information table for storing information of node H;

Otherwise, node J updates the distance and lifetime LTM in the neighbor information table corresponding to node H;

The survival time LTM indicates the survival time of the neighbor information table of the corresponding node H without further receiving any information from the node H; in the life cycle LTM, if the node J does not receive the packet from H again, for J For example, H will no longer be a neighbor node, and when the LTM expires, it will be removed from the neighbor information table; if any form of packet is received from the neighbor node in the LTM, it means that the neighbor node is still the node J Neighboring nodes, the LTM needs to be updated. the

(1-2) Send or forward broadcast packets:

(1-2-1) When node J needs to send a broadcast packet, node J sets the distance threshold value D _th according to the number of neighbor nodes J _num and the distribution of neighbor nodes, and selects a maximum neighbor distance among neighbor nodes _Dmax ;

When the number of neighbor nodes J _num is 1, set D _max to the distance between the neighbor node and J, and set D _th to 0;

When the number of neighbor nodes J _num is 2-4, set D _th as the minimum value of the distance between each neighbor node and node J, and set D _max as the maximum value of the distance between each neighbor node and node J ;

When the number of neighbor nodes J _num is greater than 4, set D _max as the maximum distance between each neighbor node and node J, set D _th , and make D _th satisfy the neighbor nodes whose distance from node J is greater than D _th Number ≥ J _num / 2;

Node J records the distance threshold value D _th and the neighbor distance maximum value D _max into the packet header of the broadcast packet, and sends the broadcast packet;

The preset response time A _ckt in node J, when node J does not receive the same broadcast packet from any neighbor node within the time A _ckt after node J forwards the broadcast packet, then node J makes a failure to send the broadcast packet or In case of a collision, node J resends the broadcast packet, and does not set the response time A _ckt after the second sending to wait for the neighboring node to forward the same broadcast packet;

When node J receives the same broadcast packet from any neighbor node within the A _ckt time, node J makes a judgment that the broadcast packet has been successfully sent;

(1-2-2) When any neighbor node K of node J receives the broadcast packet, if K has not forwarded the broadcast packet of node J, then node K calculates the distance D _KJ from node J, and establishes the corresponding neighbor The neighbor information table of node J or update the neighbor distance and LTM in the neighbor information table of the corresponding adjacent node J; compare D _KJ with D _th and D _max in the packet header of the broadcast packet to determine whether node K needs to forward the broadcast grouping:

When D _KJ <D _th , node K does not forward the broadcast packet;

When D _KJ =D _max , node K directly forwards the broadcast packet;

When D _th <D _KJ <D _max , node K uses the formula Calculate the forwarding weight PI, where α is a constant set in the network, R is the radius of the wireless coverage of the node, E _k is the current remaining energy of node K, and E _max is the maximum energy that the battery of any node can provide value; using the formula Calculate the forwarding delay time Ti, where tanh() is the hyperbolic tangent function operator, MT is the maximum delay time set, PI _max is the maximum value of PI, and n is the time constant; then K is based on the forwarding delay time T ₁ delays and waits for the above-mentioned broadcast packet to be forwarded;

When D _KJ >D _max , it indicates that there is no K information in J's neighbor information table, in this case K will not forward the broadcast packet;

(1-2-3) When node K needs to forward a broadcast packet, node K uses the same method as node J to determine D _th and D _max , and records D _th and D _max in the forwarded broadcast packet header, and sends the broadcast packet The value in the previous hop node address field in the header is changed to the address of this node, and then node K sends a broadcast packet;

(1-3) All nodes in the network repeatedly and alternately perform steps (1-1) to (1-2), until all nodes stop broadcasting the broadcast packet. the

In a mobile Ad Hoc network, in order to achieve reliable broadcasting, the broadcast storm problem caused by information redundancy and the unreliable broadcast problem caused by collision must be solved at the same time. At the same time, the remaining energy balance of nodes is very important for the network life. The distance and Energy-Balance based Reliable Broadcast (DEBRB) proposed by the present invention can not only suppress broadcast storms, realize reliable broadcast, dynamically adapt to changes in network topology, but also balance the energy consumption of network nodes. Improve network longevity. the

