CN105554705A - AD HOC network service system based on routing and location awareness - Google Patents

Abstract

The invention discloses an AD HOC network service system based on routing and location awareness. The AD HOC network service system comprises a service platform module, a registration module and a service discovery module, wherein the service platform module is mainly used for storing registered service information, namely, service properties and properties of nodes providing services for the service discovery module to call; in order to provide a single entry point, the registration module collects all properties and stores the properties in the service platform module; the information is supplied to a resolver in the service discovery module in conjunction with a semantic service identifier in service registration; and all known local or remote services are cached temporarily in a service list. Through adoption of the AD HOC network service system, the service discovery efficiency can be increased, and the message overhead is reduced. A request node can be assisted in discovering a service provider being closest to the request node by awareness, so that the aim of performing rapid rescue is fulfilled. Compared with service discovery methods of the same type, the method is more superior on the aspects of time delay and message overhead.

Description

A kind of AD HOC network service system based on route and location aware

Technical field

The present invention relates to network service system technical field, particularly relate to a kind of ADHOC network service system based on route and location aware.

Background technology

ADHOC network is the provisional autonomous system of the multi-hop that one group of mobile node with wireless transmitter forms, and can be widely used in the emergency relief after the natural calamity such as earthquake, hurricane, have broad application prospects.Thus, how to find timely and effectively in ADHOC network and to use service, be the key realizing the practical application of ADHOC network, is also the difficult problem always seeking in recent years to solve.Form the SLP of standard at present, the service discovery methods such as Jini, SSDP, Salutation do not consider the characteristic of ADHOC network self, be not suitable for applying in ADHOC network, but, the problem of following two aspects of above-mentioned service discovery method ubiquity: first, they all do not have well and Routing Protocol combines, thus, before service discovery, need advanced row route discovery, the time delay of service discovery is longer, and message overhead is larger.Secondly, they do not consider the non-functional requirement (i.e. service quality) of service.And service quality (QualityofService, QoS) reflects the ability that a service is met consumers' demand, it is the important indicator that ADHOC network service performance is evaluated.Such as, because above-mentioned service discovery method cannot determine nearest ISP, the rescue to service requester may be incured loss through delay, and in earthquake disaster, wounded are badly in need of an ambulance, he wishes to find nearest one instead of need to find multiple, so just to have taken many troubles to people.

Summary of the invention

Based on the technical problem that background technology exists, the present invention proposes a kind of ADHOC network service system based on route and location aware.

A kind of ADHOC network service system based on route and location aware that the present invention proposes, comprise services platform module, Registering modules and service discovery module, services platform module mainly stores the information on services of registration, i.e. Service Properties and the nodal community that service is provided, call for service discovery module, in order to provide single entrance, Registering modules is collected all attributes and is stored in services platform module by them, be combined in the semantic service indications in service registry, these information are supplied to the resolver in service discovery module, in service list, the service of all known local and remote is all by temporal cache, use for resolver, when service discovery module receives local or remote service request, resolver performs matching process, the most backward requesting node return service return information,

The flow process of this ADHOC network service system specifically comprises the following steps:

S1, service a: service is made up of parts such as COS, service name, service describing, Service Properties and nodal communitys, and its formal definitions is as following formula:

S＝＜ST,SN,SD,SA,NA＞(1)

In formula (1), S represents service; The type of ST representative service, the title of SN representative service, the descriptor of SD representative service, the attribute of SA representative service, NA representative provides the nodal community of service;

S2, service request: the formal definitions of service request is as following formula:

SREQ＝＜ST _Q,SA _Q,NA _Q,D _Q,A,R _Q＞(2)

In formula (2), SREQ represents service request, ST _qrepresent the type of request service, determine the application of asking thus, SA _qthe Service Properties of representative request, NA _qthe nodal community of representative request, D _qrepresent indications, A represents indications, R _qthe reserved indications of representative;

S3, service is replied:

