CN115696448B - AIS self-organizing time division multiple access network implementation method and device - Google Patents
AIS self-organizing time division multiple access network implementation method and device Download PDFInfo
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Abstract
The invention discloses a realization method and a device of an AIS self-organizing time division multiple access network, comprising the following steps: initializing system parameters; monitoring a channel and receiving time slot information, and acquiring and marking the use condition of the channel time slot; selecting a first available NTS; selecting other NTS in the same frame and carrying out framing operation; and according to the selected NTS and the grouped frames, transmitting SOTDMA messages, and continuously completing the realization of the AIS self-organizing time division multiple access network. The invention decomposes each state in SOTDMA, sets reasonable state machine, loose coupling of external function and SOTDMA reserved time slot module, modularizes calculation and transmission setting in SOTDMA reserved time slot module. Therefore, the invention is easy to realize in engineering, has short debugging period, can effectively ensure the rationality of time slot reservation, reduces the time slot conflict rate and improves the navigation safety of ships.
Description
Technical Field
The invention relates to the field of AIS systems, in particular to a method and a device for realizing an AIS self-organizing time division multiple access network.
Background
A reliable ship-shore communication network is constructed by a universal Automatic Identification System (AIS) of a ship, and plays an important role in ship collision avoidance navigation, distress search and rescue and the like. The AIS transmits the static data and the dynamic data of the ship in a self-organizing time division multiple access (SOTDMA) mode, lightens the labor of ship drivers and improves the management of ship navigation safety, and the SOTDMA is a key technology influencing the communication performance of the AIS system. With the increasing demand of AIS equipment, how to rapidly develop the SOTDMA protocol with low reservation conflict rate becomes an important research direction of current navigation technology.
Disclosure of Invention
Aiming at the defects in the prior art, the AIS self-organizing time division multiple access network implementation method and device provided by the invention provide the AIS self-organizing time division multiple access network implementation method and device with low reservation conflict rate.
In order to achieve the purpose of the invention, the invention adopts the technical scheme that:
an AIS self-organizing time division multiple access network implementation method is provided, which comprises the following steps:
s1, entering an initialization stage and initializing system parameters;
s2, entering a monitoring stage, monitoring a channel, receiving time slot information, and acquiring and marking the use condition of the channel time slot;
s3, entering a network entering stage, and selecting a first available NTS; wherein NTS represents a nominal transmit time slot;
s4, entering a first frame stage, selecting other NTSs in the same frame, and performing framing operation;
and S5, entering a continuous working stage, and transmitting SOTDMA messages according to the selected NTS and the grouped frames to continuously complete AIS self-organizing time division multiple access network implementation.
An AIS self-organizing time division multiple access network implementing device is provided, which includes:
the initialization module is used for initializing system parameters;
the monitoring module is used for monitoring the channel and receiving the time slot information, and acquiring and marking the service condition of the channel time slot;
a network entry module for selecting a first available NTS; wherein NTS represents a nominal transmit time slot;
the first frame module is used for selecting other NTSs in the same frame and carrying out framing operation;
and the continuous working module is used for sending SOTDMA messages according to the selected NTS and the grouped frames and continuously completing the realization of the AIS self-organizing time division multiple access network.
The invention has the beneficial effects that: the invention decomposes each state in SOTDMA, sets reasonable state machine, loose coupling of external function and SOTDMA reserved time slot module, modularizes calculation and transmission setting in SOTDMA reserved time slot module. Therefore, the invention is easy to realize in engineering, has short debugging period, can effectively ensure the rationality of time slot reservation, reduces the time slot conflict rate and improves the navigation safety of ships.
Drawings
FIG. 1 is a schematic flow diagram of the process;
FIG. 2 is a schematic flow diagram of an intercept phase;
FIG. 3 is a schematic flow chart of a network entry phase;
FIG. 4 is a flow chart of a first frame phase;
FIG. 5 is a schematic flow chart of a continuous phase of operation;
FIG. 6 is a schematic flow chart of step C2;
FIG. 7 is a schematic view of the processing flow of step F1 in the report rate change phase;
FIG. 8 is a schematic flow chart of steps F2 to F12 of the report rate change phase;
FIG. 9 is a flow diagram illustrating the calculation of NTS in the new selection interval SI and the framing operation;
fig. 10 is a schematic flow chart of calculating the transmission time slots outside the new selection interval SI;
FIG. 11 is a schematic illustration of an AIS device in an example embodiment;
fig. 12 is a control logic diagram in an embodiment.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.
