KR20100080267A - Base station, and apparatus and method for controlling link fault in base station - Google Patents

Abstract

The present invention relates to an apparatus and method for handling a link failure of a radio unit in a base station including a radio unit and a digital unit. ) Detects the failure of the first link with the activated path, and if the failure of the first link is detected, the path change is performed by activating the IPC signal path of the second link among the remaining links except the first link among the plurality of links. And IPC communication with the digital unit via the second link.

Description

Base station, apparatus and method for controlling link fault in base station

The present invention relates to an apparatus and method for processing a link failure in a base station, and more particularly, in a separate base station, a digital unit (DU) and a multi-carrier radio unit (MCRU) in a separate base station. Link failure processing apparatus and method for handling a link failure between a unit (hereinafter referred to as 'MCRU').

In general, in a wireless communication system, a base station is composed of a DU processing a digital baseband signal and a radio unit (RU) processing an analog high frequency signal. In this case, the base station may configure the DU and RU as one device in the base station, or may be configured by separating the DU and RU by a predetermined distance. As such, the RU under the control of the DU in the detachable base station configured by separating the DU and the RU is called a remote radio frequency unit (RU), and may be configured by connecting a plurality of remote RUs to one DU.

The DU is connected to a plurality of remote RUs through an optical cable or an electric cable.In a separate base station, a wireless signal path and a DU in which a valid data is transmitted and received in a wireless communication such as IQ Sample Data between the DU and the plurality of remote RUs. A link of a Common Public Radio Interface (CPRI) standard including an IPC (Inter Process Communication) path through which control signals for controlling a remote RU are transmitted and received is generated.

Recently, in the next generation wireless communication system, a remote RU (hereinafter referred to as 'MCRU') capable of processing multiple carriers in wireless communication has been developed to process a larger amount of data quickly. Such MCRUs and DUs are being developed. A plurality of CPRI links are established between the livers.

However, in a typical MCRU, one main processor may control the overall operation of the MCRU, and may perform IPC communication with the DU through an IPC signal path formed on one of a plurality of CPRI links established with the DU. Accordingly, when a failure occurs in the corresponding link of the IPC signal path during the IPC communication through one IPC signal path between the MCRU and the DU, the MCRU may not be controlled and all services may be interrupted.

Accordingly, an object of the present invention is to solve the above-described problems. An object of the present invention is to transmit and receive a normal control signal when a failure occurs in an IPC signal path activated link among a plurality of links established between a DU and an RU in a base station. The present invention provides a link failure processing apparatus and method.

Another object of the present invention is to provide a link failure processing apparatus and method for efficiently handling a failure occurring in a link established between a DU and an RU in a base station according to a link failure situation.

For this purpose, the link failure processing apparatus of a radio unit provided in a base station according to an embodiment of the present invention, the plurality of links with the digital unit provided in the base station (set), An interface unit configured to detect a failure of the first link according to whether an IPC signal transmission through the first link in which an inter process communication (IPC) signal path of a plurality of links is activated is successful; Failure detecting means for detecting a failure of the first link through a keep alive confirmation procedure through the first link; And failure processing means for performing IPC communication through a second link of the remaining links other than the first link among the plurality of links when the occurrence of a failure of the first link is detected.

In addition, the method for processing a link failure of the radio unit in a base station including a radio unit and a digital unit according to another embodiment of the present invention, the IPC of the plurality of links established with the digital unit Detecting a failure of the first link on which the Inter Process Communication path is activated; Activating an IPC signal path of a second link among remaining links except for the first link among the plurality of links, if a failure occurs in the first link; And performing IPC communication with the digital unit via the second link.

In addition, the separate base station according to another embodiment of the present invention, at least one radio unit (Radio Unit) for transmitting and receiving a radio signal with a terminal and a digital unit for transmitting and receiving data to and from the radio unit (Digital) And a radio unit, the interface unit providing a plurality of common public radio interface (CPRI) interfaces with the digital unit; And a processor configured to select one of the plurality of CPRI interfaces to perform inter process communication (IPC) communication with the digital unit for the control, and to change the CPRI interface in a predetermined order when a failure of the CPRI interface is detected. It is characterized by including.

