Embodiment
Hereinafter will and combine embodiment to specify the present invention with reference to accompanying drawing.Need to prove that under the situation of not conflicting, embodiment and the characteristic among the embodiment among the application can make up each other.
Fig. 3 is the structured flowchart based on the label transaction system of RF identification according to the embodiment of the invention.As shown in Figure 3, this label transaction system comprises: label 10 and central controller 20;
Wherein, label 10 is used to send the up-link frame data, receives the downlink frame data that come from central controller;
Central controller 20 may further include: transmitting-receiving control module 200, be used for the up-link frame data that come from label are sent to resource pool, and select to send the antenna of downlink frame data, the antenna transmission downlink frame data that control is selected.Application processing unit 202 comprises: resource pool, be used to handle the up-link frame data, and organize the downlink frame data.
In the correlation technique, exist up-link and downlink to face interference problem between label and the reader, Transaction Success rate is low, exchange hour is long, and the vehicle that carries label can only accomplish transaction in a track, and vehicle can not lane change.In system as shown in Figure 3; The resource pool of central controller 20 is handled the up-link frame data, organizes after the downlink frame data, and central controller selects to send the antenna of downlink frame data; Control the antenna transmission downlink frame data of above-mentioned selection and give label 10; And then can effectively reduce the downlink Lin Dao interference that exists between label and the reader, and improved the Transaction Success rate one time, reduced exchange hour.Simultaneously, also can solve the problem that does not allow lane change in the label process of exchange, and different label is to the uplink channel interference problem of reader.
Preferably; As shown in Figure 4; Above-mentioned transmitting-receiving control module 200 may further include one of following module: first selects module 2000, is used to detect the signal intensity of each antenna receiving uplink frame data, selects the maximum antenna transmission downlink frame data of signal intensity; Second selects module 2002, is used for calculating the positional information of label according to the position of each antenna and the signal intensity of each antenna receiving uplink frame data, selects antenna transmission downlink frame data according to the positional information of label.
Preferably, as shown in Figure 4, the label transaction system can also comprise: the antenna 30 of selection is used to adopt the timesharing send mode to send the downlink frame data.
In preferred implementation process, the antenna 30 of selection adopts the timesharing send modes to send the downlink frame data can include but not limited to one of following processing:
Handle one: the antenna 30 of above-mentioned selection detects its adjacent antenna and whether is in transmit status; If be not in transmit status; Then after first schedule time, continue to detect adjacent antenna and whether be in transmit status, if be not in transmit status then send the downlink frame data; If adjacent antenna is in transmit status always, then after second schedule time, send the downlink frame data;
Handle two: central controller is controlled the time of the antenna transmission downlink frame data of above-mentioned selection according to the time that adjacent antenna sends the downlink frame data.
Preferably, as shown in Figure 4, above-mentioned transmitting-receiving control module 200 can further include: sending module 2004, be used for the up-link frame data are sent to the resource pool corresponding with label, wherein, the corresponding same resource pool of each label.
Preferably; As shown in Figure 4, above-mentioned transmitting-receiving control module 200 can further include: assignment record module 2006, and being used at the up-link frame data is when coming from first frame data of label; Be the label distribution resource pool, and the occupied status information of record resource pool; Search module 2008, being used at the up-link frame data is when coming from non-first frame data of label, to search in each resource pool of central controller according to the identification information of label, obtains resource pool.
The up-link information that 200 of control modules of transmitting-receiving will have OBUI sends to the resource pool of a correspondence, thereby has solved the uplink channel interference problem, has improved work efficiency.
Preferably, as shown in Figure 4, above-mentioned transmitting-receiving control module 200 can further include: empty module 2010, be used for after resource pool is accomplished this transaction, emptying the identification information of the corresponding label of resource pool, and the record resource pool is the information of idle condition.
Further describe above-mentioned preferred implementation below in conjunction with instance shown in Figure 5.
Fig. 5 is the transaction principles synoptic diagram of the integrated control mode of the instance according to the present invention.As shown in Figure 5, this ETC system comprises: central controller, antenna (illustrated among Fig. 5 and be numbered 1,2,3,4 antenna) and label (illustrated among the figure and be numbered 1,2,3,4,5,6,7,8 label).Wherein, central controller is formed by transmitting-receiving control module (being equivalent to above-mentioned transmitting-receiving control module 200), application processing unit (being equivalent to above-mentioned application processing unit 202), PSAM processing unit with the track computer interface unit.
