Patent Description:
In recent years, for example, with the development of Internet of Things (IoT) services, communication systems increasingly cope with services having various requirements. Thus, in the communication standard for the fifth generation mobile communication (<NUM> or New Radio (NR)), in addition to the standard technology of the fourth generation mobile communication (<NUM>), there is a demand for a technology that implements higher-data-rate, higher-capacity, and lower-latency communication.

In the communication systems including <NUM>, various communication devices provided by different vendors are used and, in recent years, open interfaces common to these communication devices are studied. Specifically, for example, an industry group called the open radio access network alliance (O-RAN alliance) founded in <NUM> is trying to design interfaces interoperable among communication devices provided by different vendors. Patent Document <NUM>: International Publication Pamphlet No. <CIT>.

However, even if the interface is in conform to the standard specifications, such as the O-RAN architecture, interconnection of communication devices is not guaranteed, and thus, there is a problem in that the cost needed to construct a communication system is increased.

Specifically, functions installed in communication devices and profiles used by each of the vendors are different for each vendor, even if devices are connected by interfaces that are in conform to the standard specifications, the communication system constructed by these devices are not always correctly operated. Accordingly, for example, in the case of further adding a new device to the communication system, there is a need to perform an operation process for verifying the connections between the existing devices and the device to be added, and the cost for adding the device is increased.

In particular, if a base station included in a communication system is structured by nodes, such as a central unit (CU), a distributed unit (DU), and a remote unit (RU), the cost needed at the time at which each of the vendors adds a different node is increased. Furthermore, in the future, for example, if virtualization of a network, such as a software base station, Network Slicing, Radio Access Network (RAN) sharing, or the like are developed, interconnection among the devices becomes an issue, a huge cost may possibly be needed to construct the communication systems among different vendors.

Accordingly, the present invention has been conceived in light of the circumstances described above and an object thereof is to provide a communication system, a communication process device, and a device addition method that are able to reduce the cost at the time of connecting devices. Reference may be made to any of:.

The invention is defined by the independent claims, to which reference should now be made. Specific embodiments are defined in the dependent claims.

Preferred embodiments of the present invention will be explained with reference to accompanying drawings. Furthermore, the present invention is not limited to the embodiments.

<FIG> is a diagram illustrating a configuration example of a communication system according to one embodiment. The communication system illustrated in <FIG> includes a central unit (CU) <NUM>, a distributed unit (DU) 200a, a remote unit (RU) 300a, and a terminal device <NUM>.

The CU <NUM> is connected to a core network (not illustrated), and sends and receives data to and from the DU 200a that is connected to the lower level. Furthermore, the CU <NUM> sends and receives, via a service management and orchestration (SMO) <NUM>, a signal used for maintenance management to and from the DU 200a that is located at the lower level. It is possible to newly connect a DU 200b to the CU <NUM> in addition to the DU 200a. In other words, it is possible to add the DU 200b at the lower level of the CU <NUM>.

The DU 200a sends and receives data to and from the CU <NUM> that is connected to the upper level, and also sends and receives data to and from the RU 300a that is connected to the lower level. It is possible to newly connect a RU 300b to the DU 200a in addition to the RU 300a. In other words, it is possible to add the RU 300b at the lower level of the DU 200a.

The RU 300a sends and receives data to and from the DU 200a that is connected to the upper level, and performs wireless communication between the terminal device <NUM> that is present in a cell formed by the own unit.

In this way, in the communication system, the CU <NUM>, the DU 200a, and the RU 300a constitutes a base station that performs wireless communication with the terminal device <NUM>. In other words, the base station included in the communication system according to the present embodiment is constituted from a plurality of nodes. Furthermore, in the present embodiment, the device located on the side closer to the core network is sometimes referred to an "upper level node", and the device located on the side away from the core network is sometimes referred to as a "lower level node". In other words, for example, the CU <NUM> is an upper level node of the DU 200a, whereas the DU 200a is a lower level node of the CU <NUM>. Similarly, for example, the DU 200a is an upper level node of the RU 300a, whereas the RU 300a is a lower level node of the DU 200a.

