CN1299478C - Route searching of detgredd of node based on radio self-organizing network and maitenance method thereof - Google Patents

Abstract

The present invention relates to a route searching and maintaining method based on node degrees in radio self-organizing networks, which belongs to the radio communication network technology. The present invention is characterized in that based on the statistic characteristics of node degrees, the present invention provides a route selection rule taking node competition and congestion states into account in order that nodes can select routes having few competition nodes when flowing across the nodes as transmission routes of data packets; accordingly, under the preconditions that network cost is not increased and node moving speeds are the same, the data packets have high delivery rate and short time delay. When routes are particularly selected for parameter selection, requirements of service characteristics of an upper layer are taken into account; in addition, the present invention can also be easily embedded into the existing route algorithm. The rout method with route selection rules, which is provided by the present invention, has advantages of simplicity, high efficiency and fair node energy consumption.

Description

In the wireless self-organization network based on the route search and the maintaining method of the degree of node

Technical field

Wireless self-organization network, i.e. Ad Hoc network, in based on the route search and the maintaining method of the degree of node, belong to the cordless communication network technical field.

Background technology

At present, various communications and network technology develop rapidly, particularly the use of cordless communication network has entered into maturation gradually, comprises various wireless cellular communication networks (as: GSM, WCDMA, CDMA2000 etc.), WLAN (wireless local area network) (as: the HiperLAN standard in IEEE 802.11 series standards, Europe etc.) and causes industry just day by day and the wireless self-organization network (AdHoc network) of academia's attention.Wireless lan (wlan) and Ad Hoc network are generally believed will become the useful part of following whole cordless communication network, with realize conveniently, at a high speed, wireless access effectively.Ad Hoc network both can be used as the following a kind of mode that realizes wireless access, but it also constitutes a wireless network separately in self-organizing ground simultaneously, in this network, node can random motion, each node is source node and destination node, the function of also taking on simultaneously router, that is: the packet to the local node of flowing through carries out the pathfinding forwarding.Because the structure of Ad Hoc network is very simple, convenient, therefore it is highly suitable for Military Application, Conference Room, student classroom, fights flood and relieve victims, earthquake is speedily carried out rescue work and the generation scene of some accidents, it can be rapidly for people provide reliable, a valid wireless communication network, and do not need to make up in advance any communications infrastructure.

For Ad Hoc network,, need good routing algorithm of design realize routing function for realizing that any two nodes in the network all can proper communication.And the multiple time-varying characteristics of Ad Hoc network, such as: the variation of the variation of wireless channel, the variation of network topology structure, upper-layer service, variation of the node energy content of battery or the like make the design of routing algorithm face significant challenge.In the routing algorithm that has proposed, mostly with shortest path as the routing criterion, as: purpose sequence number Distance Vector Routing Algorithm (DSDV-Destination Sequenced Distance Vector Routing), Ad Hoc be Distance Vector Routing Algorithm (AODV-Ad Hoc On-Demand Distance Vector Routing), DSR algorithm (DSR-Dynamic Source Routing) etc. as required.In addition, some document also proposes some routing criterions in conjunction with other factors, guarantee (Quality-of-Service), load balancing etc. such as: the relevant stability between the signal strength signal intensity between the adjacent node, the adjacent node, the power consumption of node, professional service quality, some routing algorithm and then considered the factor of several respects simultaneously.But there is following shortcoming in these algorithms:

1) the congestion condition in the network is not taken in;

2) need node periodically to send the control information relevant mostly, thereby increased network overhead, and make that further network is more congested with Route Selection;

3) owing to the congestion condition of network is not taken in, thereby it is unfair to cause the energy consumption of node in the network to distribute, that is: some node may be owing to the overweight and too early depleted of energy of load, and this is with further emphasis network changes of topology structure;

4), be to represent the offered load situation mostly with the number of data packets of the node buffering area memory space of data (that is: be used for preserving) or the linking number (that is: the number of routes of communicating by letter) of communicating by letter for those load balancing routing algorithms of having considered the network congestion situation.A consequence of doing like this is: have coupling between routing algorithm and the business, that is: can influence each other between number of data packets of preserving in the routing result of routing algorithm and the node buffering area or the linking number.Thereby cause unstable networks, even reforming phenomena can take place in selected route.Particularly when the upper-layer service rate variation is rapid, the performance of these algorithms will further reduce.And the professional sudden difficulty that increases these algorithm process offered loads more greatly.And the great majority in these algorithms need node periodically to send control information equally, thereby have increased network overhead.

In order to make that routing algorithm can efficient operation, the routing algorithm design in Ad Hoc network should be followed following two principles:

1) simple;

2) reduce network overhead as far as possible.

Summary of the invention

The object of the present invention is to provide in the comparatively simple Ad Hoc network of a kind of network overhead race condition, search and maintenance lower, that consider each node simultaneously route search and maintaining method based on the degree of node.

