JP2019029850A - Base station device establishing connection with terminal, control method, and program - Google Patents

Abstract

An object of the present invention is to establish a connection in an appropriate procedure even when a base station apparatus receives a connection request with an unexplainable establishment reason. A base station device that executes processing for establishing a connection between a terminal device and a network in a radio resource control (RRC) layer sends a connection request in which a reason for establishing the connection is set from the terminal device. Receive and process connection requests based on establishment reasons. Here, the value indicating the establishment reason is classified into one of a plurality of groups each corresponding to one or more reasons. When the base station apparatus does not support the establishment reason set in the connection request, the connection with the terminal apparatus is performed for a predetermined reason supported by the base station apparatus in the group including the value indicating the establishment reason. The process is executed by treating it as the reason for establishment of. [Selection] Figure 3

Description

  The present invention relates to connection control between a base station apparatus and a terminal apparatus.

  A base station apparatus in a cellular communication system such as LTE (Long Term Evolution) and 5G establishes a connection with a terminal apparatus in response to a connection request transmitted from the terminal apparatus. For example, when there is data to be transmitted, the terminal apparatus transmits a connection request message to the base station apparatus for transmitting the data. Further, when there is an incoming voice or data to the own device, the terminal device sends a connection request message to the base station device in response to receiving a paging message from the network (for example, Mobility Management Entity (MME)). Send. The connection request is, for example, an RRC Connection Request message in the radio resource control (RRC) layer.

  The RRC Connection Request message includes a connection establishment reason (Establishment Cause). According to this, for example, in a predetermined case such as when a disaster occurs, the base station apparatus preferentially establishes a connection with a reason for establishment with high urgency, and establishes a connection with a reason for establishment with low urgency. Connection control such as suppression can be executed.

  Currently, the reason for establishment is defined as emergency call, high priority access, access to terminal, signaling transmission from terminal, data transmission from terminal, etc., and further establishment reasons according to future functional enhancement It is assumed that will be added. In such a case, if the terminal device transmits an RRC Connection Request message for a newly defined establishment reason, the base station device may not be able to interpret the content and may not be able to establish a connection with the terminal device. is there. On the other hand, in Cited Document 1, when the base station apparatus receives an RRC Connection Request message for an unsupported establishment reason, the establishment reason is treated as data transmission from the terminal, thereby establishing a connection. A technique is described that prevents it from becoming impossible.

JP 2017-103536 A

  In the technique described in the cited document 1, for example, when a new establishment reason for the incoming call to the terminal is defined and the new establishment reason is used, the base station apparatus cannot interpret the establishment reason. It can happen that it is handled as a call from the terminal. In this case, for example, although the MME transmits a paging message to the terminal device, it may not be possible to communicate because the connection related to the incoming call to the terminal device is not established.

  The present invention has been made in view of the above problems, and an object of the present invention is to enable a base station apparatus to establish a connection in an appropriate procedure even when it receives a connection request for an establishment reason that cannot be interpreted. To do.

  The base station apparatus which concerns on 1 aspect of this invention is a base station apparatus which performs the process for establishing the connection between terminal devices in a radio | wireless resource control (RRC) layer, Comprising: From the said terminal device, Receiving means for receiving a connection request in which an establishment reason is set; and processing means for processing the connection request based on the establishment reason, each of the establishment reasons corresponding to one or more reasons If the base station device does not support the establishment reason set in the connection request, the processing means determines a predetermined reason in the group including the establishment reason. The process is executed as a reason for establishing a connection with the terminal device.

  According to the present invention, even when the base station apparatus receives a connection request with an establishment reason that cannot be interpreted, the connection can be established by an appropriate procedure.

The figure which shows the structural example of a radio | wireless communications system. The figure for demonstrating the flow of the conventional connection process. The figure which shows the structural example of an establishment reason and SST. The figure which shows the hardware structural example of a base station apparatus. The figure which shows the function structural example of a base station apparatus. The figure which shows the example of the flow of the process which a base station apparatus performs.

