In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, is not intended to limit the present invention.
In embodiments of the present invention, the user utilizes the certainly group vehicle-carrying communication network of the Vehicular communication system of framework, sets up the vehicle-carrying communication link with member in the net, by the audio, video data collection, and member's audio/video communication in realization and the net.
Fig. 1 shows the structure of the Vehicular communication system that the embodiment of the invention provides, and for convenience of explanation, only shows the part relevant with the embodiment of the invention.
Data acquisition module 11 gathers user's audio or video data;
In embodiments of the present invention, comprise the required camera of collection audio or video data and microphone etc. in the data acquisition module 11.
The network routing agreement of networking module 12 configuration Vehicular communication systems, network access node is carried out safety certification, information flow to transmission is encrypted or deciphers, and sets up the route between requesting node and destination node, the audio or video data that the transmission of data acquisition module 11 gathers.
In embodiments of the present invention, networking module 12 realizes comprising network routing agreement, safety certification scheme and encrypting and decrypting mode from organizing the vehicle-carrying communication network.Wherein Routing Protocol is the core of networking module, guarantees network survivability and resource utilization, and maintaining routing information carries out monitoring and controlling to network condition; The safety certification scheme relates to network members registration, password key and safe class etc., and key will prevent that unwarranted node is to access and the operation of network; The encrypting and decrypting mode is the protection to data in the network, guarantees user's information security.
The network routing agreement that the embodiment of the invention provides, employing be preferably compromise mode in conjunction with Proactive routing protocols and reaction equation Routing Protocol advantage.Details are as follows:
The embodiment of the invention disposes an aim sequence number for each routing iinformation, this aim sequence number is produced by destination node, be included in and send to any routing iinformation of requesting node, requesting node is by calculating (namely for the selection of two routes that arrive same destination node, require number large that of requesting node Selective sequence), in all routing iinformations, obtain optimum route.
In embodiments of the present invention, networking module 12 utilizes the aim sequence preserved in the destination node number to keep the validity of routing iinformation, all routing packets all to preserve aim sequence number.
The embodiment of the invention disconnects and node no longer can reach the time at link, and destination node can't provide the situation of the self information relevant with its sequence number.When these situations produced, node can make by the sequence number that operation comprises route invalid and be invalid with the routing table entry status indication.Routing algorithm allows the damaged of mobile node response link and upgrades network topology in a kind of timely mode.This operation is without loopback (loop-free), and avoided the Bel of Fast Convergent when network topology change graceful-the unlimited computational problem of Ford (bellman-ford) algorithm.
In an embodiment of the present invention, the information that obtains destination node when requesting node is overtime, then thinks this link obstructions and to make this routing operations that comprises sequence number be invalid and be invalid with the routing table entry status indication.Requesting node begins again to receive other routing iinformations and selects another route.
Network routing agreement distance-based vector operation in the embodiment of the invention, the route that only maintenance needs in routing table, usually each destination node is preserved a route, and every routing iinformation has life cycle, if overtime namely above life cycle, then this routing iinformation was invalid.
The message of Routing Protocol comprises route requests, route feedback, routing error in the embodiment of the invention, and Hello message.
In embodiments of the present invention, details are as follows for the mode of setting up of network:
When there was effective routing in the terminal room of communication connection, network was not carried out any operation.When one of needs arrived the route of new destination node, node was just broadcasted the route that a route requests finds to arrive destination node.The foundation of route comprises two steps: the one, and the foundation of reverse link, namely each node can be cached to the route of source node after receiving route request information, thereby forms reverse link, as shown in Figure 2; The 2nd, the foundation of forward link as shown in Figure 3, to the answer of route request message, both can be produced by destination node, also can be generated by an intermediate node with " enough new " route.Article one, " enough new " routes refer to the related sequence number of destination node at least and be included in the same large effective routing clauses and subclauses of sequence number in the route requests.Owing to the reverse link that had before established is arranged, so route requests adopts mode of unicast to be sent to source node.
In embodiments of the present invention, after network was set up, the user carried out the audio, video data collection by data acquisition module 11, and carried out voice call by mandatory member in network and the net, and the user can also broadcast particular message to all members in the net, such as warning message etc.
In embodiments of the present invention, network will manage and safeguard routing table as follows after setting up:
Node utilizes the Link State of active (active) router of Hello message monitoring down hop, and Hello message is that life span (Time To Live, TTL) is 1 route feedback message.If a certain link is found to disconnect in an active route, a routing error message is used to notify the generation of other this loss of link of node.Routing error message is used to refer to via disconnecting link inaccessible those destination nodes (may be subnet).In order to realize this report mechanism, each node will be preserved one " pioneer shows (precursorlist) ", agreement (the Internet Protocol that interconnects between the network comprising separately neighbor node, IP) address, these neighbor nodes refer to and may be used to as arriving the separately down hop of destination node.Information the easiest acquisition in the process that produces a route feedback message in pioneer's table.
