KR20230060158A - Method of setting a link for wireless data communication and an apparatus including the same - Google Patents

Abstract

The present invention relates to a technique for reducing an initial link setup time in adaptive automatic repeat wireless data communication.
The present invention is to reduce redundancy in the initial link establishment stage in adaptive auto repeat wireless data communication. Through means such as quality analysis, the transmission rate of the terminal is set to one of the appropriate modulation levels between the highest and lowest levels among the multi-level modulation levels, and communication between the base station and the terminal is set using the set transmission rate as the initial modulation level It includes a configuration that establishes a link and transmits data so that transmission speed adaptation is performed early.
According to the present invention, a base station communication system and a mobile station terminal device are immediately set to an appropriate transmission rate without actually having a paperweight connection. Through this, 'battery consumption' and 'effective interference in the ship' are reduced, and the error rate of data transmission is improved.

Description

Method of setting a link for wireless data communication and an apparatus including the same}

The present invention is a technology for quickly establishing a communication link in a wireless data communication system of an adaptive automatic repeat method.

Wireless data communication is usefully utilized as terrestrial communication of medium wave, medium wave, short wave (HF; High Frequency) and very high frequency (VHF) bands.

Adaptive Automatic Request (hereinafter also referred to as ‘Adaptive ARQ’), which is usefully used in wireless data communication, is a technology that controls the transmission speed while detecting whether the other party is receiving the signal transmitted by itself. When the other party fails to receive, it automatically retransmits (automatic retransmission), but in case of good reception, the transmission speed (i.e., modulation level) is increased by one step, and in case of poor reception, the transmission speed is lowered by one step. . That is, the best communication link is maintained by adjusting the transmission speed while going through the process of checking each other.

For example, when transmission fails 2 or 3 times, the speed is lowered by one level and when 2 or 3 times are successful, the transmission speed is increased by one level. This automatic retransmission method is useful in maritime communication, aviation communication, remote area communication, etc. in an ionospheric reflection or multi-path environment because only the speed is reduced and stable data transmission is possible even in a poor radio wave environment.

When a single frequency channel is shared by a plurality of terminals, occupancy time is allocated in an asynchronous time division multiple access method in order to prevent signal collision between several terminals on the channel and to transmit data stably. In the case of a wireless data communication network for position transmission for monitoring of many ships, the position of the ship is periodically transmitted to the control center and displayed on a GIS (Geographical Information System; hereinafter the same)-based screen.

In order to collect position reports of as many vessels as possible through a single or a small number of communication channels, the position report time for each vessel must be shortened. However, since the propagation environment between land and sea is mostly changed moment by moment due to fading or multipath, it takes a considerable amount of time to find a modulation level that will give the best transmission speed in the initial link setting stage. At the time of setting up wireless communication for the first time, since it is not possible to know the state of radio waves received by the other party, several exchanges of paperwork are required, which is a fundamental problem of the automatic retransmission method. After all, since reducing the link establishment time in automatic retransmission is a practically difficult problem, the present invention is an idea to solve this problem.

Republic of Korea 10-1997-0022694 (1997.06.02. Application) Republic of Korea 10-1998-0000155 (1998.01.07. Application) Republic of Korea 10-1998-0000632 (1998.01.13. Application) Republic of Korea 10-1998-0035454 (1998.08.31. Application) Republic of Korea 10-1998-0035455 (1998.08.31. Application) Republic of Korea 10-1998-0043267 (1998.10.16. Application) Republic of Korea 10-1999-0005438 (1999.02.18. Application) Republic of Korea 10-2004-0025540 (2004.04.13. Application)

A first object of the present invention is to disclose a technique for improving the traffic efficiency of a communication network by reducing the initial link setup time in an adaptive auto repeat wireless data communication system.

A second object of the present invention is to disclose a technology in which a base station communication system and a mobile terminal device are preset at an appropriate transmission speed without actual communication, and a link can be established immediately when a call is made to the other party when an event such as a location report occurs. there is.

A third object of the present invention is to disclose a technique for easily achieving the first and second objects by using a free access signal in a base station system to which a communication link method is applied.

The present invention for this purpose,

The terminal attempts to establish an initial link by receiving a basic signal (free access signal (FS) or an initial signal corresponding thereto) transmitted from the base station,

a transmission level setting step of a terminal of directly setting an initial level to an appropriate modulation level between a highest level and a lowest level among multi-level modulation levels according to determination of a basic condition; and

A link establishment method for adaptive automatic repeat wireless data communication is disclosed, comprising the configuration of initiating link establishment with a base station at the modulation level set in the transmission level setting step and proceeding with a data transmission process.

Here, the transmission level setting step may include a configuration in which an initial level is set as a result of measuring the signal quality of at least one of the free access signal (FS) and the access response signal.

In addition, the transmission level setting step may include a configuration in which an initial level is set by inferring a radio wave environment including at least one of a distance from a base station, a season, time, and weather.

In addition, the transmission level setting step may include a configuration in which an initial level is changed and set based on a reserved time during the daytime or nighttime.

The base signal may be a polling signal called by a base station, and the setting of the transmission level may include a configuration performed by detecting a quality of the polling signal or quality of polling data.

