JP7808567B2 - Access point and wireless communication system - Google Patents

Description

The present invention relates to an access point and a wireless communication system.

Technology for enabling a communication terminal (UE) to communicate data with multiple access points (APs) is known. Patent Document 1 discloses a method for transmitting control information to an access point to allow the access point to recognize the communication terminal when the communication terminal communicates data with the access point.

Patent document 1 discloses two cases: one in which a common cell ID and preamble data are set for multiple access points, and the multiple access points operate in cooperation with each other; and another in which the multiple access points do not cooperate with each other.

US Patent Publication No. 2018/0235013

When multiple access points operate in cooperation, as the number of access points communicating with a single communication terminal increases, the load of sending and receiving control information for the multiple access points to cooperate increases. On the other hand, when multiple access points do not operate in cooperation, the communication terminal must perform processing (e.g., 4-step RACH processing) to establish a wireless communication link with each of the multiple access points, which increases the load on the communication terminal.

The present invention was developed in consideration of these issues, and aims to reduce the processing load when a communication terminal communicates with multiple access points.

The access point of a first aspect of the present invention is an access point that communicates with a communication control device and a communication terminal, and includes: a memory unit that stores primary preamble data assigned to the access point and secondary preamble data assigned to another access point; a terminal-side transmitter that transmits the primary preamble data to the communication terminal; a terminal-side receiver that receives terminal preamble data and terminal identification information for identifying the communication terminal from the communication terminal; and a control unit that controls the network-side transmitter to transmit the terminal identification information to the communication control device when the terminal preamble data corresponds to either the primary preamble data or the secondary preamble data stored in the memory unit.

The network-side transmitter may transmit, together with the terminal identification information, time data indicating the time at which the terminal preamble data was received to the communication control device.

When the terminal preamble data received from the communication terminal corresponds to the main preamble data, the network-side transmitter may transmit notification data to the communication control device indicating that the terminal preamble data corresponding to the main preamble data has been received.

The control unit may store the terminal identification information in the storage unit when the terminal preamble data received from the communication terminal corresponds to the main preamble data or the secondary preamble data stored in the storage unit.

The control unit may control the terminal-side transmission unit to execute processing to establish a communication link with the communication terminal when the terminal preamble data received from the communication terminal corresponds to the main preamble data stored in the storage unit.

The control unit may control the terminal-side receiving unit to receive data transmitted and received while another access point is performing a process to establish a communication link with the communication terminal, if the terminal preamble data received from the communication terminal corresponds to the secondary preamble data stored in the storage unit.

The access point may further have a network-side receiving unit that receives, from the communication control device, scheduling information that specifies the timing and frequency for transmitting data to the communication terminal after the network-side transmitting unit transmits the terminal identification information to the communication control device, and the control unit may control the terminal-side transmitting unit to transmit data to the communication terminal based on the scheduling information.

A wireless communication system according to a second aspect of the present invention comprises a communication control device, a plurality of access points, and a communication terminal communicating with the plurality of access points. Each of the plurality of access points comprises a memory unit that stores primary preamble data assigned to the access point and secondary preamble data assigned to other access points, a terminal-side transmitter that transmits the primary preamble data to the communication terminal, a terminal-side receiver that receives terminal preamble data and terminal identification information for identifying the communication terminal from the communication terminal, and a control unit that controls the network-side transmitter to transmit the terminal identification information to the communication control device when the terminal preamble data corresponds to either the primary preamble data or the secondary preamble data stored in the memory unit. The communication terminal comprises a terminal receiver that receives the plurality of primary preamble data transmitted by the plurality of access points, and a terminal transmitter that transmits the terminal preamble data corresponding to one of the plurality of primary preamble data received by the terminal receiver.

The communication control device may have an information creation unit that creates scheduling information for the multiple access points to communicate data with the communication terminal in response to receiving the terminal identification information from the network-side transmission unit of each of the multiple access points, and an information transmission unit that transmits the scheduling information to the multiple access points.

This invention has the advantage of reducing the processing load when a communication terminal communicates with multiple access points.