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

(Network configuration)
FIG. 1 shows a configuration example of a wireless communication system according to this embodiment. The wireless communication system includes, for example, a base station device, a terminal device, and a network node (for example, Mobility Management Entity (MME)). A connection is established between the base station device and the terminal device by radio, and the base station device and the network node are connected by a line including at least one of wired and wireless, for example. In one example, the terminal device is configured to be able to communicate with the network node via the base station device. In the following, a network node may be referred to as an MME, but a network node other than the MME may be used. In a broader sense, the network node is replaced with a network such as a core network, for example. Also good. That is, the function of the network node shown in FIG. 1 can be realized by one or more logical entities in the network.

  In a radio communication system, a base station apparatus executes processing for establishing a connection with a terminal apparatus in a radio resource control (RRC) layer. For example, the terminal device transmits a connection request (RRC Connection Request), and the base station device establishes an RRC connection with the terminal device accordingly. Note that a connection establishment reason (Establishment Cause) is set in the connection request, and the base station apparatus executes connection establishment processing based on the establishment reason.

  When the base station apparatus does not support the establishment reason established in the connection request, the base station apparatus can execute the connection process by treating the establishment reason as another establishment reason. For example, it is assumed that the base station apparatus handles the unsupported establishment reason as data transmission (mo-Data) from the terminal apparatus. Thereby, the base station apparatus can establish a connection even for an unsupported establishment reason. However, in this case, for example, if a new establishment reason for an incoming call to the terminal device is used, inconvenience may occur.

  For example, an incoming voice call at a terminal device is not currently defined as a reason for establishment, but this is defined as a reason for establishment, while a base station device does not support this reason for establishment. To do. In this case, as shown in FIG. 2, first, the MME notifies the terminal device (via the base station device) that there is an incoming voice call by a paging message (PCH, Paging Channel). Thereafter, the MME waits for a connection for an incoming call in the terminal device to be established between the terminal device and the base station device. When the terminal device receives the PCH message, the terminal device transmits a connection request (RRC Connection Request) set as a reason for establishing an incoming voice call (mt-VoiceCall) in the own device to the base station device. Since the base station apparatus does not support this establishment reason, the base station apparatus treats it as data transmission (mo-Data) by the terminal, and proceeds with the process. Finally, the establishment UE indicates that the establishment reason is “mo-Data” and RRC. Notify that a connection has been established. On the other hand, the MME does not determine that the connection notified by the base station apparatus with the establishment reason “mo-Data” is a connection by a paging message. That is, the MME is waiting for the establishment of a connection for incoming calls at the terminal device, and even if the connection for outgoing calls by the terminal device is established, the connection is caused by the previously transmitted paging message. Cannot be determined. For this reason, for example, a timeout may occur in the MME, or an error may occur due to reception of a service request message for an incoming call from a terminal device that should not have established a connection related to an incoming call in the MME.

  In the present embodiment, the configuration of the establishment reason is changed so that such an error does not occur. In other words, there are values for which the reason for establishment is not defined for future function expansion or the like. This value is assigned in advance to a first group related to outgoing calls from the terminal device and a second group related to incoming calls at the terminal device. That is, at present, the value indicating the reason for establishment takes eight values from 0 to 7, and since the reason for establishment is not defined in 6 and 7, the value “6” is assigned to the first group related to outgoing call, The value “7” is assigned to the second group for incoming calls. Also, some of the values are already defined in the establishment reason (mo-Signalling, mo-Data) regarding the transmission of the terminal device and the establishment reason (mt-Access) regarding the incoming call in the terminal device. For this reason, these establishment reasons are also classified into a first group and a second group, respectively. That is, for each of outgoing and incoming calls of the terminal device, a group including an already defined establishment reason and an undefined establishment reason is formed.

  If the base station apparatus does not support the establishment reason set in the connection request, the base station apparatus in the group including the establishment reason indicates the predetermined reason supported by the base station apparatus for connection with the terminal apparatus. Treat as an establishment reason and establish a connection. According to this, when a terminal device sets a new establishment reason and transmits a connection request, even if the base station device does not support the establishment reason, the base station device responds to the establishment reason corresponding to the transmission by the terminal device. In other words, connection processing can be performed for an establishment reason corresponding to another call, and connection processing can be performed for an establishment reason corresponding to another incoming call. As a result, the MME receives the Initial UE message in which the reason for establishment of the incoming call at the terminal device is set in response to the paging message, and therefore recognizes that at least the connection for the incoming call at the terminal device has been established. Can do. At this time, the MME recognizes that a connection with a reason different from the establishment reason transmitted by the paging message is established. However, for example, by negotiating the processing when the establishment reason is changed between the base station apparatus and the MME, the MME may recognize that the established connection is due to a paging message. it can. As a result, the above-described error can be prevented from occurring.