According to the present invention, when a failure occurs in a link in which an IPC signal is transmitted and received between the DU and the RU, the base station activates an IPC signal path of another link in normal operation, so that control signals can be transmitted and received normally even when a link failure occurs.

In addition, according to the present invention, by performing a different link failure processing procedure for each failure situation between the DU and RU of the base station, it is possible to efficiently solve the link failure according to each link failure situation.

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

1 is a diagram illustrating a structure of a base station for performing link failure processing according to an embodiment of the present invention.

As shown in FIG. 1, the base station 100 according to an embodiment of the present invention includes a DU 110 for processing a digital signal and a RU 120 for processing an analog radio frequency (RF) signal. In this case, FIG. 1 shows that the RU 120 according to the embodiment of the present invention is an MCRU in which N DU 110 and N CPRI links are formed.

1 shows that the link failure processing apparatus according to the embodiment of the present invention is configured in the DU 110 of the base station 100, the link failure processing apparatus according to the embodiment of the present invention is a wireless communication system or a base station. It can also be configured as a separate device within.

In addition, in FIG. 1, in addition to the configuration for handling the link failure, which is a feature of the present invention, description of the general configuration and operation thereof according to the DU 110 and RU 120 is omitted.

As shown in FIG. 1, the DU 110 includes a main processor 112, an interface unit 114, a signal processor 116, and the like.

The main processor 112 performs a calculation function according to a program stored in the base station 100, and outputs a control signal for overall management of the base station 100.

In particular, the main processor 112 according to an embodiment of the present invention transmits an IPC signal for controlling the RU 120 through any link among the plurality of links established with the RU 120. For reference, one link includes a control signal between the DU 110 and the RU 120, that is, an IPC signal path for transmitting and receiving an IPC signal and a radio signal path for transmitting and receiving a radio frequency signal including valid data in a wireless communication. Is formed.

At this time, the main processor 112 periodically transmits a status report request message (MSG_RC_ADV) for reporting the status of the RU 120 through the IPC signal paths formed on the plurality of links, and any IPC signal path is activated. The status report reception response message (MSG_CC_ACK) for the status report of the RU 120 is transmitted through the link.

The main processor 112 determines that an IPC failure has occurred in any of the links when the IPC signal to the RU 120 is not normally transmitted through the any link in which the IPC signal path is activated. The interface unit 114 processes the CPRI communication standard signal received from the at least one RU 120 and transmits it to the main processor 112 or the signal processor 116, and receives the IPC signal or signal received from the main processor 112. The radio frequency signal received from the processor 116 is processed as a CPRI standard signal and transmitted to the RU 120.

Specifically, the interface unit 114 receives the digital baseband signal transmitted by the RU 120 through each radio signal path of the plurality of links, transmits the digital baseband signal to the signal processing unit 116, and selects a link of any link among the plurality of links. An IPC signal of the RU 120, that is, a status report message (MSG_KEEP_ALIVE_RPT), a link change notification signal, and the like are received through the IPC signal path and transmitted to the main processor 112.

In addition, the interface unit 114 detects whether a CPRI standard signal is normally transmitted and received with respect to a plurality of links (interfaces) established with the RU 120, and detects a physical failure, and detects a failure occurrence on the link. 112).

The signal processor 116 demodulates the digital baseband signal of the RU 120 received through the interface unit 114 into a valid digital transmission packet, modulates the digital transmission packet to be transmitted to the RU 120 into a digital Miracle band signal. Transfer to the interface unit 114.

Meanwhile, as shown in FIG. 1, the RU 120 includes a signal processor 123, a transceiver 125, an interface 127, a main processor 129, and the like.

The signal processor 123 converts a signal to be transmitted to the DU 110 or a terminal (not shown) into a digital baseband signal into an analog radio frequency signal.

The transceiver 125 amplifies the power of the radio frequency signal converted by the signal processor 123 to a predetermined level and transmits the power to a transmission antenna (not shown).

The interface unit 127 signals IPC signals and radio frequency signals transmitted and received through a plurality of established links (CPRI interfaces) with the DU 110 in a CPRI communication standard. In this case, the interface unit 127 transmits the IPC signal and the radio frequency signal received from the DU 110 to the signal processor 123 and the main processor 129, and inputs the signals from the signal processor 123 and the main processor 129. The signal is transmitted to the DU (110).