The present invention cancels the HELLO packet interaction and uses various received packets to obtain neighbor information, thereby achieving the purpose of reducing node energy consumption and channel competition; selecting forwarding nodes for time-sharing forwarding according to node distance and remaining energy information, which can Balance the energy consumption of nodes in the network, reduce the redundancy of broadcast information, and reduce the probability of packet collision; at the same time, a retransmission mechanism is adopted to improve the reliability of broadcast packets. the

Preferably, during the process of waiting for delayed forwarding of the node K, if K receives the same broadcast packet forwarded by any neighboring node N again, the node K calculates the distance D _KN between K and N;

If the distance between D _{and KN} is greater than r, K continues to delay and wait for forwarding;

If the distance between D _{and KN} is less than r, K cancels the delay and does not forward.

If K receives the broadcast packet more than once while waiting for the delay, K cancels the forwarding; where, the range of r is:

Preferably, the broadcast packet response time A _ckt =t ₁ +2t ₂ +MT; wherein, t ₁ is the sending time of a broadcast packet; t ₂ is the propagation delay of the network. Among them, t ₁ = data frame length (b)/sending rate (b/s); t ₂ = channel length (m)/propagation rate of electromagnetic waves on the channel (m/s).

As a preference, the remaining energy E _k of the node K is calculated by the following steps:

The energy consumed by node K sending a packet is: E _sc =P _s T _p ;

The energy consumed by node K receiving a packet is: E _re =P _r T _p ;

The energy required for node K to forward a packet is the sum of the energy required for the two operations of sending and receiving: E _ifw =(P _s +P _r )T _p ;

The total energy consumed by node K is E _kc =N _ks E _sc +N _kr E _re +N _kf E _ifw

Then the remaining energy of node K E _k =E _max -E _kc

Among them, P _s is the transmitting power of the transmitter; P _r is the receiving power of the receiver; T _p is the time required to send or receive a packet; N _ks , N _kr , N _kf are the number of packets sent by node K, the received The number of packets and the number of packets forwarded.

Preferably, the value range of α is from 0.4 to 0.6. the

As a preference, the distance between the node J and the adjacent node H is calculated using the following formula: Among them, P _t is the transmitting power, P _r is the receiving power, G _t and G _r are the transmitting antenna gain and receiving antenna gain respectively, L is the system loss factor independent of propagation, L≥1, and λ is the wavelength.

Preferably, the neighbor information table used for storing the information of the neighbor node H in the node J includes the address of H, the distance between J and H, and the lifetime LTM corresponding to the neighbor information table. the

Therefore, the present invention has the following beneficial effects:

(1) In the present invention, each node decides whether to forward according to its own situation (distance with neighboring nodes, energy), and at the same time, the forwarding node can reduce the probability of the node scrambling for the channel and signal collision by forwarding at the wrong time. Improved broadcast reliability. the

(2) Nodes in the network of the present invention dynamically update neighbor information according to received packets instead of using HELLO packets, which reduces the probability of nodes competing for channels. the

(3) The present invention adopts an energy balance method, and uses the remaining energy of nodes as a factor for determining the priority of forwarding rights. If a node satisfies the forwarding condition in terms of distance, but its residual energy is low, the probability of forwarding by this node will be reduced. Try to choose a node with higher residual energy for forwarding. Balancing the residual energy of each node in the network can improve the network efficiency. life. the

(4) The present invention cites the packet loss retransmission mechanism, which improves the reliability of the broadcast, and uses the broadcast packet forwarded by the neighbor node to "response", does not require additional response packets, and will not increase the load on the network . the

Description of drawings

Fig. 1 is a kind of flow diagram of broadcasting method of the present invention;

Fig. 2 is a kind of schematic flow chart that broadcast method of the present invention establishes neighbor information table;

