KR101352443B1 - Time division multiple access type medium access control protocol for ship station - Google Patents

Abstract

The present invention relates to a time division multiple access type medium access control method for a ship station in maritime communications and, to a time division multiple access type medium access control method designed with an enhanced ad-hoc self-organizing time division multiple access (EASO-TDMA) capable of responding to the environment change of the maritime communications and capable of solving the weak points of an ad-hoc self-organizing time division multiple access (ASO-TDMA). [Reference numerals] (AA) Start; (BB) End; (S1) Time frame synchronization level = 1; (S12,S16) Time slot release; (S17) End or Continue?; (S3) Does a neighboring ship station exist or not exist?; (S4,S8) Does a path exist or not exist?; (S9) Path table update

Description

Time division multiple access method for medium access control for ship stations {TIME DIVISION MULTIPLE ACCESS TYPE MEDIUM ACCESS CONTROL PROTOCOL FOR SHIP STATION}

The present invention relates to a time division multiple access medium access control method for a ship station, and to overcome the disadvantages of a communication method using an ad hoc self-organizing time division multiple access (TDMA). In addition, the present invention relates to a time division multiple access medium access control method for a ship station that can respond to changes in the environment of marine communications in a more practical manner.

In general, a ship station is a radio station installed in a ship, and is provided for the maritime communication environment of a marine mobile chain ship.

As shown in FIG. 1, the vessel located at sea may be randomly scattered over the entire ocean, and may perform maritime communication with neighboring ship stations or land base stations in the vicinity.

To this end, each ship is equipped with a VHF (Very High Frequency) transceiver, and in order to prepare for the communication disruption of the VHF band is also equipped with a high frequency (HF) or satellite frequency band communication system.

On the other hand, maritime vessels are ad hoc self-configuring ad hoc self-configured TDMA (Medium Access Control) for performing multi-hop data communication with neighboring ship stations or terrestrial base stations through the VHF band. Organizing Time Division Multiple Access (ASO-TDMA) is used.

In other words, the maritime vessel communicates ASO-TDMA with neighboring ship stations or land base stations, and transmits its own data or the received data through the corresponding communication path by a given routing protocol.

However, the ASO-TDMA method, which has been used as a MAC for maritime communication, serves as a service of the ship's position and identification information, is vulnerable to reception collisions, and has difficulty in transmitting stable data.

In addition, although there are many changes in the environmental conditions such as the increase of the communication data rate and the change of the maritime communication environment of the VHF band compared to the existing ones, they are not reflected substantially.

In addition, in the conventional ASO-TDMA method for maritime communication, the hop is determined according to the position of the ship station, and the sub-timeframe is divided according to the hop, but one time slot is allocated per corresponding sub-timeframe. There was a problem that the time delay must increase, the timeout occurs frequently, and there is no factor controlling network congestion.

On the other hand, the patent document of the prior art document receives from the maritime broadcast base station the maritime arrangement information including the setting information of the coastal base stations and the setting information of the maritime broadcasting stations, and sets the wireless link And a wireless link is established through a neighboring ship station where a wireless link configurable coast station is not present and a wireless link is settable. If there is no adjacent wireless link establishable coast station and a wireless link establishable adjacent ship station does not exist, INMARSAT Maritime Satellite) or MVSAT (Maritime Very Small Aperture Terminal).

[Patent Document] Korean Unexamined Patent Publication No. 10-2013-0074901 (published Jul. 05, 2013) (Name of Invention: Marine Communication System and Method)

The present invention has been made to solve the problems of the prior art as described above, the disadvantage of the communication method by the Ad Hoc Self-Organizing Time Division Multiple Access (ASO-TDMA) used in the past For Ship Stations Designed with Enhanced Ad Hoc Self-Organizing Time Division Multiple Access (EADMA-TDMA) Communication Enhancements It is an object of the present invention to provide a time division multiple access method of media access control.

The present invention provides a time division multiple access medium access control method for a ship station that can reduce overall transmission delay due to maritime communication, avoid reception collisions, and control network congestion. There is this.

The problem to be solved by the present invention is not limited to the above-mentioned problem (s), and another problem (s) not mentioned can be clearly understood by a person skilled in the art from the following description.

In order to solve the above problems, the time division multiple access medium access control method for a ship station according to a preferred embodiment of the present invention, FP processing step and NP processing step, the FP processing step,

(A) synchronizing the timeframes and setting the level to "1";

(B) an SOF step of receiving a packet with the time frame in a reception mode;

(C) After step (B), check the presence of the neighboring ship station (NS), if there is a neighbor ship station moves to step (E) to check the path, if not present N _F (ad-hoc) Reducing the number of network connection attempts once);

(D) checking whether the value of N _F is "0", but if "0" is terminated, otherwise moving to (B);

(E) checking whether the neighboring ship station is in a route, if there is a route, updating a route table (Route_table) and moving to NP processing; otherwise, moving to (F);

(F) a TROF step of processing a transmission mode for a time slot occupied in the time slot TS allocated per time frame and a reception mode for an unoccupied time slot;

