CN103561039A - Distributed type position service routing method of vehicle-mounted Ad Hoc network - Google Patents

Abstract

The invention discloses a distributed type position service routing method of a vehicle-mounted Ad Hoc network. Position servers are deployed in the middle of a road network. The position servers receive the position messages reported by mobile nodes in a region within the jurisdiction and store the position messages. Position messages of all mobile nodes in the whole network are obtained through periodical information interchange between the position servers. When the nodes need communication, source nodes send data to the position servers, the position servers obtain position servers where target nodes are located through a whole network node message list, a router between the position servers is set up to conduct data forwarding, and finally the position servers where the target nodes are located forward data to the target nodes. By the adoption of the distributed type position service routing method, the number of position messages in network broadcast can be remarkably reduced, and the delivery success rate of data can be improved.

Description

A kind of distributed location service method for routing of vehicle-mounted Ad Hoc network

Technical field

The invention belongs to intelligent transport technology field, more specifically say, relate to a kind of distributed location service method for routing of vehicle-mounted Ad Hoc network.

Background technology

In intelligent transport technology field, vehicle-mounted Ad Hoc(is point-to-point) network is as a special subset of Ad Hoc network, except thering is traditional Ad Hoc network without the features such as center, self-organizing, multi-hop, also there is node motion and be subject to the features such as road topology and driving behavior affect.But due to the vehicle node high-speed mobile in vehicle-mounted Ad Hoc network, thereby cause network topology change rapid, easily cause the phenomenons such as interrupted communication link, make originally for the Routing Protocol of Ad Hoc network design is no longer applicable.Consider the feature of vehicle-mounted Ad Hoc network, have researcher to propose location-based Routing Protocol.Location-based Routing Protocol carries out routing decision according to node self-position information, neighbor node positional information and destination node positional information, do not need maintaining routing list, reduce routing cost, be therefore highly suitable for network topology change vehicle-mounted Ad Hoc network rapidly.In location-based Routing Protocol, the distribution of positional information need to realize by location-based service agreement, so location-based service agreement is to realize the prerequisite of location-based Routing Protocol.How obtaining efficiently and accurately the positional information of destination node and effectively merge with Routing Protocol, is one of crucial research contents of vehicle-mounted Ad Hoc network in order to improve the delivery success rate of data.

In the location-based service agreement proposing at present, according to implementation, can roughly be divided into two classes: the location-based service agreement based on inundation and the location-based service agreement based on intersection.

Location-based service agreement based on inundation can be divided into proactive protocols and passive type agreement.In proactive protocols, in road network, each node is regularly inquired about GPS navigation system and is obtained self-position information, and by this information inundation to each node in network, each the node maintenance one tension position information table in network, for recording the positional information of other nodes of network.When needs are communicated by letter, the direct inquiring position information table of source node obtains the positional information of destination node and carries out route, it represents that agreement mainly contains SLS (Simple Location Service), referring to Basagni S, Chlamtac I, Syrotiuk V.R and Woodward B.A.A Distance Routing Effect Algorithm for Mobility[J] .Proc of ACM MobiCom, 2010.10, vol.18. in passive type agreement, when node need to be communicated by letter, this node within the specific limits Query Information of inundation is inquired about the positional information of destination node, it represents that agreement mainly contains RLS (Reactive Location Service), referring to Camp T, Boleng G and Wilcox L.Location Information Services in Mobile Ad Hoc Networks[J], Proc of the IEEE International Conference on Communications, 2002.

Location-based service agreement based on intersection can be divided into again agreement and the agreement based on hash function based on ranks.In the agreement based on ranks, node in each node selection North and South direction in network in certain area upgrades the positional information of oneself as location server, in the time of need to communicating by letter, source node sends along east-west direction the positional information that inquiry packets is inquired about destination node, and by the positional information of meeting to obtain destination node of inquiry packets and a certain location service node, it represents that agreement mainly contains XYLS (Column-Row Location Service), referring to Haas Z.J and Liang B.Ad Hoc Mobility Management with Uniform Quorum System[S] .IEEE/ACM Transactions on Networking, 1999.4, vol.7. in the agreement based on hash function, network is divided into grid, and location server is selected by hash function, each node selects one or more location servers to upgrade the positional information of oneself, need the node of communication by inquiring about these location servers, to obtain the positional information of destination node, it represents that agreement has GLS (Grid Location Service).