SREP＝＜SN _P,SD _P,D _P,G,R _P＞(3)

In formula (3), SREP representative service is replied, SN _pthe title of representative service, SD _pthe descriptor of representative service, indications D _pbe used for arranging the descriptor whether message comprises service, acquiescence does not comprise, and whether indications G is used for carrying out identification node is a gateway, R _pfor reserved indications, to tackle following needs;

S4, location aware: realize location aware function in service discovery, two kinds of methods are had to realize, first method is coal addition position perception information in SREQ message, second method is coal addition position information in SREP message, relative to first method, second method has two large advantages, first, the method can reduce network traffics, because service request SREQ message is that the situation broadcasted sends to all nodes, and service reply SREP message is that clean culture sends to requesting node, as can be seen here, adopt second method effectively can reduce the data volume of Internet Transmission, secondly, service availability is good, concerning service requesting node, it can receive all SREP message, and the most suitable ISP of position-based Information Selection, multiple service providing node can be selected even, adopt first method, owing to adding location aware in service request SREQ message, the situation of not serving reply can be caused to occur, this is for service requester, very fatal, namely second method is adopted, i.e. coal addition position information in SREP message, thus, reserved indications R in formula (3) _pby positional information L _psubstitute, obtain formula (4):

SREP＝＜SN _P,SD _P,D _P,G,L _P＞(4)

S5, Service Matching, according to the service request received, resolver extracts the COS ST obtaining asking _qand attribute, attribute comprises Service Properties SA _qwith nodal community NA _q, by COS ST _qassessment, can determine ask application, SA _qand NA _qassessment by regenerating attribute-operation-value table, and then and the context sight collected in registration process of service platform carry out assessment comparison and come;

S6, service discovery, the service request according to node finds required service fast and accurately.

Preferably, the SA in described S1 is abstract is the pattern of attribute-operation-value, and wherein, attribute is a title; Operation represents attribute and the relation both value; The specific restriction of a value expression attribute.

Preferably, the reserved indications R in described S2 _qbe 0 by default setting.

Preferably, add SREP message in described S3 to expand the RREP message in AODV Routing Protocol.

Preferably, the longitude and latitude of described service requesting node A is made to be (α ₁, β ₁), from the positional information L of SREP _pthe longitude and latitude of the service providing node of middle extraction is (α ₂, β ₂), then the distance d of node A and Node B is obtained by following formula:

Δα＝α ₂-α ₁(5)

Δβ＝β ₂-β ₁(6)

$\begin{array}{c}d=arc\sin \left(\sqrt{{\sin }^2\left(\frac{\mathrm{\Δ}\mathrm{\β}}{2}\right)+\cos \left({\mathrm{\β}}_1\right)\cos \left({\mathrm{\β}}_2\right){\sin }^2\left(\frac{\mathrm{\Δ}\mathrm{\α}}{2}\right)}\right)\\ \×2R\end{array}---\left(7\right).$

In the present invention on the existing ADHOC network service discovery method basis of analysis, based on AODV Routing Protocol, service discovery and route discovery are merged into a process, while route discovery, carry out service discovery, service discovery efficiency can be improved, reduce message overhead; Secondly, the method is replied in (SREP) message in service and is introduced longitude and latitude positional information, the ISP that requesting node perception detective distance oneself is nearest can be helped, reach Quick rescue object, time delay can not only be shortened, reduce message overhead, the ISP that requesting node perception detective distance oneself is nearest can also be helped, be applicable to the rescue after the natural calamity such as earthquake, hurricane.The experiment show validity of SDRLA service discovery method, improves the relieved possibility of people greatly, reduces the possibility of loss.

Accompanying drawing explanation

Fig. 1 is the service discovery Organization Chart of a kind of ADHOC network service system based on route and location aware that the present invention proposes;

Fig. 2 is the service discovery process figure of a kind of ADHOC network service system based on route and location aware that the present invention proposes;

Fig. 3 is a kind of time delay of ADHOC network service system based on route and location aware of proposing of the present invention and the graph of a relation of number of nodes;

Fig. 4 is a kind of message number of ADHOC network service system based on route and location aware of proposing of the present invention and the graph of a relation of number of nodes.