(G) re-checking whether the neighboring ship station is in a path, if there is a path, updating the path table and moving to the NP processing step; otherwise, moving to step (H);

(H) reducing one N _DL (number of timeslot holding timeframes of the ship station) in the timeframe and confirming the _NDL value;

(I) checking whether the N _DL value is "0", if "0", moves to step (J); otherwise, moving to step (E);

(J) releasing and terminating the timeslot if the N _DL value is "0";

The NP processing step,

(1) a TROF step of processing a transmission mode for a time slot occupied in the allocated time slots per timeframe and a reception mode for an unoccupied time slot;

(2) reducing one N _DL (the number of timeslot holding timeframes of the ship station) in the time frame and confirming the N _DL value;

(3) checking whether the N _DL value is "0", if "0", moves to step (4); otherwise, moving to step (1);

(4) releasing a time slot if the N _DL value is "0";

(5) after step (4), check whether it is finished, and if it is correct, end; otherwise, moving to step (A) of the FP processing step; As a basic feature of the technical construction.

The details of other embodiments are included in the detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and / or features of the present invention and the manner of achieving them will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. And is provided to fully explain the scope of the present invention to those skilled in the art.

According to the present invention, it is possible to reduce the overall transmission delay due to maritime communication by setting the level of the ship station and setting the time slot allocation zone according to the level of the ship station set within the sub time frame in which the number of timeslots is equally assigned. Incoming collisions can be avoided, using the neighboring ship station table to set the number of timeslots as the average of the number of timeslots of neighboring ship stations of the same level, and using the timeout of the physical layer or the network layer, the time in the time frame. Control such as increasing or decreasing the allocation number of slots can be performed to achieve the usefulness of controlling network congestion.

The present invention improves the shortcomings of the communication method by the Ad Hoc Self-Organizing Time Division Multiple Access (ASO-TDMA), which is being used, and performs a more substantial response to changes in the environment of marine communications. Enhanced Ad Hoc Self-Organizing Time Division Multiple Access (EADMA-TDMA) communication is provided.

1 is a diagram illustrating a general maritime communication system.
Figure 2 is a flow chart showing for processing a time division multiple access method media access control method for a ship station according to a preferred embodiment of the present invention.
3 is a view illustrating a time frame and a sub time frame in the present invention.
4 is a detailed flowchart showing for explaining SOF processing in the present invention.
Figure 5 is an exemplary view showing one type of neighboring ship station table in the present invention.
6 is an exemplary diagram showing one type of route table in the present invention.
7 is a detailed flowchart showing for explaining TROF processing in the present invention;
8 is a detailed flowchart illustrating the DTS processing in the present invention.
FIG. 9 is a diagram illustrating a time slot allocation scheme in a Sub DTS 1 for DTS in the present invention. FIG.
Fig. 10 is a detailed flowchart showing for explaining the RPP processing in the present invention.
11 is a view for explaining a queuing processing method in the present invention.
Fig. 12 is a table shown for explaining the definition of parameters described in the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in Fig. 2, the time division multiple access method for accessing a medium according to a preferred embodiment of the present invention can be configured by dividing it into a first phase (FP) processing step and a normal phase (NP) processing step. .

The FP processing step performs network entry, time slot scanning in a time frame, neighboring ship station identification, path setting, etc., and the NP processing step uses a time slot occupied in a time frame using a path given through the FP processing step. It transmits a packet to a neighboring ship station and receives a packet from a neighboring ship station.

Specifically, the FP processing step synchronizes the time frame and sets the level to "1" (S1).

In this case, the time frame has a plurality of sub time frames for one time frame, as shown in FIG. 3, and can be set to 10 sub time frames per one time frame, which means that the maximum number of hops is “3”. In this case, since five transmissions must be performed in order to perform multihop communication such as uplink processing and downlink processing in one time frame, it is preferable to set the number of sub time frames to five or more, and to perform multihop communication in one time frame. By default, at least one _timeslot defaults to a sub timeframe because the value of N _sld (number of default _timeslots occupied by ship stations with level) is "10" for ship stations with level = 1. To assign

In addition, since one time frame consists of 10 sub time frames, each sub time frame may be defined as constituting 225 timeslots.

A scan one frame (SOF) for receiving a packet is performed by using the time frame as a reception mode (S2).

In this case, a time slot number (NO _TS) = 1, the sub-time frame number (NO _SF) = 1, from a time slot number (NO _TS) = 220, the sub-time frame number (NO _SF) receives a packet = to 10, athletics It is preferable to receive until the beacon of the station is received.

In detail, as illustrated in FIG. 4, the SOF checks whether there is an error in the received packet (S2-1), and if so, drops (S2-2), otherwise extracts information from the received packet. The neighboring ship station table NS_table is updated (S2-3).

FIG. 5 is an exemplary diagram showing a neighboring ship station table, in which [N _DL (number of timeslot maintenance frames of a ship station) = 0] in the network parameter shown in FIG. 5 is configured to not end when the maintenance of the timeslot expires. In this case, the neighboring ship station table may be maintained without being reset, so that the neighboring ship station table may be updated and utilized when the FP processing step is performed again, and may be an indicator for identifying the idle timeslot.