1 is a diagram for explaining an overview of a wireless communication system S. [0023] FIG. 1 is a diagram for explaining an overview of a wireless communication system S. FIG. 1 is a diagram for explaining an overview of a wireless communication system S. FIG. 1 is a diagram for explaining an overview of a wireless communication system S. [0023] FIG. FIG. 1 is a diagram illustrating a configuration of a communication control device 1. FIG. 2 is a diagram showing the configuration of a communication terminal 3. FIG. 2 is a diagram illustrating a configuration of an access point 2. 10 is a flowchart showing the flow of processing in the access point 2. FIG. 2 is a sequence diagram showing a processing flow in the wireless communication system S.

[Overview of wireless communication system S]
1 to 4 are diagrams illustrating an overview of a wireless communication system S. The wireless communication system S includes a communication control device 1, multiple access points 2, and multiple communication terminals 3. The wireless communication system S is a mobile communication system that enables the communication terminals 3 to communicate with other communication terminals 3 via a network. The wireless communication system S is a system that enables data communication between the communication terminals 3 without forming fixed cells, by having the communication terminals 3 transmit and receive data to and from the multiple access points 2, and having the multiple access points 2 transmit and receive data to and from the communication control device 1.

The communication control device 1 is a computer managed by a mobile communication system operator, such as a CU (Central Unit) in 5G. The communication control device 1 transmits and receives data to and from multiple access points 2, and also communicates with other devices via the network.

The communication terminal 3 is a mobile information terminal, such as a smartphone, tablet, personal computer, or IoT (Internet of Things) device. The communication terminal 3 transmits and receives data to and from the communication control device 1 via multiple access points 2 by using the multiple access points 2 as MIMO (Multi-Input Multi-Output) antenna ports. When the communication terminal 3 establishes wireless communication links with the multiple access points 2, a cluster including the multiple access points 2 is formed.

The multiple access points 2 are configured to be able to communicate with the communication control device 1 and the communication terminal 3. The multiple access points 2 are, for example, connected to the communication control device 1 by wire, but may also be connected to the communication control device 1 wirelessly.

Each of the multiple access points 2 stores its own set primary preamble data, and transmits the primary preamble data when establishing a wireless communication link with the communication terminal 3. The access point 2 transmits the primary preamble data using, for example, SS/PBCH (Synchronization Signal/Physical Broadcast Channel), which is an example of a broadcast signal.

Access point 2 stores the primary preamble data of other nearby access points 2 as its own secondary preamble data. For example, access point 2 stores the primary preamble data of other access points 2 notified by communication control device 1 as secondary preamble data.

The access point 2 determines whether the terminal preamble data transmitted by the communication terminal 3 corresponds to either the primary preamble data or the secondary preamble data, and switches subsequent processing depending on whether the terminal preamble data corresponds to the primary preamble data or the secondary preamble data.

Below, an overview of the wireless communication system S will be explained with reference to Figures 1 to 4. Figures 1 to 4 show four access points 2 and one communication terminal 3, but the number of access points 2 and communication terminals 3 can be any number.

In Figure 1, "P:1" displayed below access point 2-1 indicates that access point 2-1 stores preamble data 1 (hereinafter sometimes referred to as "PR1") as its primary preamble data. "S:2" indicates that access point 2-1 stores preamble data 2 (hereinafter sometimes referred to as "PR2"), which is the primary preamble data of nearby access point 2-2, as its secondary preamble data.

The "P:2" displayed below access point 2-2 indicates that access point 2-2 has stored PR2 as its primary preamble. "S:1, 3" indicates that access point 2-2 has stored PR1, the primary preamble data of access point 2-1, which is nearby access point 2-2, and preamble data 3 (hereinafter sometimes referred to as "PR3"), the primary preamble data of access point 2-3, as secondary preamble data.

Similarly, "P:3" displayed below access point 2-3 indicates that access point 2-3 has stored PR3 as its primary preamble data. "S:2, 4" indicates that access point 2-3 has stored PR2, the primary preamble data of access point 2-2, which is nearby access point 2-3, and preamble data 4 (hereinafter sometimes referred to as "PR4"), the primary preamble data of access point 2-4, as its secondary preamble data.