In preferred implementation process, application processing unit contains a plurality of resource pools, the up-link frame information of each resource pool parallel processing label.Antenna receives the data of label, is reported to the transmitting-receiving control module of central controller, and the transmitting-receiving control module is given application resource pond of this label distribution, and this resource pool is handled this uplink data frames, and the downlink frame after handling is sent to the transmitting-receiving control module.The transmitting-receiving control module selects an antenna that data are sent to this label.Uses such as access credentials, message authentication code are calculated in the supply of PSAM processing unit with the unit.Accomplish and the communicating by letter of track computing machine with the track computer interface unit.The central controller controls antenna sends order to label, returns to the antenna reply data after label receives orders, and antenna is sent to central controller with data.Antenna is accomplished coding, modulation and the transmission of downlink information according to the DSRC agreement; And the reception of uplink, decoding also is sent to central controller with decoded data.Central controller is responsible for application processes; Comprise and check tag command (BeaconService Table; Abbreviate BST as) all control in all interior downlink command through it; Central controller distributes a resource pool for each reader, and promptly each antenna can concurrent working, and can avoid the phase mutual interference.
Fig. 6 is the process flow diagram based on the label method of commerce of RF identification according to the embodiment of the invention.As shown in Figure 6, mainly comprise following processing based on the label method of commerce of RF identification:
Step S602: the up-link frame data that central controller will come from label are sent to the resource pool in the central controller;
Step S604: handle the up-link frame data at resource pool, organize after the downlink frame data, central controller selects to send the antenna of downlink frame data;
Step S606: the antenna transmission downlink frame data that central controller controls is selected.
Adopt method as shown in Figure 6; The resource pool of central controller is handled the up-link frame data, organizes after the downlink frame data, and central controller selects to send the antenna of downlink frame data; Control the antenna transmission downlink frame data of above-mentioned selection; And then can effectively reduce the downlink Lin Dao interference that exists between label and the reader, and improved the Transaction Success rate one time, reduced exchange hour.Simultaneously, also can solve the problem that does not allow lane change in the label process of exchange.
Preferably, among the step S604, the antenna that above-mentioned central controller selects to send the downlink frame data includes but not limited to one of following processing:
Handle one: central controller detects the signal intensity of each antenna receiving uplink frame data, selects the maximum antenna transmission downlink frame data of signal intensity;
Handle two: central controller calculates the positional information of label according to the position of each antenna and the signal intensity of each antenna receiving uplink frame data, selects antenna transmission downlink frame data according to the positional information of label.
Preferably, the antenna of above-mentioned selection can adopt following mode to send the downlink frame data: the timesharing send mode.
In preferred implementation process, the antenna of selection adopts the timesharing send mode to send the downlink frame data can include but not limited to one of following processing:
Handle one: whether the antenna detection adjacent antenna is in transmit status, if be not in transmit status, then first schedule time after, continue the detection adjacent antenna and whether is in transmit status, if be not in transmit status then send the downlink frame data; If adjacent antenna is in transmit status always, then after second schedule time, send the downlink frame data;
Handle two: the time that central controller sends the downlink frame data according to adjacent antenna, control antenna sends the time of downlink frame data.
Preferably, central controller comprises following processing with the resource pool that the up-link frame data are sent in the central controller: central controller is sent to the resource pool corresponding with label with the up-link frame data, wherein, and the corresponding same resource pool of each label.
Preferably; If above-mentioned up-link frame data are first frame data that come from label; Before central controller is sent to the resource pool corresponding with label with the up-link frame data; Can also comprise following processing: central controller is the label distribution resource pool, and the occupied status information of record resource pool; If above-mentioned up-link frame data be come from label non-first frame data (for example; Second frame data; The 3rd frame data etc.), can also comprise following processing: central controller is searched in each resource pool of central controller according to the identification information of label, obtains resource pool.
This mode has solved the interference problem of facing of up-link.After central controller receives the up-link frame data that come from certain label, only select to use a resource pool of this label correspondence, avoided of the interference of different labels, improved work efficiency and Transaction Success rate of system reader.
Preferably, after resource pool was accomplished this transaction, central controller need empty the identification information of the corresponding label of resource pool, and the record resource pool is the information of idle condition.During so that conclude the business next time, this resource pool is distributed to the label that needs transaction.
Further describe above-mentioned preferred implementation below in conjunction with Fig. 7.
