KR102136327B1 - Method for transmitting and receiving data in a communication network system and a communication network system - Google Patents

Abstract

The present invention provides a method for transmitting and receiving data in a communication network system including a base station and a plurality of terminals.
According to the present invention, a base station and a plurality of terminals select a subcarrier in a subcarrier pool, a plurality of terminals determine a bit value to be used to determine whether to collide, and the determined bit through the selected subcarrier A value is transmitted to the base station, the base station detects a collision between a plurality of terminals based on the bit value transmitted through the selected subcarrier, and based on the detection result, the base station generates a collision among the selected subcarriers It is possible to provide a method for transmitting a signal through an uncarried subcarrier.

Description

A communication network system and a method for transmitting and receiving data in a communication network system {METHOD FOR TRANSMITTING AND RECEIVING DATA IN A COMMUNICATION NETWORK SYSTEM AND A COMMUNICATION NETWORK SYSTEM}

The present disclosure provides a communication network system and a method for transmitting and receiving data in a communication network system.

Recently, IEEE 802.11 wireless LANs (WLANS) technology has been widely used. In the IEEE 802.11 WLANS technology, many physical layer technologies have been proposed so that a large amount of data can be transmitted.

For example, in the IEEE 802.11 WLANS technology, orthogonal frequency-division multiplexing (OFDM) technology and multiple-input multiple-output (MIMO) technology are used so that a large amount of data can be transmitted. Was proposed.

On the other hand, when using the contention (contention) method in the time domain, an overhead may occur, and in the case of a time-to-frequency (T2F) method, the number of terminals using it may be limited.

At this point in time, when the necessity of efficient use of resources has been greatly increased due to the rapid increase of users of communication network systems, it is time to propose and research channel competition technologies that minimize resource waste in communication networks and increase the efficiency of resource utilization.

Disclosed is a communication network system and a method for transmitting and receiving data at a base station in a communication network system. The technical problems to be achieved by the present embodiment are not limited to the technical problems as described above, and other technical problems may be inferred from the following embodiments.

As a technical means for achieving the above technical problem, a first aspect of the present disclosure is a method of transmitting and receiving data in a communication network system including a base station and a plurality of terminals, wherein the base station and the plurality of terminals are subcarriers. Selecting a subcarrier in a subcarrier pool; Determining, by the plurality of terminals, a bit value to be used to determine whether to collide, and transmitting the determined bit value to the base station through the selected subcarrier; The base station detecting a collision between the plurality of terminals based on a bit value transmitted through the selected subcarrier; And based on the detection result, the base station transmitting a signal through a subcarrier in which collision does not occur among the selected subcarriers.

In addition, when the number of bit values transmitted through a specific subcarrier in the subcarrier pool is plural, determining whether the plurality of bit values are the same; And when the plurality of bit values are not the same, determining that collisions between terminals transmitting bit values through the specific subcarrier have occurred.

In addition, the base station selecting a subcarrier of the fastest sequence number in the subcarrier pool; And randomly selecting any one of the remaining subcarriers except for the fastest sequence subcarriers in the subcarrier pool.

In addition, the plurality of terminals by determining the subcarrier carrying a signal transmitted from the base station, and determining whether it corresponds to a non-collision (non-collision) terminal; it may provide a method comprising a.

In addition, the base station and the non-collision terminal transmitting data and acknowledgment (ACK); It can provide a method comprising a.

In addition, the step of transmitting data and ACK according to the sequence number of the sub-carrier corresponding to the base station and the non-collision terminal; It can provide a method comprising a.

In addition, the base station and the plurality of terminals may provide a method in which half duplex communication is possible.

In a second aspect of the present disclosure, in a communication network system including a base station and a plurality of terminals, the base station and the plurality of terminals select a subcarrier in a subcarrier pool, and the plurality of terminals determine collision. Determine the bit value to be used to, and transmits the determined bit value to the base station through the selected subcarrier, the base station, the collision between the plurality of terminals based on the bit value transmitted through the selected subcarrier It is possible to provide a communication network system that detects and transmits a signal through a subcarrier without collision among the selected subcarriers based on the detection result.

In addition, when the number of bit values transmitted through a specific subcarrier in the subcarrier pool is plural, the base station determines whether the plural bit values are the same, and when the plural bit values are not the same It is possible to provide a communication network system, which determines that a collision between terminals transmitting a bit value through a specific subcarrier has occurred.