The invention is characterized in: it is at wireless transmitting-receiving equipments, and promptly node also claims router, and the wireless Ad Hoc of formation is realized in each mobile device in the i.e. Ad Hoc, communication network successively according to the following steps:

Initializing set: the type of packet and the data item that includes thereof, and deposit in each node memory:

1) route request packet, i.e. RREQ includes following data item:

Type of data packet is with " Type " expression; Source node address is with " Src_Addr " expression; The destination node address is with " Dest_Addr " expression; The sequence number of the RREQ packet that node sends is with " Seq_Num " expression; The life-span of the packet of representing with jumping figure with " TTL " expression, is MaxM+1 according to the default maximum life of network size, and wherein MaxM is maximum intermediate node number that may comprise in the route; Route length from the source node to the present node is with " Cur_Len " expression; The N jumping degree of source node is represented with " Src_Degree ", N jumping degree is meant the doubly node number in the scope that transmits and receives radius of node of N, in practice, because node can't be known stationary node, be inactive node, existence, so the active section that it also is equal in the above-mentioned scope is counted, the number of the node of packets need transmission is promptly arranged, and General N selects 1 or 2; The N jumping degree of destination node, with " Dest_Degree " expression, wherein, the definition of N jumping degree is as mentioned above; The node address of the intermediate node that RREQ flows through, with " Addr_1～Addr_MaxM " expression, wherein MaxM represents maximum intermediate node number possible in the route; The N jumping degree of the various intermediate nodes that RREQ flows through, with " Degree_1～Degree_MaxM " expression, same, MaxM represents maximum intermediate node number possible in the route;

2) route replies packet, be RREP, include following data item: Type, Src_Addr, Dest_Addr, Seq_Num, Cur_Len, Src_Degree, Dest_Degree, Addr_1～Addr_X and Degree_1～Degree_X, wherein constitute a complete route by Addr_1～Addr_X, Degree_1～Degree_X represents the N jumping degree information corresponding to the node of Addr_1～Addr_X, all the other each data item described as defined above, wherein X represents that the intermediate node number of the route that comprises among the RREP is X, and X is not more than MaxM;

3) routing failure packet, be RERR, include following data item: Type, Src_Addr, Dest_Addr, Cur_Len, Src_Degree, Dest_Degree, Addr_1～Addr_X, Degree_1～Degree_X, Error_Up_Addr and Error_Down_Addr, wherein the implication of Type, Src_Addr, Dest_Addr, Src_Degree, Dest_Degree, Addr_1～Addr_X and Degree_1～Degree_X as previously mentioned, and Cur_Len represents from the node that the makes a mistake jumping figure of node up till now; Error_Up_Addr represents the node address of finding that next-hop node can't arrive; Error_Down_Addr represents the node address of the next-hop node that can't arrive;

4) business data packet includes following data item: Type, Src_Addr, Dest_Addr, Cur_Len, Src_Degree, Dest_Degree, Addr_1～Addr_X, Degree_1～Degree_X, Traffic_Data and Alpha, wherein the implication of Type, Src_Addr, Dest_Addr, Cur_Len, Src_Degree, Dest_Degree, Addr_1～Addr_X, Degree_1～Degree_X as previously mentioned, Traffic_Data represents the upper-layer service data of business data packet; Alpha represents the require parameter of user for the time-delay of business data packet, packet loss, bandwidth;

Set following parameter and relevant intermediate variable thereof, deposit in respectively in the memory in the node:

The time-out time threshold value in path life-span, its expression: if during this period of time, node does not monitor any traffic data bag along this path, and then node thinks that this path lost efficacy, thus with this path, promptly route is deleted from the routing cache district;

The routing cache district, it refers to preserve in the memory of each node the memory space of route;

Data packet buffer, it refers to preserve in the memory of each node the memory space of upper-layer service packet;

The maximum of the predefined business data packet of network allows to send number of times;

The maximum that contains in the predefined route of network allows the node number;

Following three kinds of algorithm routines of the Route Selection parameters R SM of a route of designing and calculating calculate three kinds of routing parameter RSM ₁, RSM ₂And RSM ₃, its calculation procedure together with routing criterion is deposited in the memory of each node, described routing criterion is meant: when α value value hour, the RSM value is got RSM ₃, in the routing cache district, select one to jump RSM with minimum ₃The route of the arrival destination node of value; When the α value was big, the RSM value was from RSM ₁Or RSM ₂In choose one, when the RSM value is got RSM ₁The time, in the routing cache district, select one and have minimum RSM ₁The route of the arrival destination node of value; Described RSM ₁, RSM ₂And RSM ₃Computational methods as follows:

${\mathrm{<figure-callout\; id="1"\; label="RSM"\; filenames="C20041000346600191.png"\; state="\{\{state\}\}">RSM</figure-callout>}}_1=\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i,$