Fig. 3 is a kind of flow schematic diagram that the node of broadcast method of the present invention sends broadcast packet;

Fig. 4 is a schematic diagram of the flow of broadcast packet receiving and forwarding in the broadcast method of the present invention. the

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. the

As shown in Figure 1, a reliable broadcast method based on distance and energy balance in a mobile Ad Hoc network comprises the following steps:

Step 100, set up a neighbor information table:

Any node J in the mobile Ad Hoc network receives a packet from any of its neighbor nodes H, node J obtains the address of H from the broadcast packet, and calculates the distance between J and H;

If node J receives a packet from node H for the first time, node J establishes a neighbor information table for storing information of node H;

Otherwise, node J updates the distance and lifetime LTM in the neighbor information table corresponding to node H;

The survival time LTM indicates the survival time of the neighbor information table of the corresponding node H without further receiving any information from the node H; in the life cycle LTM, if the node J does not receive the packet from H again, for J For example, H will no longer be a neighbor node, and when the LTM expires, it will be removed from the neighbor information table; if any form of packet is received from the neighbor node in the LTM, it means that the neighbor node is still the node J Neighboring nodes, the LTM needs to be updated. The size of the LTM can be set to different values according to specific network conditions. the

Step 200, send or forward the broadcast packet:

Step 210, when node J needs to send a broadcast packet, node J sets the distance threshold value D _th according to the number of neighbor nodes J _num and the distribution of neighbor nodes, and selects a neighbor distance maximum value D _max among the neighbor nodes;

When the number of neighbor nodes J _num is 1, set D _max to the distance between the neighbor node and J, and set D _th to 0;

When the number of neighbor nodes J _num is 2-4, set D _th as the minimum value of the distance between each neighbor node and node J, and set D _max as the maximum value of the distance between each neighbor node and node J ;

When the number of neighbor nodes J _num is greater than 4, set D _max as the maximum distance between each node and node J, set D _th , and make D _th satisfy the number of neighbor nodes whose distance from node J is greater than D _{th ≥Jnum} /2;

Node J records the distance threshold value D _th and the neighbor distance maximum value D _max into the packet header of the broadcast packet, and sends the broadcast packet;

Node J presets the response time A _ckt , when node J does not receive the same broadcast packet from any neighbor node within the time of A _ckt after node J sends the broadcast packet, then node J makes a broadcast packet transmission failure or a collision occurs. Judgment: When A _ckt is timed out, node J resends the broadcast packet, and does not set the response time A _ckt after the second sending to wait for the neighboring node to forward the same broadcast packet;

When node J receives the same broadcast packet from any neighbor node, node J makes a judgment that the broadcast packet has been successfully sent;

Step 220, when any neighbor node K of node J receives the broadcast packet, if K has not forwarded the broadcast packet of node J, then node K calculates the distance D _KJ from node J, and uses D _KJ to update the corresponding neighbor The neighbor distance in the neighbor information table of node J; compare D _KJ with D _th and D _max in the packet header of the broadcast packet to determine whether node K needs to forward the broadcast packet:

When D _KJ <D _th , node K does not forward broadcast packets;

When D _KJ =D _max , node K forwards broadcast packets directly;

When D _th <D _KJ <D _max , node K uses the formula Calculate the forwarding weight PI, where α is a constant set in the network, R is the radius of the wireless coverage of the node, E _k is the current remaining energy of node K, and E _max is the maximum energy value that the battery of node K can provide ; using the formula Forwarding delay time Ti, where, tanh() is hyperbolic tangent function operator, MT is the set maximum delay time, PI _max is the maximum value of PI, n is the time constant; then K is based on the forwarding delay time T _1. Delay and wait for the above-mentioned broadcast packet to be forwarded;

When D _KJ >D _max , it means that there is no K information in J's neighbor information table, in this case K will not forward;

