CN102098793B - Link access method for AIS (Automatic Identification System) Class B shipborne responder - Google Patents
Link access method for AIS (Automatic Identification System) Class B shipborne responder Download PDFInfo
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- CN102098793B CN102098793B CN 201010617498 CN201010617498A CN102098793B CN 102098793 B CN102098793 B CN 102098793B CN 201010617498 CN201010617498 CN 201010617498 CN 201010617498 A CN201010617498 A CN 201010617498A CN 102098793 B CN102098793 B CN 102098793B
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Abstract
The invention relates to an information technology. The invention aims at solving the problem that message sending flexibility is limited because the existing AIS (Automatic Identification System) Class B 'CS (client-server)' shipborne responder adopts a CSTDMA (Carrier Sense Time Division Multiple Access) link access scheme. The invention provides a link access method for an AIS Class B shipborne responder, wherein the technical scheme of the invention is as follows: an RATDMA (Random Access Time Division Multiple Access) link access technology and a CSTDMA link access technology are combined in the AIS Class B 'CS' shipborne responder. The method has the beneficial effect that the flexibility of the equipment in practical application is enhanced, and the method is suitable for AIS ClassB 'CS' shipborne responder systems.
Description
Technical field
The present invention relates to information technology, particularly the technology of AIS boat-carrying answering machine.
Background technology
AIS (Automatic Identification System, ship automatic identification system) is a kind of novel navaid and equipment, can be used for water transportation contact and commander's bank ship or the communication between ship bank or the ship ship, secondary navigation system, this system provides a kind of novel effectively means for navigation safety and navigation management, it is based on the relevant monitoring technology of radio answering machine, can be used for the accurate tracking of delivery vehicles such as boats and ships, to remedy traditional radar monitoring in the deficiency of identifying target automatically and obtaining aspects such as navigation activity information, radar monitoring is played auxiliary or substitution effect, because the advance of AIS technology, ease and economy, the AIS technology is adopted as international standard, and (ITU-R M.1371, IEC61993-2), International Maritime Organization (IMO) installs AIS Class A as sail boats and ships (〉=300 tons) Compulsory Feature safety means, China national fish-farming operation portion regulation in 2008, domestic all fishing boats must install AIS Class B additional, so AIS Class B has market application foreground very widely, it is the AIS key technologies for application that data link inserts, it has determined whether the equipment of AIS can effectively be identified by other AIS equipment, thereby given play to automatic identification, the function of communication navaid, all AIS equipment are in order to visit the VHF data link, must realize that at first TDMA is synchronous, synchronous time reference is general adopt with UTC directly synchronously or with the UTC indirect synchronization, the AIS system has adopted the concept of superframe, soon be divided into 2250 little timeslices in 1 minute, each timeslice is called a time slot again, take about 26.67ms, and the initial time slot of each superframe is fully synchronous with UTC minute starting point, all devices in the AIS system must be followed this regulation, safeguard the order of whole data link jointly, insert the process of data link, determine when and how armed AIS packet to be synchronized to the process of time slot and superframe exactly, because the AIS system is a self-organizing time-division multiple address system, AIS equipment in the system is shared whole data link, this system wants and can effectively play a role, depend on " harmonious coexistence " between each AIS equipment in the system, its basis is exactly each AIS equipment taking and discharge " just right " for time slot separately, how reasonably to take and discharge time slot, then relate to VHF (Very High Frequency) data link access technology, the message that AIS equipment sends is divided into two types, be the cycle message of fixed time period and the message at random of not timing transmission (such as send the relevant note message of some safety as the user temporarily), the cycle message is the fixing message of content format, timed sending is as longitude and latitude, bow is to the multidate information that waits boats and ships, safeguard the transmission cycle voluntarily by equipment, take a time slot width, interim message mostly is user's operation to be caused, the message of picture note and so on, message content length is controlled by the user, can take a plurality of time slots continuously, so have randomness, in international standard " ITU-RM.1371 " and " IEC 62287-1 ", mentioned RATDMA (Random access time division multiple access respectively, insert time division multiple access at random) and CSTDMA (Carrier sense time division multiple access, the carrier detect time division multiple access) the principle explanation of link access scheme, and at present, stipulate according to international standard " IEC 62287-1 ", AIS Class B " CS " boat-carrying answering machine adopts the link access scheme of CSTDMA, this scheme has limited AIS Class B " CS " boat-carrying answering machine and must adopt carrier detect to add the mode of retry in each message transmission, the success rate that message sends is subject on the result of carrier detect and the VHF data link whether have available time slot, and because carrier detect can only carry out at a time slot, so can only launch the message of a slot length each time, influence the flexibility that sends message.