Yet the location-based service agreement based on inundation is extensive inundation mechanism distribution positional information as SLS adopts, its load expense is larger.For node motion speed, vehicle-mounted Ad Hoc network that network size is larger, adopt the location-based service agreement based on intersection such as GLS need to spend a large amount of expenses for chosen position server, affected the extensibility of agreement.In addition, the position service agreements such as SLS, RLS, XYLS, GLS are applicable to node and arbitrarily change moving direction and the fixing mobile context of motion track not, do not consider the impact of barrier on communication quality such as building in actual road network.In vehicle-mounted Ad Hoc network, the movement of vehicle node is limited by road topology and traffic rules, and motion track affected by driving behavior larger, therefore above-mentioned location-based service agreement can not well be applicable to vehicle-mounted Ad Hoc network.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, a kind of distributed location service method for routing of vehicle-mounted Ad Hoc network is provided, reduce the positional information quantity of propagating in network, improve the delivery success rate of data.

For achieving the above object, the distributed location service method for routing of the vehicle-mounted Ad Hoc of the present invention network, comprises the following steps:

S1: according to road network situation deployed position server, location server is followed the agreement identical with mobile node;

S2: when vehicle-mounted Ad Hoc netinit, each location server is inundation in network-wide basis by self ID and self-position information, and other location servers and the mobile node that receive this positional information store the ID of this location server and positional information into local location server list; After this new access mobile node is broadcasted a query messages when accessing for the first time, by the location server that receives this query messages, the information of all location servers is sent to this mobile node;

S3: each mobile node is with fixed cycle T ₁self-position is positioned, select a location server to use location-based method for routing to report self ID and positional information;

S4: location server is saved to local jurisdiction node location list by the ID of the mobile node receiving and positional information, and location server is with fixed cycle T ₂carry out renewal and the maintenance of jurisdiction node location list of entries;

S5: each location server is used location-based method for routing, with fixed cycle T ₃mutual jurisdiction node location list, makes each location server can obtain ID and positional information and the affiliated location server ID thereof of the whole network mobile node, is saved to local the whole network node location list;

S6: while having mobile node to communicate by letter, communication means is:

S6.1: source node is used location-based method for routing to carry the location server of the data retransmission of destination node ID to its last reporting position information;

S6.2: receive the location server of data according to the list of destination node ID inquiry jurisdiction node location, if there is destination node, enter step S6.4, if there is no, enter step S6.3;

S6.3: inquire about the location server under this destination node in the list of the whole network node location, use location-based method for routing to the location server forwarding data under this destination node, return to step S6.2;

S6.4: this location server is used location-based method for routing to destination node forwarding data.

Further, cycle T in described step S3 ₁adopt following formula to calculate:

$T_1=\frac{R_{\mathrm{Tr}}}{\mathrm{\α}\×\stackrel{\‾}{v}}$

Wherein, R _trfor the transmission range of this mobile node,

for the average translational speed of this mobile node, α is default scale factor.

Further, in step S3, the system of selection of location server is: mobile node is selected the location server nearest with it in the server list of position, if there are a plurality of nearest location servers, according to the moving direction of this mobile node, select close location server, if still there are a plurality of location servers, select arbitrarily one.

Further, cycle T in step S4 ₂adopt following formula to calculate:

$T_2=\frac{R_{\mathrm{Tr}}^{*}}{\mathrm{\α}\×\stackrel{\‾}{V}}$

$\stackrel{\‾}{V}=\left(\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\‾}{v}}_k\right)/n$

Wherein,

for the transmission range of this location server, for the average translational speed of all mobile nodes in this location server region within the jurisdiction, n is jurisdiction number of nodes, be the average translational speed of k node, α is default scale factor.

Further, in step S4, the renewal of jurisdiction node location list of entries and the concrete grammar of maintenance are:

If location server is in cycle T ₂inside receive the new positional information of existing node in jurisdiction node listing, when expired, the positional information of this node is upgraded;

If location server is in cycle T ₂inside do not receive in jurisdiction node listing the new positional information of existing node, the relevant entry of this node in delete list when expiring;

If location server is in cycle T ₂inside receive the positional information of the new node not recorded in jurisdiction node listing, when expired, set up new entry for preserving the relevant information of newly added node.

Further, in step S6.3, when the location server forwarding data under destination node, the preferential location server that adopts when the selection of via node.