In the present embodiment, at the time at which a lower level node is newly added to an upper level node, the lower level node transmits function identification information that indicates the own functions to the upper level node. Then, the upper level node enables or disables the own function and a function of the lower level node on the basis of the function identification information that is received from the lower level node, and also, conducts a test related to the enabled function. In other words, at the time at which the lower level node is added, the connection between the upper level node and the lower level node is automatically verified on the basis of the function identification information related to the lower level node. The device addition method will be described in detail later.

The terminal device <NUM> performs wireless communication with a nearby RU. In other words, if the terminal device <NUM> is present in the cell formed by the RU 300a, the terminal device <NUM> performs wireless communication with the RU 300a.

<FIG> is a block diagram illustrating a configuration of the CU <NUM> and the DU <NUM> according to one embodiment. In <FIG>, the CU <NUM> is the upper level node of the DU <NUM>. Furthermore, the DU <NUM> is the lower level node of the CU <NUM> and has the same configuration as that of each of the DUs 200a and 200b illustrated in <FIG>.

The CU <NUM> illustrated in <FIG> includes a lower level interface unit (hereinafter, simply referred to as a "lower level IF unit") <NUM>, a processor <NUM>, and a memory <NUM>.

The lower level IF unit <NUM> is an interface for connecting to the DU <NUM> that is the lower level node. The lower level IF unit <NUM> is connected to the DU <NUM> by using the O1 interface via, for example, the F1AP interface and the SMO <NUM>. Then, at the time at which the DU <NUM> that is the lower level node is newly connected, the lower level IF unit <NUM> receives the function identification information that indicates the functions installed in the DU <NUM> from the DU <NUM>. At this time, the lower level IF unit <NUM> receives, together with the function identification information, verification completion information that indicates a test item in which verification related to the DU <NUM> has already been completed and profile information that indicates a version of a profile handled by the DU <NUM>. Furthermore, the lower level IF unit <NUM> transmits various kinds of information to the DU <NUM> in accordance with an instruction received from the processor <NUM>.

The processor <NUM> includes, for example, a central processing unit (CPU), a field programmable gate array (FPGA), a digital signal processor (DSP), or the like, and performs overall control of the CU <NUM>. Specifically, the processor <NUM> includes a function control unit <NUM>, a profile control unit <NUM>, and a test control unit <NUM>.

The function control unit <NUM> acquires the function identification information transmitted from the DU <NUM>, and enables or disables the function of the DU <NUM> on the basis of the function identification information. Specifically, the function control unit <NUM> compares the functions of the CU <NUM> to the functions of the DU <NUM>, and decides to enable the function supported by both of the nodes. Furthermore, the function control unit <NUM> decides to disable the function that is not supported by the CU <NUM> out of the functions of the DU <NUM>. Then, the function control unit <NUM> instructs the DU <NUM> to enable or disable the function.

The profile control unit <NUM> acquires the profile information transmitted from the DU <NUM>, and determines whether or not a change of the profile is needed. Specifically, the profile control unit <NUM> compares the version of the profile of the CU <NUM> to the version of the profile of the DU <NUM>, and determines that, if the versions of the profiles of both of the nodes match, a change of the profile is not needed. Furthermore, if the version of the profile of the DU <NUM> is the version in which backward compatibility with respect to the profile of the CU <NUM> is guaranteed, the profile control unit <NUM> determines that a change of the profile is not needed.

In contrast, if the version of the profile of the DU <NUM> is the version in which backward compatibility with respect to the profile of the CU <NUM> is not guaranteed, the profile control unit <NUM> determines that a change of the profile of the DU <NUM> or the CU <NUM> is needed. Then, if it is determined that a change of the profile is needed, the profile control unit <NUM> instructs the DU <NUM> to update the profile, or, updates the profile of the CU <NUM>. Furthermore, if the profile control unit <NUM> updates the profile of the CU <NUM>, the profile control unit <NUM> also instructs, as needed, the other DU <NUM> that has already connected to the CU <NUM> to update the profile. Furthermore, the profile control unit <NUM> may also adjust, for each test item as needed, a set value of the profile of each of the CU <NUM> and the DU <NUM>.