Also, the present invention

In a wireless data communication wireless modem or terminal terminal that establishes a communication link between a base station and a terminal using an adaptive automatic repeat method and transmits data,

Channel connection means for receiving a free access signal (FS) transmitted from a base station, requesting access from a terminal, and responding to a call or access response signal transmitted from the base station;

By detecting the basic signal received at least one of the free access signal (FS) of the base station, the call, and the access response signal received from the channel access means, an appropriate value between the highest level and the lowest level among the multi-level modulation levels is detected. Modulation level setting means for setting the initial level of the terminal to any one modulation level;

A terminal apparatus including a link method of adaptive automatic repeat wireless data communication, characterized in that it includes; Initiate.

Also, the present invention

In a wireless data communication wireless modem or base station apparatus for establishing a communication link between a base station and a terminal and transmitting data through an adaptive automatic repeat scheme,

Channel access means for receiving an access request signal from the terminal;

Modulation level setting means for setting the initial level of the base station to an appropriate modulation level between the highest level and the lowest level among the multi-level modulation levels according to the result of measuring the signal quality of the access request signal received from the channel access means;

A base station device including a link setting method for adaptive automatic repeat wireless data communication, characterized in that it comprises; communication execution means for setting up a communication link with a terminal and transmitting or receiving data with the modulation level obtained from the modulation level setting means. Initiate.

Meanwhile, the present invention

In the base station communication network service method of wireless data communication in which a communication link between a base station and a terminal is established and data is transmitted by an adaptive automatic retransmission method,

A free access signal transmission step of periodically transmitting a free access signal (FS) to an unspecified terminal so that the terminal can measure the channel access request and signal quality; and

A polling call step of calling a specific terminal after stopping the free access signal for a call of a specific terminal in the base station;

The wireless data communication network service comprising a configuration in which the terminal transmits multiple free access signals sequentially combining signals of different modulation levels so that the terminal can measure a plurality of communication qualities as basic signals in the free access signal transmitting step. start the way These service methods can be specified by dividing them into separate claims.

On the other hand, the polling calling step is called at any one modulation level between the highest level and the lowest level included in the base station, and the modulation level is the distance, season, time, and weather based on the link setting history set immediately before the terminal. It may include a configuration for setting an initial modulation level through analogy of a propagation environment further including at least one of the following.

In addition, the free access signal can be transmitted including the ID of the base station, a message informing that free access is possible, and a call command and ID for calling a specific ship.

According to the present invention, substantially ineffective redundancy in data transmission of wireless data communication is eliminated, thereby improving traffic capacity and frequency utilization. It also has the effect of reducing transmission power and reducing the possibility of interference with other equipment within the ship.

According to the present invention, by immediately following the ever-changing propagation environment in the long wave, medium wave, medium frequency band, short wave, and very short wave band, and setting the transmission speed in advance, there is an effect of immediately making the best link when data transmission is necessary.

According to the present invention, since a terminal measures a free signal periodically transmitted from a base station of a maritime wireless data communication network and establishes a link at once when an event occurs, traffic is significantly improved compared to the prior art. Through the free access signal, it is possible to provide a communication network service capable of free access to other ships at the same time while calling a specific vessel.

1 to 3 are flowcharts depicting an example of a procedure in which a terminal requests a base station to access a communication network to establish a communication link and transmit data in the prior art.
4 is a flowchart illustrating an example of a procedure in which a base station calls a specific terminal to establish a communication link and transmit data in the prior art.
5 and 6 are flowcharts illustrating a link establishment method according to the present invention.
7 is a flowchart illustrating another embodiment of the present invention.
8 is a block diagram showing an example of the configuration of a terminal device and a base station device including an embodiment of the present invention of FIG. 5, FIG. 6 or FIG. 7;
9 is a flowchart illustrating how the present invention is implemented programmatically.

Singular expressions used herein include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "consisting of" or "comprising" should not be construed as necessarily including all of the various components or steps described in the specification, and some of the components or some of the steps It should be interpreted as a technical idea that may not be included, or may further include additional components or steps. In addition, terms such as "...unit", "..module", "..step", and "..means" described in the specification mean a unit that processes at least one function or operation, which is hardware or It can be implemented in software or a combination of hardware and software.

Under this premise, the contents of the present invention will be described in detail below.

In the present invention, if a free access signal (FS; Free Signal) is periodically transmitted, the terminal receiving it recognizes that it is within the service range of the corresponding base station, and when it is time to report its position, establishes a link on the channel through which the FS is received try

Typically, the FS signal is transmitted as a low transmission rate signal limited to no data or a small number of notification data, and location data is transmitted at high speed. This is to allow all unspecified 1:n ships to know the low-speed FS, while location data is transmitted 1:1 between a specific ship and a base station at high speed.

In communications where ionospheric reflection or ionospheric reflection is mixed, such as by sea, air, or remote areas, noise, attenuation distortion, fading, etc. are accompanied by different radio waves according to conditions such as the place, season, and time of the terminal. To overcome this, a technology for high-speed transmission of location data through automatic retransmission is used.