Summary of the invention
The objective of the invention is to overcome the shortcoming that link access scheme that present AIS Class B " CS " boat-carrying answering machine adopts CSTDMA causes sending the limited flexibility of message, a kind of link cut-in method of AIS Class B boat-carrying answering machine is provided.
The present invention solves its technical problem, and the technical scheme of employing is that the link cut-in method of AIS Class B boat-carrying answering machine is characterized in that, may further comprise the steps:
A. system boot is mourned in silence, and receives outside ship message, sets up the time slot table, keeps the real-time update of time slot table afterwards according to the message that receives;
B. judging whether needs transmission cycle message, if then enter the c step, if not then enter the h step;
C. adopt CSTDMA link access technology, according to message report rate, determine initial time slot (NTT:Nominal transmission time) and the time slot transmitting boundary (TI:Transmission Interval) in each emission cycle of this machine, according to the time slot Table Properties, therefrom select ten candidate's time slots (CP:Candidate Period);
D. system adopts carrier detect from first candidate's time slot of time slot transmitting boundary;
Whether the state of e. judging this candidate's time slot is " not using ", if then send this message and enter the p step, if not then enter the f step;
F. judge whether all ten candidate's time slots all carrier detect finish, if then enter the g step, if not then wait for next candidate's time slot, and it is adopted carrier detect, get back to the e step;
G. abandon this transmission and enter the b step;
H. judge whether to send message at random, if then enter the i step, if not then enter the b step;
I. adopt RATDMA link access technology, in four seconds of current time, determine time slot range of choice (SI:Selection Interval), and the numbering of last time slot in definite time slot range of choice, be designated as RTES;
J. in time slot range of choice restricted portion, according to the time slot Table Properties, determine the available total number RTCSC of candidate's time slot, the initial value of RTCSC must be more than or equal to 4, if do not satisfy, need to adopt time slot to reuse principle and supply 4, candidate's time-gap number can not surpass RTES;
K. determine initial probability RTPS, its computing formula is: RTPS=100/RTCSC, then 0＜RTPS≤25;
L. determine as prior probability RTP2, make RTPS≤RTP2≤100;
M. selected candidate's time slot at random, and give its derivation probable value RTP1 at random;
Whether the value of n. judging this RTP1 is less than or equal to current probable value RTP2, if then this candidate's time slot is selected and send message at random at this candidate's time slot, enters the p step again, if not then enter the o step;
O. select next candidate's time slot, given RTP1 at random, and upgrade the total number RTCSC of current candidate's time slot, make RTCSC=RTCSC-1, upgrade as prior probability RTP2, make RTP2=RTP2+RTPI, wherein RTPI is the probability increment, its computing formula is: RTPI=(100-RTP2)/RTCSC, time slot select frequency of failure RTA to add 1, get back to the n step;
P. upgrade this ship time crack Table Properties, get back to the b step.
Concrete, comprise the time slot Table Properties of this ship time crack Table Properties and outside ship in the described time slot table of step a.
Further, the described time of mourning in silence of step a is at least one minute.