As shown in fig. 1, the AIS ad-hoc time division multiple access network implementation method includes the following steps:
s1, entering an initialization stage and initializing system parameters;
s2, entering a monitoring stage, monitoring a channel, receiving time slot information, and acquiring and marking the use condition of the channel time slot;
s3, entering a network entering stage, and selecting a first available NTS; wherein NTS represents a nominal transmit time slot;
s4, entering a first frame stage, selecting other NTSs in the same frame, and performing framing operation;
and S5, entering a continuous working stage, and transmitting SOTDMA messages according to the selected NTS and the grouped frames to continuously complete AIS self-organizing time division multiple access network implementation.
The specific method of the step S1 is as follows: initializing a reserved time slot table, recording a transmitting time slot set and a first NTS selection success flag _ NTS1; the reservation time slot table is used for recording the time slot state, station number, station distance and channel corresponding to each occupied time slot, and when the interruption of the time slot arrives, the current time slot index is automatically added with 1; recording a transmitting time slot set for increasing the index NTSIndex of the NTS when each NTS is transmitted, and setting the index NTSIndex as 0 when the number of the index NTSIndex is equal to the maximum number of the NTS; the initial value of NTSIndex is 0; the initial value of a first NTS selection success flag _ NTS1 is 1, which indicates that the selection is unsuccessful; NTS denotes the nominal transmit time slot; the slot states include idle, internal partition, external partition, available and unavailable; the channels include a channel and B channel, each having a period of 7 frames, 1 minute per frame, including 2250 slots.
As shown in fig. 2, the specific method of step S2 includes the following steps:
b1, monitoring two channels for 1 minute, receiving 2250 time slot information, judging the communication state of the received information, if the received information is ITDMA, entering step B2, and if the received information is SOTDMA, entering step B4;
b2, analyzing the increment content, updating the state of the opposite channel of the current receiving channel in the reserved time slot table, and modifying the time slot state of the current time slot backward time slot increment into external division;
b3, judging whether the keeping mark is true, if so, updating the state of an opposite channel of the current receiving channel, modifying the time slot state of the current time slot + time slot increment +2250 into external division, and modifying the time slot state of the current time slot + time slot increment +2250 x 2 into external division; updating the current receiving channel state, modifying the time slot state of the current time slot +2250 into external division, and modifying the time slot state of the current time slot +2250 x 2 into external division; otherwise, not processing;
b4, judging whether the time slot timeout value TMO and the time slot offset are not both 0, if so, updating the reserved time slot table one by one in a time slot timeout value frame according to a 1371 protocol; otherwise, entering the step B5;
b5, checking whether a time slot reserved by other stations exists in a time slot of the same time slot number as the current time slot in the forward frame, and if so, changing the time slot state of the time slot of the same time slot number as the current time slot in the forward frame into an idle state; otherwise, no processing is performed.
As shown in fig. 3, the specific method of step S3 includes the following steps:
c1, judging whether the first NTS is successfully selected when the time slot synchronous interruption is received, and if so, entering a step C3; otherwise, entering the step C2;
c2, recalculating the first NTS by taking the current time slot as a reference, judging whether the first NTS is successfully calculated, and if so, entering the step C3; otherwise, waiting for the next time slot and returning to the step C1;
c3, judging whether the current time slot is positioned in the previous time slot of the selected first NTS or not, and if so, entering a step C4; otherwise, returning to the step C1;
c4, delaying and judging whether the NTS of the next frame and the NTS of the next frame are both available, if so, entering the step S4; otherwise, returning to the step C1.
As shown in fig. 4, the specific method of step S4 includes the following sub-steps:
d1, when time slot interruption comes, judging whether the current time slot is a transmitting time slot according to the use condition of the channel time slot, and if so, entering a step D2; otherwise, entering the step D4;
d2, transmitting the position information, adding 1 to the index NTSIndex of the NTS, judging whether the NTSIndex in the current frame is more than or equal to the report rate Rr, and if so, entering the step D3; otherwise, entering the step D4;
d3, setting the index of the NTS to be 0, randomly setting a time slot timeout value in a range of 3~7 for the Rr NTSs, and entering the step S5;
d4, judging whether the current time slot is the previous time slot of the transmitting time slot or not, and entering the step D5 if the current time slot is the previous time slot of the transmitting time slot; otherwise, returning to the step D1;
d5, judging whether NTSIndex in the current frame is equal to Rr-1, if so, setting the time slot offset to be 0, carrying out framing operation, and returning to the step D1; otherwise, entering the step D6;
d6, calling a probability persistence algorithm to calculate the time slot number of the NTSIndex +2 NTS, judging whether the time slot number is reserved successfully or not, and if so, entering the step D7; otherwise, returning to the step S3;
d7, setting the current transmitting channel as the reverse channel of the last NTS transmitting channel, taking the difference value of the current NTS transmitting time slot number and the last NTS transmitting time slot number as the time slot offset, carrying out framing operation, and returning to the step D1.