For this adaptive ARQ method, the wireless modem has multi-level transmission rates corresponding to many levels of modulation, and this multi-level transmission rate is possible through modulation technology that arranges the modulation index per symbol low or high. do.

A low transmission rate refers to a technology that not only lowers the modulation index but also increases the error correction code (ECC) that recovers data loss, thereby lowering the code rate.

Here, the high modulation index means that the transmission rate (bps) is increased by carrying one or more bits for each multi-tone (multiple parallel symbol tones arranged in a band) composed of a plurality of symbols, and the modulation index is Low refers to lowering the transmission rate by bundling several symbol tones into one bit.

Therefore, at high transmission rates, data errors occur when even one symbol is broken, but at low transmission rates, data can be transmitted as one correct symbol even if several symbols are broken, in principle that one bit is loaded on several symbols. .

Error Correction Code (ECC) is to complete the data by reproducing the broken data within a certain range. The higher the ECC rate, the higher the data correction rate, but the disadvantage is that the amount of data transmitted is greater than the actual data (i.e., code efficiency decreases disadvantage), the higher the transmission rate, the lower the ECC rate.

The transmission speed steps of adaptive automatic repeat are, for example, 200bps at level 0, 400bps at level 1, 800bps at level 2, 1,200bps at level 3, 2,400bps at level 4, 3,600bps at level 5, ..... change, etc. (Hereinafter, description will be made on the assumption that adaptation is made at an arbitrary level between level 5, which is the highest speed of 3,600 bps, and level 0, which is the minimum speed of 200 bps.) As the maximum speed goes up, the modulation index increases.

In addition, the free access signal and acknowledgment (ACK) can be made at a lower transmission speed of 100bps or 50bps, and bad reception (NACK; No ACK) is transmitted as a code corresponding to a separate NACK or no ACK for a certain period of time It can be.

When the modulation index is low, the modulation techniques include ASK (Amplitude Shift Keying), FSK (Frequency Shift Keying), and PSK (Phase Shift Keying) series, and when the modulation index is high, QAM (Quadrature Amplitude Modulation) using multi-tone and multi-phase ) series of modulation techniques are used.

On the other hand, the free access signal and the ACK (Acknowledge) signal are usually composed of signals of low transmission speed, and the number of multi-tones is relatively small (for example, 18 multi-tones in high-speed data transmission, medium speed In transmission, 8 multi-tones, the lowest free access signal and ACK signal are arranged in 2 multi-tones, etc.).

In this basic principle, the operation of the prior art shown in FIG. 1 will be described as follows.

First, while receiving the base station's free access signal FS(1, 2, 3), when the terminal station arrives at the event (location report, etc.) time, it calls the base station (4) and the base station receives it (5) to identify itself. When recognizing that a call is being made, the base station responds (5), and when the terminal normally receives the response signal (4), link establishment, which is an initial call**answering process, is performed.

In this call*?*response, the process of exchanging the identification code (ID) of the other party is the main purpose.

After that, the link setting process of setting the data transmission speed is performed between the two parties. Usually, before actual data transmission, pseudo data (hereinafter referred to as a pilot signal) is transmitted to transmit the transmission speed between the two parties. will coordinate

First, after the call response is made, the terminal transmits the pilot signal modulated to level 5 to the base station (6a), and when the terminal normally receives it (7a), it will proceed to the next step, data transmission (10). Since such a case is very low when the distance exceeds a certain distance in the shortwave communication used, there is a high probability that the first link attempt will not be received or will be answered as poor reception.

At this time, the terminal adjusts the modulation index one step down (8a) and transmits the pilot signal as level 4 (6b). is transmitted (6c), and when the reception is poor (7c) again, the modulation index is adjusted (8c) and then the pilot signal is transmitted (6d) as level 2. In most cases, it is stable at level 3 or level 2.

At this time, if transmission (6d) and reception (7d) of the pilot signal are successful, the terminal maintains the level 2 as it is (9) and transmits the actual data (10), and ends with an ACK signal when reception is completed (11). When the signal 12 is sent out and the reception *** responses 13 and 12 are completed between the two parties, one transmission procedure is completed.

Here, each step until calibrating the communication speed by transmitting and receiving the pilot signal is shown in '6a↔7a', '6b↔7b', '6c↔7c' and '6d↔7d' in FIG. As shown, since each step is performed 2 to 3 times (these 2 to 3 times indicate the process of calibrating the transmission speed between the two parties), even if it is only taken twice for 2 seconds each step, it is '(2 Second * 2 times) * 4 steps', since it takes 16 seconds to establish a link at this time, it can be seen that 8 times redundancy is added compared to 2 seconds of actual data transmission.

That is, it can be seen that it is very inefficient to transmit one packet frame (2 seconds), and this is because the adaptive retransmission method was studied to be suitable for transmitting long data (multiple packet frames).

In shortwave communication dealing with short messages, it is inefficient to have 8-fold redundancy to establish a communication link.

Although FIG. 2 shows a connection starting from level 0 as a transport level, since it is in principle the same as that of FIG. 1, redundant descriptions are omitted.