${\mathrm{<figure-callout\; id="2"\; label="RSM"\; filenames="C20041000346600191.png,C20041000346600201.png"\; state="\{\{state\}\}">RSM</figure-callout>}}_2=(H+1)\sqrt{\frac{1}{M-1}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{(D_i-\stackrel{\&OverBar;}{D})}^2},$ Wherein $\stackrel{\&OverBar;}{D}=\frac{1}{M}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i,$

${\mathrm{<figure-callout\; id="3"\; label="RSM"\; filenames="C20041000346600191.png,C20041000346600201.png"\; state="\{\{state\}\}">RSM</figure-callout>}}_3=(H+1)[\frac{1}{M}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i+\mathrm{\&alpha;}\sqrt{\frac{1}{M-1}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{(D_i-\stackrel{\&OverBar;}{D})}^2},(0<\mathrm{\&alpha;}<1)$

Wherein, M is the node number that comprises in the route; H is the jumping figure that comprises in the route, H=M-1; D _iN jumping degree for i node of route flow warp; D is the average N jumping degree of M node of route flow warp; α is user's appointment in business data packet, it is the parameter that the user sets according to time-delay, packet loss, the bandwidth of packet, simultaneously, this parameter has shown the stress degree of upper-layer service characteristic to the standard variance of the competition node number of the total competition node number of route and each node, 0＜α＜1, when standard variance being stressed degree hour, it is littler that the α value is wanted, otherwise then the α value is bigger;

Described route method for searching contains following each step successively:

(1) when certain node produces a upper-layer service packet, this node just becomes source node, and it has judged whether that at first packet sends, if having, then this business data packet is inserted in the data packet buffer, waited for after this packet transmission finishes sending current data packet again; If there is not packet to send, then it selects an effective route that arrives destination node according to above-mentioned RSM routing criterion from the routing cache district of oneself;

(2) if do not have effective route from this node in the routing cache district of this node, just initiate the route search process, promptly this node is packed among the RREQ also broadcast transmission to self address and N jumpings degree; If exist, just change route maintenance procedure over to;

(3) intermediate node is after receiving RREQ, just checks whether receive this RREQ first, if non-ly receive first, just abandons this RREQ, and search process finishes; If receive this RREQ first, intermediate node just is packed into self address and N jumping degree among the RREQ and transmits;

(4) after destination node is received RREQ, each RSM value according to each paths in predetermined routing criterion and routing cache district in the memory, select best route, selected each paths comprises that also destination node extracts the path that arrives source node that node corresponding address and N jumping degree form from RREQ;

(5) destination node is packed into the best routing iinformation that comprises each node address and N jumping degree among the RREP and to source node and sends;

(6) after the intermediate node of best route receives RREP, just go to upgrade the N jumping degree information of node corresponding among the RREP, and be forwarded to the upstream node that comprises route among the RREP with oneself according to the N jumping degree of own node;

(7) after source node receives RREP, just obtain an effective route from the source node to the destination node, and deposit in the routing cache device of oneself, the route search process finishes;

Described route maintenance method contains following each step successively:

(1) the source node effective route from the source node to the destination node that can obtain according to above-mentioned steps (7), also can be according to producing effective route that the back directly obtains at the upper-layer service packet from the routing cache district in the above-mentioned steps (2), node address and corresponding N jumping degree information are packed in the current business data packet that will send, and this business data packet is sent;

(2) source node is if find that its down link can't proper communication, and promptly next-hop node can't arrive, and just upgrades the routing iinformation in the routing cache district, and the transmission number of times of counting current business packet, changes step (11); Source node is if find that its down link can proper communication, then step (3);

(3) intermediate node goes to upgrade in the business data packet N jumping degree information with own corresponding node according to the N jumping degree of own node, and transmits this business data packet according to the routing iinformation in the business data packet;

(4) intermediate node can't be kept proper communication if find its down link, and promptly next-hop node can't arrive, and just upgrades the routing iinformation of own node, and makes the transmission number of times of this business data packet add 1, changes step (5) then; If all intermediate nodes all can be kept proper communication, then destination node can receive business data packet, and route maintenance procedure finishes;

(5) intermediate node checks whether the repeating transmission number of times of current business packet reaches the transmission number of times that network sets in advance, if reach, then abandons this packet, sends the routing failure packet to source node then, and promptly RERR changes step (7); If do not reach, then judge whether there are other effective routes in the routing cache district;

(6) if there are other effective routes in the routing cache district, then send the current business packet along new route, route maintenance procedure finishes; If do not exist, then abandon the current business packet, send RERR to source node then;

(7) receive the intermediate node of RERR, upgrade corresponding routing iinformation in the local routing cache district, and, then RERR is forwarded to the upstream node that comprises route among this RERR with corresponding N jumping degree information among the N jumping degree information updating RERR of local node;

(8) after source node receives RERR, upgrade the routing iinformation in the local routing cache district;

(9) source node checks that whether to still have business data packet etc. in the data buffer zone to be sent, if having, then checks whether there are other effective routes in the routing cache district, changes step (10); If there is not in the data buffer zone business data packet etc. to be sent, then route maintenance procedure finishes;

(10) if source node finds do not have effective route in the routing cache district, then initiate the route search process again, route maintenance finishes; If find to have effective route in the routing cache district, then business data packet sends along new route, and route maintenance procedure finishes;

(11) source node judges whether the transmission number of times of current business packet reaches the predetermined transmission number of times of network, if reach, then abandons this packet, changes step (9); If do not reach, then judge whether there are other effective routes in the routing cache district, change step (10).