After step S2-3, it is checked whether the reception packet is beaconed in the reception mode (R2) (S2-4), and if it is correct, check whether the reception packet is the routing packet (R_packet) (S2-5), otherwise Check whether the reception packet is a beacon of the land station (S2-6).

In step S2-5, if the reception packet matches the routing packet, the MAC address header is removed and transmitted to the Q _NL (network layer packet storage queue) (S2-7). Otherwise, the packet is sent to step S2-2 for drop processing.

In addition, in step S2-6, if the reception packet is matched with the beacon of the land station, the route table (Route_table) is updated (S2-8). Otherwise, the procedure goes to step S2-9 below.

FIG. 6 is an exemplary diagram showing a route table. When receiving a beacon of a land station, FIG. 6 is capable of one-hop communication with the land station. Therefore, the route table is cleaned and updated as shown in FIG. This is also configured as [N _DL (time slot maintenance frame number of ship station) = 0] so that it is not terminated even if the maintenance of the time slot expires, so that it is not reset and remains updated and utilized when the FP processing step is resumed. Through the route table, it is possible to identify that there are different levels and to be an indicator of identifying the highest level.

After step S2-7 or step S2-8, time slot number NO _TS is increased by one (S2-9).

Subsequently, after step S2-9, it is checked whether the sub time frame number NO _{SF of the} time frame is "10" (S2-10), and if it is correct, the time slot number is greater than "220" ( S2-11), otherwise check whether the timeslot number is greater than "225" (S2-12).

If the time slot number is greater than " 220 " in step S2-11, after performing DTS for setting the time slot in the sub time frame according to the level (S2-13), a packet to be sent in the next time frame is transmitted. The data is transmitted to the physical layer PL (S2-14).

In addition, if the time slot number is greater than " 225 " in step S2-12, the sub time frame number is increased by one while the time slot number is " 1 " (S2-15).

Subsequently, in step S2-15, whether the sub time frame number increased by one is greater than "10" (S2-16).

Here, in step S2-11, step S2-12 and step S2-16, when the NO signal, respectively, go to step S2.

After step S2 of performing the SOF process of steps S2-1 to S2-16 described above, the presence or absence of the neighboring ship station (NS) (S3), if the neighboring ship station exists, whether the route (S4) If not present, N _F (number of ad-hoc network connection attempts) is decreased once (S5).

After step S5, it is checked whether the N _F value is "0" (S6). If "0", the process is terminated. Otherwise, the process moves to step S2 for SOF processing.

Subsequently, in step S4, whether the neighboring ship station is in a path is checked, if there is a path, the route table is updated, and the process moves to TROF (S13) of the NP processing step.

In step S4, it is determined whether the neighboring ship station is a route. If there is no route, the transmission mode is processed for the time slot occupied in the time slot (TS) allocated per time frame, and the reception mode is processed for the time slot not occupied. Transmit Receive One Frame (TROF) is performed (S7).

Here, the same processing is performed for the TROF step S7 of the FP processing step and the TROF step S13 of the NP processing step, respectively.

Incidentally, as in the detailed flow chart shown in 7, the TROF includes the following detailed steps.

First, it is checked whether the _timeslot number NO _TS and the reserved _timeslot number NO _TSrsv are the same (S21), but if they are the same, the transmission mode (TX) is switched and the packet is transmitted in the reserved _timeslot (S22).

If not the same in step S21, switch to the receive mode (RX) to receive the packet, but performs the RPP (Received Packet Processing) for processing according to the type of the packet (S23).

After step S22 or after step S23, the time slot number NO _TS is increased by one (S24).

After step S24, it is checked whether the sub time frame number (NO _SF ) is "10" (S25), if correct, checks whether the time slot number is greater than "224" (S26), otherwise the time slot number is " Check whether the number is greater than 225 "(S27).

Here, if the timeslot number is greater than "224", after performing a DTS (Determine Time Slot) for setting the timeslot in the sub timeframe according to the level (S28), the packet to be transmitted in the next timeframe is physical layer. (PL) (S29).

Further, if the time slot number is greater than " 225 " in step S27, the sub time frame number is increased by one while the time slot number is " 1 " (S30).

Then, it is checked whether the sub time frame number is larger than "10" (S31), and if it is correct, it ends, otherwise it moves to the beginning of TROF.

In addition, if the time slot number NO _TS and the reserved time slot number NO _TSrsv are not the same in step S21, _{checking whether the} time slot number NO _TSrsv is the new sub time frame number NO _SF without performing step S23. S32) may be performed.

At this time, in step S32, if it is correct, check whether the packet storage queue Q _{TX _ PL} storing the packet to be transmitted to the physical layer is empty (S33), otherwise, if the time slot number is smaller than the reserved time slot number. Check (S34).

If the packet storage queue is empty in step S33, the process moves to step S24. Otherwise, a packet to be sent in the next time frame is transmitted to the physical layer (S35).

If the time slot number is smaller than the reserved time slot number in step S34, the process moves to step S33, otherwise, the procedure goes to step S24.