In addition, the base station selects a subcarrier of the fastest sequence number in the subcarrier pool, and the plurality of terminals randomly selects one of the remaining subcarriers except for the fastest sequence subcarrier in the subcarrier pool. And a communication network system.

In addition, the plurality of terminals, by identifying the sub-carrier carrying a signal transmitted from the base station to determine whether it corresponds to the non-conflicting terminal, it is possible to provide a communication network system.

In addition, the base station and the non-conflicting terminal can provide a communication network system that transmits data and an ACK according to the sequence number of a subcarrier corresponding to each.

In addition, the base station and the plurality of terminals can provide a communication network system, which is capable of half-duplex communication.

According to the present invention, by providing a channel competition technology for detecting collisions between terminals, it is possible to allow more terminals to transmit data through single channel competition and to improve the data transmission speed.

1 is a diagram illustrating a communication network structure according to an embodiment.
2 is a diagram for describing competition in a time domain according to an embodiment.
3 is a view for explaining a method for detecting collision between terminals according to an embodiment.
4 is a flowchart of a method for detecting collisions between terminals according to an embodiment.
5 is a block diagram showing a hardware configuration of a base station according to an embodiment.
6A to 6C are graphs showing effects according to the present invention.

The phrases “in some embodiments” or “in one embodiment” appearing in various places in this specification are not necessarily all referring to the same embodiment.

Some embodiments of the present disclosure can be represented by functional block configurations and various processing steps. Some or all of these functional blocks may be implemented with various numbers of hardware and/or software configurations that perform particular functions. For example, the functional blocks of the present disclosure can be implemented by one or more microprocessors, or by circuit configurations for a given function. Also, for example, functional blocks of the present disclosure may be implemented in various programming or scripting languages. The functional blocks can be implemented with algorithms running on one or more processors. In addition, the present disclosure may employ conventional techniques for electronic environment setting, signal processing, and/or data processing. Terms such as “mechanism”, “element”, “means” and “composition” can be used widely, and are not limited to mechanical and physical configurations. In addition, terms such as “?? unit” and “?? module” described in the specification mean a unit that processes at least one function or operation, which may be implemented in hardware or software, or a combination of hardware and software. have.

In addition, the connection lines or connection members between the components shown in the drawings are merely illustrative of functional connections and/or physical or circuit connections. In an actual device, connections between components may be represented by various functional connections, physical connections, or circuit connections that are replaceable or added.

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

The communication network system of the present invention is described based on the IEEE 802.11 wireless LAN standard, but it is obvious that the present invention is not limited thereto and the same technical idea can be applied to various communication network systems.

In the following description, it is assumed that the terminal collectively refers to any node of a mobile or fixed user terminal such as a user equipment (UE) or a mobile station (MS), and the base station is an arbitrary network terminal communicating with a terminal such as an AP. It is assumed that the node is collectively.

1 is a diagram illustrating a communication network structure according to an embodiment.

Referring to FIG. 1, the communication network 100 may include a plurality of terminals and base stations.

A plurality of terminals in the communication network 100 communicate with a base station, and communication between terminals is limited. In addition, a plurality of terminals and a base station are all half duplex (half duplex) communication.

A specific terminal in the communication network 100 may transmit a request to send (RTS) message to the base station. After receiving the RTS message, the base station may transmit a Clear to Send (CTS) message to a specific terminal that has transmitted the RTS message.

2 is a diagram for describing competition in a time domain according to an embodiment.

In a medium access control (MAC) layer of IEEE 802.11 wireless LANs (WLANs), a backoff algorithm may be used as a contention method in the time domain.

Referring to FIG. 2, a random backoff time must be waited before transmitting a Request To Send (RTS) and Clear To Send (CTS) message. That is, in the back-off algorithm, a user (that is, a terminal) that desires data transmission must wait for a random back-off time, and such a random back-off time may cause medium access control (MAC) overhead.

Jardosh, Amit P., et al. "Understanding congestion in IEEE 802.11 b wireless networks." Proceedings of the 5th ACM SIGCOMM conference on Internet Measurement. The USENIX Association, 2005. shows that the overhead of using the backoff algorithm accounts for over 30% of the total.

To reduce MAC overhead, a time-to-frequency (T2F) method can be used. The T2F scheme is not a competition in the time domain but a competition in the frequency domain. The T2F scheme may consist of two rounds contention.

In round 1, a terminal desiring data transmission may arbitrarily select a subcarrier in a subcarrier pool. The terminal may transmit a symbol through the selected subcarrier. In Round 1, the terminal that selects the fastest subcarrier may be the winner.