The interface unit 127 detects a physical failure including normal transmission / reception of CPRI standard signals of a plurality of links established with the DU 110, and transmits the detected physical failure occurrence report to the main processor 129.

The main processor 129 detects a software failure of a link through which an IPC signal is transmitted and received among a plurality of links formed between the RU 120 and the DU 110 through a keep alive check procedure, and detects a failure. If necessary, change the path to activate the IPC signal path of any link except the corresponding link. Here, the keep-alive confirmation procedure is a procedure in which the RU 120 receives a status report request from the DU 110 and reports a current status, and then receives a status report receiving response corresponding to the report from the DU 110. . Through the keep-alive confirmation procedure as described above, the DU 110 may determine whether the plurality of RUs 120 are currently operating normally.

The main processor 129 transmits an IPC signal path change notification (ARP Announcement) and a status report message (MSG_KEEP_ALIVE_RPT) to the DU 110 through the IPC signal path activated according to the path change.

Hereinafter, a detailed configuration and operation of the main processor of the RU 120 according to the present invention will be described with reference to FIG. 2.

2 is a diagram illustrating a configuration of a main processor of an RU according to an embodiment of the present invention.

As shown in FIG. 2, the main processor 129 of the RU 120 according to the embodiment of the present invention includes a failure detecting unit 210, a failure processing unit 220, and an IPC signal processing unit 230.

The failure detection unit 210 determines whether a software link failure occurs by checking whether an IPC signal according to a keep-alive confirmation procedure is normally transmitted and received through the currently activated IPC signal path among each of the IPC signal paths formed in the plurality of links. When it is determined that a failure has occurred, the software link failure occurrence report is transmitted to the failure processing means 220.

 Specifically, when the failure detection means 210 does not receive the status report request message (MSG_RC_ADV) of the DU 110 through the activated IPC signal path within the first reference period after the initialization of the RU 120, IPC, IPC When the status report reception response message MSG_CC_ACK is not received from the DU 110 within the second reference period after transmitting the status report message MSG_KEEP_ALIVE_RPT through the signal processing means 230 and the status report message MSG_KEEP_ALIVE_RPT is predetermined. It is determined that a software link failure occurs when the status report reception response message MSG_CC_ACK corresponding to the predetermined number of status report messages MSG_KEEP_ALIVE_RPT is not received from the DU 110 during the transmission.

When the failure processing unit 220 receives the physical link failure report from the interface unit 127 or the software link failure report from the failure detection unit 210, the current IPC among the plurality of links established with the DU 110. Activates the IPC signal path formed on any of the remaining links except the link on which the signal path is activated. In this case, the failure processing unit 220 may select the arbitrary link according to a predetermined IPC signal path activation priority.

In other words, upon receiving the physical or software link failure occurrence report, the failure processing means 220 changes the currently active IPC signal path to another IPC signal path formed on the normal link. In this case, the failure processing unit 220 may stop using the link in which the failed IPC signal path is formed.

In addition, the fault handling means 220 performs a fault handling procedure corresponding to a fault occurrence situation of the RU 120. Here, the failure occurrence state of the RU 120 may be divided into a state in which the RU 120 is in an initial setting operation state (that is, an initialization state) and a state in which it is in a normal operation state (that is, currently in IPC communication with the DU).

In detail, when the RU 120 receives the link failure occurrence report when the RU 120 is in an initial setting operation state, the failure processing means 220 includes an IPC signal formed on a link other than a link on which a currently activated IPC signal path is formed. After performing the path change to the path, the IPC signal processing means 230 is controlled to transmit a path change notification (ARP Announcement) after receiving the status report request message (MSG_RC_ADV) from the DU (110).

In this case, the failure processing unit 220 checks whether the status report request message MSG_RC_ADV of the DU 110 is received through the rerouted IPC signal path to the IPC signal processing unit 230 after performing the path change. When the reception of the status report request message MSG_RC_ADV is confirmed, the failure processing unit 220 transmits a path change notification (ARP Announcement) through the rerouted IPC signal path and then the status report request message (MSG_RC_ADV). IPC signal processing means 230 to control the status report message (MSG_KEEP_ALIVE_RPT) corresponding to the control.