Here, receive and transmit from [NO _TS = 1, NO _SF = 1 to (NO _TS ) = 224, NO _SF = 10], and timeslot through DTS for [NO _TS = 225, NO _SF = 10]. _{Retransmission of the} packet and the packet to send to the physical layer is transmitted, but when the packet is transmitted to the physical layer, the time slot number (NO _TS ) and the reserved time slot number (NO _TSrsv ) is not the same, the new NO _SF and Q _{TX _} performed when _PL is not empty, and the new _SF nO nO is not a _TS <nO _TSrsv and Q _{TX _ PL} is also preferable to perform this when it is not empty.

In step S8, if there is a route of the neighboring ship station, the route table is updated (S9) and then moved to step S13, which is an NP processing step. Otherwise, N _DL (number of timeslot maintenance time frames of the ship station) in the time frame is obtained. One by one (S10).

Subsequently, after step S10, it is checked whether the N _DL value is "0" (S11). If the N _DL value is "0", the time slot is released (S12), otherwise, the process moves to step S7. .

In addition, in step S4, whether the neighboring ship station is checked or not, if there is a path, moves to the NP processing step, but the transmission mode is processed in the time slot occupied in the time slot (TS) allocated per time frame. In the unsuccessful timeslot, a TROF for processing a reception mode is performed (S13).

After the step S13, in the time frame N _DL (the number of timeslot holding time frame of the ship station) is reduced by one (S14), and then check whether the N _DL value is "0" (S15), but N _DL If the value is "0", the time slot is released (S16), otherwise, the procedure goes to step S13.

After the step S16, it is confirmed whether or not to terminate (S17), and if it is correct, it terminates, otherwise it moves to the step S1 which is the FP processing step.

On the other hand, in performing the DTS in step S2-13 in the SOF step, as in the detailed flowchart shown in FIG. 8, it is determined whether or not the step FP is performed (step S41). _slavg (average value of N _sl of neighboring ship stations of the same level in a ship station with a neighboring ship station), I _NOsf (number of idle _timeslots per sub timeframe), N _sl (ship station with a level) Sub DTS to determine any one or more of the occupied _timeslots ) and to set N _DL (the number of _timeslot holding _timeframes of the ship station) = N _DLd (the number of _timeslot holding _timeframes of the ship station) Only performs (1) (S42).

This is to set the timeslot in the sub time frame according to the ship station level.

On the other hand, in performing the DTS which is the step S28 in the TROF step, as shown in the detailed flowchart shown in FIG. 8, it is first determined whether it is the FP processing step (S41), and if it is not the FP processing step, it is determined whether the level of the ship station has changed. Check (S43).

If the level is changed in step S43, N _slavg (the ship station having the level is the average value of N _sl of the neighboring ship stations of the same level in the neighboring ship station) and I _NOsf (per sub time frame) using the neighboring ship station table. idle number of time slots), N _sl of (the number of time slots a ship station is occupied with level) determining at least one of a and, N _DL (number of ship station time slot holding time frame) = N _DLd ( Sub DTS 1 is set to set the default timeslot holding timeframe of the ship station (S44).

After the step S44 of performing the Sub DTS (1), it is checked whether the level has been increased (S45), and if it is raised, it is checked whether a timeout has occurred in the network layer (S46), and if so, N _slmin (ship having a level). Perform Sub DTS (2) to release the timeslot per sub timeframe and send the release information to the timeslot to release by comparing the minimum number of timeslots that the station can occupy to the current N _sl value. (S47).

Then, if there is no level change in step S43, it is checked whether the level of the ship station is "3" (S48).

At this time, if the ship station level is "3", check whether N _B (the number of timeslots occupied by the land station) is changed (S49), and if it is changed, check whether the value of N _B is increased (S50), and if so, N Due to the increase in the value of _B, Sub DTS (3) is performed to release the timeslot and transmit the release information to the timeslot to be released (S51).

If the N _B value does not increase in step S50, it is checked whether a timeout has occurred in the physical layer or the network layer (S52), otherwise the Sub DTS (4) for adding a time slot due to the decrease of the N _B value Perform (S53).

If the ship station level is not "3" in step S48, it is checked whether a timeout has occurred in the physical layer or the network layer (S54), and if so, the sub DTS (2) is performed (S55). .

Further, the process proceeds to a step S54 to check whether the above steps S49 N _B (land station the number of the occupied time slot), but if the confirmation that the change has not been changed this time-out is generated in the physical layer and network layer.

That is, in performing the DTS in step S28 in the above-described TROF step, the sub DTS such as Sub DTS (1), Sub DTS (2), Sub DTS (3), and Sub DTS (4) in consideration of the time slot increase / decrease factor This is done by determining the type or maintaining the timeslot.

Here, if time slot increase and decrease factor exist at the same time, it is maintained without changing the time slot.Except when time slot decrease occurs due to timeout when time slot increase due to level increase occurs, it is duplicated but has the following priority. It is preferable to.