As shown in FIG. 1, first, multiple access points 2 transmit broadcast signals including stored main preamble data when no clusters have been formed. Specifically, access points 2-1 to 2-4 transmit broadcast signals including PR1 to PR4, respectively. Communication terminal 3 receives these broadcast signals.

Of the received beacons, the communication terminal 3 selects the access point 2 that transmitted the beacon that satisfies a predetermined condition. For example, this predetermined condition may be the highest received signal level, but the predetermined condition is not limited to this and may be a combination of multiple conditions. In this example, the beacon signal containing PR2 has the highest received signal level, so the communication terminal 3 selects access point 2-2.

In this case, as shown in FIG. 2, communication terminal 3 transmits a signal including PR2 as terminal preamble data to establish a wireless communication link with access point 2-2. The terminal preamble data is preamble data included in the data transmitted by communication terminal 3. The wireless communication link establishment process is, for example, a 4-step Random Access Channel (RACH) process, and communication terminal 3 transmits an Msg 1 signal including PR2 as Msg 1 in the 4-step RACH process. The Msg 1 signal includes UE-ID, which is terminal identification information used to identify communication terminal 3.

Multiple access points 2 receive signals containing PR2 and compare them with the primary and secondary preamble data they store. If the received PR2 corresponds to either the primary or secondary preamble data stored by the access point 2, the access point 2 transmits to the communication control device 1 the UE-ID contained in the received Msg 1 signal and reception timing data indicating the timing at which the Msg 1 signal was received.

When the received PR2 corresponds to either the primary or secondary preamble data stored by the access point 2, it means that it can be determined that the received PR2 was created based on either the primary or secondary preamble data stored by the access point 2 itself; for example, when the received PR2 matches either the primary or secondary preamble data. If the received PR2 does not correspond to either the primary or secondary preamble data stored by the access point 2 itself, the access point 2 terminates processing without transmitting the UE-ID and reception timing data to the communication control device 1.

In the example shown in FIG. 3, access point 2-2, whose PR2 included in the Msg 1 signal corresponds to its own primary preamble data, and access points 2-1 and 2-3, whose PR2 included in the Msg 1 signal corresponds to their own secondary preamble data, transmit their UE-IDs to the communication control device 1. The timing at which the access point 2 transmits the UE-ID is arbitrary, but for example, multiple access points 2 transmit their UE-IDs between receiving terminal preamble data from communication terminal 3 and completing 4-step RACH processing between access point 2-2 and communication terminal 3.

For example, the multiple access points 2 transmit the UE-ID at the timing when the access point 2-2 selected by the communication terminal 3 is expected to complete the 4-step RACH process. The multiple access points 2 may transmit the UE-ID while the access point 2-2 is performing the 4-step RACH process, or may monitor the data being transmitted and received in the 4-step RACH process and transmit the UE-ID when the 4-step RACH process is completed.

When access point 2-2 receives its own main preamble data, PR2, from communication terminal 3, it establishes a wireless communication link between access point 2-2 and communication terminal 3 by exchanging Msg 2 and subsequent steps in the 4-step RACH process. Upon completion of the 4-step RACH process, access point 2-2 notifies communication control device 1 that a wireless communication link has been established. By observing the 4-step RACH process performed between access point 2-2 and communication terminal 3, access point 2-1 and access point 2-3 recognize that a wireless communication link between access point 2-2 and communication terminal 3 has been established.

Next, as shown in FIG. 4, the communication control device 1 creates scheduling information to be notified to each of the three access points 2: access point 2-2, and access points 2-1 and 2-3, which received the UE-ID from the communication terminal 3 at approximately the same time as access point 2-2, so that they can transmit and receive data with the communication terminal 3. The scheduling information includes the frequency and time (slot) to be allocated to each access point 2, as well as the precoding coefficient to be used in the download link. The communication control device 1 notifies access point 2-1, access point 2-2, and access point 2-3 of the scheduling information. Access point 2-2 then transmits the notified scheduling information to the communication terminal 3.