Embodiment

Below in conjunction with specific embodiment, further explanation is done to the present invention.

With reference to Fig. 1-4, a kind of ADHOC network service system based on route and location aware that the present invention proposes, comprise services platform module, Registering modules and service discovery module, services platform module mainly stores the information on services of registration, i.e. Service Properties and the nodal community that service is provided, call for service discovery module, in order to provide single entrance, Registering modules is collected all attributes and is stored in services platform module by them, be combined in the semantic service indications in service registry, these information are supplied to the resolver in service discovery module, in service list, the service of all known local and remote is all by temporal cache, use for resolver, when service discovery module receives local or remote service request, resolver performs matching process, the most backward requesting node return service return information,

The flow process of this ADHOC network service system specifically comprises the following steps:

S1, service a: service is made up of parts such as COS, service name, service describing, Service Properties and nodal communitys, and its formal definitions is as following formula:

S＝＜ST,SN,SD,SA,NA＞(1)

In formula (1), S represents service; The type of ST representative service, the title of SN representative service, the descriptor of SD representative service, the attribute of SA representative service, NA representative provides the nodal community of service, in order to describe the context sight of service, we by abstract for the attribute SA of service be the pattern of attribute-operation-value, wherein, attribute is title, such as temperature, a space coordinates etc.; Operation represents attribute and the relation both value, such as, equal, be less than; The specific restriction of a value expression attribute.Such as the case of this attributed scheme of battery, >, 60}, the dump energy that it represent node should be greater than 60%;

S2, service request: the formal definitions of service request is as following formula:

SREQ＝＜ST _Q,SA _Q,NA _Q,D _Q,A,R _Q＞(2)

In formula (2), SREQ represents service request, ST _qrepresent the type of request service, determine the application of asking thus, SA _qthe Service Properties of representative request, NA _qthe nodal community of representative request, utilizes indications D _q, node can point out that whether the result returned is containing service describing.We do not define service name and service describing in service request, because service request is multicast, flow is too large.The substitute is, in service is replied, service is described, like this, replying due to service is clean culture, huge network traffics burden can not be caused as service request, greatly save network traffics, and, service requester can also be helped after service discovery to select most suitable service.Utilize indications A, can determine whether to provide the node of same services the service of obtaining to reply from all, if so, service request can constantly be broadcasted in a network, even if there has been node to respond this service request.Finally, reserved indications R _qto tackle following needs, and be 0 by default setting, we expand route requests (RREQ) message in AODV Routing Protocol by adding service request (SREQ) message, make source node carry out service request while route requests arrives destination node route.One after expansion important feature all services is replied all to carry out buffer memory at intermediate node.Like this, when remaining node sends service request to these intermediate nodes, these nodes can make reply to service request immediately.If do not need to return routing iinformation, intermediate node can answer service request information (SREQ) alone, does not but need the participation of route request information (RREQ).Consequently, after expanding route request information (RREQ), if node request service, ask to carry out flooded broadcast in the mode of RREQ/SREQ bag, open service discovery process;

S3, service is replied:

SREP＝＜SN _P,SD _P,D _P,G,R _P＞(3)

In formula (3), SREP representative service is replied, SN _pthe title of representative service, SD _pthe descriptor of representative service, indications D _pbe used for arranging the descriptor whether message comprises service, acquiescence does not comprise, and whether indications G is used for carrying out identification node is a gateway, R _pfor reserved indications, to tackle following needs, such as setting position perception information, its default value is set to 0, and we expand routing reply (RREP) message in AODV Routing Protocol by adding service reply (SREP) message.After routing reply message (RREP) is expanded, if RREQ/SREQ message bag arrives destination node, RREP/SREP bag just can turn back to service requesting node by the mode of clean culture from destination node, or the intermediate node of destination node can be found to turn back to initiation node from one;