However, FIG. 2 has the advantage of reaching level 2 quickly in a communication environment at a distance of 200 km or more or at night, while it takes longer to reach high-speed communication (eg, level 4) in the daytime within 200 km. There are downsides.

If it is transmitted only at low level 0 unconditionally, one packet frame in data transmission (10) is not 2 seconds, but 4 seconds to 6 seconds (the amount of ECC increases and the data capacity decreases, so eventually packets This is because the frame lengthens.) Accordingly, only the normal location report needs to be transmitted in two or more packet frames (8 to 12 seconds), so inefficiency remains the same. In spite of these problems, in the case of the sea, it is impossible to determine the basic transmission speed in advance because the land base station cannot know where the base station is located in the wide sea.

Accordingly, the present invention aims to eliminate or drastically reduce the redundancy of 16 seconds mentioned above by attempting an initial link with variable adaptation to the most suitable transmission rate in order to solve such a problem. Furthermore, the present invention is not limited thereto, and in the present invention, for example, a fixed variable means for setting the initial link transmission rate differently at a time set to start from level 5 as shown in FIG. 1 during the daytime and from level 1 as shown in FIG. 2 at night, or the position of the terminal Also disclosed is a configuration in which an initial level for a corresponding base station is different according to.

FIG. 3 depicts that the process of adjusting the transmission speed with the pilot signal in FIGS. 1 and 2 is omitted and data transmission 10a is directly transmitted, and each step is controlled according to whether or not the data is received 11a. However, even in this case, 8 seconds of redundancy is added as ‘(2 seconds * 2 times) * 2 steps’ until level 3.

Since FIG. 4 depicts a procedure for calling a terminal from a base station in the opposite order to that when a terminal calls a base station in FIG. do it with

However, the difference is that in FIG. 1, the base station stops the FS signal after receiving the call signal when the terminal makes a call, whereas in FIG. 4, the base station first stops the FS and then the base station calls the terminal. Accordingly, FIG. 1 is operated in the mutual competition access method, and FIG. 4 is additionally configured to be operated in the individual calling method (Polling) when necessary.

Prior to describing FIG. 5 of the present invention, terms are defined as follows.

First of all, the adaptive automatic retransmission method refers to automatic retransmission that sends a bad reception (NACK) when transmitted data is not normally received, and transmits the previous data (or frame) again when this NACK is received or there is no response for a certain period of time. (ARQ) method as the basis. If poor reception is repeated even after several retransmissions, the speed is lowered by one step to adapt to the propagation environment. .

If acknowledgment (ACK) is reached several times in succession, the speed is increased by one level. This increase in speed results in the transmission of long data within a short period of time, resulting in a reduction in channel occupancy time.

In general, a frame check sequence (FCS) such as a Cyclic Repetition Check (CRC) is used to determine whether reception is successful or reception is poor. As such means, forward error control and backward error control methods such as Reed-Solomon, Hamming code, Huffman code, and Gray code can be adopted.

As the measurement results for each condition through the signal quality measurement method, the degree of signal size, signal-to-noise (S/N), frequency deviation (FE), phase deviation (PE), signal distortion (SD), etc. is measured, and each measured value By setting the transmission rate corresponding to in advance, for example, if the S/N is 40 dB or more, FE is 5 Hz or less, PE is 5 ° or less, and SD is 5% or less, the maximum transmission rate (an example of the maximum rate in the present invention for convenience) 3,600 bps or more), and, for example, if the S / N is 3 dB or less, FE is 100 Hz, PE is 45 °, and SD is 20%, the lowest transmission rate (for convenience, in the present invention, an example of the minimum speed is 200 bps or less ), and set the transmission rate corresponding to the measured value in the middle.

In the present invention, measuring signal quality means a means selectively including at least one of S/N, FE, PE, and SD, and in terms of circuit, digital signal processing (DSP), a component of a wireless modem A chip can be used and as a software detection, the measurement result can be output through a serial port such as RS-232 or the modulation level can be determined in conjunction with the internal central processing unit (CPU). As such, the execution of the present invention can be implemented in a platform using a computer.

If the base station and the terminal set one transmission rate, the result is transmitted to the other party as a frame header or a synchronization signal, so the other party performs demodulation of the transmission rate suitable for the corresponding transmission rate.

On the other hand, when the other party performs demodulation by adapting to the above transmission rate, it is automatically adapted to the transmission rate (modulation level) at the time of demodulation and its own transmission rate is matched thereto, so that both parties can set the same rate. By separately measuring the signal quality of the other party and setting the appropriate transmission rate, the transmission rate between the two parties can be set differently. 5, 6, and 7 together explain the operation of the terminal device and the base station.

In the present invention, a target for measuring signal quality may be a free access signal, a call signal, or a response signal. In some cases, the packet frame itself that transmits data may be measured.

In the present invention, a channel refers to a communication channel for performing a communication service in a frequency allocated or distributed according to the Radio Waves Act in order to perform a wireless data service.

In the present invention, adapting the transmission rate means transmitting data at a relatively fast transmission rate within a range in which transmission errors do not occur in the propagation environment at the time or complete data can be received by restoring the error.