When the timeslot reduction factor overlaps, the priority is such that when there is no level change, the time slot decrease due to increase of N _B takes precedence over the time slot decrease due to timeout, and when there is a level change, The time slot reduction caused by time slots takes precedence over the time slot reduction caused by timeouts.

In the Sub DTS 1, as shown in FIG. 9, the receiving stations can reduce the reception impulse rate by changing the starting point for allocating the timeslot according to the level value, and continuously uplink in one sub time frame. (uplink) can be configured to transmit data.

For example, when the level is set to 1 to 3, the Sub DTS (1) and the Sub DTS (2) perform operations at all of Levels 1, 2, and 3, and the Sub DTS (3) and the Sub DTS (4). Is limited to level 3 to perform the task.

On the other hand, in the TROF process, the RPP in step S23 confirms whether there is an error in the received packet (S23-1) as shown in FIG. 10, but if it is correct, drops the received packet (S23-2). Otherwise, the neighboring ship station table (NS table) is updated (S23-3).

After step S23-3, it is checked whether the received packet is a beacon (Beacon) (S23-4).

In step S23-4, if the beacon is N _B (number of timeslots occupied by the land station) is checked (S23-5), if it is changed, it is checked whether the value of N _B is increased (S23-6), and if so, the level In step S23-7, a DTS for setting a timeslot in the sub time frame is performed.

At this time, since the DTS in step S23-7 is the same as the procedure of processing step S2-13 or step S28 having the above-described description, a detailed description thereof will be omitted.

In this case, if the signal is NO in steps S23-5 and S23-6, the process proceeds to step S23-2 to maintain the time slot as it is and drop the beacon.

In step S23-4, if the beacon is not a data packet (D_packet), it is checked (S23-8). If the data packet is IP based or non-IP based on Q _{RX _ PL _IP} (IP based data packet storage received from the physical layer) Queue) or Q _{RX _ PL _ NIP} (non-IP based data packet storage queue received from the physical layer) (S23-9).

After the step S23-9, it is checked whether the data packet has been downlinked (S23-10), and if it is downlinked, it is checked whether the number of pieces LEN of the MAC frame is "1" (S23). -11).

If the number of pieces (LEN) of the MAC frame (MAC) in step S23-11 is "1", check whether the receiving ship station (D) is the same in the route table ID (SID) of the ship station (S23-12), If the receiving ship station (D) is the same in the ship station's ID (SID) and in the route table, the MAC address header is removed and transmitted to Q _{TX_NL} (packet storage queue to be transmitted to the network layer) (S23-13).

In step S23-12, if the ID (SID) of the ship station and the receiving ship station (D) are not the same in the route table, the MAC address header value is changed to Q _{TX _ PL} (packet storage queue to be transmitted to the physical layer). It transmits (S23-14).

In addition, in step S23-8, if it is not a data packet, whether it is a routing packet (R_packet) is checked (S23-15), and if the routing packet is correct, the Q _{RX _ PL _R} (routing packet storage queue received from the physical layer) is checked. After storing (S23-16), the flow proceeds to step S23-13.

If it is not the routing packet in step S23-15, the release information is received to check the NO _SF (sub time frame number) and NO _TS (time slot number) and update the neighboring ship station table (S23-17).

Further, if the downlink process is not performed in step S23-10, the ship station ID (SID) and the neighboring ship station (RN) in the route table are checked (S23-18), but the same auss (MAC) frame fragment It is checked whether the number LEN is "1" (S23-19).

At this time, if the NO signal in step S23-18 to go to step S23-2 to drop processing.

In step S23-19, when the number of pieces of the MAC frame MAC is "1", the value of the MAC address header is changed and transmitted to Q _{TX _ PL} (packet storage queue to be transmitted to the physical layer). If the number of pieces of the MAC frame MAC is not "1", it is checked whether the number of pieces of the MAC frame FN and the number of MAC frames of the MAC frame are the same (S23-20). ).

If the fragment number (FN) and MAC (MAC) frame fragment number (LEN) of the MAC frame is the same in step S23-20, the value of the MAC address header is changed to Q _{TX _ PL} (packet storage queue to be transmitted to the physical layer). In step _S23-14 , the data packet is transmitted to Q _{TX _DL} (Data Packet Temporary Storage Queue).

In step S23-11, if the number of pieces of the MAC frame MAC is not "1", it is checked whether the number of pieces of the MAC frame FN and the number of pieces of the MAC frame MAC are the same (S23). -22).

If the piece number (FN) of the MAC frame and the number of pieces (LEN) of the MAC frame are the same in step S23-22, check whether the receiving ship station (D) is the same in the ship station ID (SID) and the route table (S23). Otherwise, go to step S23-21 for transmitting the data packet to Q _{TX _ DL} (data packet temporary storage queue).

If the ID (SID) of the ship station and the receiving ship station (D) are the same in the route table in step S23-23, the MAC address header is removed and transmitted to Q _{TX _ NL} (packet storage queue to be transmitted to the network layer). Go to step 13, otherwise, go to step _{S23-15 where} the value of the MAC address header is changed and transmitted to Q _{TX_PL} (packet storage queue to be transmitted to the physical layer).