The distributed location service method for routing of the vehicle-mounted Ad Hoc of the present invention network, at road network deployed position server, location server receives and stores the positional information that in region within the jurisdiction, mobile node reports, and between location server, regularly carry out the positional information that information interaction obtains all mobile nodes of the whole network, when node need to be communicated by letter, source node sends data to location server, location server obtains the location server under destination node by the list of the whole network nodal information, the route of setting up again between location server is carried out data retransmission, last by the location server under destination node to destination node forwarding data.

Adopt the present invention, can obtain following beneficial effect:

(1), each mobile node only need be to location server reporting position information, location server carries out information interaction and obtains the whole network node location information, can significantly reduce the positional information quantity of propagating in network, reduces network resource consumption;

(2) when, mobile node is communicated by letter, between mobile node, without setting up route, only needs and affiliated location server are set up route, then carry out route and transfer of data by two fixing location servers, can reduce route difficulty, improve the delivery success rate of data.

Accompanying drawing explanation

Fig. 1 is the application scenarios schematic diagram of the embodiment of the present invention;

Fig. 2 is the schematic diagram of node chosen position server in the embodiment of the present invention;

Fig. 3 is a kind of embodiment flow chart during node communication in the present invention.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described, so that those skilled in the art understands the present invention better.Requiring particular attention is that, in the following description, when perhaps the detailed description of known function and design can desalinate main contents of the present invention, these are described in here and will be left in the basket.

Embodiment

The distributed location service method for routing of the vehicle-mounted Ad Hoc of the present invention network has proposed a kind of position information service method, specifically comprises:

S101: according to road network situation deployed position server, location server is followed the agreement identical with mobile node.In actual applications, need to, according to concrete road network situation and ambient environmental conditions etc. because usually considering the deployment of location server, conventionally be arranged on place, crossing.Fig. 1 is the application scenarios schematic diagram of the embodiment of the present invention.As shown in Figure 1, the present embodiment has all been disposed a location server in each crossroad, other mobile nodes in each location server and network are the equal of vehicle, follow the agreement identical with mobile node, also dispose navigation system, also need to configure certain memory capacity and computing capability, the same with mobile node, location server also can distribute fixedly ID for mark identity.

S102: when vehicle-mounted Ad Hoc netinit, each location server is inundation in network-wide basis by self ID and self-position information, and other location servers and the mobile node that receive this positional information store the ID of this location server and positional information into local location server list; After this new access mobile node is broadcasted a query messages when accessing for the first time, by the location server that receives this query messages, the information of all location servers is sent to this mobile node.Table 1 is location server list.

Location server ID

Positional information

Table 1

By this step, completed the location information service of location server.If there is afterwards new location server to add network, fashionablely also self ID and self-position information should be carried out to inundation in network-wide basis adding.

S103: each mobile node is with fixed cycle T ₁self-position is positioned, select a location server to use location-based method for routing to report self ID and positional information.Location-based method for routing adopts prior art, according to the node between distance far and near selection sending node and receiving node as via node, by the mode of single-hop or multi-hop, carry out communication.

Cycle T ₁can directly arrange as required, also adopt following formula to calculate:

$T_1=\frac{R_{\mathrm{Tr}}}{\mathrm{\α}\×\stackrel{\‾}{v}}$

Wherein, R _trfor the transmission range of this mobile node,

for the average translational speed of this mobile node, the scale factor of α for arranging.

During the location server of report, the factors such as position that can position-based server, signal strength signal intensity, jurisdiction number of nodes are selected in the choice.The method of using in the present embodiment is: mobile node is selected the location server nearest with it in the server list of position, if there is a plurality of nearest location servers, according to the moving direction of this mobile node, select close location server, if still there are a plurality of location servers, select arbitrarily one.

Fig. 2 is node chosen position server schematic diagram in the embodiment of the present invention.As shown in Figure 2, certain mobile node X in the present embodiment between location server 10 and location server 20 needs reporting position information, because it is just positioned at the center of two location servers at present, there are two nearest location servers, because mobile node X sails to the direction of location server 10, meeting is near location server 10, so chosen position server 10 reports.

S104: location server is saved to local jurisdiction node location list by the ID of the mobile node receiving and positional information, and location server is with fixed cycle T ₂carry out renewal and the maintenance of jurisdiction node location list of entries.Table 2 is the lists of jurisdiction node location.