In multi-hop Ad Hoc network, although there are above-mentioned multiple time-varying characteristics, the local topology of network remains metastable.This be because, if the network topology structure variation abnormality is rapid, then the transmission of packet can only be adopted " spreading unchecked " (so-called " spreading unchecked " will be meant that source node do not specify any paths and directly packet is sent, receive the node of packet if find that local node is not that destination node then forwards packet, arrive till destination node or life-span end until packet) form send, any routing algorithm all will lose efficacy.Therefore, in order to make routing algorithm more effective than the method for " spreading unchecked ", the relatively stable of localized network topological structure is a necessary condition.Based on this, the present invention proposes in the Ad Hoc network routing algorithm (NDBR) based on the degree of node, this algorithm has made full use of the stability of local topology in the Ad Hoc network just.The distance that transmits and receives of supposing node is R, and then the present invention is defined as follows " the N jumping degree of node and N jump mobility ":

Be the center with the node, NR is that the interior interstitial content of scope of radius is called " degree that the N of node jumps ", abbreviation " the N jumping degree of node " (N=1,2 ..., be natural number); Be the center with the node, NR is that the interior active node of the scope of radius (that is: this node has packets need to send) number is called " mobility that the N of node jumps ", abbreviation " N of node jumps mobility " (N=1,2 ..., be natural number).

It is worthy of note, in actual communication networks, because node can't be known the existence of the inactive node (that is: node sends without any packets need) around it, so the N jumping degree N jumping in fact just mobility that can know of each node.

NDBR is used as the routing criterion with route flow through the statistical property of the N of node jumping degree.Thereby can be so that source node is selected those few routes of competition interstitial content of flowing through, thereby avoided the more route of competition node of data packet stream warp, like this, on the one hand can be so that packet arrives destination node faster, make that on the other hand the energy consumption situation of node is fair as far as possible, be unlikely to make that the node consumption at those congestion link places is too much.

Suppose that comprising M node, H in the route jumps, that is: H=M-1, and the N jumping degree of i node of path flow warp is D _i(1≤i≤M).Definition $D=\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i,\stackrel{\&OverBar;}{D}=\frac{1}{M}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i.$ The present invention proposes, and can utilize following statistic as Route Selection parameter (RSM).

$1)---{\mathrm{<figure-callout\; id="1"\; label="RSM"\; filenames="C20041000346600191.png"\; state="\{\{state\}\}">RSM</figure-callout>}}_1=\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i,$

$2)---{\mathrm{<figure-callout\; id="2"\; label="RSM"\; filenames="C20041000346600191.png,C20041000346600201.png"\; state="\{\{state\}\}">RSM</figure-callout>}}_2=(H+1)\sqrt{\frac{1}{M-1}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{(D_i-\stackrel{\&OverBar;}{D})}^2},$ Wherein $\stackrel{\&OverBar;}{D}=\frac{1}{M}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i,$

$3)---{\mathrm{<figure-callout\; id="3"\; label="RSM"\; filenames="C20041000346600191.png,C20041000346600201.png"\; state="\{\{state\}\}">RSM</figure-callout>}}_3=(H+1)\left[\frac{1}{M}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i\mathrm{\&alpha;}\sqrt{\frac{1}{M-1}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{(D_i-\stackrel{\&OverBar;}{D})}^2}\right],(0<\mathrm{\&alpha;}<1)$

Determining RSM (RSM ₁, RSM ₂Or RSM ₃) afterwards, routing criterion is as follows: in routing cache district (that is: the memory space of preservation route in the node memory), select a route with arrival destination node of minimum RSM value.For RSM ₃; the size of α is specified according to upper-layer service characteristic (as: time-delay, packet loss, bandwidth etc.) by the user; mainly show as total competition interstitial content of route and the degree that stresses of competing the interstitial content standard variance; if total competition interstitial content of route is more important for the successful transmission of upper-layer service; then α can be smaller as far as possible, otherwise more greatly.