Routing table entry comprises in the embodiment of the invention: purpose IP address, aim sequence number, effectively aim sequence number sign, route indication (for example: effective, invalid, can repair, be repaired), network interface, required jumping figure, down hop, the pioneer's tabulation of arrival destination node, and life span (termination of route or erasing time) field.
Because the embodiment of the invention has adopted above table to drive route and the mixing routing mechanism of route as required, and it can be adapted to from the rate travel of low speed, medium-to-high speed, the while also is applicable to various data service ranks.The applicable network of this Routing Protocol is to trust each other between node, does not have the node of malicious intrusions.The design of network has reduced distributing of control message and has eliminated expense on data flow, in order to improve scale adaptability and performance.
In the safety certification scheme of certainly organizing the vehicle-carrying communication network that the embodiment of the invention provides, identify label number (the Identity that each user assignment is unique, ID), this ID is written to user's terminal equipment and (the Authentication Center of AUC, AUC) in, its flow process as shown in Figure 4.Wherein, the pseudo-noise code generator among the AUC produces a uncertain pseudo random number (RAND); RAND and user ID produce an authentication code (Kau) through authentication arithmetic, produce a key (Kc) through cryptographic algorithm; Kau, Kc that RAND and it produce form user's a parameters for authentication group together, and are stored in the AUC subscriber data storehouse.
The effect of AUC is very important in the embodiment of the invention safety certification scheme, and the authentication parameter of its generation is the source of safe key, and this will guarantee the reliability of embodiment.
The user needs authentication before start, the flow process of authentication as shown in Figure 5.Wherein, terminal equipment is to AUC request access, and AUC returns a RAND, and the user produces Kc with ID and RAND through authentication arithmetic.The Kau that this Kc and AUC store compares, when the result affirms then to allow access that negative then refusal accesses.
The encrypting and decrypting mode of the vehicle-carrying communication network that the embodiment of the invention provides, as shown in Figure 6, the Kc that the information flow that is sent by the user produces with authentication is sent on the channel through cryptographic algorithm and transmits, and receiving terminal obtains information flow by corresponding deciphering.
Application module 13 carries out the mutual of application data with the networking module, calls the audio or video data that networking module the transmission of data acquisition module gathers.
Comprise human interface software in the application module 13 in embodiments of the present invention, and the related hardware equipment such as screen, wherein man-machine interface can realize initiating the request of networking, carry out the man-machine interactive operation such as voice call, display network situation with network members.
In embodiments of the present invention networking module 12 is most important parts in the Vehicular communication system, has comprised the network layer protocol stack, can realize the functions such as transfer of data, network management and control, is the carrier of all business functions; Application module 13 is major functions that the vehicle-carrying communication network will be realized; Data acquisition module 11 is instruments of realizing network audio-video communication in the embodiment of the invention.
Fig. 7 shows the system configuration of the vehicle-carrying communication network system that the embodiment of the invention provides, and for convenience of explanation, only shows the part relevant with the embodiment of the invention.
Application module 13 is responsible for the audio, video data that calling data acquisition module 11 gathers, and proposes network connecting request, and carries out the mutual of application data to networking module 12; Networking module 12 realizes the professional passage that transmits, and is responsible for finishing the dynamic assignment of Dynamic Establishing and the Internet resources of network connection, and the management of network and maintenance.
Fig. 8 shows the operation flow of the Vehicular communication system that the embodiment of the invention provides, and details are as follows:
1. new node sends the request of networking to certainly organizing the vehicle-carrying communication network.
2. certainly organize the vehicle-carrying communication network new node is carried out safety certification.
3. new node sends safety certification message to certainly organizing the vehicle-carrying communication network.
4. certainly organize the vehicle-carrying communication network and pass through information to new node transmission safety certification.
5. the member sends route requests to new node in the vehicle-carrying communication network net to certainly organizing.
6. certainly organize the interior member of vehicle-carrying communication network net and reply the route requests that new node sends, set up communication link.
7. new node is with the member begins audio/video communication in the vehicle-carrying communication network net from organizing.
In embodiments of the present invention, when the user will communicate by letter with the mandatory member, the user sent communication request to this member IP; When the user sent broadcast message will for all members, the user sent communication request to broadcasting IP; When in the communication process during interrupted communication link, node will be initiated route requests again, and rebulid link.
In embodiments of the present invention, certainly organize the vehicle-carrying communication network by framework, the user can set up the vehicle-carrying communication link with member in the net, by the audio, video data collection, realize and the interior member's of net audio/video communication, can also broadcast particular message to all members in the network simultaneously, satisfy the user out of doors, particularly the communication requirement in the poor situation of signal conditioning is of great significance the communication support ability.
The above only is preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.