The test control unit <NUM> selects at least a test item used for verifying the function that has been enabled by the function control unit <NUM>, and then, conducts a test related to the selected test item. Specifically, on the basis of the verification completion information transmitted from the DU <NUM>, the test control unit <NUM> selects the test item in which verification has not been completed out of the test items used for verifying the functions to be enabled in the DU <NUM>. At this time, regarding the test item that is likely to be operated under the condition that is different from that used at the time of the conducted test even regarding the test item in which verification has been completed, the test control unit <NUM> selects the test item as an item to be conducted. Furthermore, as the test item used for verifying the function, for example, a test item of O-RAN Inter-Operability Test (IOT), a test item of a conformance test provided by a predetermined certification authority, or the like may be used.

After the test control unit <NUM> selects at least a test item, if compatibility of the profile of each of the CU <NUM> and the DU <NUM> is guaranteed by the profile control unit <NUM>, the test control unit <NUM> conducts a test related to the selected test item. In other words, the test control unit <NUM> conducts, for each selected test item, a needed operation test including transmission and reception of the signal between the CU <NUM> and the DU <NUM>, and verifies whether or not the function that is to be enabled in the DU <NUM> is normally performed.

The memory <NUM> includes, for example, a random access memory (RAM), a read only memory (ROM), or the like, and stores information that is used for a process performed by the processor <NUM>.

The DU <NUM> illustrated in <FIG> includes an upper level interface unit (hereinafter, simply referred to as an "upper level IF unit") <NUM>, a processor <NUM>, a memory <NUM>, and a lower level IF unit <NUM>.

The upper level IF unit <NUM> is an interface for connecting to the CU <NUM> that is the upper level node. The upper level IF unit <NUM> is connected to the CU <NUM> by the O1 interface via, for example, the F1AP interface and the SMO <NUM>. Then, at the time at which the DU <NUM> is newly connected to the CU <NUM> that is the upper level node, the upper level IF unit <NUM> transmits the function identification information that indicates the functions installed in the DU <NUM> to the CU <NUM>. At this time, the upper level IF unit <NUM> transmits, together with the function identification information, the verification completion information that indicates the test item in which verification related to the DU <NUM> has already been completed and the profile information that indicates the version of the profile handled by the DU <NUM>. Furthermore, the upper level IF unit <NUM> receives various kinds of information from the CU <NUM>.

The processor <NUM> includes, for example, a CPU, an FPGA, a DSP, or the like, and performs overall control of the DU <NUM>. Specifically, the processor <NUM> includes a function control unit <NUM>, a profile control unit <NUM>, and a test control unit <NUM>.

If the DU <NUM> is connected to the CU <NUM> that is the upper level node, the function control unit <NUM> reads the function identification information, the verification completion information, and the profile information related to the DU <NUM> from the memory <NUM>, and transmits the read information to the CU <NUM> from the upper level IF unit <NUM>. Furthermore, if the function control unit <NUM> receives an instruction to enable or disable the function from the CU <NUM>, the function control unit <NUM> enables or disables the function of the DU <NUM> in accordance with the instruction.

When an RU <NUM> that is the lower level node is newly connected, the function control unit <NUM> acquires the function identification information transmitted from the RU <NUM>, and enables or disables the function of the RU <NUM> on the basis of the function identification information. Specifically, the function control unit <NUM> compares the functions of the DU <NUM> to the functions of the RU <NUM>, and decides to enable the function supported by both of the nodes. Furthermore, the function control unit <NUM> decides to disable the function that is not supported by the DU <NUM> out of the functions of the RU <NUM>. Then, the function control unit <NUM> instructs the RU <NUM> to enable or disable the function.

If the profile control unit <NUM> receives an instruction to update the profile from the CU <NUM>, the profile control unit <NUM> updates the profile of the DU <NUM> in accordance with the instruction.