L-G simulation test shows, when the rate travel of node was identical, the transmission delay of packet delivery rate of the present invention, packet all was better than traditional DSR method, i.e. DSR; But network overhead is lower than DSR.Along with the increase of node motion speed, the route search that the present invention proposes and the advantage of maintaining method are more obvious, when speed reaches 10 meter per seconds, aspect packet delivery rate, adopt RSM ₃The method for routing of routing criterion improves about 20% than DSR method; Aspect the data packet transmission time-delay, adopt RSM ₃The method for routing of routing criterion improves about 40% than DSR method performance.And for network overhead, along with the increase of node speed, the method that the present invention proposes is compared with traditional DSR method, and the difference of network overhead reduces gradually, but adopts RSM ₃The method for routing of the routing criterion still network overhead than DSR method is little, and is when node speed is 10 meter per seconds, approximately little by about 5%.

Description of drawings

Fig. 1 .RREQ packet structure schematic diagram.

Fig. 2 .RREP packet structure schematic diagram.

Fig. 3 .RERR packet structure schematic diagram.

Fig. 4. the business data packet structural representation.

Fig. 5. the program flow chart of the route method for searching that the present invention proposes.

Fig. 6. the program flow chart of the route maintenance method that the present invention proposes.

Fig. 7. packet delivery rate comparison diagram.

Fig. 8. data packet transmission time-delay comparison diagram.

Fig. 9. the network overhead comparison diagram.

Embodiment

The routing algorithm based on the degree of node that the present invention proposes can easily embed in the existing DSR algorithm, and the alms giver will comprise following components in fact: the 1) estimation of N the jumpings degree of node, and this can be realized by the method that adopts forefathers' proposition; 2) N's determines that for the sake of simplicity, General N may be selected to be 1 or 2; 3) software of the route search of algorithm and route maintenance procedure is realized.

The N jumping degree of needed node in the NDBR criterion can obtain by the certain methods that forefathers propose, such as: by use the method for Kalman filter at MAC (access control of Media Access Control-medium) layer; By the method (this will increase network overhead) that periodically sends control information etc.Simultaneously, in concrete routing algorithm is realized, NDBR adopt a jumping degree, two jumping degree still more the statistic of multi-hop degree be used as the routing parameter and then depend primarily on three aspects of MAC agreement that adopted in complexity, network overhead and the Ad Hoc network of network design.In practice, the acquisition of N jumping degree has error inevitably, but because the NDBR algorithm is by the RSM value of each bar route relatively to the selection of best route, so N the jumpings degree error of node influences not quite algorithm performance.

These statistics of it should be noted that in the present invention to be proposed can be used as the Route Selection parameter, can also design other based on the statistic of the degree of node as the Route Selection parameter, this depends primarily on the designer of communication network.

The NDBR algorithm is the same with DSR algorithm (DSR), is a kind of source route algorithm that drives as required.In this algorithm, the routing iinformation that is using is only preserved and safeguarded to node.The NDBR algorithm comprises two stages: 1) route search; 2) route maintenance.In NDBR, every kind of type of data packet has all comprised " address " and " degree " territory, and they have write down node address and the node N jumping degree of data packet stream through node.In addition, each node is understood any packet of monitoring stream through this node, and therefrom extracts node address and the N jumping degree of data packet stream through node.Under they all can be preserved in the routing cache district of node, preserve the settling time of route simultaneously, and start overtime timer (that is: the default time-out time value of network in path life-span, if during this period of time, the packet that node does not monitor any this path of flowing through passes through, then node thinks that this path lost efficacy, thereby this path is deleted from the routing cache district).

The route search of this algorithm and route maintenance procedure are as follows substantially:

When a business data packet arrived, node was at first selected route according to RSM routing criterion from the routing cache district.If node can not find a route that arrives destination node, node will trigger following route search process.Source node broadcast transmission route request packet (RREQ), as shown in Figure 1, wherein " Type " represents type of data packet (comprising route requests RREQ, route replies RREP, routing failure RERR and business data packet) in this packet; " Src_Addr " represents source node address; " Dest_Addr " expression destination node address; The sequence number of the RREQ packet that " Seq_Num " expression node sends is used for the uniqueness of the RREQ that the identification sources node sends; The packet life-span that " TTL " expression is represented with jumping figure; " Cur_Len " expression is from the source node route length of node up till now; The N jumping degree of " Src_Degree " expression source node; The N jumping degree of " Dest_Degree " expression destination node; " Addr_1～Addr_MaxM " and " Degree_1～Degree_MaxM " represents the node address and the N jumping degree of the intermediate node of RREQ data packet stream warp respectively, and wherein MaxM represents the maximum intermediate node number of a route.

After receiving RREQ, node is if find to receive this RREQ first, and this node is not destination node, and then address and the N jumping degree with self adds in the RREQ packet and forward.Like this, not only comprise the node address of all nodes that it flows through in the RREQ packet, and comprised the N jumping degree of these nodes.After RREQ arrived destination node, destination node can be extracted the route that node corresponding address and N jumpings degree constitute an arrival source node from RREQ, and according to the RSM value in definite this path of Route Selection calculation of parameter of the routing criterion of NDBR.Thereby destination node can be from its routing cache district be selected a best route according to NDBR routing criterion, and this route is included in the route replies packet (RREP) is sent to source node.The RREP packet structure as shown in Figure 2, the implication in each territory is with the data field implication among the RREQ, difference only is that the route in the RREP packet fixes.