As shown in fig. 5, the specific method of step S5 includes the following steps:
e1, when time slot interruption comes, judging whether the current time slot is a transmitting time slot or not, and if so, entering a step E2; otherwise, entering a step E3;
e2, transmitting, adding 1 to the index of the NTS, and updating the NTS time slot number and the time slot offset; judging whether the index of the current NTS is equal to Rr, if so, setting the index of the current NTS to be 0, and entering a step E3; otherwise, directly entering the step E3;
e3, delaying and judging whether the current time slot is the previous time slot of the transmitting time slot or not, and if so, entering a step E4; otherwise, returning to the step E1;
e4, subtracting one from the current time slot timeout value, judging whether the subtraction result is 0, if so, calling a probability persistence algorithm to calculate new NTS and corresponding time slot offset, framing and reserving NTS, and entering a step E5; otherwise, setting the time slot offset as 0, framing and returning to the step E1;
e5, judging whether the reservation NTS is successful, if so, randomly setting a time slot timeout value in the range of 3~7, and returning to the step E1; otherwise, the time slot timeout value is set to 1, and the step E1 is returned to.
As shown in fig. 6, the specific method of step C2 includes the following steps:
c2-1, judging whether the time slot between the current time slot and the forward nominal interval NI is traversed or not, if so, judging that the first NTS calculation fails, waiting for the next time slot and returning to the step C1; otherwise, entering the step C2-2;
c2-2, randomly selecting a time slot between the current time slot and the forward nominal interval NI as NSSA, and taking the time slot corresponding to the sum of NSSA and NI as NSSB;
c2-3, calculating a first NTS by adopting a probability persistence algorithm based on NSSA and NSSB, and recording the time slot number of the first NTS and the corresponding transmitting channel number;
c2-4, judging whether the first NTS is successfully selected, if so, modifying a selection success flag _ NTS1 of the first NTS to 0, and entering a step C3; otherwise, the selection success flag _ NTS1 is modified to 1, and the step C2-1 is returned.
As shown in fig. 7 and 8, in the system operation process, whether a report rate change occurs is detected in real time, if yes, the report rate change stage is entered, and the following steps are performed:
f1, updating the report rate Rr, and acquiring the state value of the current state machine:
if the network is in a network entering stage or an interception stage, directly changing the report rate Rr, and entering a step F2;
if the current frame is in the first frame stage or the continuous working stage, entering a report rate changing stage and carrying out the following operations:
finding out the next NTS to be transmitted and setting the next NTS to be a nominal starting time slot NSS, setting NTSIndex to be 0, recording a transmitting channel corresponding to the NSS by using a Ch _ txnew array, and recording a time slot sequence number corresponding to the NSS by using an NTSnew array; adopting a flag _ newall variable as a new NTS selection completion flag, and setting the flag _ newall variable to be 1 to indicate that the selection is not completed; setting the time slot state corresponding to the selected NSS in the reserved time slot table as internal division, setting the time slot state of the opposite channel of the adjacent time slot as unavailable, and entering step F2;
if the report rate is in the report rate changing stage, the following operations are carried out:
acquiring the number Pnew of the time slots of the next NSS recorded in the NTSnew array and the number Pmin of the time slots nearest to the next NTS, judging whether the Pnew is smaller than the Pmin, if so, taking the next NSS recorded in the NTSnew array as a nominal starting time slot, otherwise, taking the next NTS as the nominal starting time slot, and setting a flag _ newall variable to be 1 to indicate that the selection is not finished; setting NTSIndex to 0, and entering step F2;
f2, taking the next NTS to be transmitted as a new NSS, and taking the time slot corresponding to the sum of the nominal starting time slot of the next transmission channel and the forward nominal interval NI as the NSS of another channel;
f3, recording the time slot and the transmitting channel number where the new NTS is corresponding to through the NTSnew array and the Chnew array; assigning the NtSIndex + X elements of the NTS array to the Xth element of the NTSnew array, and assigning the NtSIndex + X elements of the Ch array to the Xth element of the Chnew array; wherein the NTS array is used for recording the NTS; the Ch array is used for recording a transmitting channel corresponding to the NTS;
f4, setting NTSIndex as 0, and setting all NTS setting and sending completion marks in the NTSnew array as incomplete;
f5, when the time slot synchronous interruption is received, judging whether incomplete NTS still exists in the NTSnew array, if so, entering a step F6, otherwise, entering a step F7;
f6, judging whether the current time slot is the transmitting time slot recorded in the NTSnew array, if so, transmitting the position information, calculating the transmitting time slot outside the new selection interval SI, and returning to the step S5; otherwise, entering step F7 and step F10 simultaneously;
f7, judging whether the current time slot is not in the new selection interval SI and is positioned in the time slot recorded by the TxRecordNew array, if so, transmitting position information, and entering the step F8; otherwise, returning to the step F5; wherein, the TxRecordNew array records NTS which is not transmitted at present but needs to be transmitted;
f8, judging whether the time slots recorded by the TxRecordNew are all transmitted, if so, entering a step F9; otherwise, returning to the step F5;
f9, setting NTSIndex to be 0, setting a time slot timeout value, assigning a value in the current NTSnew array to an NTS array, assigning a value of the current Chnew array to a Ch array, and returning to the step S5;
f10, judging whether the current time slot is the previous time slot of the next time slot to be transmitted in the NTSnew array, if so, delaying and entering the step F11; otherwise, not processing;
f11, judging whether the current NTSIndex is equal to Rr-1, if so, performing framing operation and returning to the step F5; otherwise, calculating the NTS in the new selection interval SI and performing framing operation, and entering the step F12;
f12, judging whether framing of the next time slot is successful, if so, returning to the step F5; otherwise, the step S3 is returned to.