Furthermore, at the time at which the RU <NUM> that is the lower level node is newly connected, the profile control unit <NUM> acquires the profile information transmitted from the RU <NUM>, and determines whether or not a change of the profile is needed. Specifically, the profile control unit <NUM> compares the version of the profile of the DU <NUM> to the version of the profile of the RU <NUM>, and determines that, if the versions of the profiles of both of the nodes match, a change of the profile is not needed. Furthermore, if the version of the profile of the RU <NUM> is the version in which backward compatibility with respect to the profile of the DU <NUM> is guaranteed, the profile control unit <NUM> determines that a change of the profile is not needed.

In contrast, if the version of the profile of the RU <NUM> is the version in which backward compatibility with respect to the profile of the DU <NUM> is not guaranteed, the profile control unit <NUM> determines that a change of the profile of the RU <NUM> or the DU <NUM> is needed. Then, if it is determined that a change of the profile is needed, the profile control unit <NUM> instructs the RU <NUM> to update the profile, or, updates the profile of the DU <NUM>. Furthermore, if the profile control unit <NUM> updates the profile of the DU <NUM>, the profile control unit <NUM> also instructs, as needed, the other RU <NUM> that is already connected to the DU <NUM> and the CU <NUM> that is the upper level node to update the profile. Furthermore, the profile control unit <NUM> may also adjust, for each test item as needed, a set value of the profile of each of the DU <NUM> and the RU <NUM>.

The test control unit <NUM> conducts an operation test in accordance with an instruction received from the CU <NUM> at the time of conducting the test related to the function of the DU <NUM> to be enabled. Furthermore, after the test related to the function of the DU <NUM> is conducted, if information indicating that it has been confirmed that the function is normally performed is notified from the CU <NUM>, the test control unit <NUM> causes the memory <NUM> to store information indicating that verification of the test item related to the subject function has been completed as the verification completion information.

The test control unit <NUM> selects at least a test item used for verifying the function that has been enabled by the function control unit <NUM> at the time at which the RU <NUM> that is the lower level node is newly connected, and conducts the test related to the selected test item. Specifically, the test control unit <NUM> selects, on the basis of the verification completion information transmitted from the RU <NUM>, the test item in which verification has not been completed out of the test items used for verifying the functions to be enabled in the RU <NUM>. At this time, regarding the test item that is likely to be operated under the condition that is different from that used at the time of the conducted test even regarding the test item in which verification has been completed, the test control unit <NUM> selects the test item as an item to be conducted.

After the test control unit <NUM> selects at least a test item, if compatibility of the profile of each of the DU <NUM> and the RU <NUM> is guaranteed by the profile control unit <NUM>, the test control unit <NUM> conducts a test related to the selected test item. In other words, the test control unit <NUM> conducts, for each selected test item, a needed operation test including transmission and reception of the signal between the DU <NUM> and the RU <NUM>, and verifies whether or not the function that is to be enabled in the RU <NUM> is normally performed.

The memory <NUM> includes, for example, a RAM, a ROM, or the like, and stores information that is used for a process performed by the processor <NUM>.

The lower level IF unit <NUM> is an interface for connecting to the RU <NUM> that is the lower level node. The lower level IF unit <NUM> is connected to the RU <NUM> by an interface of, for example, the management plane (M-Plane). Then, at the time at which the RU <NUM> that is the lower level node is newly connected, the lower level IF unit <NUM> receives the function identification information that indicates the function to be installed in the RU <NUM> from the RU <NUM>. At this time, the lower level IF unit <NUM> receives, together with the function identification information, the verification completion information that indicates the test item in which verification related to the RU <NUM> has already been completed and the profile information that indicates the version of the profile handled by the RU <NUM>. Furthermore, the lower level IF unit <NUM> transmits various kinds of information to the RU <NUM> in accordance with an instruction from the processor <NUM>.

<FIG> is a block diagram illustrating a configuration of the DU <NUM> and the RU <NUM> according to one embodiment. In <FIG>, the DU <NUM> is an upper level node of the RU <NUM>. Furthermore, the RU <NUM> is a lower level node of the DU <NUM> and has the same configuration as that of each of the RUs 300a and 300b illustrated in <FIG>. The DU <NUM> illustrated in <FIG> has the same configuration as that illustrated in <FIG>; therefore, a description thereof will be omitted.