Here, in step S23-12, the route table is checked to determine whether the ID (SID) of the ship station and the receiving ship station D are the same in the route table.

In step S23-17, upon receiving the release information, the NO _SF (sub time frame number) and the NO _TS (time slot number) are checked, the NO _SF and NO _TS values are deleted from the neighboring ship station table, and the idle time slot is checked. It is desirable to update by processing.

Meanwhile, in the present invention, it is preferable to perform a queuing process on the received packet. As shown in FIG. 11, a packet received from the network layer is transferred to the physical layer to queue, and the physical layer is queued. The received packet is transmitted to the network layer or back to the physical layer for queuing.

In this case, the data packet in the received packet is to transmit its own data, not forwarding, and can be divided into IP-based and non-IP-based, and the routing packet is generated for establishing a communication path of another ship station or its own communication path. It means to be.

In this case, the packets received from the network layer are transmitted to the physical layer for queuing (PQ1). The queuing priority is determined based on a route setting packet (R_packet)> an IP based data packet (D_packet) (D_packet).

In addition, the packet received from the physical layer is transmitted to the network layer or back to the physical layer for queuing processing (PQ2), and the queuing priority is IP-based data packet (D_packet)> routing packet> non-IP-based data packet (D_packet). It is preferable to process with.

12 is a diagram for explaining the definition of parameters described in the present invention, which defines various network parameters used in the present invention, and the parameters may be more easily understood.

As mentioned above, although preferred embodiments of the present invention have been described with reference to some embodiments, such descriptions are merely exemplary, and the present invention may not be construed as being limited thereto by any means. Those skilled in the art will understand from the above description that the present invention can be variously modified, modified, or substituted, or the equivalent can be carried out with the present invention.

Claims (13)