In Round 2, the winner in Round 1 can randomly select a subcarrier in the same way as in Round 1, and transmit a symbol through the selected subcarrier. Finally, the winner can transmit data and ACK according to the sequence number of the subcarrier.

Hereinafter, a channel contention scheme for detecting collision between terminals in a T2F scheme will be described in detail.

3 is a view for explaining a method for detecting collision between terminals according to an embodiment.

Hereinafter, it is assumed that one base station and three terminals are included in the communication system, and five subcarriers are included in the subcarrier pool.

Referring to FIG. 3, in round 1 310, a base station and a plurality of terminals that want to transmit data can select a subcarrier in a subcarrier pool.

In one embodiment, the base station may select the earliest subcarrier in the subcarrier pool. The plurality of terminals may randomly select any one of the remaining subcarriers except for the earliest subcarrier in the subcarrier pool.

For example, the base station may select a first subcarrier, terminal 1 may select a second subcarrier, and terminal 2 and terminal 3 may select a third subcarrier. The fourth subcarrier and the fifth subcarrier are subcarriers not selected by the base station and the terminal.

Also, a plurality of terminals may determine a bit value to be used to determine whether there is a collision. For example, a bit value selected by a plurality of terminals may be a two-digit bit value, and in this case, the bit value may be one of '00', '01', '10', and '11'. Meanwhile, the bit value may be referred to as a symbol having a predetermined bit position.

The base station may detect a collision between a plurality of terminals based on a bit value transmitted through a subcarrier selected by a plurality of terminals.

In one embodiment, the base station may determine whether a plurality of bit values are the same when the number of bit values transmitted through a specific subcarrier in a subcarrier pool is plural. When a plurality of bit values are not the same, the base station may determine that a collision has occurred between terminals transmitting bit values through a specific subcarrier. On the other hand, when the number of bit values transmitted through a specific subcarrier in the subcarrier pool is 1, the base station may determine that collision between terminals has not occurred.

For example, terminal 1 transmits the bit value '11' through the second subcarrier, terminal 2 transmits the bit value '01' through the third subcarrier, and terminal 3 transmits the bit value through the third subcarrier. The value '10' can be transmitted. In this case, since a plurality of (2) bit values are transmitted through the third subcarrier, and a plurality of bit values are different from '01' and '10', respectively, the base station determines the bit value through the third subcarrier. It can be determined that a collision between the transmitting terminal 2 and the terminal 3 occurs.

In round 2 320, based on the detection result in round 1 310, the base station may transmit a signal through a subcarrier in which collision does not occur among subcarriers selected by the base station and a plurality of terminals.

For example, among the first to third sub-carriers selected by the base station and the terminals 1 to 3, the base station transmits a predetermined signal ('10') through the first and second sub-carriers having no collision. Can.

Meanwhile, when a plurality of bit values transmitted through a specific subcarrier in the subcarrier pool are the same, the base station cannot detect whether there is a collision between terminals transmitting the bit value through the specific subcarrier. In this case, the base station can transmit signals to all terminals that transmit bit values through a specific subcarrier.

In the present disclosure, a channel contention technique for detecting collisions between UEs is provided using the above-described processes of Round 1 (310) and Round 2 (320), so that more UEs can transmit data through single channel contention. .

When a base station transmits a signal through a subcarrier in which collision does not occur, a plurality of terminals can determine whether or not they correspond to a non-collision terminal by identifying a subcarrier carrying a signal transmitted from the base station. have.

For example, since the terminal 1 transmitted the bit value from the round 1 310 to the base station through the second subcarrier, after the round 1 310 and the round 2 320 are finished, the terminal 1 receives a signal '10 from the base station. By identifying that this is carried on the second sub-carrier, it can be determined that the terminal 1 itself corresponds to the non-conflicting terminal.

Thereafter, the base station and the non-conflicting terminal may transmit data and acknowledgment (ACK) according to the sequence number of the subcarrier corresponding to each. For example, in round 1 310, the base station selects the first sub-carrier, and terminal 1 selects the second sub-carrier, so that after the base station transmits the data and the ACK, the terminal 1 can transmit the data and the ACK. .

4 is a flowchart of a method for detecting collisions between terminals according to an embodiment.

Hereinafter, it is assumed that a plurality of terminals in a communication network communicate with a base station, and communication between terminals is limited. In addition, it is assumed that a plurality of terminals and a base station all perform half duplex communication.

Referring to FIG. 4, in step 410, a base station and a plurality of terminals may select a subcarrier in a subcarrier pool.