As shown in fig. 9, the specific method for calculating NTS in the new selection interval SI and performing framing operation in step F11 includes the following steps:
g1, solving a current candidate time slot NS according to the NSS, and updating a new selection interval SI; setting flag _ NTS1new to be 1, and indicating that the selection of the NTSnew array is not completed; wherein the new selection interval SI is obtained according to the current broadcast rate;
g2, judging whether an array formed by time slot numbers corresponding to NTS to be transmitted in the frame being transmitted is traversed or not, and if so, entering a step G6; otherwise, entering a step G3;
g3, judging whether the channels of the NTS which are not traversed are the same as the corresponding channels of the NTS to be transmitted in the NTSnew array after adding 2 to the index value of the NTS which is not traversed, and if so, entering the step G4; otherwise, returning to the step G2;
g4, judging whether the NTS which is not traversed is in the new selection interval SI, if so, selecting the NTS which is not traversed and entering the step G5; otherwise, returning to the step G2;
g5, updating the NTSindex +2 elements of the NTSnew array by using the selected traversed NTS, recording a corresponding channel number, and setting flag _ NTS1new to be 0 to represent that the selection of the NTSnew array is completed;
g6, judging whether a flag _ NTS1new =0 exists in the new selection interval SI, if so, performing framing operation, and entering a step F12; otherwise, entering a step G7;
g7, solving new NTS in the new selection interval SI through a probability persistence algorithm, judging whether the solving is successful, if so, performing framing operation, and entering a step F12; otherwise framing fails.
As shown in fig. 10, the specific method for calculating the transmission time slots outside the new selection interval SI in step F6 includes the following steps:
h1, adding 1 to the index number of the NTS, finding the NTS from the current time slot to the next new selection interval SI, and recording all the NTS in the TxRecordNew array, recording the time slot timeout value as 0, and setting the message type as SOTDMA;
h2, judging whether the index of the current NTS is equal to Rr or not, and if so, entering a step H3; otherwise, finishing calculating the transmitting time slot outside the new selection interval SI;
h3, setting all NTS and sending completion flags to be completed, judging whether the TxRecordNew array has no data or not, and if yes, entering the step H4; otherwise, finishing calculating the transmitting time slot outside the new selection interval SI;
h4, setting NTSIndex to be 0, setting a time slot timeout value, and returning to the step S5.
The AIS self-organizing time division multiple access network implementation device comprises:
the initialization module is used for initializing system parameters;
the monitoring module is used for monitoring the channel and receiving the time slot information, and acquiring and marking the service condition of the channel time slot;
a network entry module for selecting a first available NTS; wherein NTS represents a nominal transmit time slot;
the first frame module is used for selecting other NTSs in the same frame and carrying out framing operation;
and the continuous working module is used for sending SOTDMA messages according to the selected NTS and the grouped frames and continuously completing the realization of the AIS self-organizing time division multiple access network.
In the specific implementation process, the function of the autonomous operation state of the system is to transmit the SOTDMA message at the previously selected transmission time slot, which is the default operation stage of the SOTDMA protocol; the function of the system report rate change state is to reselect the transmission slot according to the new report rate, and the system returns to the autonomous operation state after one frame. And when the time slot reservation of the first frame stage, the continuous working stage and the report rate change stage is unsuccessful, the network is accessed again.