The RU <NUM> illustrated in <FIG> includes an upper level IF unit <NUM>, a processor <NUM>, a memory <NUM>, and a wireless communication unit <NUM>.

The upper level IF unit <NUM> is an interface for connecting to the DU <NUM> that is the upper level node. The upper level IF unit <NUM> is connected to the DU <NUM> by, for example, the M-Plane interface. Then, at the time at which the RU <NUM> is newly connected to the DU <NUM> that is the upper level node, the upper level IF unit <NUM> transmits the function identification information that indicates the functions installed in the RU <NUM> to the DU <NUM>. At this time, the upper level IF unit <NUM> transmits, together with the function identification information, the verification completion information that indicates the test item in which verification has already been completed related to the RU <NUM> and profile information that indicates the version of the profile handled by the RU <NUM>. Furthermore, the upper level IF unit <NUM> receives various kinds of information from the DU <NUM>.

The processor <NUM> includes, for example, a CPU, an FPGA, a DSP, or the like, and performs overall control of the RU <NUM>. Specifically, the processor <NUM> includes a function control unit <NUM>.

If the RU <NUM> is connected to the DU <NUM> that is the upper level node, the function control unit <NUM> reads the function identification information, the verification completion information, and the profile information related to the RU <NUM> from the memory <NUM> and causes the upper level IF unit <NUM> to transmit the read information from the upper level IF unit <NUM> to the DU <NUM>. Furthermore, if the function control unit <NUM> receives an instruction to enable or disable the function from the DU <NUM>, the function control unit <NUM> enables or disables the function of the RU <NUM> in accordance with the instruction.

Furthermore, if the function control unit <NUM> receives an instruction to update the profile from the DU <NUM>, the function control unit <NUM> updates the profile of the RU <NUM>. Furthermore, at the time of conducting the test related to the function of the RU <NUM> to be enabled, the function control unit <NUM> conducts an operation test in accordance with the instruction received from the DU <NUM>. Then, after the test related to the function of the RU <NUM> has been conducted, if information indicating that it has been confirmed that the function is normally performed is notified from the DU <NUM>, the function control unit <NUM> causes the memory <NUM> to store information indicating that verification of the test item related to the subject function has been completed as the verification completion information.

The wireless communication unit <NUM> performs wireless communication with the terminal device <NUM>. In other words, the wireless communication unit <NUM> wirelessly transmits the signal that is addressed to the terminal device <NUM> and that is output from the processor <NUM> to the terminal device <NUM> via an antenna. Furthermore, the wireless communication unit <NUM> wirelessly receives, via the antenna, the signal transmitted from the terminal device <NUM>, and then, outputs the reception signal to the processor <NUM>.

In the following, a device addition method used in the communication system configured as described above will be described with reference to <FIG> and <FIG>. <FIG> is a sequence diagram illustrating the device addition method used at the time at which the DU <NUM> is added to the lower level of the CU <NUM>.

When the DU <NUM> that is the lower level node is added, the DU <NUM> is physically connected to the CU <NUM> (Step S101). Then, the function identification information, the verification completion information, and the profile information related to the DU <NUM> are read from the memory <NUM> by the function control unit <NUM> included in the DU <NUM>, and are transmitted from the upper level IF unit <NUM> to the CU <NUM> (Step S102). The function identification information, the verification completion information, and the profile information are received by the lower level IF unit <NUM> included in the CU <NUM> that is the upper level node.

Then, enabling and disabling of the functions of the DU <NUM> are set by the function control unit <NUM> included in the CU <NUM> on the basis of the function identification information on the DU <NUM> (Step S103). Specifically, the functions of the CU <NUM> and the functions of the DU <NUM> are compared, and it is decided to enable the function supported by the CU <NUM> out of the functions supported by the DU <NUM>, whereas it is decided to disable the function that is not supported by the CU <NUM> out of the functions supported by the DU <NUM>. Setting of the function of the DU <NUM> to be enabled and the disabled is notified to the DU <NUM> via the lower level IF unit <NUM>, and each of the functions of the DU <NUM> is enabled or disabled by the function control unit <NUM> included in the DU <NUM>.