In addition, when the RU 120 receives a link failure occurrence report when the RU 120 is in a normal operation state, the failure processing unit 220 may move to an IPC signal path formed on a link other than a link on which a currently activated IPC signal path is formed. After performing the path change, the IPC signal processing means 230 is controlled to transmit a status report message (MSG_KEEP_ALIVE_RPT) after transmitting an ARP Announcement to the DU 110 through the changed IPC signal path. .

In this case, when the RU 120 is in the normal operation state in which the DU 120 performs IPC communication with the DU 120, the failure processing unit 220 changes the path to the DU 110 immediately after performing the path change of the failed IPC signal path. By sending an ARP Announcement to inform IPC signal path recovery and performing status reporting, IPC communication can be quickly resumed.

The IPC signal processing unit 230 provides the failure processing unit 220 with the reception of the IPC signal received from the DU 110, that is, the status report request message MSG_RC_ADV and the status report reception response message MSG_CC_ACK. In addition, the IPC signal processing unit 230 transmits an IPC signal, that is, a signal of a path change notification (ARP Announcement) and a status report message (MSG_KEEP_ALIVE_RPT) to the DU 110 at the time when the failure processing unit 220 requests it. send. At this time, the IPC signal processing means 230 transmits and receives an IPC signal with the DU 110 through the interface unit 127.

In addition, the IPC signal processing means 230 according to an embodiment of the present invention determines a control signal for controlling the operation of the RU 120 of the IPC signal of the DU 110 received through the interface unit 127, The main processor 129 may control the operation of the RU 120.

Hereinafter, a method of handling an IPC failure of a link established between the DU 110 and the RU 120 in a base station according to an embodiment of the present invention will be described in detail with reference to FIGS. 3 to 4.

3 is a flowchart illustrating a link failure processing method according to an embodiment of the present invention.

In this case, in FIG. 3, N links between the RU 120 and the DU 110 in the base station according to the embodiment of the present invention (in FIG. 3, three links are set as an example) are set, and the RU 120 is set. ) Shows an example in which the IPC signal path of the first link is activated after the initial configuration operation.

In addition, FIG. 3 illustrates a link failure recovery method when a software link failure occurs between the DU 110 and the RU 120 in the initial setting operation state of the RU 120, but between the DU 110 and the RU 120. Even when a physical link failure occurs, the physical link failure can be recovered by performing the same steps after the path change step.

First, as shown in FIG. 3, the RU 120 determines whether an IPC signal, that is, a status report request message MSG_RC_ADV, is received from the DU 110 for a predetermined period (first reference period) after being initialized (S310). For reference, in FIG. 3, the DU 110 periodically transmits a status report request message MSG_RC_ADV to the RU 120 through a plurality of links (first to third links) established with the RU 120 at regular intervals. It was shown.

At this time, in the link failure processing method according to an embodiment of the present invention, the status report request message (MSG_RC_ADV) transmitted from the DU (110) through the IPC signal path of the first link within the first reference period RU (120) If not received, the RU 120 may determine that a software link failure has occurred. Meanwhile, in the link failure processing method according to an embodiment of the present invention, whether the IPC signal is normally transmitted through the link in which the IPC signal path is activated among the plurality of links established with the DU 110 after the RU 120 is initialized. It is also possible to detect the occurrence of a physical link failure by judging.

In addition, if it is determined that a link failure occurs as a result of determining whether the status report request message MSG_RC_ADV is received within the first reference period, the RU 120 determines that a link failure occurs. The path is changed to the IPC signal path of an arbitrary link (S320). At this time, the RU 120 according to an embodiment of the present invention activates the IPC signal path of the second link for IPC communication with the DU 110.

After performing the path change as described above, the RU 120 determines whether a status report request message MSG_RC_ADV is received from the DU 110 during the first reference period (S330). In this case, in FIG. 3, the DU 110 shows a state in which the status report request message MSG_RC_ADV is transmitted again through the plurality of links after a certain period of time after transmitting the status report request message MSG_RC_ADV. 120 indicates receiving the status report request message MSG_RC_ADV through the IPC signal path of the rerouted second link within the first reference period.