The reason why there is no K information in J’s neighbor information table is mainly due to the following situations: ①Node K is in a dormant state and has never actively sent any unicast, multicast or broadcast packets; ②During a life cycle LTM, K does not send or forward any packets again, so when the LTM time is up, J deletes the corresponding record of K from the neighbor information table; ③K plays the role of receiving terminal in the network, that is, K is only responsible for receiving and not forwarding any grouping. the

Step 230, when node K needs to forward a broadcast packet, node K uses the same method as node J to determine D _th and D _max , and records D _th and D _max in the forwarded broadcast packet header, and saves the last The value in the jump node address field is changed to the address of this node, and then node K forwards the broadcast packet;

In step 300, all nodes in the network repeatedly and alternately perform steps 110 to 200 until all nodes stop broadcasting the broadcast packet. the

The forwarding right of the broadcast packet in this embodiment is determined by the receiving node itself, and each node in the network has a neighbor information table for recording neighbor node information. The node calculates the distance between itself and the sending node according to the signal power of the packet received from the neighbor node (whether it is unicast, multicast or broadcast), and obtains the topology information around itself. When a node J wants to send a broadcast packet, it first checks its own neighbor information table, selects the maximum neighbor distance according to the number and distance of neighbor nodes, and calculates a neighbor distance threshold value, and adds these two values to the broadcast packet middle. After J's neighbor nodes receive the broadcast packet, they first calculate the distance between them and J, and then compare it with the distance threshold in the broadcast packet header. Nodes whose distance is less than the threshold will not forward; if the distance of neighboring nodes is greater than the threshold, these nodes will be used as candidate forwarding nodes, and further consider their own residual energy. According to its own remaining energy and distance, determine the forwarding priority, calculate the forwarding delay time according to the priority, and perform time-sharing cooperative forwarding. the

In order to ensure the reliability of the broadcast packet transmission process in this embodiment, a packet loss retransmission mechanism is introduced. After the relay node forwards the broadcast information, if it does not receive the same broadcast information forwarded by the neighbor node again, it is considered that the forwarding is wrong. Success, resend. the

In this embodiment, HELLO packet interaction is canceled, and various received packets are used to obtain neighbor information, so as to reduce node energy consumption and reduce channel competition; select forwarding nodes according to the distance and remaining energy information of nodes for time-sharing forwarding, It can balance the energy consumption of nodes in the network, reduce the redundancy of broadcast information, and reduce the probability of packet collision; at the same time, a retransmission mechanism is adopted to increase the reliability of broadcast packets. the

Figures 2 to 4 show the specific execution process and interaction process of each mobile station in the network using this embodiment, respectively introducing the process of establishing a neighbor information table, sending a broadcast packet by a node, and receiving a broadcast packet by a node. the

The establishment process of the neighbor information table is shown in Figure 2. When node J receives a packet from a certain node H, it first obtains the address of node H and the distance between J and H. At the same time, J checks whether there is a record table of node H in the neighbor information table. If there is no record, add the information of H to the neighbor information table, set the life cycle LTM of H, and wait for whether to receive a packet from H again within the LTM time. If there is a record, then check whether the distance between J and H is consistent with the record in the neighbor table. If it is consistent, immediately update the life cycle LTM of node H and set it to the maximum value; if not, update the neighbor information about node H and LTMs. If a packet from H is received within the LTM time, continue to check whether the distance between J and H is consistent with the record in the neighbor table; if no packet from node H has been received as soon as LTM arrives, delete it from node J Corresponding to the neighbor information table of node H. the

After the neighbor information table is established, the processing flow of the sending node is shown in Figure 3. When sending node J wants to send a broadcast packet, it first checks the neighbor information table. If there is only one neighbor node, set D _max as the distance value of this neighbor node, and set D _th as 0. If there are 2-4 neighbor nodes, the smallest distance among these neighbor nodes is taken as D _th , and the largest distance is taken as D _max . If the number of neighbor nodes is greater than 4, the threshold value D _th is calculated according to the distribution of neighbor nodes, and the distance of the furthest neighbor node is taken as D _max .