It consists of FP processing step and NP processing step,
The FP processing step,
(A) synchronizing the timeframes and setting the level to "1";
(B) an SOF step of receiving a packet with the time frame in a reception mode;
(C) After step (B), check the presence of the neighboring ship station (NS), if there is a neighbor ship station moves to step (E) to check the path, if not present N _F (ad-hoc) Reducing the number of network connection attempts once);
(D) checking whether the value of N _F is "0", but if "0" is terminated, otherwise moving to (B);
(E) checking whether the neighboring ship station is in a route, if there is a route, updating a route table (Route_table) and moving to NP processing; otherwise, moving to (F);
(F) a TROF step of processing a transmission mode for a time slot occupied in the time slot TS allocated per time frame and a reception mode for an unoccupied time slot;
(G) re-checking whether the neighboring ship station is in a path, if there is a path, updating the path table and moving to the NP processing step; otherwise, moving to step (H);
(H) reducing one N _DL (number of timeslot holding timeframes of the ship station) in the timeframe and confirming the _NDL value;
(I) checking whether the N _DL value is "0", if "0", moves to step (J); otherwise, moving to step (E);
(J) releasing and terminating the timeslot if the N _DL value is "0";
The NP processing step,
(1) a TROF step of processing a transmission mode for a time slot occupied in the allocated time slots per timeframe and a reception mode for an unoccupied time slot;
(2) reducing one N _DL (the number of timeslot holding timeframes of the ship station) in the time frame and confirming the N _DL value;
(3) checking whether the N _DL value is "0", if "0", moves to step (4); otherwise, moving to step (1);
(4) releasing a time slot if the N _DL value is "0";
(5) after step (4), check whether it is finished, and if it is correct, end; otherwise, moving to step (A) of the FP processing step; Time division multiple access method medium access control method for a ship station comprising a.
The method of claim 1,
SOF of the FP processing step,
(B-1) checking whether there is an error in the received packet, if it is correct, dropping the packet, otherwise updating the neighboring ship station table NS_table;
(B-2) After updating the neighboring ship station table, check whether the reception packet is beaconed in the reception mode (RX), if it is, check whether the routing packet is R_packet, otherwise the beacon of the land station. Checking whether it is;
(B-3) if the routing packet is correct in step (B-2), removing the MAC address header and transmitting it to Q _NL (Network Layer Packet Storage Queue); otherwise, drop processing;
(B-4) updating the route table if the beacon of the land station is correct in step (B-2); otherwise, moving to step (B-5);
(B-5) after step (B-3) or after step (B-4), increasing a time slot number (NO _TS ) by one;
(B-6) After step (B-5), it is checked whether the sub time frame number (NO _SF ) of the time frame is "10", and if it is correct, the time slot number is greater than "220". Otherwise checking if the timeslot number is greater than "225";
(B-7) If the timeslot number is greater than " 220 " in step (B-6), after performing the DTS for setting the timeslot in the sub timeframe according to the level, it should be sent in the next time frame. Transmitting a packet to a physical layer PL;
(B-8) if the timeslot number is greater than " 225 " in step (B-6), setting the timeslot number to " 1 " and incrementing the sub timeframe number by one;
(B-9) checking whether the increasing sub time frame number is greater than "10" in step (B-8), and ending if correct; Time division multiple access method medium access control method for a ship station comprising a.
The method of claim 1,
TROF of the FP processing step or TROF of the NP processing step, respectively,
(F1-1) checking whether the _timeslot number NO _TS and the reserved _timeslot number NO _TSrsv are the same;
(F1-2) if the same in step (F1-1), switching to a transmission mode (TX) and transmitting a packet in a reserved timeslot;
(F1-3) an RPP step for receiving a packet by switching to a reception mode (RX) if it is not the same in the step (F1-1), but processing the packet according to the type of the packet;
(F1-4) after the step (F1-2) or after the step (F1-3), increasing the time slot number (NO _TS ) by one;
(F1-5) After the step (F1-4), it is checked whether the sub time frame number (NO _SF ) is "10". If it is correct, the time slot number is greater than "224". Checking that the number is greater than "225";
(F1-6) If the timeslot number is greater than " 224 " in step (F1-5), after performing the DTS for setting the timeslot in the sub timeframe according to the level, it should be sent in the next time frame. Transmitting a packet to a physical layer PL;
(F1-7) if the time slot number is greater than "225" in step (F1-5), increasing the number of sub time frame numbers by setting the time slot number to "1";
(F1-8) checking whether the sub time frame number increasing in step (F1-7) is greater than "10", and ending if correct; Time division multiple access method medium access control method for a ship station comprising a.
The method of claim 3, wherein
In the step (F1-3),
If not the same in the step (F1-1), switch to the reception mode (RX) to receive the packet, but does not perform the RPP to process according to the type of packet,
A first step of checking whether a new sub time frame number (NO _SF ) is performed, and if it is correct, a second step of checking whether a packet storage queue (Q _{TX _ PL} ) storing a packet to be transmitted to the physical layer is empty. Otherwise, perform the third step of checking whether the timeslot number is smaller than the reserved timeslot number,
In step 2, if the packet storage queue is empty, move to step F1-7; otherwise, perform step 4 of transmitting a packet to be transmitted in the next time frame to the physical layer,
In the third step, if the time slot number is smaller than the reserved time slot number, move to the second step; otherwise, perform the fifth step of moving to step (F1-7). Connection method Medium access control method.
3. The method of claim 2,
The DTS in the step (B-7),
(B-7a) determining whether or not the FP processing step;
(B-7b) In the case of FP processing in step (B-7a), N _slavg (the average value of N _sl of neighboring ship stations of the same level in a ship station having a level is _determined by using a neighboring ship station table). _{Determine one} or more of I _NOsf (number of idle time slots per sub timeframe), N _sl (number of time slots occupied by a ship station with level), and maintain N _DL (time slot of ship station) _Performing Sub DTS 1 to set N _DLd (the number of time slots maintaining time frames of the ship station) = N _DLd ; Time division multiple access method medium access control method for a ship station comprising a.
The method of claim 3, wherein
The DTS in the step (F1-6),
(F1-6a) determining whether it is an FP processing step;
(F1-6b) checking whether the level of the ship station has changed, if not in the FP processing step;
(F1-6c) If the level has been changed in the above (F1-6b), N _slavg (the ship station having the level is the average value of N _sl of the neighboring ship stations of the same level in the neighboring ship station using the neighboring ship station table). ), I _NOsf (number of idle _timeslots per sub timeframe), N _sl (number of _timeslots occupied by ship stations with levels), and N _DL (time slots of ship stations). _Performing Sub DTS (1) to set N _DLd (the number of default time slot holding time frames of the ship station) = N _DLd ;