S4, location aware: realize location aware function in service discovery, two kinds of methods are had to realize, first method is coal addition position perception information in SREQ message, second method is coal addition position information in SREP message, relative to first method, second method has two large advantages, first, the method can reduce network traffics, because service request SREQ message is that the situation broadcasted sends to all nodes, and service reply SREP message is that clean culture sends to requesting node, as can be seen here, adopt second method effectively can reduce the data volume of Internet Transmission, secondly, service availability is good, concerning service requesting node, it can receive all SREP message, and the most suitable ISP of position-based Information Selection, multiple service providing node can be selected even, adopt first method, owing to adding location aware in service request SREQ message, the situation of not serving reply can be caused to occur, this is for service requester, very fatal, namely second method is adopted, i.e. coal addition position information in SREP message, thus, reserved indications R in formula (3) _pby positional information L _psubstitute, obtain formula (4):

SREP＝＜SN _P,SD _P,D _P,G,L _P＞(4)

S5, Service Matching, according to the service request received, resolver extracts the COS ST obtaining asking _q(Service Properties SA is comprised with attribute _qwith nodal community NA _q).By to COS ST _qassessment, the application of asking can be determined, if service is the service that this locality of a standard or far-end are known, then evaluation attribute; If the service that unknown, assessment stops.Attribute (SA _qand NA _q) assessment by regenerating attribute-operation-value table, and then and the context sight (attribute-operation of SA and NA-value is shown) collected in registration process of service platform carry out assessment comparison and come.If service discovery module searches is to available service, then return service return information;

S6, service discovery, service discovery is exactly find required service fast and accurately according to the service request of node.When a node needs a certain or some service, first search in the service list of node itself, if do not find required service, it will broadcast RREQ/SREQ message bag, start a service discovery process, certain node carries out service discovery in conjunction with Service Matching after receiving a RREQ/SREQ message bag.First the type of service request is judged.If service request comprises all services, this node checks whether oneself exists available service, if had, returns RREP/SREP message bag to source node with mode of unicast, and forwards RREQ/SREQ message bag to neighbor node; Otherwise, only forward RREQ/SREQ message bag to neighbor node.If this service request comprises the service of certain type, node is searched in the service list of self, sees whether there is available service, if do not had, forwards RREQ/SREQ message bag to neighbor node; If there is available service, then node checks oneself whether to there is available route in the route list of self, if had, RREP/SREP message bag is returned to requesting node with mode of unicast, otherwise, send RREQ/SREP message bag and carry out route finding process to neighbor node, wait finding after the route of source requesting node, carry out transfer of data again, SREP message is returned to requesting node.

After requesting node receives the RREP/SREP message bag returned, extract the longitude and latitude positional information in each SREP, and in conjunction with the longitude and latitude positional information of requesting node self, just can try to achieve the distance of each service providing node and service requesting node.

Up to the present, the range measurement of position-based information mainly contains traditional longitude and latitude range finding, Vincenty range finding and Haversine range finding.In these three kinds range finding models, the error of traditional longitude and latitude range finding is maximum, is mainly used in the occasion that some required precisions are not high; The error of Vincenty range finding formula is minimum, and its error range is between 5 ~ 10cm, but the computational process of this range finding formula is too complicated, is not suitable for applying in the ad hoc network; Haversine finds range the error of formula within the scope of meter level, can meet range finding requirement herein, and due to its formula simple, quick calculating can be realized, be applicable to applying in the ad hoc network.Therefore, in this article, we carry out based on Vincenty range finding formula the distance that calculation services provides node and service requesting node.

The longitude and latitude of service requesting node A is made to be (α ₁, β ₁), from the positional information L of SREP _pthe longitude and latitude of the service providing node of middle extraction is (α ₂, β ₂).Suppose that the earth is a perfect spheroid, its radius is exactly the mean radius of the earth, is designated as R=6371.004 km ^[20].Then the distance d of node A and Node B can be obtained by following formula.