Jurisdiction node ID

Positional information

Table 2

Same, cycle T ₂can directly arrange as required, also can adopt following formula to calculate:

$T_2=\frac{R_{\mathrm{Tr}}^{*}}{\mathrm{\α}\×\stackrel{\‾}{V}}$

$\stackrel{\‾}{V}=\left(\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\‾}{v}}_k\right)/n$

Wherein,

for the transmission range of this location server,

for the average translational speed of all mobile nodes in this location server region within the jurisdiction, n is jurisdiction number of nodes,

be the average translational speed of k node, α is default scale factor.Adopting computing cycle T in this way ₂time, all mobile nodes in region within the jurisdiction need to report to this location server the average translational speed of this mobile node.

When carrying out the renewal of jurisdiction node location list of entries and safeguarding, with fixed cycle T ₂upgrade and safeguard, every T ₂carry out once-through operation, the positional information that all the other times only receive and buffer memory mobile node reports, concrete grammar is:

If location server is in cycle T ₂inside receive the new positional information of existing mobile node in jurisdiction node listing, when expired, the positional information of this node is upgraded;

If location server is in cycle T ₂inside do not receive in jurisdiction node listing the new positional information of existing mobile node, the relevant entry of this node in delete list when expiring;

If location server is in cycle T ₂inside receive the positional information of the new mobile node not recorded in jurisdiction node listing, when expired, set up new entry for preserving the relevant information of newly added node.

S105: each location server is used location-based method for routing, with fixed cycle T ₃mutual jurisdiction node location list, makes each location server can obtain ID and the positional information of the whole network mobile node, and affiliated location server ID, is saved to local the whole network node location list.Cycle T ₃arrange according to actual needs.

By above step, realized the service of each node location information in vehicle-mounted Ad Hoc network, the positional information of all preserving each location server in each mobile node, the positional information of preserving all mobile nodes in the whole network in each location server.In the present invention, each mobile node only need to be selected a location server reporting position information, each location server obtains the positions of mobile nodes information of the whole network again by information interaction, thereby reduces the positional information quantity of propagating in network, reduces network resource consumption.

When having mobile node to communicate by letter, the positional information that can use said method to obtain communicates.Fig. 3 is a kind of embodiment flow chart during node communication in the present invention.As shown in Figure 3, in the present invention, node communication method is:

S301: source node reporting position information: source node is used location-based method for routing to carry the location server of the data retransmission of destination node ID to its last reporting position information.

In the present invention, source node does not need the route of foundation and destination node, only needs the route of foundation and belonging positions server, and belonging positions server is the location server of mobile node the last time reporting position information.Take scene shown in Fig. 1 as example, suppose that in Fig. 1, vehicle S is source node, destination node is vehicle D, the location server of the last reporting position information of vehicle S is location server 10, and vehicle S is used location-based method for routing that the data that carry destination node ID are sent to location server 10.Broken circle in Fig. 1 represents each node one jumping scope, and visible vehicle S cannot directly send to location server 10, need to pass through other vehicles, and for example vehicle M is forwarded to location server 10 as via node.

S302: receive the location server of data according to the list of destination node ID inquiry jurisdiction node location.

S303: the location server that receives data judges whether the list of jurisdiction node location exists destination node, if there is destination node, enters step S305, if there is no, enters step S304.

Location server 10, after receiving data, is searched vehicle D in the list of jurisdiction node location, according to not having vehicle D in the 10 jurisdiction node location lists of location server in the present embodiment shown in Fig. 1, therefore enters step S304.

S304: forward the data to the affiliated location server of destination node: this location server is inquired about the location server under this destination node in its whole network node location list, use location-based method for routing to the location server forwarding data under this destination node, return to step S302.

Location server 10 is the location server under enquiring vehicle D in the list of the whole network node location, and what suppose now that inquiry obtains is location server 30, and location server 10 is to location server 30 forwarding datas so.Because location server is fixedly installed, therefore in repeating process, can preferentially adopt location server as via node, to guarantee higher transmission quality.

Location server 30 receives after data, to in the list of jurisdiction node location, search vehicle D equally, because vehicle D in data transmission procedure before is still moving, suppose that now vehicle D is not in location server 30 regions within the jurisdiction, location server 30 also needs to continue forwarding data so.Suppose that location server now 30 obtains the location server 40 under vehicle D now through information interactions in the list of the whole network node location, to location server 40 forwarding datas.Location server 40 receives after data, can obtain vehicle D in jurisdiction node location list query, enters step S305.

S305: this location server is used location-based method for routing to destination node forwarding data.In the present embodiment, location server 40, according to the positional information of vehicle D, adopts location-based method for routing, according to the far and near mode by single-hop or multi-hop of distance, data are sent to destination node D.As can be seen from Figure 1, vehicle D, outside a jumping scope of location server 40, therefore needs to select one or more vehicles to forward as via node in the present embodiment.