In one embodiment, the base station may select the earliest subcarrier in the subcarrier pool. The plurality of terminals may randomly select any one of the remaining subcarriers except for the earliest subcarrier in the subcarrier pool.

In step 420, the plurality of terminals may determine a bit value to be used to determine whether there is a collision, and transmit the determined bit value through the selected subcarrier to the base station.

The plurality of terminals may determine a bit value having a preset bit digit. Meanwhile, the bit value may be referred to as a symbol having a predetermined bit position.

In step 430, the base station may detect a collision between a plurality of terminals based on the bit value transmitted through the selected subcarrier.

In one embodiment, the base station may determine whether a plurality of bit values are the same when the number of bit values transmitted through a specific subcarrier in a subcarrier pool is plural.

When a plurality of bit values are not the same, the base station may determine that a collision has occurred between terminals transmitting bit values through a specific subcarrier. On the other hand, when the number of bit values transmitted through a specific subcarrier in the subcarrier pool is 1, the base station may determine that there is no collision between terminals.

In step 440, the base station may transmit a signal through a subcarrier in which collision has not occurred among the selected subcarriers based on the detection result in step 430.

A plurality of terminals can determine whether or not they correspond to non-collision terminals by identifying a subcarrier carrying a signal transmitted from the base station. Thereafter, the base station and the non-conflicting terminal may transmit data and ACK according to the sequence number of the subcarrier corresponding to each.

5 is a block diagram showing a hardware configuration of a base station according to an embodiment.

Referring to FIG. 5, the base station 500 may include a control unit 510, a communication unit 520, and a memory 530. The base station 500 of FIG. 5 shows only the components related to the embodiment. Accordingly, those skilled in the art may understand that other general-purpose components may be further included in addition to the components illustrated in FIG. 5.

The control unit 510 may control a series of processes for providing a channel contention technique for detecting collisions between terminals described in FIGS. 1 to 4. The control unit 510 serves to control the overall functions of the base station 500. For example, the controller 510 controls the overall operation of the base station 500 by executing programs stored in the memory 530. The control unit 510 may be implemented as a central processing unit (CPU), graphics processing unit (GPU), or application processor (AP), but is not limited thereto.

The communication unit 520 may include a short-range communication unit, a mobile communication unit, and a broadcast reception unit. In one embodiment, the communication unit 520 may communicate with a plurality of terminals to transmit and receive data.

The memory 530 is hardware storing various data processed by the controller 510. For example, the memory 530 includes SIR values for a transmission target terminal of a transmission terminal and information on a transmission target terminal group for each transmission terminal. Etc. can be stored. Further, the memory 530 may store applications, drivers, and the like to be driven by the controller 510. The memory 530 includes random access memory (RAM) such as dynamic random access memory (DRAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and CD- ROM, Blu-ray or other optical disk storage, hard disk drive (HDD), solid state drive (SSD), or flash memory.

6A to 6C are graphs showing effects according to the present invention.

6A to 6C are result values calculated under the parameter conditions of Table 1 below. In Table 1, T _SIFS is duration of short interframe space (SIFS), T _PIFS is duration of PCF interframe space (PIFS), T _DIFS is duration of DCF interframe space (DIFS), and T _Signal is signal ).

parameter value Data length 1500 bytes Data rate 300Mbps T _SIFS 16μs T _PIFS 25μs T _DIFS 34μs T _Signal 4 μs S 52 K 2, 3

6A to 6B, it can be seen that even if the number of terminals increases, the number of successful subcarriers 611 and 621 has a larger value than the number of non-collision subcarriers 613 and 623 without collision. That is, it can be seen that the difference values 612 and 622 between the number of non-collision detected subcarriers 613 and 623 and the number of successful subcarriers 611 and 621 have a large value even if the number of terminals increases.

Referring to FIG. 6C, when the number of bit digits (ie, bps (bits per symbol)) is 2 and 3, the channel contention technology 631 and 632 for detecting collisions between terminals according to the present invention is a conventional T2F scheme ( 633).

The embodiments can be implemented in the form of an application stored in a recording medium readable by an electronic device that stores instructions and data executable by the electronic device. The instruction may be stored in the form of program code, and when executed by a processor, a predetermined program module may be generated to perform a predetermined operation. In addition, the instructions, when executed by the processor, may perform certain operations of the disclosed embodiments.