In one embodiment of the present invention, as shown in fig. 11 and 12, the AIS ad hoc network TDMA multiple access software is used as the core processing software of the AIS device, and its module is located in the DSP module of the AIS system, and when each time slot arrives, the FPGA provides the DSP with a time slot interrupt, and sends the received message to the DSP. The invention adopts FPGA to provide accurate clock and is responsible for sending signals. The DSP processes the interrupt function to perform time slot reservation and framing, the labor division is reasonable, and the time keeping accuracy and the engineering feasibility are ensured. The invention decomposes each state in SOTDMA, sets reasonable state machine, the external function and SOTDMA preengage time slot module are loosely coupled, the calculation and transmission setting is modularized in the SOTDMA preengage time slot module. Therefore, the method is easy to realize in engineering, has short debugging period, can effectively ensure the reasonability of time slot reservation, reduces the time slot conflict rate and improves the navigation safety of ships.
Claims (8)
1. An AIS self-organizing time division multiple access network implementation method is characterized by comprising the following steps:
s1, entering an initialization stage and initializing system parameters;
s2, entering a monitoring stage, monitoring a channel, receiving time slot information, and acquiring and marking the use condition of the channel time slot;
s3, entering a network entering stage, and selecting a first available NTS; wherein NTS represents a nominal transmit time slot;
s4, entering a first frame stage, selecting other NTSs in the same frame, and performing framing operation;
s5, entering a continuous working stage, and continuously completing AIS self-organization time division multiple access network realization by sending SOTDMA messages according to the selected NTS and the grouped frames;
the specific method of the step S1 is as follows:
initializing a reserved time slot table, recording a transmitting time slot set and a first NTS selection success flag _ NTS1; the reservation time slot table is used for recording the time slot state, station number, station distance and channel corresponding to each occupied time slot, and when the interruption of the time slot comes, the current time slot index is automatically added with 1; recording a transmitting time slot set for increasing the index NTSIndex of the NTS when each NTS is transmitted, and setting the index NTSIndex as 0 when the number of the index NTSIndex is equal to the maximum number of the NTS; the initial value of NTSIndex is 0; the initial value of the first NTS selection success flag _ NTS1 is 1, which indicates that the selection is unsuccessful; NTS denotes the nominal transmit time slot; the slot states include idle, internal partition, external partition, available and unavailable; the channels comprise an A channel and a B channel, the period of each channel is 7 frames, each frame is 1 minute, and the channels comprise 2250 time slots;
the specific method of step S2 includes the steps of:
b1, monitoring two channels for 1 minute, receiving 2250 time slot information, judging the communication state of the received information, if the received information is ITDMA, entering step B2, and if the received information is SOTDMA, entering step B4;
b2, analyzing the increment content, updating the state of the opposite channel of the current receiving channel in the reserved time slot table, and modifying the time slot state of the current time slot backward time slot increment into external division;
b3, judging whether the keeping mark is true, if so, updating the state of an opposite channel of the current receiving channel, modifying the time slot state of the current time slot + time slot increment +2250 into external division, and modifying the time slot state of the current time slot + time slot increment +2250 x 2 into external division; updating the current receiving channel state, modifying the time slot state of the current time slot +2250 into external division, and modifying the time slot state of the current time slot +2250 x 2 into external division; otherwise, not processing;
b4, judging whether the time slot timeout value and the time slot offset are not both 0, if so, updating the reserved time slot table one by one in a time slot timeout value frame according to a 1371 protocol; otherwise, entering the step B5;
b5, checking whether a time slot reserved by other stations exists in a time slot of the same time slot number as the current time slot in the forward frame, and if so, changing the time slot state of the time slot of the same time slot number as the current time slot in the forward frame into an idle state; otherwise, no processing is performed.
2. The AIS ad hoc time division multiple access network implementing method of claim 1, wherein the specific method of step S3 comprises the steps of:
c1, judging whether the first NTS is successfully selected when the time slot synchronous interruption is received, and if so, entering a step C3; otherwise, entering the step C2;
c2, recalculating the first NTS by taking the current time slot as a reference, judging whether the calculation of the first NTS is successful, and if so, entering the step C3; otherwise, waiting for the next time slot and returning to the step C1;
c3, judging whether the current time slot is positioned in the previous time slot of the selected first NTS or not, and if so, entering a step C4; otherwise, returning to the step C1;
c4, delaying and judging whether the NTS of the next frame and the NTS of the next frame are both available, if so, entering the step S4; otherwise, returning to the step C1.