(F1-6d) After performing Sub DTS (1) in step (F1-6c), it is checked whether the level has risen, but if it has risen, it is checked whether a timeout has occurred in the network layer, and if so, N _slmin (level Sub DTS (2) for releasing time slots per sub timeframe and sending the release information to the time slots to be released by comparing the current N _sl value with the minimum number of timeslots that can be occupied by a ship station with Performing;
(F1-6e) if there is no level change in step (F1-6b), checking whether the level of the ship station is "3";
(F1-6f) of the level of the ship station is "3" N _B (land station the number of the occupied time slot), but confirm that the change, if change and verify whether this N _B value increases, then the value N _B Performing a Sub DTS (3) to release the timeslot due to the increase and to send the release information to the timeslot to be released;
(F1-6g) above did not this N _B value increases from (F1-6f) step checks whether a timeout has occurred in the physical layer and network layer, otherwise the reduction of the N values _B for the addition of a time slot because of the Performing a Sub DTS 4; Time division multiple access method medium access control method for a ship station comprising a.
The method according to claim 6,
If the level of the ship station is not "3" in step (F1-6e), checking whether a timeout has occurred in the physical layer or the network layer, and if so, performing a Sub DTS (2); Time division multiple access method medium access control method for a ship station comprising a.
The method according to claim 6,
In step (F1-6f), check whether N _B (the number of timeslots occupied by the land station) has changed, and if not, check whether a timeout has occurred in the physical layer or the network layer, and if so, the Sub DTS ( Performing 2); Time division multiple access method medium access control method for a ship station comprising a.
The method of claim 3, wherein
RPP in the step (F1-3),
(F1-3a) checking whether there is an error in the received packet, if correct, drop processing, otherwise updating the neighboring ship station table NS_table;
(F1-3b) checking whether the received packet is a beacon;
(F1-3c) the (F1-3b) but ensure that the beacon is N in Step _B (land station the number of the occupied time slot) is changed, and determine whether to change if N _B value increases, and if so, the sub-levels in accordance with the Performing a DTS for setting a timeslot in a timeframe;
(F1-3d) the IP-based data, receiving the (F1-3b) if the beacon in phase or, but confirm that the data packet (D_packet), data packets from the _RX Q _{_ _IP PL} (physical layer in accordance with the IP-based or non-IP-based Packet storage queue) or Q _{RX _ PL _ NIP} (non-IP based data packet storage queue received from the physical layer);
(F1-3e) checking whether the data packet is downlinked in the step (F1-3d);
(F1-3f) if the downlink process is performed in the step (F1-3e), checking whether the number of pieces (LEN) of the MAC frame is "1";
(F1-3g) If the number of pieces (LEN) of the MAC frame is "1" in the step (F1-3f), check whether the ID (SID) of the ship station and the receiving ship station (D) in the route table are the same. Making;
(F1-3h) If the ID (SID) of the ship station and the receiving ship station (D) are the same in the route table in step (F1-3g), the MAC address header is removed and Q _{TX _ NL} (packet to be transmitted to the network layer). Storage queue);
(F1-3i) If the ID (SID) of the ship station and the receiving ship station (D) are not the same in the route table in step (F1-3g), the MAC address header value is changed and transmitted to Q _{TX _PL} (physical layer). Transmitting a packet storage queue); Time division multiple access method medium access control method for a ship station comprising a.
The method of claim 9,
(F1-3j) checking whether it is a routing packet (R_packet) if it is not a data packet in step (F1-3d);
(F1-3k) storing the routing packet in Q _{RX _ PL _R} (routing packet storage queue received from the physical layer) if the routing packet in the step (F1-3j);
(F1-3l) In step (F1-3j), if the routing packet is not set, the release information is received to check the NO _SF (sub time frame number) and NO _TS (time slot number) and update the neighboring ship station table. step; Time division multiple access method medium access control method for a ship station comprising a.
The method of claim 9,
(F1-3m) checking the ID of the ship station (SID) and the neighboring ship station (RN) in the route table if the downlink process has not been performed in step (F1-3e);
(F1-3n) If in step (F1-3m) the ID (SID) of the ship station and the neighboring ship station (RN) are the same in the route table, check whether the number of pieces (LEN) of the MAC frame is "1". Making;
(F1-3o) If the number of fragments (LEN) of the MAC frame is "1" in step (F1-3n), change the value of the MAC address header to store the packet to be transmitted to the Q _{TX _ PL} (physical layer). Queue);
(F1-p) In step (F1-3n), if the number of pieces of the MAC frame MAC is not "1", the number of pieces of the MAC frame FN and the number of pieces of MAC frame MAC are LEN. Verifying equality;
(F1-q) If the fragment number (FN) of the MAC frame and the number of fragments (LEN) of the MAC frame are the same in step (F1-p), the value of the MAC address header is changed to Q _{TX _ PL} (physical). Packet storage queue to be transmitted to the layer);
(F1-r) If the fragment number (FN) of the MAC frame and the fragment number (LEN) of the MAC frame (MAC) of the MAC frame in step (F1-p) are not the same, the data packet is Q _{TX _ DL} (data packet temporary storage queue). Transmitting); Time division multiple access method medium access control method for a ship station comprising a.
The method of claim 9,
(F1-s) If the number of pieces of MAC frames MAC in the step (F1-3f) is not "1", the number of pieces of the MAC frames (FN) and the number of pieces of MAC frames (MAC) (LEN) Verifying equality;
(F1-t) If the fragment number (FN) of the MAC frame and the fragment number (LEN) of the MAC frame in the (F1-s) step are the same, the receiving ship station (SID) of the ship station and the route table ( D) step of the check is the same, otherwise, sending the data packets to a _TX Q _{_ DL} (data packet temporary storage queue);
(F1-u) If the ID (SID) of the ship station and the receiving ship station (D) are the same in the route table in step (F1-t), the MAC address header is removed to store the Q _{TX _ NL} (packet to be transmitted to the network layer). Queue), otherwise changing the value of the MAC address header and sending it to Q _{TX _ PL} (packet storage queue to be sent to the physical layer); Time division multiple access method medium access control method for a ship station comprising a.
The method according to any one of claims 1 to 3,
In the received packet,
Packets received from the network layer are transmitted to the physical layer for queuing, but the queuing priority is processed as routing packets (R_packet)> IP-based data packets (D_packet)> non-IP-based data packets (D_packet).
Packets received from the physical layer are transmitted to the network layer or back to the physical layer for queuing processing, but the queuing priority is processed as IP-based data packets (D_packet)> routing packets> non-IP-based data packets (D_packet). Time division multiple access method medium access control method for ship stations.

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