Record D _th and D _max in corresponding fields of the broadcast packet, then send the broadcast packet, and set a response time A _ckt at the same time. If within this time, node J does not receive the same broadcast packet from the neighbor node, then J considers that the broadcast packet fails to be sent or a collision occurs at the receiving node, and J resends the broadcast packet to ensure the reliability of the broadcast . If node J receives the same broadcast packet from the neighbor node, then this broadcast packet is equivalent to the response to the broadcast packet sent by node J, then J thinks that the neighbor node has successfully received the broadcast packet sent by it, and no longer Process tasks related to the broadcast packet.

The processing flow of node forwarding is shown in Figure 4. When any neighbor node K receives the broadcast packet from node J, it first calculates the distance D _KJ between the two according to the received signal strength, and updates the neighbor information table The relevant records of J. D _KJ is then compared with D _th and D _max in the broadcast packet header.

If D _KJ <D _th , node K does not consider forwarding.

If D _KJ =D _max , it means that K is far away from J, and the extra coverage area obtained by forwarding is larger, then K will have the priority of forwarding, without delay, and directly forwards.

If D _th ≤ D _KJ < D _max , then K may forward: node K will further determine the forwarding weight PI according to the distance and remaining energy. Determine the forwarding waiting time according to the PI, delay it, and wait for forwarding.

If D _KJ >D _max , it means that there is no K information in J's neighbor information table, so K will not forward in this case.

After the above judgment, if node K needs to forward, node K uses the same method as node J to determine D _th and D _max , record these two values in the broadcast packet header, and record the previous hop node address field in the packet header Change the value in to the address of this node. In the process of node K waiting for delayed forwarding, if K receives the same broadcast packet forwarded from node N again, then K calculates the distance D _KN between K and N. If the distance between D _{and KN} is greater than r, K continues to delay and wait for forwarding. If the distance between D _{and KN} is less than r, then the additional coverage area obtained by K retransmitting will be very small, and K cancels the delay and does not retransmit. If K receives the broadcast packet more than once while waiting for the delay, K cancels the forwarding.

If the same broadcast packet is received within the response time A _ckt , node K deletes the stored broadcast packet; if not, it sends the broadcast packet again, and does not send the broadcast packet again.

All nodes in the network repeatedly and alternately perform neighbor information table updating, sending and forwarding processes until all nodes stop broadcasting the broadcast packet. the

According to the flow of this embodiment, the program code of the protocol method of the present invention can be written, and after the code is successfully compiled, it can be applied to network broadcasting. In order to better reflect the performance improvement of the protocol method of the present invention, the protocol method of the present invention is simulated with network simulation simulation software. According to the simulation results, the advantages of the protocol in the arrival rate, the proportion of forwarding nodes, the average end-to-end delay, and the network survival time are analyzed. The protocol method of the present invention can be mainly analyzed from four performance indicators: (1) reachability (Reachability): also known as reachability, defined as the number of broadcast packets received by all destination nodes and the number of broadcast packets that all destination nodes should receive The ratio of the number of broadcast packets. The number of broadcast packets that all destination nodes should receive is the product of the number of broadcast packets sent by the source node and the number of all destination nodes. (2) Retransmitted ratio: defined as the ratio of the number of nodes participating in forwarding broadcast packets to the number of all nodes in the network. (3) Average end-to-end delay (Average end-to-end delay): defined as the average value of the delay between the source node generating the broadcast packet and all the destination nodes receiving the broadcast packet. (4) Network life time (Network life time): defined as the duration from the start of network simulation to the exhaustion of the energy of the first node in the network. In order to better see the advantages of the protocol method of the present invention in these four indicators, it is compared with the DP protocol. It mainly observes the performance of the two protocols when the nodes are stationary and when the nodes are moving. Through data analysis after simulation, the arrival rate of the protocol method of the present invention is significantly higher than that of the DP protocol method in the two situations of node static and node movement, which reduces the probability of broadcast packet collision, improves network efficiency, and further ensures the reliability of broadcast However, the DP algorithm only dynamically adjusts the forwarding probability of the node according to the number of neighbors of the node, and does not consider the possible collision problem at the receiving node, so the arrival rate is lower than that of the DEBRB algorithm; in terms of the proportion of forwarding nodes, As the network node density increases, this protocol method maintains a relatively stable value, and is always better than the DP method. That is to say, DEBRB reduces the number of nodes participating in broadcasting and better suppresses broadcast storms; In terms of average end-to-end delay, when the node density in the network increases, the average delay of the two protocol methods will increase, but the average delay of the DEBRB algorithm is always lower than that of the DP algorithm, because in the DEBRB algorithm, the network The node dynamically updates the neighbor information according to the received packet, and selects the forwarding node for time-sharing forwarding, which reduces the probability of the node competing for the channel and the waiting time of the packet in the queue, so the delay is small; in the network lifetime performance In terms of indicators, the network survival time of this protocol method is significantly higher than that of the DP algorithm, and has a longer network survival time. This is because DEBRB considers energy balance and does not use HELLO grouping to exchange neighbor information, which reduces energy consumption and balances the network. The energy of the middle node. the