3. The AIS ad-hoc time division multiple access network implementation method according to claim 2, wherein the specific method of step S4 comprises the following sub-steps:
d1, when time slot interruption comes, judging whether the current time slot is a transmitting time slot according to the use condition of the channel time slot, and if so, entering a step D2; otherwise, entering the step D4;
d2, transmitting the position information, adding 1 to the index NTSIndex of the NTS, judging whether the NTSIndex in the current frame is more than or equal to the report rate Rr, and if so, entering the step D3; otherwise, entering the step D4;
d3, setting the index of the NTS to be 0, randomly setting a time slot timeout value in a range of 3~7 for the Rr NTSs, and entering the step S5;
d4, judging whether the current time slot is the previous time slot of the transmitting time slot or not, and entering the step D5 if the current time slot is the previous time slot of the transmitting time slot; otherwise, returning to the step D1;
d5, judging whether NTSIndex in the current frame is equal to Rr-1, if so, setting the time slot offset to be 0, carrying out framing operation, and returning to the step D1; otherwise, entering the step D6;
d6, calling a probability persistence algorithm to calculate the time slot number of the NTSIndex +2 NTS, judging whether the time slot number is reserved successfully or not, and if so, entering the step D7; otherwise, returning to the step S3;
d7, setting the current transmitting channel as the reverse channel of the last NTS transmitting channel, taking the difference value of the current NTS transmitting time slot number and the last NTS transmitting time slot number as the time slot offset, carrying out framing operation, and returning to the step D1.
4. The AIS self-organizing time division multiple access network implementing method of claim 3, wherein the specific method of step S5 comprises the steps of:
e1, when time slot interruption comes, judging whether the current time slot is a transmitting time slot, and if so, entering a step E2; otherwise, entering a step E3;
e2, transmitting, adding 1 to the index of the NTS, and updating the NTS time slot number and the time slot offset; judging whether the index of the current NTS is equal to Rr, if so, setting the index of the current NTS to be 0, and entering a step E3; otherwise, directly entering the step E3;
e3, delaying and judging whether the current time slot is the previous time slot of the transmitting time slot or not, and if so, entering the step E4; otherwise, returning to the step E1;
e4, subtracting the current time slot timeout value by one, judging whether the subtraction result is 0, if so, calling a probability persistence algorithm to calculate new NTS and corresponding time slot offset, framing and reserving NTS, and entering step E5; otherwise, setting the time slot offset as 0, framing and returning to the step E1;
e5, judging whether the reservation NTS is successful, if so, randomly setting a time slot timeout value in the range of 3~7, and returning to the step E1; otherwise, setting the time slot timeout value to 1, and returning to the step E1.
5. The AIS ad-hoc time division multiple access network implementing method according to claim 2, wherein the specific method of step C2 comprises the steps of:
c2-1, judging whether the time slot between the current time slot and the forward nominal interval NI is traversed or not, if so, judging that the first NTS calculation fails, waiting for the next time slot and returning to the step C1; otherwise, entering a step C2-2;
c2-2, randomly selecting a time slot between the current time slot and the forward nominal interval NI as NSSA, and taking the time slot corresponding to the sum of NSSA and NI as NSSB;
c2-3, calculating a first NTS by adopting a probability persistence algorithm based on NSSA and NSSB, and recording the time slot number of the first NTS and the corresponding transmitting channel number;
c2-4, judging whether the first NTS is successfully selected, if so, modifying a selection success flag _ NTS1 of the first NTS to 0, and entering a step C3; otherwise, the selection success flag _ NTS1 is modified to 1, and the step C2-1 is returned.