  When a new establishment reason is defined, a value for which the corresponding establishment reason for the second group is not defined is set as the new establishment reason for the incoming call in the terminal device, for example. To be associated with the reason for establishment. Here, it should be noted that at present, the reason for establishment only takes values from 0 to 7, but it will be expanded in the future and can take on more values. That is, there may be many values for which the reason for establishment is undefined. For this reason, the establishment reasons are classified into a plurality of groups so that they can correspond to a number of establishment reasons defined in the future, and even in a base station apparatus that does not support the establishment reasons, in a form suitable for the group. It is beneficial to ensure that a connection is established.

  FIG. 3A and FIG. 3B show configuration examples of establishment reasons when a group related to outgoing calls and a group related to incoming calls are defined. FIGS. 3A and 3B show examples of the case where the establishment reason is represented by 3 bits as in the present case and the case where the reason for establishment is extended to 4 bits, respectively. The elements not underlined are items defined as the reason for establishment at the present time, and the items underlined indicate items for adapting to grouping according to the present embodiment.

  In FIG. 3A, for example, mo-Data exists as an existing establishment reason when transmitting from a terminal device. On the other hand, mo-spare is defined as an item regarding transmission from a terminal device whose establishment reason is undefined. The mo-spare is an item that is determined to be a reason for establishment regarding transmission from a terminal device, but a detailed reason for establishment is not defined. In the present embodiment, a group including mo-Data and mo-spare, which are the reasons for establishment when making a call from these terminal devices, is formed. In the future, when a detailed reason for establishing mo-spare (for example, a terminal-originated voice call) is newly defined, the terminal device can use it. When a base station device receives a connection request for an establishment reason that is not supported by the device itself newly defined for mo-spare, the establishment reason is assumed to be mo-Data belonging to the same group. You can handle and proceed. In this case, the base station apparatus transmits an Initial UE message including mo-Data as an establishment reason to the MME. In FIG. 3A, mt-Access exists as an existing establishment reason when a terminal device receives a call. On the other hand, mt-spare is defined as an item related to incoming calls in a terminal device whose establishment reason is undefined, and a group including mt-Access and mt-spare is formed. As a result, when the base station apparatus receives a connection request for an establishment reason that is not supported by the own apparatus newly defined for mt-spare, the establishment reason is mt-Access belonging to the same group. You can treat it as a thing and proceed. In this case, the base station apparatus transmits an Initial UE message including mt-Access as the establishment reason to the MME.

  FIG. 3B shows an example in which the establishment reason is expressed by 4 bits. In this case, 10 reasons can be expressed in addition to the existing 6 reasons. In the example of FIG. 3B, the values corresponding to these ten reasons are set to five undefined reasons (mo-spare) for outgoing call by the terminal device and undefined for incoming call at the terminal device. The reason (mt-spare) is assigned. Note that the number of values assigned to the undefined reason of each group does not have to be equal, and can be set as appropriate according to future availability. A value may be assigned to an undefined reason other than for outgoing and incoming calls. Furthermore, although FIG. 3A and FIG. 3B show examples where existing establishment reasons remain, it should be noted that these reasons may be deleted. That is, even in the case of FIG. 3A, three or more undefined reasons may be included. However, also in this case, grouping is performed so that at least a part of the value indicating the undefined reason belongs to the same group as the value corresponding to the defined reason.

  Note that the plurality of groups need not be classified into groups relating to outgoing and incoming calls, and may be classified according to other scales. For example, the plurality of groups may include one or more groups classified for each connection priority as illustrated in FIG. That is, for example, there are a plurality of first groups having a high connection priority, a second group having a low connection priority, and a third group relating to a priority that does not belong to the first group and the second group. It may be included in the group. In the example of FIG. 3C, the undefined reasons for the first group, the second group, and the third group are respectively “High-Priority-spare”, “Low-Priority-spare”, and This is indicated by “Mid-Priority-spare”. Note that the priority may be determined, for example, in two steps or four or more steps, and the number of undefined reasons for each of the plurality of priorities may be different from each other.