In the present invention, the initial link setting means that, unless otherwise specified, it is set to one of the modulation levels between the highest speed and the lowest speed according to the signal quality of the other party measured according to the radio wave environment at every moment. Means for changing by day*?* may also be included so that the initial link is attempted at the highest speed (level 5, etc.) and the initial link is performed at around the lowest speed (level 1, etc.) at night.

In the present invention, the free access signal (FS), call signal, and response signal are made of signals such as minimum speed or separate simple FSK, and communication link and data transmission are adaptive multi-level levels (array-type FSK or array-type PSK modulation level, etc.) ) can be made.

In the present invention, the spatial analysis function is to analyze attribute data on an electronic chart or electronic map with a spatial recognition means to obtain, for example, the distance and bearing of a ship from a coast station. can apply the initial link speed as the lowest speed, and can also be interlocked with daytime/nighttime.

In the present invention, switching at a given time refers to a means for adapting the transmission rate by attempting a link from the highest level during the daytime after sunrise, and attempting a link from a level close to the lowest speed at night after sunset. , Therefore, the day/night switching time may of course be set differently depending on the season.

From now on, the principle of the present invention will be described in more detail through each embodiment.

5 and 6 are flowcharts showing an embodiment of the present invention added to the communication link procedure between the base station and the terminal device of FIGS. 1 to 3,

The terminal attempts to establish an initial link by receiving (4) the basic signal (free access signal (FS 1, 2, 3) or an initial signal corresponding thereto) transmitted from the base station,

According to the determination of the basic condition (4-1), the initial level is directly set (6a-7a, 6b-7b) to an appropriate one of the modulation levels (6a, 6b) between the highest and lowest levels among the multi-stage modulation levels. Terminal transmission level setting step (9); and

Link establishment of adaptive automatic repeat wireless data communication initiating link establishment (6a, 8a, 6b) with the base station at the modulation level (6a, 6b) set in the transmission level setting step and proceeding with data transmission (10, 11). method was initiated.

Here, the transmission level setting step includes a configuration of setting an initial level as a result of measuring the signal quality (4-1) of one or more of the free access signal (FS) or the access response signal.

In the transmission level setting step, the initial level may be set by inferring a radio wave environment including at least one of distance from the base station, season, time, and weather. At this time, the base station includes a configuration that infers the radio environment by considering how far away from the coast station is the set distance from the coast station by spatial analysis of the geographic information system (GIS), the current point in time, the seasonal radio wave characteristics, the temporal radio wave characteristics, and the weather conditions. You may. It may include a configuration in which an initial level is set based on a scheduled time during the day or night. Utilizing the fact that the radio wave environment changes from sunrise to sunset, the modulation level may be switched based on a set time of day or night.

In the above configuration, the base signal is a polling signal called by a base station, and the step of setting the transmission level may be performed by detecting the quality of the polling signal or the quality of polling data.

The operation of the present invention will be described using the flow charts of FIGS. 5 and 6 as follows.

In FIG. 5, a base station installed on land periodically transmits a free access signal (FS) indicating that any terminal can access a corresponding channel, for example, every 1 to 2 seconds (1, 2, 3). The terminal receives the FS signal and determines whether the condition is suitable for communicating with itself, and if the conditions such as the appropriate signal level are not met, it scans to another channel. With this procedure, the terminal waits on a good channel through which it can communicate with the base station when an event occurs.

When a terminal is installed on a maritime vessel, since the quality of a signal from a base station varies depending on the ionosphere conditions during the day and night and the effect of fading every moment, the channel of the terminal is frequently switched.

On the other hand, if there is fading or interference even within the same channel, signal reduction or distortion occurs, so transmission speed conversion may occur even while data is being transmitted in packets. That is, even if the base station and the terminal are located in the same place, there is a case where the transmission rate needs to be calibrated whenever data is to be transmitted.

In the present invention, the terminal can infer the radio wave environment by receiving (4) the free access signal transmitted periodically and measuring the signal quality (4-1), and as inferred from it, the terminal is able to receive it easily so that the other party can easily receive it. From the beginning of establishing the communication link, the transmission speed (modulation level) is set according to the propagation environment (4-1).

In FIG. 5, if the FS signals (1, 2, 3) or the connection response signal (5) corresponding to the terminal's connection request are measured (4-1) with signal quality corresponding to level 2, the terminal The pseudo signal 6a set as 2 (4-1) is transmitted to confirm the link (7a). Then, when confirmed, the actual data is transmitted (10) while maintaining the set level 2 (9). The base station that has received the data through this link setup procedure transmits a reception success certificate (11, ACK) upon completion of reception, and when exchanging an end message with the terminal that has received the reception success certificate, all communication procedures are terminated (12, 13).

That is, by the function of setting the level by measuring the signal quality of the FS signal, etc., the redundancy (6b↔7b, 6c↔7c, 6d↔7d in FIG. 1) is immediately adapted to the radio wave environment at the time, and if Even if it is not immediately adapted at the beginning, the probability of adaptation increases as about one additional time (6b↔7b), and FIG. 6 depicts the state.