Fig. 7 is according to the preferred embodiment of the invention based on the process flow diagram of the label method of commerce of RF identification.As shown in Figure 7, should mainly comprise following processing (step S702-step S710) based on the label method of commerce of RF identification:
Step S702: central controller controls sky alignment communication zone sends BST.Under the control of central controller; Each antenna cycle is sent BST; After certain antenna is received the link setup information (label is to the response of BST) of label, show in the communication zone of this antenna to have label that this antenna of transmitting-receiving control module control stops to send BST; After this antenna and the success of label link setup, the control of transmitting-receiving control module recovers the function of this antenna cycle transmission BST.This step is accomplished by the transmitting-receiving control module of central controller.
Step S704: after the label in the communication zone is received the data of antenna, to antenna transmission up-link frame data.
Step S706: after antenna receives the up-link frame data of label, report the transmitting-receiving control module of central controller.The transmitting-receiving control module sends to the up-link frame data in the respective resources pond (if not to this label distribution resource pool, then distributing a resource pool) of application processing unit.
In a preferred embodiment, the application processing unit of central controller is safeguarded a plurality of resource pools, to conclude the business with the OBU in each track concurrently.The transaction flow of central controller controls and each OBU; Behind antenna and the OBU link setup; After the transmitting-receiving control module receives the first frame OBU up-link frame data, distribute a resource pool for this OBU according to the id information of this OBU, and it is occupied to write down this resource pool.All use same resource pool and this OBU to conclude the business in the process of exchange.
When the transmitting-receiving control module receives other up-link frame data of this OBU, search each resource pool, select the corresponding resource pool of ID of this OBU, send the up-link frame data to this resource pool according to the id information of this OBU.
Step S708: the corresponding resource pool of application processing unit is handled the data of label, organizes downlink data frame and selects an antenna transmission.
In preferred implementation process, when central controller issued the downlink frame data to certain label, central controller should be selected these downlink frame data of a suitable antenna transmission.In theory, should select to help most the antenna that label receives downlink frame.The communication range of this antenna covers must cover this label.
For example, unidirectional 4 tracks, an antenna is placed in each track, when label is positioned at certain track, should select the antenna transmission in this track, when label is positioned at the intersection position in two tracks, selects one of them track respective antenna to send.
Introduce the mode that two kinds of selections issue antenna below.
Mode one: detect the signal intensity that antenna receives the label uplink; The positional information of this intensity reflects label, promptly the antenna receiving intensity over against label is big, and side is little from the receiving intensity of the antenna of label; The antenna receiving intensity near apart from label is big, otherwise receiving intensity is little.The antenna transmission downlink frame data that central controller selective reception intensity is maximum.This mode complexity is low, but antijamming capability is low.
As shown in Figure 5; Label 2 sends uplink to each antenna; It is big to face the signal intensity that the antenna 2 of label receives; The signal intensity that other antennas receive is little, and antenna sends to the transmitting-receiving control module of central controller together with this signal intensity and up-link frame information, and the transmitting-receiving control module selects the maximum antenna of signal intensity 2 to send the downlink frame data.
Mode two: a plurality of receiving antennas are placed in each track, the tag signal power of utilizing a plurality of receiving antennas to receive, the location of realizing label.Central controller is according to the best antenna emission of the choice of location of label.
In a track, place receiving antenna and an emitting antenna of a plurality of location awares; After receiving antenna receives the uplink of label; All be reported to the transmitting-receiving control module of central controller; The transmitting-receiving control module can calculate the relative position information (its ultimate principle has adopted a plurality of receiving antennas to improve locating accuracy with mode one) of OBU according to the position and the signal intensity that each antenna receives of each receiving antenna.According to the position of relative position information and the emitting antenna of OBU, can select certain emitting antenna to send descending chain circuit frame.
Through said method, central controller can select an emitting antenna to send the corresponding downstream isl frame according to the up-link frame data of each OBU, can solve the lane change problem in the label process of exchange.
For example, as shown in Figure 5, in the process of exchange label 1 by track 1 lane change to the track 2, in the lane change process, can be to antenna transmission up-link frame information, central controller selects antenna 1 and antenna 2 to send descending chain circuit frames according to the position of label successively.