  In addition, as shown in FIG. 3D, the plurality of groups may include, for example, one or more groups classified according to the use of communication. For example, high-speed and large-capacity communication (for example, eMBB, enhanced Mobile Broad Band), connection by multiple terminals (mMTC, massive machine type communications), ultra-reliable and low-latency communications (URLLC, Ultra-Reliable and Low Latency Communications), etc. In addition, a group may be formed. In the example of FIG. 3D, undefined reasons for the group of high-speed and large-capacity communication, the group of connections by a large number of terminals, and the group of ultra-reliable and low-delay communication are respectively represented by “eMBB-spare” and “mMTC- This is indicated by “spare” and “URLLC-spare”. Note that uses other than these may be used, and the number of undefined reasons for each of a plurality of uses may be different from each other.

  Further, as shown in FIG. 3E, the plurality of groups may include one or more groups classified according to the form of the terminal device to be connected. For example, a group such as a group related to a smartphone, a group related to a wireless LAN router, and a group related to subscriber premises equipment can be formed. In the example of FIG. 3 (E), the undefined reasons for the smart phone group, the wireless LAN router group, and the subscriber premises equipment group are respectively “SP-spare”, “wRouter-spare”, and “CPE”. -spare ". Note that the terminal devices may be classified into other forms, and the number of undefined reasons for each of the plurality of forms may be different from each other.

  The various groups described above can coexist. For example, connection reasons that should clearly distinguish between outgoing and incoming calls are classified into groups related to either outgoing or incoming calls, and connection reasons that do not need to be distinguished between outgoing and incoming calls are classified into groups related to priority, etc. May be. In addition, as a group related to priority, for example, only a group with high priority may be formed, and other connection reasons that do not have high priority may be classified as groups not based on priority. Similarly, a group related to the use of communication and the form of the terminal device does not necessarily need to be formed with a plurality of groups when the viewpoint is used, and one or more groups may be formed.

  Regardless of which group configuration is used, the value indicating the establishment reason is classified so that a value for which the establishment reason is not defined belongs to at least some of the groups. Then, when the base station apparatus receives a connection request in which a value for which the establishment reason is not defined is set, the base station apparatus receives the connection request for a predetermined reason supported by the base station apparatus in the group to which the value belongs. The connection establishment process is executed and the connection establishment process is executed. Thereby, even if the base station does not support the establishment reason set by the terminal device, the connection is established for a predetermined reason corresponding to the establishment reason.

  Although the reason for establishment has been described above, for example, a similar method can be used for Slice Service Type (SST). That is, the network transmits, for example, a paging message in which SST is set to the terminal device via the base station device. Thereafter, RRC connection processing between the terminal device and the base station device is executed, and in this processing, the terminal device transmits the SST value set in the paging message, for example, included in the RRC Connection Setup Complete message. . At this time, if the base station apparatus supports the SST in the message, the base station apparatus transmits an Initial UE message in which the SST is set, but if the SST is not supported, An Initial UE message in which SST is set can be transmitted. However, if the SST set in the Initial UE message at this time is irrelevant to the SST set in the paging message, an error may occur because there is a conflict with the SST managed by the network.

  For this reason, as in the case of the establishment reason described above, values indicating SST are classified into a plurality of groups related to the same or related SST. When the base station apparatus receives a message in which an unsupported SST value is set, the base station apparatus assumes that another SST supported by the own apparatus is set in the group to which the SST value belongs. To continue the connection process. The SST may be related to the communication application described above, for example. In this case, as shown in FIG. 3F, for example, the SST is classified into high-speed and large-capacity communication, connection by a large number of terminals, ultra-reliable and low-delay communication, and the like, and can be grouped for each classification. The SST may be classified for each service such as voice call, video and music streaming, and grouped for each classification. Note that a plurality of groups each corresponding to at least one SST can be formed on various scales other than these scales.

  According to this, when the terminal device sets a new SST and transmits a message, even if the base station device does not support the SST, the terminal device treats it as another SST corresponding to the SST, Connection processing can be performed. As a result, the network receives an Initial UE message in which an SST corresponding to the SST set in the paging message is set. At this time, the network recognizes that the connection for the SST different from the SST transmitted by the paging message is established. However, for example, by negotiating the processing when the SST is changed between the base station apparatus and the network, the network can recognize that the established connection is due to the paging message. .