In FIG. 5, data transmission/reception (10, 11) can be performed directly without pseudo signal transmission/reception (6a, 7a, 9) as in the case of FIG. That is, in FIG. 5 , the 16-second redundancy (6a↔7a, 6b↔7b, 6c↔7c, 6d↔7d) process in FIG. 1 is all eliminated.

7 is a flowchart illustrating a case in which a base station calls a terminal station as an example.

When making an individual call to a specific terminal, the base station first stops transmitting free access signals (1, 2, 3) and then calls the specific terminal (4).

At this time, if the terminal is waiting on the calling channel, it immediately responds to the call signal (5), and the base station receives the response signal, measures the signal quality according to the same principle as before, and sets the transmission rate (4). -One).

In addition, the base station transmits (10) data at the set transmission rate, for example, level 2, and completes reception (11) and termination (12, 13).

If the base station calls the terminal and commands the terminal to transmit data stored in the terminal, the terminal transmits data (10) at the same transmission speed as the level setting (4-1) of FIG. 5 (ie, in FIG. 5 The artificial signal tuning process of 6a and 7a may be omitted).

Therefore, a process of directly adapting the data transmission speed based on the pre-measured signal quality before establishing the link is performed.

On the other hand, in the case of an individual call, if a polling table is used, a call can be made immediately regardless of which channel the terminal is waiting on. The polling table at this time is history information in which the history of the location, time, and modulation level of the terminal is stored as a table.

That is, the base station infers the propagation environment including at least one of the distance to the terminal, season, time, and weather based on the previous terminal location or the (pre-stored) modulation level at which the link with the previous terminal was established. This can be configured to be set. The detailed technology applied at this time can apply the bar described in FIGS. 4 and 6 .

In the above description, the terms transmission, transmission, and communication are used interchangeably, but in principle, transmission means that a signal is transmitted regardless of whether the other party is aware of it. Transmission means transmission and confirmation reception on the premise that it will reach a specific counterpart. Communication is meant to include transmitting to the other party or receiving information transmitted by the other party.

Among the terms of the present invention, the terminology that a terminal attempts a link includes not only responding immediately to a call from a base station but also accessing a path requesting access in a mutual competition method after receiving a free access signal without immediately responding after a call from the base station. is a term that This also takes into account the loading of information for collectively calling terminals within a specific range in the free access signal of the base station. At this time, it is preferable to transmit the free access signal including the ID of the base station and a message informing that free access is possible, along with a call command and a specific vessel ID of the called target.

8 is a block diagram of a terminal device and a base station device of wireless data communication including a link procedure simplification method of the present invention.

First, regarding the terminal device,

As a wireless data communication wireless modem or terminal terminal that establishes a communication link between a base station and a terminal using an adaptive automatic repeat method and transmits data,

Channel connection means for receiving a free access signal (FS) transmitted from a base station, requesting access from a terminal, and responding to a call or access response signal transmitted from the base station;

By detecting the basic signal received at least one of the free access signal (FS) of the base station, the call, and the access response signal received from the channel access means, an appropriate value between the highest level and the lowest level among the multi-level modulation levels is detected. Modulation level setting means for setting the initial level of the terminal to any one modulation level;

A terminal apparatus including a link method for adaptive automatic repeat wireless data communication comprising; communication execution means for establishing a communication link with a base station and transmitting or receiving data with the modulation level obtained from the modulation level setting means.

Next, regarding the base station device,

A wireless modem or base station device for wireless data communication that establishes a communication link between a base station and a terminal and transmits data through an adaptive automatic retransmission method,

Channel access means for receiving an access request signal from the terminal;

Modulation level setting means for setting the initial level of the base station to an appropriate modulation level between the highest level and the lowest level among the multi-level modulation levels according to the result of measuring the signal quality of the access request signal received from the channel access means;

A base station apparatus including a link setting method for adaptive automatic repeat wireless data communication comprising; communication execution means for establishing a communication link with a terminal and transmitting or receiving data with the modulation level obtained from the modulation level setting means.

The operation of the block diagram of FIG. 8 is described as follows.

The terminal device 1000 may be externally configured as an antenna 101, a transceiver 102, a wireless modem 103 including modulation and demodulation technology, and a terminal 104 in which interface and termination functions are implemented. .

The wireless modem 103 and the terminal 104 may be formed by interlocking a digital signal processing (DSP) chip and a central processing unit (CPU), and may be configured by integrating or separating them according to the purpose.

A plurality of terminals 1000 can be normally connected to each channel of the base station, and through this, they can be sequentially accessed differently in time to receive a location report or to receive a broadcast service at once.

The internal configuration of the base station 2000 also consists of an antenna 201, a transceiver 202, a wireless modem 203, and a communication server 204 having the same or similar polarization characteristics as the configuration of the terminal, and each service channel A plurality of the same base station 2000 may be configured. The communication server 2004 of the base station may include a GIS (Geographical Information System) function.

In the interlocking operation inside the terminal, the transceiver 102 and the wireless modem 103 are configured so that the transceiver receives the modulated signal from the wireless modem and propagates it to the space, and also the transceiver receives the signal received from the space and demodulates it in the wireless modem. perform the function of transmission.