The invention has the beneficial effects as follows, link cut-in method by above-mentioned AIS Class B boat-carrying answering machine, overcome result and the time slot table that the success rate that now only adopts the CSTDMA link access technology pattern to issue to deliver newspaper literary composition is subject to carrier detect whether available time slot has been arranged, and can only launch the defective (because having increased message at random) of the message of a slot length each time, flexibly CSTDMA and RATDMA link access technology are fused to together, namely satisfied the technical specification of international standard to AIS Class B " CS " boat-carrying answering machine, strengthened the flexibility in actual applications of this equipment again, effectively satisfy the user's communications demand, strengthened the practical value of this equipment greatly.
Embodiment
Below in conjunction with embodiment, describe technical scheme of the present invention in detail.
The link cut-in method of AIS Class B boat-carrying answering machine of the present invention is: at first system boot is mourned in silence, receive outside ship message, set up the time slot table, the real-time update that keeps the time slot table afterwards according to the message that receives, need to judge whether transmission cycle message then, if need transmission cycle message, then adopt CSTDMA link access technology, according to message report rate, determine initial time slot (NTT:Nominal transmission time) and the time slot transmitting boundary (TI:Transmission Interval) in each emission cycle of this machine, according to the time slot Table Properties, therefrom select ten candidate's time slots (CP:Candidate Period), system is from first candidate's time slot of time slot transmitting boundary then, adopt carrier detect, and whether the state of judging this candidate's time slot is " not using ", return and need to judge whether that step of message in transmission cycle if then send this message and upgrade the time slot Table Properties, if not then judge whether all ten candidate's time slots all carrier detect finish, need to judge whether that step of message in transmission cycle if then abandon the transmission of this cycle message and get back to, if not then wait for next candidate's time slot, and it is adopted carrier detect, get back to and judge this that step of candidate's time slot state, then do not judge whether to send message at random if do not need to send the cycle message, need not judge whether that step of message in transmission cycle if do not need then to get back to, if need then adopt RATDMA link access technology, in four seconds of current time, determine time slot range of choice (SI:Selection Interval), and the numbering of last time slot in definite time slot range of choice, be designated as RTES, again in time slot range of choice restricted portion, according to the time slot Table Properties, determine the available total number RTCSC of candidate's time slot, the initial value of RTCSC must be more than or equal to 4, if do not satisfy, need to adopt time slot to reuse principle and supply 4, candidate's time-gap number can not surpass RTES, determine initial probability RTPS again, its computing formula is: RTPS=100/RTCSC, 0＜RTPS≤25 then, and then determine as prior probability RTP2, make RTPS≤RTP2≤100, select candidate's time slot more at random, and give its derivation probable value RTP at random, and whether the value of judging this RTP1 is less than or equal to current probable value RTP2, if then this candidate's time slot is selected and send message at random at this candidate's time slot, upgrade the time slot Table Properties again and get back to and need to judge whether that step of message in transmission cycle, if not then select next candidate's time slot, given RTP1 at random, and upgrade the current available total number RTCSC of candidate's time slot, make RTCSC=RTCSC-1, upgrade as prior probability RTP2, make RTP2=RTP2+RTPI, wherein RTPI is the probability increment, its computing formula is: RTPI=(100-RTP2)/RTCSC, time slot selects frequency of failure RTA to add 1, get back to the value of judging this RTP1 and whether be less than or equal to that step of current probable value RTP2, the method for calculating probability of RATDMA link access technology has determined in the scope of RTCSC one to find the RTP1 value of certain time slot to equal the RTP2 value for a short time surely, namely one selects certain candidate's time slot surely and is used for the emission of message at random.
Embodiment
This example adopts the link cut-in method of AIS Class B boat-carrying answering machine of the present invention.