6. The AIS self-organizing TDMA network implementing method according to claim 2 wherein during system operation, real-time detecting if a report rate change occurs, if so, entering a report rate change phase and performing the following steps:
f1, updating the report rate Rr, and acquiring the state value of the current state machine:
if the network is in a network entering stage or an interception stage, directly changing the report rate Rr, and entering a step F2;
if the current frame is in the first frame stage or the continuous working stage, entering a report rate changing stage and carrying out the following operations:
finding out the next NTS to be transmitted and setting the next NTS to be a nominal starting time slot NSS, setting NTSIndex to be 0, recording a transmitting channel corresponding to the NSS by using a Ch _ txnew array, and recording a time slot sequence number corresponding to the NSS by using an NTSnew array; adopting a flag _ newall variable as a new NTS selection completion flag, and setting the flag _ newall variable to be 1 to indicate that the selection is not completed; setting the time slot state corresponding to the selected NSS in the reserved time slot table as internal division, setting the time slot state of the opposite channel of the adjacent time slot as unavailable, and entering step F2;
if the report rate is in the report rate changing stage, the following operations are carried out:
acquiring the number Pnew of the time slots of the next NSS recorded in the NTSnew array and the number Pmin of the time slots nearest to the next NTS, judging whether the Pnew is smaller than the Pmin, if so, taking the next NSS recorded in the NTSnew array as a nominal starting time slot, otherwise, taking the next NTS as the nominal starting time slot, and setting a flag _ newall variable to be 1 to indicate that the selection is not finished; setting NTSIndex to 0, and entering step F2;
f2, taking the next NTS to be transmitted as a new NSS, and taking the time slot corresponding to the sum of the nominal starting time slot of the next transmission channel and the forward nominal interval NI as the NSS of another channel;
f3, recording the time slot and the transmitting channel number where the new NTS is corresponding to through an NTSnew array and a Chnew array; assigning the Nth and X elements of the NTS array to the Xth element of the NTSnew array, and assigning the Nth and X elements of the Ch array to the Xth element of the Chnew array; wherein the NTS array is used for recording the NTS; the Ch array is used for recording a transmitting channel corresponding to the NTS;
f4, setting NTSIndex as 0, and setting all NTS setting and sending completion marks in the NTSnew array as incomplete;
f5, when the time slot synchronous interruption is received, judging whether incomplete NTS still exists in the NTSnew array, if so, entering a step F6, otherwise, entering a step F7;
f6, judging whether the current time slot is the transmitting time slot recorded in the NTSnew array, if so, transmitting the position information, calculating the transmitting time slot outside the new selection interval SI, and returning to the step S5; otherwise, entering step F7 and step F10 simultaneously;
f7, judging whether the current time slot is not in the new selection interval SI and is positioned in the time slot recorded by the TxRecordNew array, if so, transmitting position information, and entering the step F8; otherwise, returning to the step F5; wherein the TxRecordNew array records NTS which is not transmitted but needs to be transmitted;
f8, judging whether the time slots recorded by the TxRecordNew are all transmitted, if so, entering a step F9; otherwise, returning to the step F5;
f9, setting NTSIndex to be 0, setting a time slot timeout value, assigning a value in the current NTSnew array to an NTS array, assigning a value of the current Chnew array to a Ch array, and returning to the step S5;
f10, judging whether the current time slot is the previous time slot of the next time slot to be transmitted in the NTSnew array, if so, delaying and entering the step F11; otherwise, not processing;
f11, judging whether the current NTSIndex is equal to Rr-1, if so, performing framing operation and returning to the step F5; otherwise, calculating the NTS in the new selection interval SI and performing framing operation, and entering step F12;
f12, judging whether framing of the next time slot is successful, if so, returning to the step F5; otherwise, the step S3 is returned to.
7. The AIS self-organizing TDMA network implementing method according to claim 6 wherein the specific method of calculating and framing the NTS in the new selection interval SI in step F11 comprises the steps of:
g1, solving a current candidate time slot NS according to the NSS, and updating a new selection interval SI; setting flag _ NTS1new to be 1, and indicating that the selection of the NTSnew array is not completed; the new selection interval SI is obtained according to the current broadcast rate;
g2, judging whether an array formed by time slot numbers corresponding to NTS to be transmitted in the frame being transmitted is traversed or not, and if so, entering a step G6; otherwise, entering a step G3;
g3, judging whether the channels of the NTS which are not traversed are the same as the corresponding channels of the NTS to be transmitted in the NTSnew array after adding 2 to the index value of the NTS which is not traversed, and if so, entering the step G4; otherwise, returning to the step G2;
g4, judging whether the NTS which is not traversed is in the new selection interval SI, if so, selecting the NTS which is not traversed and entering the step G5; otherwise, returning to the step G2;
g5, updating the NTSindex +2 elements of the NTSnew array by using the selected traversed NTS, recording a corresponding channel number, and setting flag _ NTS1new to be 0 to indicate that the selection of the NTSnew array is completed;
g6, judging whether a flag _ NTS1new =0 exists in the new selection interval SI, if so, performing framing operation, and entering a step F12; otherwise, entering a step G7;
g7, solving new NTS in the new selection interval SI through a probability persistence algorithm, judging whether the solving is successful, if so, performing framing operation, and entering a step F12; otherwise framing fails.