From this point on, the multiple access points 2 and communication terminal 3 begin data communication based on the scheduling information. Specifically, communication terminal 3 transmits data at frequencies and times when access points 2-1, 2-2, and 2-3 can receive data, and receives data at frequencies and times when access points 2-1, 2-2, and 2-3 transmit data. The configurations and operations of the communication control device 1, access points 2, and communication terminal 3 are described in detail below.

[Configuration of communication control device 1]
5 is a diagram showing the configuration of the communication control device 1. The communication control device 1 has an information receiving unit 11, an information transmitting unit 12, a storage unit 13, and a device control unit .

The information receiving unit 11 receives various information from multiple access points 2. For example, the information receiving unit 11 receives UE-IDs received from communication terminals 3 with which multiple access points 2 communicate.

The information transmission unit 12 transmits various types of information to multiple access points 2. For example, the information transmission unit 12 transmits scheduling information created by the device control unit 14 to multiple access points 2.

The storage unit 13 includes storage media such as ROM (Read Only Memory), RAM (Random Access Memory), and SSD (Solid State Drive). The storage unit 13 stores programs executed by the device control unit 14. The storage unit 13 also stores scheduling information corresponding to each of the multiple access points 2.

The device control unit 14 has, for example, a CPU (Central Processing Unit) and executes programs stored in the storage unit 13 to realize the various functions performed by the communication control device 1. The device control unit 14 functions, for example, as an information creation unit that creates scheduling information in response to the information receiving unit 11 receiving UE-IDs from each of the multiple access points 2.

[Configuration of communication terminal 3]
6 is a diagram showing the configuration of the communication terminal 3. The communication terminal 3 has a terminal receiving unit 31, a terminal transmitting unit 32, a storage unit 33, and a terminal control unit .

The terminal receiving unit 31 receives various information from multiple access points 2. For example, the terminal receiving unit 31 receives main preamble data transmitted by multiple access points 2.

The terminal transmitter 32 transmits various information to multiple access points 2. For example, the terminal transmitter 32 transmits terminal preamble data corresponding to one of the multiple main preamble data received by the terminal receiver 31 using a RACH (Random Access Channel). Specifically, for example, the terminal transmitter 32 transmits terminal preamble data corresponding to the main preamble data received from an access point 2 selected by the terminal control unit 34 from the multiple access points 2. The terminal preamble data may be data that matches the main preamble data, or may be data created by converting the main preamble data based on a predetermined conversion rule.

The storage unit 33 has storage media such as ROM and RAM. The storage unit 33 stores programs executed by the terminal control unit 34. The storage unit 33 also stores the UE-ID.

The terminal control unit 34 has, for example, a CPU, and executes programs stored in the memory unit 33 to realize various functions performed by the communication terminal 3. The terminal control unit 34 selects one access point 2, for example, based on the level of the signal received by the terminal receiving unit 31 from each of multiple access points 2. The terminal control unit 34 creates terminal preamble data corresponding to the main preamble data received from the selected access point 2, and causes the terminal transmitting unit 32 to transmit the created terminal preamble data.

[Configuration of Access Point 2]
7 is a diagram showing the configuration of the access point 2. The access point 2 has a terminal-side communication unit 21, a network-side communication unit 22 (hereinafter referred to as the “NW-side communication unit 22”), a storage unit 23, and a control unit 24.

The terminal-side communication unit 21 includes a device that executes communication processing for transmitting and receiving data to and from the communication terminal 3, and has a terminal-side transmission unit 211 and a terminal-side reception unit 212. The terminal-side transmission unit 211 and the terminal-side reception unit 212 operate under the control of the control unit 24. The terminal-side transmission unit 211 and the terminal-side reception unit 212 operate in cooperation with each other to execute 4-step RACH processing with the communication terminal 3.