After intermediate node receives RREP, the N jumping degree of node corresponding among the RREP can be upgraded, and this packet is mail to the upstream node that comprises route among the RREP.Finally, the RREP packet arrives source node, thereby source node obtains to arrive a route of destination node.Like this, business data packet just can be sent to destination node along this route.The route search process serves as that sign is finished with the complete route that source node obtains the arrival destination node.Fig. 5 has expressed the route search process schematic diagram of NDBR algorithm.

In the business data packet transmission course, if node is found its down link and can't be kept proper communication, the routing iinformation of this node updates this locality then, and whether the transmission number of times of checking the current business packet reaches the transmission number of times that network sets in advance, if reach, then abandon this packet, send routing failure packet (RERR) to source node then; If do not reach, then judge whether there is the active path that arrives destination node in the routing cache district, if exist, then send the current business packet along new route; If do not exist, then abandon the current business packet, send routing failure packet (RERR) to source node then.Receive the node of RERR, upgrade local corresponding routing iinformation and the corresponding N jumping degree information among the RERR, and be forwarded to the upstream node that comprises the path among the RERR.After RERR arrives source node, source node at first upgrades the routing iinformation in the local routing cache district, whether the transmission number of times of checking the current business packet then reaches the transmission number of times that network sets in advance, if reach, then abandon this packet, judge simultaneously whether upper-layer service data buffer zone (node is used for storing the memory space of upper-layer service packet) still has packet etc. to be sent, if being arranged, the routing criterion of then determining according to NDBR searches best route from the routing cache district, if do not find best route, then source node will be initiated another time route search process again; If find, then business data packet sends along new route.If node is found the transmission number of times of current business packet and is not reached the transmission number of times that network sets in advance, then node is searched best route according to the routing criterion that NDBR determines from the routing cache district, if do not find best route, then source node will be initiated another time route search process again; If find, then business data packet sends along new route.The structural representation of routing failure packet and business data packet respectively as shown in Figure 3 and Figure 4.Concrete route maintenance procedure is seen the route maintenance schematic diagram of Fig. 6.

Be checking and comparison algorithm performance, we have carried out emulation to the routing algorithm that proposes in this invention, and the simulation hardware condition is as follows: computer main frequency 2.6Ghz, hard disk 20G, internal memory 512M.

Concrete simulated environment is as follows: 30 nodes move at random according to " random way point " model (transfer point model at random) in 600 meters * 600 meters scope, node motion speed minimum in this model is set to 1m/s, and maximum node movement rate is set to 2m/s, 4m/s, 6m/s, 8m/s and 10m/s respectively.Each node produces CBR (Constant BitRate-constant rate of speed) professional (each packet 2048 bit produces 4 packets 1 second), selects one at random as destination node from remaining 29 nodes.Physical layer and MAC layer adopt IEEE 802.11a standard, speed is 54Mbps, the MAC agreement is chosen as basic CSMA/CA agreement (the carrier sense multiple agreement of Carrier Sense Multiple Access with CollisionAvoidance-band conflict monitoring), that is: source node sends business data packet, destination node sends confirms packet, can finish transmission of data packets one time.In the route maintenance algorithm, it is 2 that the maximum of setting business data packet allows to send number of times.In emulation, setting N=1, and the evenly distribution of N jumping degree deviation obedience of supposition node, error is 10%, that is: the deviation between the N jumping degree of the N jumping degree of node and reality is 10% to the maximum.We represent to adopt RSM respectively with " NDBR-1 ", " NDBR-2 " and " NDBR-3 " ₁, RSM ₂And RSM ₃The routing algorithm of (α=0.5) Route Selection parameter; " DSR " is expressed as the DSR algorithm of the N jumping degree of considering node.Fig. 7, Fig. 8, Fig. 9 and table 1 have expressed the simulation result under this condition.As seen, the NDBR algorithm can obtain higher packet and drop rate, the time-delay of littler data packet transmission under the situation that does not increase network overhead, and is adopting RSM ₃The situation of Route Selection parameter under, the number-of-packet purpose standard variance minimum that node sends, see the following form and since the energy consumption of node depend mainly on node send packet number what, therefore this routing algorithm is the most fair for the energy consumption situation of node.