The invention obtains the topology information around the nodes through the packets received from neighbor information in the network, which reduces the probability of broadcast packet collision; each node determines its own forwarding priority through distance and remaining energy, thereby reducing the number of forwarding times , better restrain the broadcast storm; adopt the method of energy balance, balance the remaining energy of each node in the network, improve the life of the network; adopt the packet loss retransmission mechanism, improve the reliability of the broadcast. The present invention can be better applied to the broadcasting technology of the mobile Ad Hoc network. the

It should be understood that this embodiment is only used to illustrate the present invention but not to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application. the

Claims (7)

1. the broadcasting method based on distance and balancing energy in mobile Ad Hoc network, is characterized in that, comprises the steps:

(1-1) set up neighbor information table:

The grouping that any node J in mobile Ad Hoc network receives its arbitrary neighbor node H, node J obtains the address of H from broadcast packe, and calculates the distance between J and H;

If node J receives the grouping from node H for the first time, node J sets up the neighbor information table for the information of memory node H;

Otherwise, distance and life span LTM in the neighbor information table of node J renewal corresponding node H;

(1-2) send or forward broadcast packe:

(1-2-1), in the time that node J need to send broadcast packe, node J is according to neighbor node number J _numdistribution situation setpoint distance threshold value D with neighbor node _th, and in neighbor node, select neighbours apart from maximum D _max;

As neighbor node number J _numit is 1 o'clock, by D _maxbe made as the distance between this neighbor node and J, and by D _thbe made as 0;

As neighbor node number J _numduring for 2-4, by D _thbe made as the minimum value of distance in each neighbors and between node J, by D _maxbe made as the maximum of distance in each neighbors and between node J;

As neighbor node number J _numbe greater than at 4 o'clock, by D _maxbe made as the maximum of distance in each neighbors and between node J, set D _th, and make D _thmeet with the distance of node J and be greater than D _thneighbor node number>=J _num/ 2;

Node J is by distance threshold value D _thwith neighbours apart from maximum D _maxbe recorded in the packets headers of broadcast packe, and send broadcast packe;

Default response time A in node J _ckt, the A after node J forwards broadcast packe _cktin time, node J does not receive the identical broadcasts grouping from arbitrary neighbor node, and node J makes the judgement that broadcast packe sends failure or bumps, and node J resends this broadcast packe, and response time A is no longer set after being sent for the second time _cktwait for that neighbors forwards identical broadcast packe;

When node J is at A _cktin time, receive the identical broadcasts grouping from arbitrary neighbor node, node J makes the judgement that broadcast packe has successfully sent;

(1-2-2) when any one neighbor node K of node J receives after this broadcast packe, if K did not forward the broadcast packe of node J, the distance B of node K calculating and node J _kJ, and set up the neighbor information table of corresponding neighbors J or upgrade neighbours' distance and the LTM in the neighbor information table of corresponding neighbors J; By D _kJwith the D in the packets headers of broadcast packe _thand D _maxcompare, determine whether node K needs to forward this broadcast packe:

Work as D _kJ<D _thtime, node K does not forward this broadcast packe;

Work as D _kJ=D _maxtime, node K directly forwards this broadcast packe;

Work as D _th<D _kJ<D _maxtime, node K utilizes formula calculate and forward power PI, wherein, α is the constant of setting in network, the radius of the wireless coverage that R is node, E _kfor the current remaining of node K, E _maxthe maximum energy value that can provide for the battery of arbitrary node; Utilize formula calculate Forwarding Latency time T i, wherein, tanh () is hyperbolic tangent function operator, and MT is the maximum delay time of setting, PI _maxbe the maximum of PI, n is time constant; Then K is according to Forwarding Latency time T ₁carry out time delay, wait for and forward above-mentioned broadcast packe;

Work as D _kJ>D _maxtime, K does not forward this broadcast packe;

(1-2-3), when node K need to forward broadcast packe, node K utilizes the method identical with node J to determine D _thand D _max, and by D _thand D _maxbe recorded in the broadcast packe head of forwarding, the value in upper hop node address field in broadcast packe head is revised as to this address of node, then node K sends broadcast packe;

(1-3) in network, all nodes alternately perform step (1-1) repeatedly to (1-2), until all node stop are broadcasted this broadcast packe.

2. the broadcasting method based on distance and balancing energy in mobile Ad Hoc network according to claim 1, it is characterized in that, described node K waits in the process of time delay forwarding, if K receives the identical broadcast packe that arbitrary neighbors N forwards, the distance B of node K calculating K and N again _kN;

If D _kNdistance be greater than r, K continues time delay, wait for forward;

If D _kNdistance be less than r, K cancel time delay, do not forward.

If K receives that the number of times of this broadcast packe is greater than 1 time in the process of waiting for time delay, K cancels forwarding; Wherein, the scope of r is:

3. the broadcasting method based on distance and balancing energy in mobile Ad Hoc network according to claim 1, is characterized in that described broadcast packe response time A _ckt=t ₁+ 2t ₂+ MT; Wherein, t ₁it is the transmitting time of a broadcast packe; t ₂for the propagation delay of network.

4. the broadcasting method based on distance and balancing energy in mobile Ad Hoc network according to claim 1, is characterized in that the dump energy E of described node K _kutilizing following steps to calculate obtains:

Node K sends a grouping institute consumed energy: E _sc=P _st _p;

Node K receives an energy that divides into groups to consume: E _re=P _rt _p;

It is two kinds of operation institute energy requirement sum: E of sending and receiving that node K forwards a required energy of grouping _ifw=(P _s+ P _r) T _p;

The gross energy that node K has consumed is E _kc=N _kse _sc+ N _kre _re+ N _kfe _ifw

The dump energy E of node K _k=E _max-E _kc

Wherein, P _sfor the transmitting power of transmitter; P _rfor the received power of receiver; T _pfor sending or receive a grouping required time; N _ks, N _kr, N _kfbe respectively the packet count of node K transmission, the packet count of reception, the packet count of forwarding.

5. the broadcasting method based on distance and balancing energy in mobile Ad Hoc network according to claim 1, is characterized in that, the span of described α is 0.4 to 0.6.

6. the broadcasting method based on distance and balancing energy in mobile Ad Hoc network according to claim 1, is characterized in that, the distance between described node J and neighbors H utilizes following formula to calculate: wherein, P _tfor transmitting power, P _rfor received power, G _tand G _rbe respectively transmitter antenna gain (dBi) and receiving antenna gain, L is and propagates the irrelevant system loss factor, L>=1, and λ is wavelength.

7. according to the broadcasting method based on distance and balancing energy in the mobile Ad Hoc network described in claim 1 or 2 or 3 or 4 or 5 or 6, it is characterized in that the distance between the address, J that comprises H in node J for storing the neighbor information table of information of neighbors H and H and the life span LTM of corresponding this neighbor information table.