  The establishment reason may be associated with the SST. In this case, when a terminal device requests a connection at a certain SST, the terminal device transmits a connection request in which a reason for establishment corresponding to the SST is set to the base station device. For example, the SST for the voice call service corresponds to a reason for establishment with a high priority, and the SST for the video streaming service corresponds to a reason for establishment with a low priority. This association can be performed for each network operator, for example. As a result, the network operator can customize the relationship between the service and the reason for establishing the connection. For example, it is possible to realize differentiation of the service, such as making communication easier for a predetermined service. . Further, for example, in a mixed situation such as a concert venue, the relationship between the establishment reason and the SST may be changed according to the situation, such as lowering the priority of the voice call service and increasing the priority of the messaging service. . The association information between the establishment reason and the SST is notified to the terminal device by, for example, broadcast transmission from the base station device. Thereby, the terminal device sets the establishment reason and the SST based on the notified association information. For example, the base station apparatus can select whether to accept or reject the connection request according to the priority level indicated by the establishment reason and the congestion level of the network.

  Moreover, although the application of the above-described method to SST has been described, this method can also be applied to the call type, and the establishment reason can be associated with the call type. In this case, when connecting with a certain call type, the terminal device transmits a connection request in which the establishment reason corresponding to the call type is set to the base station device. The association between the call type and the establishment reason can be performed, for example, for each network operator. In this case, the association information between the establishment reason and the call type can be notified to the terminal device by broadcast transmission from the base station device, for example, as in the case of the above-described SST.

(Device configuration)
Next, the configuration of the base station apparatus that performs connection processing with the terminal apparatus based on the establishment reason configured as described above will be described. FIG. 4 shows a hardware configuration example of the base station apparatus. For example, the base station apparatus has a hardware configuration as shown in FIG. 4, and includes, for example, a CPU 401, a ROM 402, a RAM 403, an external storage device 404, and a communication device 405. In the base station device, for example, the CPU 401 executes a program that realizes each function of the base station device as described above, which is recorded in any of the ROM 402, the RAM 403, and the external storage device 404. The CPU 401 may be replaced by one or more processors such as an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), and a DSP (Digital Signal Processor).

  And a base station apparatus controls the communication apparatus 405 by CPU401, for example, and performs communication between a terminal device and a network node. In addition, in FIG. 4, although the base station apparatus has shown the schematic diagram which has the one communication apparatus 405, it is not restricted to this. For example, the base station device may include a communication device for communication with a terminal device and a communication device for communication with a network node.

  Note that the base station apparatus may include dedicated hardware for executing each function, or may execute other parts with a computer that executes part of the hardware and operates the program. All functions may be executed by a computer and a program.

  Subsequently, a functional configuration example of the base station apparatus will be described with reference to FIG. In one example, the base station apparatus includes a wireless communication unit 501, a determination unit 502, and a connection processing unit 503. The wireless communication unit 501 performs wireless communication for at least wireless terminal establishment processing. The determination unit 502 determines whether or not the base station device itself supports the establishment reason set in the RRC Connection Request received from the terminal device and the SST set in RRC Connection Setup Complete. Based on the determination result of the determination unit 502, the connection processing unit 503 belongs to the same reason as the reason for establishment or SST as described above, and is supported by the base station apparatus itself as described above. A wireless connection process with the terminal device is executed by treating it as another establishment reason or SST. For example, the connection processing unit 503 holds a value indicating the establishment reason or SST in the message received from the terminal device by the wireless communication unit 501. When the determination unit 502 determines that the establishment reason or SST is not supported, the connection processing unit 503 assigns the unsupported establishment reason or SST value to the same group and the base station apparatus. Replace with other supported establishment reasons or values indicating SST. In addition, the base station apparatus, for example, a correspondence table between values corresponding to unsupported establishment reasons or SSTs and values indicating supported establishment reasons and SSTs to be replaced when the values are received. And conversion processing may be performed according to the received establishment reason or a value indicating SST. In this case, the function of determining whether or not the establishment reason or SST is supported as in the determination unit 502 may be omitted.