The terminal-side transmitter 211 functions as a terminal-side transmitter that transmits a broadcast signal including main preamble data stored in the memory unit 23, for example. When the access point 2 performs 4-step RACH processing with the communication terminal 3, the terminal-side transmitter 211 transmits an Msg 2 signal and an Msg 4 signal to the communication terminal 3. After a wireless communication link with the communication terminal 3 is established, the terminal-side transmitter 211 also transmits to the communication terminal 3 data that was transmitted by the communication control device 1 to the communication terminal 3.

The terminal-side receiving unit 212 receives various data from the communication terminal 3. For example, the terminal-side receiving unit 212 receives terminal preamble data and terminal identification information for identifying the communication terminal 3 from the communication terminal 3. When the access point 2 performs 4-step RACH processing with the communication terminal 3, the terminal-side receiving unit 212 receives the Msg 1 signal and Msg 3 signal transmitted by the communication terminal 3. After a wireless communication link with the communication terminal 3 is established, the terminal-side receiving unit 212 receives data transmitted by the communication terminal 3 to the communication control device 1, and notifies the control unit 24 of the received data.

The NW-side communication unit 22 includes a device that executes communication processing for transmitting and receiving data to and from the communication control device 1, and has a network-side transmitting unit 221 (hereinafter referred to as the "NW-side transmitting unit 221") and a network-side receiving unit 222 (hereinafter referred to as the "NW-side receiving unit 222"). The NW-side transmitting unit 221 and the NW-side receiving unit 222 operate under the control of the control unit 24.

When the terminal preamble data received from the communication terminal 3 corresponds to either the primary preamble data or the secondary preamble data stored in the memory unit 23, the network-side transmitter 221 transmits the UE-ID of the communication terminal 3 and time data indicating the time the terminal preamble data was received to the communication control device 1.

When the terminal preamble data received from the communication terminal 3 corresponds to the main preamble data, the NW-side transmitter 221 may transmit to the communication control device 1 notification data indicating that the terminal preamble data corresponding to the main preamble data has been received. When the terminal preamble data received from the communication terminal 3 corresponds to the secondary preamble data, the NW-side transmitter 221 may transmit to the communication control device 1 notification data indicating that the terminal preamble data corresponding to the secondary preamble data has been received. After a wireless communication link between the access point 2 and the communication terminal 3 is established, the NW-side transmitter 221 transmits the data received from the communication terminal 3 and addressed to the communication control device 1 to the communication control device 1.

The NW-side receiving unit 222 receives data transmitted from the communication control device 1. For example, the NW-side receiving unit 222 receives scheduling information from the communication control device 1 that specifies the timing and frequency at which data is transmitted to the communication terminal 3. The NW-side receiving unit 222 notifies the control unit 24 of the received scheduling information. The NW-side receiving unit 222 may store the received scheduling information in the storage unit 23.

The memory unit 23 has storage media such as ROM (Read Only Memory), RAM (Random Access Memory), and SSD (Solid State Drive). The memory unit 23 stores programs executed by the control unit 24. The memory unit 23 also stores primary preamble data assigned to the access point 2 and secondary preamble data assigned to other access points 2. The memory unit 23 also stores various data used by the access point 2 to relay data transmitted and received between the communication control device 1 and the communication terminal 3.

The control unit 24 includes, for example, a CPU (Central Processing Unit). By executing programs stored in the storage unit 23, the control unit 24 establishes a wireless communication link with the communication terminal 3 and performs various processes for relaying data sent and received between the communication control device 1 and the communication terminal 3.

The control unit 24 controls the operation of the terminal-side transmitter 211, terminal-side receiver 212, network-side transmitter 221, and network-side receiver 222. For example, the control unit 24 notifies the terminal-side transmitter 211 of the main preamble data stored in the memory unit 23 and controls the terminal-side transmitter 211 to transmit a notification signal including the main preamble data. Furthermore, the control unit 24 controls the network-side transmitter 221 to transmit a UE-ID to the communication control device 1 when the terminal preamble data received from the communication terminal 3 corresponds to either the main preamble data or the secondary preamble data stored in the memory unit 23.

When the terminal preamble data received from the communication terminal 3 corresponds to the main preamble data or secondary preamble data stored in the memory unit 23, the control unit 24 may store a UE-ID, which is terminal identification information for identifying the communication terminal 3, in the memory unit 23.