Furthermore, a test item that is conducted in order to verify the function enabled by the test control unit <NUM> included in the CU <NUM> is selected (Step S104). Specifically, on the basis of the verification completion information transmitted from the DU <NUM>, the test item in which verification has not been completed out of the test items used for verifying the function to be enabled in the DU <NUM> is selected. At this time, regarding the test item that is likely to be operated under the condition that is different from that used at the time of conducted test even regarding the test item in which verification has been completed, the test item is selected as the test item to be conducted.

Then, whether or not a change of the profile is needed is determined on the basis of the profile information by the profile control unit <NUM> included in the CU <NUM> (Step S105). Specifically, the version of the profile of the CU <NUM> is compared to the version of the profile of the DU <NUM>, and, if the versions of the profiles of both of the nodes match, it is determined that a change of the profile is not needed. Furthermore, it is also determined that a change of the profile is not needed in the case where the version of the profile of the DU <NUM> is the version in which backward compatibility with respect to the profile of the CU <NUM> is guaranteed.

In contrast, if the version of the profile of the DU <NUM> is the version in which the backward compatibility with respect to the profile of the CU <NUM> is not guaranteed, it is determined that a change of the profile of the DU <NUM> or the CU <NUM> is needed. If it is determined that a change of the profile is needed, an update of the profile is instructed to the DU <NUM> by the profile control unit <NUM>, or, the profile of the CU <NUM> is updated. As a result, compatibility of the profile of the CU <NUM> and the profile of the DU <NUM> is guaranteed.

Furthermore, in the profile that is related to each of the CU <NUM> and the DU <NUM> and in which the compatibility has been guaranteed, each of the set values may be adjusted for each test item in accordance with the condition conceivable at the time of actual operation performed in the CU <NUM> and the DU <NUM>.

Then, the test related to the selected test item is conducted by the test control unit <NUM> (Step S106). In other words, a needed operation test including transmission and reception of the signal between the CU <NUM> and the DU <NUM> is conducted for each selected test item, it is verified whether or not the function to be enabled in the DU <NUM> is normally operated. If it is verified that the function of the DU <NUM> is normally operated, it is possible to start a service that uses this function.

The test result of the function of the DU <NUM> is notified from the lower level IF unit <NUM> to the DU <NUM> (Step S107). In other words, the test result indicating whether the function that is to be enabled is normally operated in the DU <NUM> is notified to the DU <NUM>. At this time, the setting of enabling and disabling the functions of the DU <NUM> decided at Step S103 described above may also be notified to the DU <NUM> together with the test result.

Then, regarding the test item related to the normally operating function, the verification completion information indicating that the verification has been completed is stored in the memory <NUM> by the test control unit <NUM> included in the DU <NUM> (Step S108). At the same time, information on the function that has been enabled in the DU <NUM>, the version of the profile, and the like may be stored in the memory <NUM>. After these pieces of information have been stored, the function may be enabled in the DU <NUM> and the service that uses the function in which a normal operation has been verified may be automatically started.

In this way, if the DU <NUM> that is the lower level node is physically connected to the CU <NUM> that is the upper level node, the function identification information on the DU <NUM> is transmitted to the CU <NUM>, enabling and disabling of the functions of the DU <NUM> are set by the CU <NUM>, and an operation test of the function that is to be enabled is conducted. As a result, at the time at which the DU <NUM> is added, verification of the connection between the CU <NUM> and the DU <NUM> is efficiently performed, and it is thus possible to reduce the cost at the time of connecting a device.

<FIG> is a sequence diagram illustrating a device addition method at the time at which the RU <NUM> is added to the lower level of the DU <NUM>.