(Process flow)
FIG. 6 illustrates an example of the flow of processing executed by the base station apparatus. First, the base station apparatus obtains, for example, the establishment reason in the RRC connection request and the SST in the RRC connection setup complete from the terminal apparatus (S601). Here, the base station apparatus may acquire both the establishment reason and the SST, or may acquire only one of them. Note that the terminal device can acquire and hold information on the association between the establishment reason and the SST from the network in advance, for example. In this case, the terminal apparatus can notify the base station apparatus of both the establishment reason and the SST by being notified of either the SST or the establishment reason by a paging message from the network, for example.

  Thereafter, the base station apparatus determines whether or not the base station apparatus supports the establishment reason or SST acquired in S601 (S602). Then, when the established establishment reason or SST is not supported (NO in S602), the base station apparatus belongs to the establishment reason or SST that belongs to the same group as the establishment reason or SST and is supported by the base station apparatus itself. The corresponding connection process is executed / continued (S603). For example, it is assumed that the reasons for establishment are classified into a group relating to outgoing calls by a terminal device and a group relating to incoming calls. In this case, when the base station device does not support a new establishment reason for transmission by the terminal device, the base station device executes connection processing based on another establishment reason for transmission by the terminal device supported by the base device. sell. On the other hand, when the establishment reason or SST acquired in S601 is supported (YES in S602), the base station apparatus can execute / continue the connection process based on the acquired establishment reason or SST (S604).

  As described above, the base station apparatus according to the present embodiment can appropriately establish a connection with a terminal apparatus even if it does not support a new establishment reason or SST. It is possible to prevent the occurrence of errors in the network due to the reason.

  The typical configuration and the flow of processing according to the present embodiment have been described above. However, these are merely examples, and various modifications to the embodiments described in the present specification can be made within the scope described in the claims. Various modifications and changes are naturally included in the scope of the present invention.

Claims (8)

A base station device that executes processing for establishing a connection with a terminal device in a radio resource control (RRC) layer,
Receiving means for receiving a connection request in which a connection establishment reason is set from the terminal device;
Processing means for processing the connection request based on the establishment reason;
Have
The value indicating the establishment reason is classified into one of a plurality of groups each corresponding to one or more reasons,
When the base station apparatus does not support the establishment reason set in the connection request, the processing means is a predetermined unit supported by the base station apparatus in a group including a value indicating the establishment reason. The processing is executed by treating the reason as the reason for establishing the connection with the terminal device.
A base station apparatus. The plurality of groups include a first group related to outgoing calls by the terminal device and a second group related to incoming calls to the terminal device.
The base station apparatus according to claim 1. The plurality of groups includes one or more groups classified by connection priority.
The base station apparatus according to claim 1, wherein the base station apparatus is a base station apparatus. The plurality of groups include one or more groups classified according to communication usage.
The base station apparatus according to claim 1, wherein the base station apparatus is a base station apparatus. The plurality of groups include one or more groups classified according to a form of a terminal device to which a connection is established.
The base station apparatus according to claim 1, wherein the base station apparatus is a base station apparatus. When the base station apparatus supports the establishment reason set in the connection request, the processing means executes the processing based on the establishment reason.
The base station apparatus according to claim 1, wherein the base station apparatus is a base station apparatus. A control method of a base station apparatus that executes processing for establishing a connection between a terminal apparatus and a network in a radio resource control (RRC) layer,
Receiving from the terminal device a connection request in which a connection establishment reason is set;
Processing the connection request based on the establishment reason;
Including
The value indicating the establishment reason is classified into one of a plurality of groups each corresponding to one or more reasons,
If the base station apparatus does not support the establishment reason set in the connection request, the predetermined reason supported by the base station apparatus in a group including a value indicating the establishment reason is the terminal apparatus. The above processing is executed by being treated as the reason for establishing a connection with
A control method characterized by that. In a computer provided in a base station device that executes processing for establishing a connection between a terminal device and a network in a radio resource control (RRC) layer,
From the terminal device, a connection request in which a connection establishment reason is set is received,
Processing the connection request based on the establishment reason;
A program for
The value indicating the establishment reason is classified into one of a plurality of groups each corresponding to one or more reasons,
If the base station apparatus does not support the establishment reason set in the connection request, the predetermined reason supported by the base station apparatus in a group including a value indicating the establishment reason is the terminal apparatus. The above processing is executed by being treated as the reason for establishing a connection with
A program characterized by that.

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