When the terminal preamble data received from the communication terminal 3 corresponds to the primary preamble data stored in the memory unit 23, the control unit 24 controls the terminal-side transmitting unit 211 to execute processing to establish a wireless communication link with the communication terminal 3. When the terminal preamble data received from the communication terminal 3 corresponds to the secondary preamble data stored in the memory unit 23, the control unit 24 controls the terminal-side receiving unit 212 to receive data transmitted and received while another access point 2 executes processing to establish a wireless communication link with the communication terminal 3.

The control unit 24 controls the terminal-side transmitting unit 211 so that the network-side receiving unit 222 transmits data to the communication terminal 3 based on the scheduling information received from the communication control device 1. The control unit 24 controls the terminal-side receiving unit 212 so that it receives data from the communication terminal 3 based on the scheduling information. For example, when the UE-ID included in the scheduling information corresponds to a UE-ID stored in the storage unit 23, the control unit 24 controls the terminal-side transmitting unit 211 and the terminal-side receiving unit 212 so that data is transmitted and received between the communication terminal 3 and the network-side receiving unit 211 based on the frequency and time included in the scheduling information.

[Processing flow at access point 2]
8 is a flowchart showing the flow of processing in the access point 2. The flowchart shown in FIG.

The control unit 24 controls the terminal-side transmitting unit 211 to transmit a notification signal including the main preamble data stored in the memory unit 23 (S1). The control unit 24 causes the terminal-side transmitting unit 211 to transmit the notification signal, for example, periodically. Thereafter, the control unit 24 determines whether the terminal-side receiving unit 212 has received the main preamble data from the communication terminal 3 (S2). Specifically, the control unit 24 determines whether the terminal preamble data received by the terminal-side receiving unit 212 from the communication terminal 3 corresponds to the main preamble data transmitted by the terminal-side transmitting unit 211.

When the terminal-side receiver 212 receives the main preamble data transmitted by the terminal-side transmitter 211 from the communication terminal 3 (YES in S2), the control unit 24 stores the UE-ID of the access point 2 that transmitted the terminal preamble data corresponding to the main preamble data in the storage unit 23 (S3). The control unit 24 transmits the UE-ID and the time the UE-ID was received to the communication control device 1 (S4).

The control unit 24 also executes a process to establish a wireless communication link with the communication terminal 3 (S5). Specifically, the control unit 24 executes a 4-step RACH process with the communication terminal 3. When the process to establish the wireless communication link is complete, the control unit 24 transmits a connection completion notification to the communication control device 1 (S6). Note that the control unit 24 may also execute the process of transmitting the UE-ID and reception time of S4 after executing the process to establish the wireless communication link.

If the control unit 24 determines in S2 that primary preamble data has not been received from the communication terminal 3 (NO in S2), the control unit 24 determines whether secondary preamble data has been received from the communication terminal 3 (S7). Specifically, the control unit 24 determines whether the terminal preamble data received by the terminal-side receiving unit 212 from the communication terminal 3 corresponds to the secondary preamble data stored in the memory unit 23.

When the terminal-side receiving unit 212 receives secondary preamble data stored in the memory unit 23 from the communication terminal 3 (YES in S7), the control unit 24 stores the UE-ID of the access point 2 that transmitted the terminal preamble data corresponding to the secondary preamble data in the memory unit 23 (S8). The control unit 24 transmits the UE-ID and the time the UE-ID was received to the communication control device 1 (S9).

Then, after processing S6 or S9, the control unit 24 receives scheduling information from the communication control device 1 via the NW-side receiving unit 222 (S10). The control unit 24 transmits and receives data to and from the communication terminal 3 based on the frequency and timing included in the scheduling information (S11). The control unit 24 transmits and receives data to and from the communication terminal 3, for example, until it receives a control signal to terminate communication from the communication control device 1 or the communication terminal 3 (NO in S12).