When the RU <NUM> that is the lower level node is added, the RU <NUM> is physically connected to the DU <NUM> (Step S201). Then, the function identification information, the verification completion information, and the profile information related to the RU <NUM> are read from the memory <NUM> by the function control unit <NUM> included in the RU <NUM>, and are transmitted from the upper level IF unit <NUM> to the DU <NUM> (Step S202). The function identification information, the verification completion information, and the profile information are received by the lower level IF unit <NUM> included in the DU <NUM> that is the upper level node.

Then, enabling and disabling of the functions of the RU <NUM> are set by the function control unit <NUM> included in the DU <NUM> on the basis of the function identification information on the RU <NUM> (Step S203). Specifically, the functions of the DU <NUM> and the function of the RU <NUM> are compared, and it is decided to enable the function supported by the DU <NUM> out of the functions supported by the RU <NUM>, whereas it is decided to disable the function that is not supported by the DU <NUM> out of the functions supported by the RU <NUM>. The setting of enabling and disabling the function of the RU <NUM> is notified to the RU <NUM> via the lower level IF unit <NUM>, and each of the functions of the RU <NUM> is enabled or disabled by the function control unit <NUM> included in the RU <NUM>.

Furthermore, a test item that is conducted in order to verify the function enabled by the test control unit <NUM> included in the DU <NUM> is selected (Step S204). Specifically, on the basis of the verification completion information transmitted from the RU <NUM>, the test item in which verification has not been completed out of the test items used for verifying the function to be enabled in the RU <NUM> is selected. At this time, regarding the test item that is likely to be operated under the condition that is different from that used at the time of conducted test even regarding the test item in which verification has been completed, the test item is selected as the test item to be conducted.

Then, whether or not a change of the profile is needed is determined on the basis of the profile information by the profile control unit <NUM> included in the DU <NUM> (Step S205). Specifically, the version of the profile of the DU <NUM> is compared to the version of the profile of the RU <NUM>, and, if the versions of the profiles of both of the nodes match, it is determined that a change of the profile is not needed. Furthermore, it is also determined that a change of the profile is not needed in the case where the version of the profile of the RU <NUM> is the version in which backward compatibility with respect to the profile of the DU <NUM> is guaranteed.

In contrast, if the version of the profile of the RU <NUM> is the version in which the backward compatibility with respect to the profile of the DU <NUM> is not guaranteed, it is determined that a change of the profile of the RU <NUM> or the DU <NUM> is needed. If it is determined that a change of the profile is needed, an update of the profile is instructed to the RU <NUM> by the profile control unit <NUM>, or, the profile of the DU <NUM> is updated. As a result, the compatibility of the profile of the DU <NUM> and the profile of the RU <NUM> is guaranteed.

Furthermore, in the profile that is related to each of the DU <NUM> and the RU <NUM> and in which the compatibility has been guaranteed, each of the set values may be adjusted for each test item in accordance with the condition conceivable at the time of actual operation in the DU <NUM> and the RU <NUM>.

Then, the test related to the selected test item is conducted by the test control unit <NUM> (Step S206). In other words, a needed operation test including transmission and reception of a signal between the DU <NUM> and the RU <NUM> is conducted for each selected test item, it is verified whether or not the function to be enabled in the RU <NUM> is normally operated. If it is verified that the function of the RU <NUM> is normally operated, it is possible to start a service that uses this function.

The test result of the function of the RU <NUM> is notified from the lower level IF unit <NUM> to the RU <NUM> (Step S207). In other words, the test result indicating whether the function that is to be enabled is normally operated in the RU <NUM> is notified to the RU <NUM>. At this time, the setting of enabling and disabling the functions of the RU <NUM> decided at Step S203 described above may also be notified to the RU <NUM> together with the test result.

Then, regarding the test item related to the normally operating function, the verification completion information indicating that the verification has been completed is stored in the memory <NUM> by the function control unit <NUM> included in the RU <NUM> (Step S208). At the same time, information on the function that has been enabled in the RU <NUM>, the version of the profile, and the like may be stored in the memory <NUM>. After these pieces of information have been stored, the function may be enabled in the RU <NUM> and the service that uses the function in which a normal operation has been verified may be automatically started.