Δα＝α ₂-α ₁(5)

Δβ＝β ₂-β ₁(6)

$\begin{array}{c}d=arc\sin \left(\sqrt{{\sin }^2\left(\frac{\mathrm{\Δ}\mathrm{\β}}{2}\right)+\cos \left({\mathrm{\β}}_1\right)\cos \left({\mathrm{\β}}_2\right){\sin }^2\left(\frac{\mathrm{\Δ}\mathrm{\α}}{2}\right)}\right)\\ \×2R\end{array}---\left(7\right)$

Like this, according to the size of the distance d value of each service providing node and service requesting node, service requesting node can the nearest ISP of chosen distance oneself.

In order to verify the performance of SDRLA service discovery method, the present invention adopts OMNET++ to carry out analysis of simulation experiment;

In emulation experiment, network topology scope is set to 1000m × 1000m, the transmission radius of node is set to 100m, the translational speed of node within the scope of 1m/s-20m/s at random given (movement velocity is similar to the walking speed of people and the travel speed of vehicle), Stochastic choice node is as service requester or ISP, each node can ask multiple service, and multiple node also can ask same service.Suppose existence 2 service providing node, and each node only provides a kind of service, number of nodes for increment change in [5,30] scope, simulates the relation of time delay, message overhead and number of nodes with 5 nodes respectively.

As can be seen from Figure 3, along with the increase of number of nodes, the time delay of EADP, GSD and SDRLA tri-kinds of service discovery methods all presents ascendant trend, because AdHoc network adopts the mode message transfer of multi-hop, along with number of nodes increases, the jumping figure of message propagation process increases, and the time overhead of cost increases.The time delay of EADP service discovery method is maximum, this is because the service request of EADP and service are replied all adopt multicast mechanism, easily causes network channel conflict.Compare with EADP, the time delay of GSD service discovery method decreases, and reason is that GSD service discovery method utilizes bunch head process service registration information and service request information, improves service discovery efficiency to a certain extent, reduces time delay.SDRLA service discovery method, based on AODV Routing Protocol, carries out service discovery while route discovery, and substantially increase service discovery efficiency, thus time delay is minimum.When nodes is 20, the time delay of SDRLA reduces 34.3% than GSD, reduces 64.7% than EADP.

As can be seen from Figure 4, the message number of EADP is maximum, this is because the service request of EADP and service are replied all adopt multicast mechanism, produces a large amount of broadcast message.Compare with EADP, the message number of GSD service discovery method reduces to some extent, and reason is that GSD service discovery method introduces a bunch mechanism, avoids and produce a large amount of broadcast messages in network range.The message number of SDRLA service discovery method is minimum, reason is that SDRLA service discovery method is based on AODV Routing Protocol, service discovery is carried out while route discovery, decrease message number, and, RREP/SREP bag adopts the mode of clean culture to turn back to service requesting node from destination node, further reduces message number.

The above; be only the present invention's preferably embodiment; but protection scope of the present invention is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the present invention discloses; be equal to according to technical scheme of the present invention and inventive concept thereof and replace or change, all should be encompassed within protection scope of the present invention.

Claims (5)

1. the ADHOC network service system based on route and location aware, it is characterized in that, comprise services platform module, Registering modules and service discovery module, services platform module mainly stores the information on services of registration, i.e. Service Properties and the nodal community that service is provided, call for service discovery module, in order to provide single entrance, Registering modules is collected all attributes and is stored in services platform module by them, be combined in the semantic service indications in service registry, these information are supplied to the resolver in service discovery module, in service list, the service of all known local and remote is all by temporal cache, use for resolver, service discovery module receives local or remote service request, resolver performs matching process, the most backward requesting node return service return information,

The flow process of this ADHOC network service system specifically comprises the following steps:

S1, service a: service is made up of parts such as COS, service name, service describing, Service Properties and nodal communitys, and its formal definitions is as following formula:

S＝＜ST,SN,SD,SA,NA＞(1)

In formula (1), S represents service; The type of ST representative service, the title of SN representative service, the descriptor of SD representative service, the attribute of SA representative service, NA representative provides the nodal community of service;

S2, service request: the formal definitions of service request is as following formula:

SREQ＝＜ST _Q,SA _Q,NA _Q,D _Q,A,R _Q＞(2)

In formula (2), SREQ represents service request, ST _qrepresent the type of request service, determine the application of asking thus, SA _qthe Service Properties of representative request, NA _qthe nodal community of representative request, D _qrepresent indications, A represents indications, R _qthe reserved indications of representative;

S3, service is replied:

SREP＝＜SN _P,SD _P,D _P,G,R _P＞(3)

In formula (3), SREP representative service is replied, SN _pthe title of representative service, SD _pthe descriptor of representative service, indications D _pbe used for arranging the descriptor whether message comprises service, acquiescence does not comprise, and whether indications G is used for carrying out identification node is a gateway, R _pfor reserved indications, to tackle following needs;

S4, location aware: realize location aware function in service discovery, two kinds of methods are had to realize, first method is coal addition position perception information in SREQ message, second method is coal addition position information in SREP message, relative to first method, second method has two large advantages, first, the method can reduce network traffics, because service request SREQ message is that the situation broadcasted sends to all nodes, and service reply SREP message is that clean culture sends to requesting node, as can be seen here, adopt second method effectively can reduce the data volume of Internet Transmission, secondly, service availability is good, concerning service requesting node, it can receive all SREP message, and the most suitable ISP of position-based Information Selection, multiple service providing node can be selected even, adopt first method, owing to adding location aware in service request SREQ message, the situation of not serving reply can be caused to occur, this is for service requester, very fatal, namely second method is adopted, i.e. coal addition position information in SREP message, thus, reserved indications R in formula (3) _pby positional information L _psubstitute, obtain formula (4):

SREP＝＜SN _P,SD _P,D _P,G,L _P＞(4)

S5, Service Matching, according to the service request received, resolver extracts the COS ST obtaining asking _qand attribute, attribute comprises Service Properties SA _qwith nodal community NA _q, by COS ST _qassessment, determine ask application, SA _qand NA _qassessment by regenerating attribute-operation-value table, and then and the context sight collected in registration process of service platform carry out assessment comparison and come;

S6, service discovery, the service request according to node finds required service fast and accurately.

2. a kind of ADHOC network service system based on route and location aware according to claim 1, is characterized in that, the SA in described S1 is abstract is the pattern of attribute-operation-value, and wherein, attribute is a title; Operation represents attribute and the relation both value; The specific restriction of a value expression attribute.

3. a kind of ADHOC network service system based on route and location aware according to claim 1, is characterized in that, the reserved indications R in described S2 _qbe 0 by default setting.

4. a kind of ADHOC network service system based on route and location aware according to claim 1, is characterized in that, add SREP message and expand the RREP message in AODV Routing Protocol in described S3.

5. a kind of ADHOC network service system based on route and location aware according to claim 1, is characterized in that, make the longitude and latitude of described service requesting node A be (α ₁, β ₁), from the positional information L of SREP _pthe longitude and latitude of the service providing node of middle extraction is (α ₂, β ₂), then the distance d of node A and Node B is obtained by following formula:

Δα＝α ₂-α ₁(5)

Δβ＝β ₂-β ₁(6)

$\begin{array}{c}d=arcsin\left(\sqrt{{\sin }^2\left(\frac{\mathrm{\Δ}\mathrm{\β}}{2}\right)+cos\left({\mathrm{\β}}_1\right)cos\left({\mathrm{\β}}_2\right){\sin }^2\left(\frac{\mathrm{\Δ}\mathrm{\α}}{2}\right)}\right)\\ \×2R\end{array}---\left(7\right).$