At first system boot was mourned in silence at least one minute, receive outside ship message, set up the time slot table, the real-time update that keeps the time slot table afterwards according to the message that receives, the time slot Table Properties that comprises this ship time crack Table Properties and outside ship in the time slot table, this moment is owing to the AIS Class B boat-carrying answering machine of this ship is mourned in silence, the time slot Table Properties of outside ship is then only arranged in the time slot table this moment, this ship prepares to begin to send the cycle message or at random during message, the time slot Table Properties that adds this ship in the time slot table, need to judge whether transmission cycle message then, if need transmission cycle message, then adopt CSTDMA link access technology, according to message report rate, determine initial time slot (NTT:Nominal transmission time) and the time slot transmitting boundary (TI:Transmission Interval) in each emission cycle of this machine, according to the time slot Table Properties, therefrom select ten candidate's time slots (CP:Candidate Period), system is from first candidate's time slot of time slot transmitting boundary then, adopt carrier detect, and whether the state of judging this candidate's time slot is " not using ", return and need to judge whether that step of message in transmission cycle if then send this message and upgrade the time slot Table Properties, if not then judge whether all ten candidate's time slots all carrier detect finish, need to judge whether that step of message in transmission cycle if then abandon the transmission of this cycle message and get back to, if not then wait for next candidate's time slot, and it is adopted carrier detect, get back to and judge this that step of candidate's time slot state, then do not judge whether to send message at random if do not need to send the cycle message, need not judge whether that step of message in transmission cycle if do not need then to get back to, if need then adopt RATDMA link access technology, in four seconds of current time, determine time slot range of choice (SI:Selection Interval), and the numbering of last time slot in definite time slot range of choice, be designated as RTES, again in time slot range of choice restricted portion, according to the time slot Table Properties, determine the available total number RTCSC of candidate's time slot, the initial value of RTCSC must be more than or equal to 4, if do not satisfy, need to adopt time slot to reuse principle and supply 4, candidate's time-gap number can not surpass RTES, determines initial probability RTPS again, its computing formula is: RTPS=100/RTCSC, then 0＜RTPS≤25, and then definite prior probability RTP2 that works as make RTPS≤RTP2≤100, select candidate's time slot more at random, and give its derivation probable value RTP at random, and judge whether the value of this RTP1 is less than or equal to current probable value RTP2, if then this candidate's time slot is selected and send message at random at this candidate's time slot, upgrade the time slot Table Properties again and get back to and need to judge whether that step of message in transmission cycle, if not then select next candidate's time slot, given RTP1 at random, and upgrade the current available total number RTCSC of candidate's time slot, make RTCSC=RTCSC-1, upgrade as prior probability RTP2, make RTP2=RTP2+RTPI, wherein RTPI is the probability increment, its computing formula is: RTPI=(100-RTP2)/RTCSC, time slot selects frequency of failure RTA to add 1, gets back to the value of judging this RTP1 and whether is less than or equal to that step of current probable value RTP2, if then choose this time slot and upgrade the time slot Table Properties, get back to afterwards and judge whether to send that step of cycle message, select next time slot if not then get back to, and recomputate the comparison probable value, so repeatedly, up to meeting the demands, choose time slot.From above step as can be seen, RATDMA link access technology itself has determined necessarily can choose certain time slot to be used for the emission of message at random, for long message, need take a plurality of time slots continuously, the time slot of choosing is for taking the initial time slot of time slot continuously, and the time slot of selecting meets VHF data link operating specification, can interference effect other equipment in the AIS system, therefore, under AISClass B " CS " pattern, launch message at random with RATDMA link access technology, message necessarily can successful launch at random just to have determined this, in the present invention RATDMA algorithm flexible Application is arrived in AIS Class B " CS " the boat-carrying answering machine, be the innovation and application of RATDMA link access technology, efficiently solve the inherent shortcoming of CSTDMA link access module.