8. An AIS self-organizing tdma network implementing apparatus, comprising:
the initialization module is used for initializing system parameters;
the monitoring module is used for monitoring the channel and receiving the time slot information, and acquiring and marking the service condition of the channel time slot;
a network entry module for selecting a first available NTS; wherein NTS represents a nominal transmit time slot;
the first frame module is used for selecting other NTSs in the same frame and carrying out framing operation;
the continuous working module is used for sending SOTDMA messages according to the selected NTS and the grouped frames and continuously completing the realization of the AIS self-organizing time division multiple access network;
the specific method for initializing the system parameters by the initialization module comprises the following steps:
initializing a reserved time slot table, recording a transmitting time slot set and a first NTS selection success flag _ NTS1; the reservation time slot table is used for recording the time slot state, station number, station distance and channel corresponding to each occupied time slot, and when the interruption of the time slot comes, the current time slot index is automatically added with 1; recording a transmitting time slot set for increasing the index NTSIndex of the NTS when each NTS is transmitted, and setting the index NTSIndex as 0 when the number of the index NTSIndex is equal to the maximum number of the NTS; the initial value of NTSIndex is 0; the initial value of the first NTS selection success flag _ NTS1 is 1, which indicates that the selection is unsuccessful; NTS denotes the nominal transmit time slot; the time slot state comprises idle, internal partition, external partition, available and unavailable; the channels comprise an A channel and a B channel, the period of each channel is 7 frames, each frame is 1 minute, and the channels comprise 2250 time slots;
the specific method for monitoring the channel and receiving the time slot information by the interception module to acquire and mark the use condition of the channel time slot comprises the following steps:
b1, monitoring two channels for 1 minute, receiving 2250 time slot information, judging the communication state of the received information, if the received information is ITDMA, entering step B2, and if the received information is SOTDMA, entering step B4;
b2, analyzing the increment content, updating the state of the opposite channel of the current receiving channel in the reserved time slot table, and modifying the time slot state of the current time slot backward time slot increment into external division;
b3, judging whether the holding mark is true, if so, updating the state of an opposite channel of the current receiving channel, modifying the time slot state of the current time slot + time slot increment +2250 into external division, and modifying the time slot state of the current time slot + time slot increment +2250 x 2 into external division; updating the current receiving channel state, modifying the time slot state of the current time slot +2250 into external division, and modifying the time slot state of the current time slot +2250 x 2 into external division; otherwise, not processing;
b4, judging whether the time slot timeout value and the time slot offset are not both 0, if so, updating the reserved time slot table one by one in a time slot timeout value frame according to a 1371 protocol; otherwise, entering the step B5;
b5, checking whether a time slot reserved by other stations exists in a time slot of the same time slot number as the current time slot in the forward frame, and if so, changing the time slot state of the time slot of the same time slot number as the current time slot in the forward frame into an idle state; otherwise, no processing is performed.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108811001A (en) * | 2018-04-28 | 2018-11-13 | 中国科学院上海微系统与信息技术研究所 | The discretized channel cut-in method reserved with TDMA based on CSMA competitions |
| CN112954801A (en) * | 2021-02-03 | 2021-06-11 | 山东星通易航通信科技有限公司 | VDES frame mapping table idle time slot searching method based on block division |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3851957B1 (en) * | 2006-02-06 | 2006-11-29 | 国土交通省国土技術政策総合研究所長 | Marine mobile object monitoring system near offshore structure and offshore mobile object monitoring method near offshore structure |
| CN102547584B (en) * | 2010-12-13 | 2015-05-27 | 浙江海洋学院 | Channel access method for ship-mounted wireless mobile Ad-hoc network based on self-organization time division multiple access |
| CN103051410B (en) * | 2013-01-25 | 2016-08-03 | 南京航空航天大学 | A kind of raising method of self-organizing time division multiple protocol slot efficiency |
| CN111970763B (en) * | 2020-09-03 | 2021-09-14 | 山东星通易航通信科技有限公司 | VDES dynamic time slot reservation method based on message priority and rate |
| CN113709899B (en) * | 2021-08-16 | 2024-02-27 | 杭州电子科技大学 | Self-organizing time division multiple access method for ship automatic identification system |
| CN114245474A (en) * | 2021-12-01 | 2022-03-25 | 杭州矢志信息科技有限公司 | Self-organizing time division multiple access method of automatic ship identification system |
-
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- 2023-01-03 CN CN202310000691.4A patent/CN115696448B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108811001A (en) * | 2018-04-28 | 2018-11-13 | 中国科学院上海微系统与信息技术研究所 | The discretized channel cut-in method reserved with TDMA based on CSMA competitions |
| CN112954801A (en) * | 2021-02-03 | 2021-06-11 | 山东星通易航通信科技有限公司 | VDES frame mapping table idle time slot searching method based on block division |
Non-Patent Citations (1)
| Title |
|---|
| 谢伟东 ; 郑佳春 ; 张杏谷 ; 郭建伟 ; .AIS基站通信时隙的在线监测与评估.(第06期), * |
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