In this way, if the RU <NUM> that is the lower level node is physically connected to the DU <NUM> that is the upper level node, the function identification information on the RU <NUM> is transmitted to the DU <NUM>, enabling and disabling of the functions of the RU <NUM> is set by the DU <NUM>, and an operation test of the function that is to be enabled is conducted. As a result, at the time at which the RU <NUM> is added, verification of the connection between the DU <NUM> and the RU <NUM> is efficiently performed, and it is thus possible to reduce a cost at the time of connecting a device.

As described above, according to the present embodiment, when a lower level node is added, the function identification information, the verification completion information, and the profile information related to the lower level node are transmitted to the upper level node, and the upper level node decides, on the basis of the function identification information, the function that is to be enabled in the lower level node that is added. Then, the upper level node selects, on the basis of the verification completion information, the test item that is to be conducted and that is related to the function to be enabled, and conducts, if the compatibility of the profile has been guaranteed from the profile information, the test of the selected test item. As a result, verification of the connection between the upper level node and the lower level node is efficiently performed, and it is thus possible to reduce a cost at the time of connecting a device.

Furthermore, in one embodiment described above, it is assumed that all of the processes are performed by the CU <NUM> or the DU <NUM> that is the upper level node and performed by the DU <NUM> or the RU <NUM> that is the lower level node; however, at least a part of the process may also be performed by an external device that is connected to each of the nodes. For example, a process of selecting a test item, a process of determining whether or not a change of the profile is needed, a process of controlling an update of the profile, a process of controlling conduct of a test, or the like may be performed by an external device that is connected to the CU <NUM> or the DU <NUM> that is the upper level node.

Furthermore, in one embodiment described above, at least a part of the result of the process performed by the CU <NUM> or the DU <NUM> that is the upper level node and performed the DU <NUM> or the RU <NUM> that is the lower level node may be notified to a maintenance person of each of the devices. In other words, for example, information on determination indicating that a change of the profile is needed may be notified to a maintenance person, or a result of a conducted test may be notified to a maintenance person. In this case, an update of the profile may be performed or a service may be started in accordance with an operation performed by the maintenance person who received the notification.

Claim 1:
A communication system comprising a first node (<NUM>, <NUM>) and a second node (<NUM>, <NUM>) that is connected to the first node (<NUM>, <NUM>), wherein:
the first node (<NUM>, <NUM>) is a central unit, CU, (<NUM>) and the second node (<NUM>, <NUM>) is a distributed unit, DU (<NUM>); or
the first node (<NUM>, <NUM>) is a DU (<NUM>) and the second node (<NUM>, <NUM>) is a remote unit, RU (<NUM>),
wherein
the second node (<NUM>, <NUM>) includes a transmitter (<NUM>, <NUM>) configured to transmit, when the second node (<NUM>, <NUM>) is connected to the first node (<NUM>, <NUM>), function identification information for identifying functions installed in the second node (<NUM>, <NUM>),
the first node (<NUM>, <NUM>) includes
a receiver (<NUM>, <NUM>) configured to receive the function identification information transmitted from the second node (<NUM>, <NUM>), and
a processor (<NUM>, <NUM>) that is connected to the receiver, and
the processor (<NUM>, <NUM>) is configured to execute a process including
deciding, based on the function identification information, a function to be enabled or disabled out of the functions installed in the second node (<NUM>, <NUM>),
selecting at least a test item used for verifying the function that is decided to be enabled,
conducting a test of the selected test item,
notifying a result of the test to the second node (<NUM>, <NUM>), and
starting, when obtaining a test result indicating that the function that is decided to be enabled is normally operated, a service that uses the function,
wherein:
for each selected test item, an operation test including transmission and reception of a signal between the first node (<NUM>, <NUM>) and the second node (<NUM>, <NUM>) is conducted;
the receiver (<NUM>, <NUM>) is configured to receive verification completion information indicating a test item for which verification has already been completed in the second node (<NUM>, <NUM>); and
the selecting includes selecting, based on the verification completion information, a test item for which verification has not been completed out of test items used for verifying the function that is decided to be enabled.