The wireless modem 103 and the terminal 104 are exemplified in a structure in which the wireless modem receives digital data from the terminal to perform modulation, and the wireless modem demodulates the signal received from the transceiver and transmits the signal to the terminal. However, in the case of a simple location report function, the wireless modem and the terminal may be integrated externally, but shown as a separate structure for effective explanation.

The transmission rate setting means of the present invention may be mainly composed of software installed and operated in a wireless modem and a terminal (or communication server). The present invention has software multi-step modulation levels in the adaptive wireless modem. This configuration may include a means for setting an initial value to any one of multi-level modulation levels according to the signal quality of the other party or according to the time or location directly measured by the receiver.

In terms of the signal path, the present invention first measures the signal quality result from the wireless modem (103, 203) and supplies it to the terminal (104, 204), then the terminal (104, 204) measures the transmission rate corresponding to the signal quality. inference, and commands the wireless modems 103 and 203 to adjust the modulation rate (modulation level). (These quality measures and rate adjustments can be performed on a wireless modem or terminal.)

Accordingly, the wireless modems 103 and 203 try linking by setting the variable to any commanded arbitrary level among multi-level modulation levels stored in their own CPU or DSP (digital signal processing device).

The function of automatically adapting to the other party's modulation level and setting the demodulation level is a function of the adaptive automatic repeat method.

Therefore, it will be seen from the above description that the link establishment method of the present invention is installed in the wireless modem 103 or terminal 104, and the base station system is also installed in the wireless modem 203 or communication server 204.

In addition, the base station system may be integrated in the DSP and CPU in the wireless modem, such as a separate computer or a terminal device in some cases, rather than a communication server.

9 is a flowchart illustrating a software program constituting a wireless data communication system and a terminal device including a link establishment method of the present invention.

That is, in the present invention, in a 'wireless modem or terminal terminal (or base station communication server)' of wireless data communication that establishes a communication link between a base station and a terminal using an adaptive automatic repeat scheme and transmits data,

a first-stage program constituting multi-stage modulation levels (302-1, 302-2, 302-n) as modulation and demodulation means of the adaptive automatic repeat scheme;

a second-stage program for setting the transmission rate to one of the highest and lowest rates composed of multi-stage modulation levels in the first-stage program according to the measurement result for each condition;

When an event occurs, a third-stage program that executes initial link or data transmission at the transmission rate level set in the second-stage program;

Here, the measurement result for each condition in the second stage program may be the result of measuring the signal quality of the other party as described above.

9 is a program that can be installed in any one or more of the wireless modem or communication server (or terminal device) of FIG. 8 . A more detailed description of the program is as follows.

In FIG. 9, the terminal receives the free access signal transmitted from the base station, measures the quality (303), and switches to another channel (304, 305) when it does not reach the normal range. When it is in the normal range, it stays on the corresponding channel and waits for its own event (referring to a location report, etc.) or a call from the base station.

The first stage program includes a means for setting the modulation/demodulation index (301). This is to modulate by arranging data bits in the symbol tone to set the rate at which bits are carried per unit time at which the symbol tone is generated, and demodulate it inversely. According to the result, several modulation and demodulation levels are generated (302-1, 302-2, 302-n).

In the second stage program, the modulation levels (302-1, 302-2, 302 -n) to determine (307) the transmission rate. When an event occurs (306), the third stage program attempts an initial link or data transmission (308) at the transmission rate (307) determined according to the second stage program.

In the case of determining the transmission speed by measuring the signal quality of the other party as a second stage program, it is directly determined as the modulation level (e.g., level 3) corresponding to the corresponding signal quality, but it is a time conversion including location boundaries or seasons. In this case, adaptation can be started from the lowest or highest level (for example, level 1 or level 4).

As described above, measuring the quality of a signal as the second step program is a call signal, a response signal, or a data frame transmitted from a terminal in the case of a base station as described above, but in the case of a terminal, the quality of the free access signal (FS) A means for measuring is included, and means for measuring quality such as S/N described above for any one or more signals as a whole are included.

In addition, the terminal measures the quality of the free access signal (FS) and determines whether the transmission speed is within the normal range that can be used from level 0 to level n. Means for switching 305 to may be included.

On the other hand, if the initial link is not established at the transmission rate, the process of resetting the transmission rate (310, 311, 312) as shown in FIGS. called 'program'.

Meanwhile, the present invention discloses the following wireless data communication network service method. The communication network service method related to this corresponds to a configuration forming an independent service method claim as a separate claim from the link establishment method, terminal device, and base station device described above.

The present invention provides a base station communication network service method for wireless data communication in which a communication link between a base station and a terminal is established and data is transmitted using an adaptive automatic repeat scheme,

A free access signal transmission step of periodically transmitting a free access signal (FS) to an unspecified terminal so that the terminal can measure the channel access request and signal quality (1, 2, 3 in FIGS. 5 to 7); and

A polling call step of calling a specific terminal through a direct call signal or after stopping the free access signal for a call connection of a specific terminal in the base station (4 in FIG. 7);

In the free access signal transmission step, signals of different modulation levels (302-1 in FIG. 9), 302-2, and 302-n are transmitted so that the terminal can measure a plurality of communication qualities 4-1 as basic signals. Disclosed is a wireless data communication network service method including a configuration for transmitting multiple free access signals combined with a plurality of them.