Claims (3)
1.AIS the link cut-in method of Class B boat-carrying answering machine is characterized in that, may further comprise the steps:
A. system boot is mourned in silence, and receives outside ship message, sets up the time slot table, keeps the real-time update of time slot table afterwards according to the message that receives;
B. judging whether needs transmission cycle message, if then enter the c step, if not then enter the h step;
C. adopt carrier detect time division multiple access CSTDMA link access technology, according to message report rate, determine initial time slot and the time slot transmitting boundary in each emission cycle of this machine, according to the time slot Table Properties, therefrom select ten candidate's time slots;
D. system adopts carrier detect from first candidate's time slot of time slot transmitting boundary;
Whether the state of e. judging this candidate's time slot is " not using ", if then send this message and enter the p step, if not then enter the f step;
F. judge whether all ten candidate's time slots all carrier detect finish, if then enter the g step, if not then wait for next candidate's time slot, and it is adopted carrier detect, get back to the e step;
G. abandon this transmission and enter the b step;
H. judge whether to send message at random, if then enter the i step, if not then enter the b step;
I. adopt and insert time division multiple access RATDMA link access technology at random, in four seconds of current time, determine the time slot range of choice, and the numbering of last time slot in definite time slot range of choice, be designated as RTES;
J. in time slot range of choice restricted portion, according to the time slot Table Properties, determine the available total number RTCSC of candidate's time slot, the initial value of RTCSC must be more than or equal to 4, if do not satisfy, need to adopt time slot to reuse principle and supply 4, candidate's time-gap number can not surpass RTES;
K. determine initial probability RTPS, its computing formula is: RTPS=100/RTCSC, then 0＜RTPS≤25;
L. determine as prior probability RTP2, make RTPS≤RTP2≤100;
M. selected candidate's time slot at random, and give its derivation probable value RTP1 at random;
Whether the value of n. judging this RTP1 is less than or equal to current probable value RTP2, if then this candidate's time slot is selected and send message at random at this candidate's time slot, enters the p step again, if not then enter the o step;
O. select next candidate's time slot, given RTP1 at random, and upgrade the total number RTCSC of current candidate's time slot, make RTCSC=RTCSC-1, upgrade as prior probability RTP2, make RTP2=RTP2+RTPI, wherein RTPI is the probability increment, its computing formula is: RTPI=(100-RTP2)/RTCSC, time slot select frequency of failure RTA to add 1, get back to the n step;
P. upgrade this ship time crack Table Properties, get back to the b step.
2. according to the link cut-in method of the described AIS Class of claim 1 B boat-carrying answering machine, it is characterized in that, comprise the time slot Table Properties of this ship time crack Table Properties and outside ship in the described time slot table of step a.
3. according to the link cut-in method of claim 1 or 2 described AIS Class B boat-carrying answering machines, it is characterized in that the described time of mourning in silence of step a is at least one minute.
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| CN 201010617498 CN102098793B (en) | 2010-12-31 | 2010-12-31 | Link access method for AIS (Automatic Identification System) Class B shipborne responder |
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Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103149905B (en) * | 2013-02-21 | 2015-01-14 | 福建师范大学 | AIS (Automatic Identification System) Class B terminal-based DSC (Digital Selective Calling) control method |
| CN103178921B (en) * | 2013-02-28 | 2016-01-20 | 大连海事大学 | A kind of AIS system candidate time slot optimum choice method of improvement |
| CN113247050B (en) * | 2021-07-07 | 2021-09-24 | 天津七一二移动通信有限公司 | Method for realizing train approaching early warning and collision avoidance based on CSTMDMA |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1889716A (en) * | 2006-07-21 | 2007-01-03 | 南京南大万和科技有限公司 | Riverboat-carrying information managment and automatic identifying method and system |
| CN101644576A (en) * | 2009-05-15 | 2010-02-10 | 天津七一二通信广播有限公司 | Method for realizing filtration display of electronic chart ship |
| CN101699314A (en) * | 2009-10-27 | 2010-04-28 | 天津七一二通信广播有限公司 | Onboard AIS equipment adopting DDS frequency synthesizer |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1889716A (en) * | 2006-07-21 | 2007-01-03 | 南京南大万和科技有限公司 | Riverboat-carrying information managment and automatic identifying method and system |
| CN101644576A (en) * | 2009-05-15 | 2010-02-10 | 天津七一二通信广播有限公司 | Method for realizing filtration display of electronic chart ship |
| CN101699314A (en) * | 2009-10-27 | 2010-04-28 | 天津七一二通信广播有限公司 | Onboard AIS equipment adopting DDS frequency synthesizer |
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