The number-of-packet purpose standard variance that table 1. node sends relatively

Routing plan	Node motion speed (meter per second)
				2	6	10
	DSR	672.07	630.29				657.10
NDBR-1				643.09	654.71	674.29
	NDBR-2	704.75	671.71				715.20
NDBR-3				605.29	579.80	585.29

Claims (1)

1, in the wireless self-organization network based on the route search and the maintaining method of the degree of node, it is characterized in that it is at wireless transmitting-receiving equipments, be node, also claim router, the wireless Ad Hoc of formation, be Ad Hoc, realize according to the following steps successively in each mobile device in the communication network:

Initializing set: the type of packet and the data item that includes thereof, and deposit in each node memory:

1) route request packet, i.e. RREQ includes following data item:

Type of data packet is with " Type " expression; Source node address is with " Src_Addr " expression; The destination node address is with " Dest_Addr " expression; The sequence number of the RREQ packet that node sends is with " Seq_Num " expression; The life-span of the packet of representing with jumping figure with " TTL " expression, is MaxM+1 according to the default maximum life of network size, and wherein MaxM is maximum intermediate node number that may comprise in the route; Route length from the source node to the present node is with " Cur_Len " expression; The N jumping degree of source node is represented with " Src_Degree ", N jumping degree is meant the doubly node number in the scope that transmits and receives radius of node of N, in practice, because node can't be known stationary node, it is the existence of inactive node, therefore its active section of also being equal in the above-mentioned scope is counted, and the number of the node that packets need sends is promptly arranged, and N selects 1 or 2; The N jumping degree of destination node, with " Dest_Degree " expression, wherein, the definition of N jumping degree is as mentioned above; The node address of the intermediate node that RREQ flows through, with " Addr_1～Addr_MaxM " expression, wherein MaxM represents maximum intermediate node number possible in the route; The N jumping degree of the various intermediate nodes that RREQ flows through, with " Degree_1～Degree_MaxM " expression, same, MaxM represents maximum intermediate node number possible in the route;

2) route replies packet, be RREP, include following data item: Type, Src_Addr, Dest_Addr, Seq_Num, Cur_Len, Src_Degree, Dest_Degree, Addr_1～Addr_X and Degree_1～Degree_X, wherein constitute a complete route by Addr_1～Addr_X, Degree_1～Degree_X represents the N jumping degree information corresponding to the node of Addr_1～Addr_X, all the other each data item described as defined above, wherein X represents that the intermediate node number of the route that comprises among the RREP is X, and X is not more than MaxM;

3) routing failure packet, be RERR, include following data item: Type, Src_Addr, Dest_Addr, Cur_Len, Src_Degree, Dest_Degree, Addr_1～Addr_X, Degree_1～Degree_X, Error_Up_Addr and Error_Down_Addr, wherein the implication of Type, Src Addr, Dest_Addr, Src_Degree, Dest_Degree, Addr_1～Addr_X and Degree_1～Degree_X as previously mentioned, and Cur_Len represents from the node that the makes a mistake jumping figure of node up till now; Error_Up_Addr represents the node address of finding that next-hop node can't arrive; Error_Down_Addr represents the node address of the next-hop node that can't arrive;

4) business data packet includes following data item: Type, Src_Addr, Dest_Addr, Cur_Len, Src_Degree, Dest_Degree, Addr_1～Addr_X, Degree_1～Degree_X, Traffic_Data and Alpha, wherein the implication of Type, Src_Addr, Dest_Addr, Cur_Len, Src_Degree, Dest_Degree, Addr_1～Addr_X, Degree_1～Degree_X as previously mentioned, Traffic_Data represents the upper-layer service data of business data packet; Alpha represents the require parameter of user for the time-delay of business data packet, packet loss, bandwidth;

Set following parameter and relevant intermediate variable thereof, deposit in respectively in the memory in each node:

The time-out time threshold value in path life-span, its expression: if during this period of time, node does not monitor any traffic data bag along this path, and then node thinks that this path lost efficacy, thus with this path, promptly route is deleted from the routing cache district;

The routing cache district, it refers to preserve in the memory of each node the memory space of route;

Data packet buffer, it refers to preserve in the memory of each node the memory space of upper-layer service packet;

The maximum of the predefined business data packet of network allows to send number of times;

The maximum that contains in the predefined route of network allows the node number;

Following three kinds of algorithm routines of the Route Selection parameters R SM of a route of designing and calculating calculate three kinds of routing parameter RSM ₁, RSM ₂And RSM ₃, its calculation procedure together with routing criterion is deposited in the memory of each node, described routing criterion is meant: when α value value hour, the RSM value is got RSM ₃, in the routing cache district, select one and have minimum RSM ₃The route of the arrival destination node of value; When the α value was big, the RSM value was from RSM ₁Or RSM ₂In choose one, when the RSM value is got RSM ₁The time, in the routing cache district, select one and have minimum RSM ₁The route of the arrival destination node of value; Described RSM ₁, RSM ₂And RSM ₃Computational methods as follows:

${\mathrm{RSM}}_1=\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i,$

${\mathrm{RSM}}_2=(H+1)\sqrt{\frac{1}{M-1}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{(D_i-\stackrel{\&OverBar;}{D})}^2},$ Wherein $\stackrel{\&OverBar;}{D}=\frac{1}{M}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i,$