Here, the multi-free access signal can be transmitted including a plurality of pilot signals arranged at transmission speeds of 50BPS, 100BPS, 500BPS, 1000BPS, etc., for example. If the terminal devices receiving this signal request connection by selecting a modulation level according to the highest rate that is received satisfactorily among them, link establishment is possible immediately, omitting the cumbersome process of adjusting the modulation level.

Furthermore, in the polling call step, the direct call signal of the base station is set to one of the modulation levels between the highest level and the lowest level, and the modulation level is selected from among the distance, season, time, and wake-up in the link setting history that was set immediately before the corresponding terminal. It may include a configuration for setting an initial modulation level through analogy of a propagation environment including at least one more.

The direct call signal includes a command signal for controlling access to a single terminal by designating an ID of a corresponding terminal.

At this time, the free access signal includes the ID of the base station? In addition to the basic FS signal indicating that free access is possible, it can be configured to call a specific vessel by including the ID of the callee in the FS signal, if necessary. This multi-function free access signal configuration can provide a wireless data communication network service with multi-access function that allows free access to other ships comprehensively while calling a specific vessel through the free access signal.

Since the above description has only described the embodiments of the present invention one by one, the present invention is not limited to the above embodiments.

On the other hand, the components of the above-described embodiment can be easily grasped from a process point of view. That is, each component can be identified as each process. In addition, the process of the above-described embodiment can be easily grasped from the viewpoint of components of the device.

In addition, the technical contents described above may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer readable medium.

The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program commands recorded on the medium may be specially designed and configured for the embodiments or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. - includes hardware devices specially configured to store and execute program instructions, such as magneto-optical media, and ROM, RAM, flash memory, etc. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler. A hardware device may be configured to act as one or more software modules to perform the operations of the embodiments and vice versa.

The present invention is a method for setting up a link for wireless data communication in wireless data communication using an adaptive automatic retransmission method for maritime, land, air, remote communication, etc., a terminal device including the same, and a base station system including the same, which can be used for manufacturing, production, construction, etc. there is.

Furthermore, the wireless data communication network service method of the present invention can be used in a form of providing a service limited to free access or additionally including a polling call as needed after the base station system is completed.

Therefore, the wireless data communication network service method can be specified as a separate claim and operated in a separate commercialization method.

Wireless data communication network (101, 201), base station (2000), terminal device (1000), transceiver (102, 202), wireless modem (103, 203), terminal terminal (104), communication server (204)

Claims (7)

The terminal attempts to establish an initial link by receiving a basic signal (free access signal (FS) or an initial signal corresponding thereto) transmitted from the base station,
a transmission level setting step of a terminal of directly setting an initial level to an appropriate modulation level between a highest level and a lowest level among multi-level modulation levels according to determination of a basic condition;
A method of establishing a link for adaptive automatic repeat wireless data communication, characterized in that it includes a configuration for starting link establishment with a base station and proceeding with a data transmission operation at the modulation level set in the transmission level setting step. According to claim 1,
The transmission level setting step comprises a configuration in which an initial level is set as a result of measuring the signal quality of at least one of the free access signal (FS) and the access response signal. method. According to claim 1,
The transmission level setting step comprises a configuration in which an initial level is set by inferring a radio wave environment including at least one of distance from a base station, season, time, and weather. How to set it up. According to claim 1,
The transmission level setting step comprises a configuration in which an initial level is set starting from a scheduled time of day or night. According to claim 1,
The base signal is a polling signal called by the base station, and the transmission level setting step comprises a configuration made by detecting the quality of the polling signal or the quality of polling data. method. In a wireless data communication wireless modem or terminal terminal that establishes a communication link between a base station and a terminal using an adaptive automatic repeat method and transmits data,
Channel connection means for receiving a free access signal (FS) transmitted from a base station, requesting access from a terminal, and responding to a call or access response signal transmitted from the base station;
By detecting the basic signal received at least one of the free access signal (FS) of the base station, the call, and the access response signal received from the channel access means, an appropriate value between the highest level and the lowest level among the multi-level modulation levels is detected. Modulation level setting means for setting the initial level of the terminal to any one modulation level;
A terminal device including a link method of adaptive automatic repeat wireless data communication, characterized in that it comprises: a communication execution means for establishing a communication link with a base station and transmitting or receiving data with the modulation level obtained from the modulation level setting means. In a wireless data communication wireless modem or base station apparatus for establishing a communication link between a base station and a terminal and transmitting data through an adaptive automatic repeat scheme,
Channel access means for receiving an access request signal from the terminal;
Modulation level setting means for setting the initial level of the base station to an appropriate modulation level between the highest level and the lowest level among the multi-level modulation levels according to the result of measuring the signal quality of the access request signal received from the channel access means;
A base station device including a link setting method for adaptive automatic repeat wireless data communication, characterized in that it comprises; communication execution means for setting up a communication link with a terminal and transmitting or receiving data with the modulation level obtained from the modulation level setting means. .

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