The embodiments can also be implemented in the form of a recording medium including instructions executable by a computer, such as program modules, being executed by a computer. Computer readable media can be any available media that can be accessed by a computer, and includes both volatile and nonvolatile media, removable and non-removable media. In addition, computer readable media may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes computer readable instructions, data structures, other data in a modulated data signal, such as program modules, or other transport mechanisms, and includes any information delivery media.

In addition, in this specification, the “part” may be a hardware component such as a processor or circuit, and/or a software component executed by a hardware component such as a processor.

The above description of the present specification is for illustration only, and those skilled in the art to which the contents of this specification belong may understand that the present invention can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. Will be able to. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present embodiment is indicated by the claims, which will be described later, rather than by the detailed description, and should be interpreted to include all modified or modified forms derived from the meaning and scope of the claims and their equivalent concepts.

Claims (15)

In a method of transmitting and receiving data in a communication network system including a base station and a plurality of terminals,
Selecting a subcarrier in a subcarrier pool by the base station and the plurality of terminals;
Determining, by the plurality of terminals, a bit value to be used to determine whether to collide, and transmitting the determined bit value to the base station through the selected subcarrier;
The base station detecting a collision between the plurality of terminals based on a bit value transmitted through the selected subcarrier; And
Based on the detection result, the base station transmits a signal through a subcarrier in which no collision has occurred among the selected subcarriers;
Including, and, how.
The step of detecting the collision,
Determining whether the plurality of bit values are the same when the number of bit values transmitted through a specific subcarrier in the subcarrier pool is plural; And
Determining that a collision between terminals transmitting a bit value through the specific subcarrier occurs when the plurality of bit values are not the same;
Further comprising,
The step of transmitting the signal,
When the plurality of bit values are not the same, the base station transmits a signal through a subcarrier in which collision does not occur among the selected subcarriers,
If the plurality of bit values are the same, the base station transmits the signal through a specific subcarrier and a subcarrier without collision among the selected subcarriers;
How to include. delete According to claim 1,
The step of selecting the subcarrier,
The base station selecting a subcarrier of the earliest sequence number in the subcarrier pool; And
The plurality of terminals randomly selecting any one of the remaining subcarriers except the earliest subcarrier in the subcarrier pool;
How to include. According to claim 1,
The above method,
Determining whether the plurality of terminals correspond to a non-collision terminal by identifying a subcarrier carrying a signal transmitted from the base station;
The method further comprising. The method of claim 4,
The above method,
Transmitting data and acknowledgment (ACK) by the base station and the non-conflicting terminal;
The method further comprising. The method of claim 5,
The step of transmitting the data and ACK,
Transmitting data and an ACK according to the sequence numbers of the subcarriers corresponding to the base station and the non-conflicting terminal;
How to include. According to claim 1,
The base station and the plurality of terminals are half duplex (half duplex) communication is possible, the method. In the communication network system including a base station and a plurality of terminals,
The base station and the plurality of terminals select a subcarrier in a subcarrier pool,
The plurality of terminals determine a bit value to be used to determine whether to collide, and transmit the determined bit value to the base station through the selected subcarrier,
The base station detects a collision between the plurality of terminals based on a bit value transmitted through the selected subcarrier, and transmits a signal through a subcarrier in which no collision occurs among the selected subcarriers based on the detection result. Transmit,
The base station,
When the number of bit values transmitted through a specific subcarrier in the subcarrier pool is plural, it is determined whether the plurality of bit values are the same, and when the plurality of bit values are not the same, bits are transmitted through the specific subcarrier. It is determined that a collision has occurred between terminals transmitting a value,
When the plurality of bit values are not the same, a signal is transmitted through a subcarrier in which no collision occurs among the selected subcarriers, and when the plurality of bit values are the same, a sub in which no collision occurs among the selected subcarriers A communication network system that transmits the signal over a carrier and a specific subcarrier. delete The method of claim 8,
The base station selects the fastest subcarrier in the subcarrier pool,
The plurality of terminals randomly selects any one of the remaining subcarriers except for the fastest sequence subcarriers in the subcarrier pool. The method of claim 8,
The plurality of terminals,
The communication network system is to determine whether or not it corresponds to a non-conflicting terminal by identifying a subcarrier carrying a signal transmitted from the base station. The method of claim 11,
The base station and the non-conflicting terminal is to transmit data and ACK, the communication network system. The method of claim 12,
The base station and the non-conflicting terminal transmit data and ACK according to a sequence number of a subcarrier corresponding to each, communication network system. The method of claim 8,
The base station and the plurality of terminals are capable of half-duplex communication, a communication network system. A computer-readable recording medium recording a program for executing the method of claim 1 on a computer.

Images