${\mathrm{RSM}}_3=(H+1)[\frac{1}{M}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{D}_i+\mathrm{\&alpha;}\sqrt{\frac{1}{M-1}\underset{i=1}{\overset{M}{\mathrm{\&Sigma;}}}{(D_i-\stackrel{\&OverBar;}{D})}^2}],(0<\mathrm{\&alpha;}<1)$

Wherein, M is the node number that comprises in the route; H is the jumping figure that comprises in the route, H=M-1; D _iN jumping degree for i node of route flow warp; D is the average N jumping degree of M node of route flow warp; α is user's appointment in business data packet, it is the parameter that the user sets according to time-delay, packet loss, the bandwidth of packet, simultaneously, this parameter has shown the stress degree of upper-layer service characteristic to the standard variance of the competition node number of the total competition node number of route and each node, 0＜α＜1, when standard variance being stressed degree hour, it is littler that the α value is wanted, otherwise then the α value is bigger;

Described route method for searching contains following each step successively:

(1) when certain node produces a upper-layer service packet, this node just becomes source node, and it has judged whether that at first packet sends, if having, then this business data packet is inserted in the data packet buffer, waited for after this packet transmission finishes sending current data packet again; If there is not packet to send, then it selects an effective route that arrives destination node according to above-mentioned RSM routing criterion from the routing cache district of oneself;

(2) if do not have effective route from this node in the routing cache district of this node, just initiate the route search process, promptly this node is packed among the RREQ also broadcast transmission to self address and N jumpings degree; If exist, just change route maintenance procedure over to;

(3) intermediate node is after receiving RREQ, just checks whether receive this RREQ first, if non-ly receive first, just abandons this RREQ, and search process finishes; If receive this RREQ first, intermediate node just is packed into self address and N jumping degree among the RREQ and transmits;

(4) after destination node is received RREQ, each RSM value according to each paths in predetermined routing criterion and routing cache district in the memory, select best route, selected each paths comprises that also destination node extracts the path that arrives source node that node corresponding address and N jumping degree form from RREQ;

(5) destination node is packed into the best routing iinformation that comprises each node address and N jumping degree among the RREP and to source node and sends;

(6) after the intermediate node of best route receives RREP, just go to upgrade the N jumping degree information of node corresponding among the RREP, and be forwarded to the upstream node that comprises route among the RREP with oneself according to the N jumping degree of own node;

(7) after source node receives RREP, just obtain an effective route from the source node to the destination node, and deposit in the routing cache device of oneself, the route search process finishes;

Described route maintenance method contains following each step successively:

(1) the source node effective route from the source node to the destination node that can obtain according to above-mentioned steps (7), also can be according to producing effective route that the back directly obtains at the upper-layer service packet from the routing cache district in the above-mentioned steps (2), node address and corresponding N jumping degree information are packed in the current business data packet that will send, and this business data packet is sent;

(2) source node is if find that its down link can't proper communication, and promptly next-hop node can't arrive, and just upgrades the routing iinformation in the routing cache district, and the transmission number of times of counting current business packet, changes step (11); Source node is if find that its down link can proper communication, then step (3);

(3) intermediate node goes to upgrade in the business data packet N jumping degree information with own corresponding node according to the N jumping degree of own node, and transmits this business data packet according to the routing iinformation in the business data packet;

(4) intermediate node can't be kept proper communication if find its down link, and promptly next-hop node can't arrive, and just upgrades the routing iinformation of own node, and makes the transmission number of times of this business data packet add 1, changes step (5) then; If all intermediate nodes all can be kept proper communication, then destination node can receive business data packet, and route maintenance procedure finishes;

(5) intermediate node checks whether the repeating transmission number of times of current business packet reaches the transmission number of times that network sets in advance, if reach, then abandons this packet, sends the routing failure packet to source node then, and promptly RERR changes step (7); If do not reach, then judge whether there are other effective routes in the routing cache district;

(6) if there are other effective routes in the routing cache district, then send the current business packet along new route, route maintenance procedure finishes; If do not exist, then abandon the current business packet, send RERR to source node then;

(7) receive the intermediate node of RERR, upgrade corresponding routing iinformation in the local routing cache district, and, then RERR is forwarded to the upstream node that comprises route among this RERR with corresponding N jumping degree information among the N jumping degree information updating RERR of local node;

(8) after source node receives RERR, upgrade the routing iinformation in the local routing cache district;

(9) source node checks that whether to still have business data packet etc. in the data buffer zone to be sent, if having, then checks whether there are other effective routes in the routing cache district, changes step (10); If there is not in the data buffer zone business data packet etc. to be sent, then route maintenance procedure finishes;

(10) if source node finds do not have effective route in the routing cache district, then initiate the route search process again, route maintenance finishes; If find to have effective route in the routing cache district, then business data packet sends along new route, and route maintenance procedure finishes;

(11) source node judges whether the transmission number of times of current business packet reaches the predetermined transmission number of times of network, if reach, then abandons this packet, changes step (9); If do not reach, then judge whether there are other effective routes in the routing cache district, change step (10).

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