Visible, when the present invention communicates by letter at mobile node, what adopt is a kind of by the distributed location service method for routing of location information service and location-based method for routing fusion use, location server can obtain by the destination node information of storing in the list of the whole network node location its current affiliated location server, after forwarding the data to the location server under it, to destination node, forward again, can effectively improve the delivery success rate of data.

Although above the illustrative embodiment of the present invention is described; so that those skilled in the art understand the present invention; but should be clear; the invention is not restricted to the scope of embodiment; to those skilled in the art; as long as various variations appended claim limit and definite the spirit and scope of the present invention in, these variations are apparent, all utilize innovation and creation that the present invention conceives all at the row of protection.

Claims (6)

1. a distributed location service method for routing for vehicle-mounted Ad Hoc network, is characterized in that, comprises the following steps:

S1: according to road network situation deployed position server, location server is followed the agreement identical with mobile node;

S2: when vehicle-mounted Ad Hoc netinit, each location server is inundation in network-wide basis by self ID and self-position information, and other location servers and the mobile node that receive this positional information store the ID of this location server and positional information into local location server list; After this new access mobile node is broadcasted a query messages when accessing for the first time, by the location server that receives this query messages, the information of all location servers is sent to this mobile node;

S3: each mobile node is with fixed cycle T ₁self-position is positioned, select a location server to use location-based method for routing to report self ID and positional information;

S4: location server is saved to local jurisdiction node location list by the ID of the mobile node receiving and positional information, and location server is with fixed cycle T ₂carry out renewal and the maintenance of jurisdiction node location list of entries;

S5: each location server is used location-based method for routing, with fixed cycle T ₃mutual jurisdiction node location list, makes each location server can obtain ID and positional information and the affiliated location server ID thereof of the whole network mobile node, is saved to local the whole network node location list;

S6: while having mobile node to communicate by letter, communication means is:

S6.1: source node is used location-based method for routing to carry the location server of the data retransmission of destination node ID to its last reporting position information;

S6.2: receive the location server of data according to the list of destination node ID inquiry jurisdiction node location, if there is destination node, enter step S6.4, if there is no, enter step S6.3;

S6.3: inquire about the location server under this destination node in the list of the whole network node location, use location-based method for routing to the location server forwarding data under this destination node, return to step S6.2;

S6.4: this location server is used location-based method for routing to destination node forwarding data.

2. distributed location service method for routing according to claim 1, is characterized in that, cycle T in described step S3 ₁adopt following formula to calculate:

$T_1=\frac{R_{\mathrm{Tr}}}{\mathrm{\α}\×\stackrel{\‾}{v}}$

Wherein, R _trfor the transmission range of this mobile node,

for the average translational speed of this mobile node, α is default scale factor.

3. distributed location service method for routing according to claim 1, it is characterized in that, in described step S3, the system of selection of location server is: mobile node is selected the location server nearest with it in the server list of position, if there are a plurality of nearest location servers, according to the moving direction of this mobile node, select close location server, if still there are a plurality of location servers, select arbitrarily one.

4. distributed location service method for routing according to claim 1, is characterized in that, cycle T in described step S4 ₂adopt following formula to calculate:

$T_2=\frac{R_{\mathrm{Tr}}^{*}}{\mathrm{\α}\×\stackrel{\‾}{V}}$

$\stackrel{\‾}{V}=\left(\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\‾}{v}}_k\right)/n$

Wherein,

for the transmission range of this location server,

for the average translational speed of all mobile nodes in this location server region within the jurisdiction, n is jurisdiction number of nodes, be the average translational speed of k node, α is default scale factor.

5. distributed location service method for routing according to claim 1, is characterized in that, in described step S4, the renewal of jurisdiction node location list of entries and the concrete grammar of maintenance are:

If location server is in cycle T ₂inside receive the new positional information of existing node in jurisdiction node listing, when expired, the positional information of this node is upgraded;

If location server is in cycle T ₂inside do not receive in jurisdiction node listing the new positional information of existing node, the relevant entry of this node in delete list when expiring;

If location server is in cycle T ₂inside receive the positional information of the new node not recorded in jurisdiction node listing, when expired, set up new entry for preserving the relevant information of newly added node.

6. distributed location service method for routing according to claim 1, is characterized in that, in described step S6.3, and when the location server forwarding data under destination node, the preferential location server that adopts while selecting via node.

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