[Processing flow in wireless communication system S]
Fig. 9 is a sequence diagram showing the flow of processing in the wireless communication system S. In Fig. 9, "CPU" represents the communication control device 1, "AP" represents the access point 2, and "UE" represents the communication terminal 3. The processing shown in Fig. 9 starts from a state in which the communication terminal 3 is not connected to the access point 2.

Each of the multiple access points 2 periodically transmits a broadcast signal including main preamble data stored in its own memory unit 23. When the communication terminal 3 receives main preamble data transmitted by multiple access points 2, it selects one access point 2 based on predetermined conditions. For example, the communication terminal 3 selects the access point 2 with the highest broadcast signal reception level (i.e., the access point 2 with the smallest transmission path loss). In Figure 9, the communication terminal 3 selects access point 2-2.

The communication terminal 3 transmits PR2, the main preamble data transmitted by the selected access point 2-2, as terminal preamble data. Multiple access points 2 receive the terminal preamble data.

Of the multiple access points 2, access point 2-2 transmits the UE-ID of communication terminal 3 to the communication control device 1 because the terminal preamble data corresponds to the primary preamble data stored in memory unit 23. Access point 2-1 and access point 2-3 transmit the UE-ID of communication terminal 3 to the communication control device 1 because the terminal preamble data corresponds to the secondary preamble data stored in memory unit 23. Access point 2-4 does not transmit the UE-ID of communication terminal 3 to the communication control device 1 because the terminal preamble data does not correspond to either the primary or secondary preamble data stored in memory unit 23.

Access point 2-2 executes a 4-step RACH process, which is a process for establishing a wireless link with communication terminal 3. When access point 2-2 completes the 4-step RACH process, it sends a connection completion notification to communication control device 1. Communication control device 1 then creates scheduling information and sends it to access points 2-1, 2-2, and 2-3, which sent the UE-ID. This allows communication terminal 3 to send and receive data to communication control device 1 via access points 2-1, 2-2, and 2-3.

[Effects of Access Point 2]
As described above, the access point 2 according to this embodiment transmits a broadcast signal including the primary preamble data stored in the storage unit 23, and when the terminal preamble data received from the communication terminal 3 corresponds to either the primary preamble data or the secondary preamble data stored in the storage unit 23, forms a cluster by transmitting the UE-ID of the communication terminal 3 that transmitted the terminal preamble data to the communication control device 1. Furthermore, when the terminal preamble data corresponds to the primary preamble data, the access point 2 executes processing to establish a wireless communication link with the communication terminal 3. By configuring the access point 2 in this way, it becomes possible for the communication terminal 3 to communicate with multiple access points 2 while suppressing an increase in the processing load when multiple access points 2 and the communication terminal 3 communicate with each other.

Furthermore, this invention will contribute to Goal 9 of the United Nations' Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote inclusive and sustainable industrialization, and promote innovation and resilience."

The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and alterations are possible within the spirit of the invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of new embodiments resulting from the combination will also have the effects of the original embodiments.

REFERENCE SIGNS LIST 1 Communication control device 2 Access point 3 Communication terminal 11 Information receiving unit 12 Information transmitting unit 13 Storage unit 14 Device control unit 21 Terminal side communication unit 22 Network side communication unit 23 Storage unit 24 Control unit 31 Terminal receiving unit 32 Terminal transmitting unit 33 Storage unit 34 Terminal control unit 211 Terminal side transmitting unit 212 Terminal side receiving unit 221 Network side transmitting unit 222 Network side receiving unit

Claims (6)