In preferred implementation process, central controller can select an antenna to issue certain bar downlink frame data.In order to prevent communication blind district, the coverage of adjacent antenna exists overlapping.As shown in Figure 5, antenna 1, antenna 2 and antenna are simultaneously and OBU1, OBU2, when OBU3 concludes the business, have the dl interference problem.Address this problem the mode that can adopt each emitting antenna timesharing to send, because the length of every downlink frame data is less than 128 bytes, therefore downstream rate 256Kbps, downgoing time can satisfy parallel requirement less than 4ms.Specifically can adopt following mode:
Mode one: detect adjacent antenna and whether be in transmit status, can realize through the mode of GPIO.For example, when antenna 2 needed to send a downlink information frame, whether the antenna that detects the next door launched (not emission think channel idle); If channel idle; Whether random delay a period of time (about 0-0.5ms) then, it is idle to detect channel again, if free time then send immediately; Then carry out Channel Detection when channel is busy always,, then force to send, take defeat, also have order and retransmit, but increased exchange hour even OBU occurs if T (time can be provided with) still fails to send downlink frame in the time.
Mode two: send by the timesharing of central controller controls different antennas.Each emitting antenna of transmitting-receiving control module control sends descending chain circuit frame, so central controller can be controlled each emitting antenna timesharing transmission.
For example; When transmitting-receiving control module control antenna 2 sends a frame downlink information; Detect the moment that last time, control antenna 1 sent descending chain circuit frames with antenna 3, if less than certain threshold values then after a period of time of delaying time, control antenna 2 sends a frame downlink information again.
In the mode two, increased the complexity of central controller, and time precision has relatively high expectations, the transmitting-receiving control module may there are differences, thereby can influence the practical implementation effect to the data transmission period of each antenna, the processing time of each antenna.
Through above-mentioned timesharing send mode, the launch time that can coordinate each antenna, avoid the interference between the descending chain circuit frame.If there is receiving downlink frame data problem in real time in OBU, promptly OBU can not receive other downlink frame during handling a downlink frame.To this problem, if certain antenna issues after the frame, issue another downlink frame immediately, can cause OBU to lose the downlink frame problem.In like manner, if after antenna 1 issued frame data, antenna 2 issued another frame data immediately, also can cause OBU to lose the downlink frame problem.
For example, Wuhan road and bridge ETC agreement second portion data link layer protocol, distribute frame data under the antenna after, should begin to receive the response message of OBU in the longest 480us.So two adjacent downlink frame shortest times of each antenna are spaced apart 480us, antenna detection is redispatched after after channel idle, also will passing through 480us.Repeating step S704 is to step S708, up to closing the transaction, and execution in step S710.
Step S710: central controller discharges this resource pool.
In preferred implementation process, the resource pool of application processing unit is after accomplishing once transaction (comprising that Fail Transaction finishes), and notice transmitting-receiving control module discharges this resource pool, promptly empties the id information of the corresponding OBU of this resource pool, and writing down this resource pool is idle condition.This resource pool can be used by other OBU after the release.
In a preferred embodiment, can also adopt following mode to reduce exchange hour:
Mode one: improve the data rate between central controller and the antenna.
Mode two: reduce the command transfer number between central controller and the antenna, can reduce the number of order through chaining of commands.
Mode three: use receiving antenna and transmitting antenna, emitting antenna carries out the coding of descending chain circuit frame, and receiving antenna is responsible for the decoding of uplink.Can utilize the concurrent operation of antenna like this, reduce the processing time of central controller.The form of link is used in the ACTION order that requires OBU to reply so as far as possible, and has the zone bit of distinguishing ACTION subcommand (subtype) in the frame format.
In sum; By the foregoing description provided by the invention; Compared with prior art; Introduced central controller, central controller can be controlled different reader concurrent workings, thereby can effectively increase work efficiency, avoid Lin Dao to disturb, improves the Transaction Success rate and reduce exchange hour.Because each reader phase co-ordination under the control of central controller; Guaranteed to have only a reader emission on the one hand to the downlink frame of certain label; And the mode that each emitting antenna adopts timesharing to send has been avoided the face interference problem of different readers to label; On the other hand, receive the up-link frame data that come from certain label after, only select a resource pool using this label corresponding, avoided of the interference of different labels to reader, improved work efficiency and Transaction Success rate of system.In addition, also solve the problem that does not allow lane change in the label process of exchange.
Obviously; It is apparent to those skilled in the art that above-mentioned each module of the present invention or each step can realize that they can concentrate on the single calculation element with the general calculation device; Perhaps be distributed on the network that a plurality of calculation element forms; Alternatively, they can be realized with the executable program code of calculation element, carried out by calculation element thereby can they be stored in the memory storage; Perhaps they are made into each integrated circuit modules respectively, perhaps a plurality of modules in them or step are made into the single integrated circuit module and realize.Like this, the present invention is not restricted to any specific hardware and software combination.
More than be merely the preferred embodiments of the present invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various changes and variation.All within spirit of the present invention and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.