An access point that communicates with a communication control device and a communication terminal,
a storage unit that stores primary preamble data assigned to the access point and secondary preamble data assigned to other access points;
a terminal side transmitting unit that transmits the main preamble data to the communication terminal;
a terminal side receiving unit that receives terminal preamble data and terminal identification information for identifying the communication terminal from the communication terminal;
a control unit that controls a network-side transmitting unit to transmit, to the communication control device, time data indicating a time when the terminal preamble data corresponds to either the main preamble data or the secondary preamble data stored in the storage unit, together with the terminal identification information ;
An access point having An access point that communicates with a communication control device and a communication terminal,
a storage unit that stores primary preamble data assigned to the access point and secondary preamble data assigned to other access points;
a terminal side transmitting unit that transmits the main preamble data to the communication terminal;
a terminal side receiving unit that receives terminal preamble data and terminal identification information for identifying the communication terminal from the communication terminal;
a control unit that controls a network-side transmitting unit to transmit the terminal identification information to the communication control device when the terminal preamble data corresponds to either the main preamble data or the secondary preamble data stored in the storage unit;
and
When the terminal preamble data received from the communication terminal corresponds to the main preamble data, the network side transmitting unit transmits notification data indicating that the terminal preamble data corresponding to the main preamble data has been received to the communication control device.
Access point. An access point that communicates with a communication control device and a communication terminal,
a storage unit that stores primary preamble data assigned to the access point and secondary preamble data assigned to other access points;
a terminal side transmitting unit that transmits the main preamble data to the communication terminal;
a terminal side receiving unit that receives terminal preamble data and terminal identification information for identifying the communication terminal from the communication terminal;
a control unit that controls a network-side transmitting unit to transmit the terminal identification information to the communication control device when the terminal preamble data corresponds to either the main preamble data or the secondary preamble data stored in the storage unit;
and
the control unit stores the terminal identification information in the storage unit when the terminal preamble data received from the communication terminal corresponds to the main preamble data or the sub preamble data stored in the storage unit.
Access point. An access point that communicates with a communication control device and a communication terminal,
a storage unit that stores primary preamble data assigned to the access point and secondary preamble data assigned to other access points;
a terminal side transmitting unit that transmits the main preamble data to the communication terminal;
a terminal side receiving unit that receives terminal preamble data and terminal identification information for identifying the communication terminal from the communication terminal;
a control unit that controls a network-side transmitting unit to transmit the terminal identification information to the communication control device when the terminal preamble data corresponds to either the main preamble data or the secondary preamble data stored in the storage unit;
and
the control unit controls the terminal-side receiving unit to receive data transmitted and received while another access point is executing a process of establishing a communication link with the communication terminal, when the terminal preamble data received from the communication terminal corresponds to the sub-preamble data stored in the storage unit.
Access point. An access point that communicates with a communication control device and a communication terminal,
a storage unit that stores primary preamble data assigned to the access point and secondary preamble data assigned to other access points;
a terminal side transmitting unit that transmits the main preamble data to the communication terminal;
a terminal side receiving unit that receives terminal preamble data and terminal identification information for identifying the communication terminal from the communication terminal;
a control unit that controls a network-side transmitting unit to transmit the terminal identification information to the communication control device when the terminal preamble data corresponds to either the main preamble data or the secondary preamble data stored in the storage unit;
a network-side receiving unit that receives, after the network-side transmitting unit transmits the terminal identification information to the communication control device, scheduling information that specifies a timing and a frequency for transmitting data to the communication terminal from the communication control device;
and
the control unit controls the terminal-side transmitting unit to transmit data to the communication terminal based on the scheduling information.
Access point. a communication control device, a plurality of access points, and a communication terminal that communicates with the plurality of access points;
Each of the plurality of access points
a storage unit that stores primary preamble data assigned to the access point and secondary preamble data assigned to other access points;
a terminal side transmitting unit that transmits the main preamble data to the communication terminal;
a terminal side receiving unit that receives terminal preamble data and terminal identification information for identifying the communication terminal from the communication terminal;
a control unit that controls a network-side transmitting unit to transmit the terminal identification information to the communication control device when the terminal preamble data corresponds to either the main preamble data or the secondary preamble data stored in the storage unit;
and
The communication terminal
a terminal receiving unit that receives the plurality of main preamble data transmitted from the plurality of access points;
a terminal transmitting unit that transmits the terminal preamble data corresponding to any one of the plurality of main preamble data received by the terminal receiving unit;
and
The communication control device
an information creating unit that creates scheduling information for the plurality of access points to perform data communication with the communication terminal in response to receiving the terminal identification information from the network side transmitting unit of each of the plurality of access points;
an information transmitting unit that transmits the scheduling information to the plurality of access points;
having
Wireless communication system.