Then, the RU 120 transmits a path change notification (ARP Announcement) to the DU 110 through the IPC signal path of the second link (S340).

Then, the RU 120 transmits a status report message MSG_KEEP_ALIVE_RPT corresponding to the status report request message MSG_RC_ADV through the IPC signal path of the second link (S350), and the second link from the DU 110. In operation S360, a status report reception response message MSG_CC_ACK is received.

Then, normal IPC communication through the second link is performed between the RU 120 and the DU 110 (S370). In this case, the periodic status report request message MSG_RC_ADV and the corresponding status report message MSG_KEEP_ALIVE_RPT and the DU 110 are included in the IPC signal transmitted and received through the second link between the RU 120 and the DU 110. Control signals, etc. for controlling the < RTI ID = 0.0 >

4 is a flowchart illustrating a link failure processing method according to another embodiment of the present invention.

In this case, in FIG. 4, N links between the RU 120 and the DU 110 (in FIG. 4, an example of setting three links) are set in the base station according to the embodiment of the present invention, and the RU 120 is established. ) And the normal operation state of the RU 120 performing normal IPC communication through the IPC signal path of the first link between the DU 110 as an example.

In addition, although FIG. 4 illustrates a link failure recovery method when a software link failure occurs between the DU 110 and the RU 120 in the normal operation state of the RU 120, the physical link between the DU 110 and the RU 120 is physically illustrated. Even if a link failure occurs, the physical link failure can be recovered by performing the same steps after the path change operation.

First, the RU 120 transmits an IPC signal, that is, a status report message (MSG_KEEP_ALIVE_RPT), to the DU 110 in a normal IPC communication state with the DU 110 (S410). In this case, the status report message MSG_KEEP_ALIVE_RPT may be a status report message MSG_KEEP_ALIVE_RPT corresponding to the status report request message MSG_RC_ADV received on the first link between the RU 120 and the DU 110.

Then, the RU 120 determines whether a status report reception response message MSG_CC_ACK is received from the DU 110 through the IPC signal path of the first link for a predetermined period (second reference period) (S420). .

When the status report reception response message MSG_CC_ACK is not received during the second reference period, the RU 120 repeatedly performs steps S410 and S420 a predetermined number of times. 4 shows that the RU 120 retransmits two status report messages MSG_KEEP_ALIVE_RPT, and the status report reception response message of the DU 110 corresponding to the status report message MSG_KEEP_ALIVE_RPT through the first link. It has been shown that (MSG_CC_ACK) is not received.

As such, when the status report reception response message MSG_CC_ACK of the DU 110 corresponding to the status report message MSG_KEEP_ALIVE_RPT repeatedly transmitted by the RU 120 is not received, the RU 120 receives the first message. It is determined that a failure has occurred in the IPC signal path of the link, and the path change of the IPC signal path is performed (S430). In this case, in FIG. 4, the RU 120 activates the IPC signal path of the second link to change the path.

Then, the RU 120 transmits a path change notification (ARP Announcement) through the IPC signal path of the second link (S440), and sends a status report message to the DU 110 through the IPC signal path of the second link (S440). MSG_KEEP_ALIVE_RPT) is transmitted (S450).

Upon receiving the status report message MSG_KEEP_ALIVE_RPT, the DU 110 transmits a status report reception response message MSG_CC_ACK corresponding to the status report message MSG_KEEP_ALIVE_RPT through the IPC signal path of the second link (S460).

Then, normal IPC communication through the IPC signal path of the second link is performed between the RU 120 and the DU 110 (S470).

Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features, The examples are to be understood in all respects as illustrative and not restrictive.

In addition, the scope of the present invention is specified by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. Should be interpreted as

1 is a diagram illustrating a structure of a base station for performing link failure processing according to an embodiment of the present invention.

2 is a diagram illustrating a configuration of a main processor of an RU according to an embodiment of the present invention.

3 is a flowchart illustrating a link failure processing method according to an embodiment of the present invention.

4 is a flowchart illustrating a link failure processing method according to another embodiment of the present invention.

Claims (12)

In the link failure processing apparatus of the radio unit (Radio Unit) provided in the base station, A plurality of links are set up with a digital unit included in the base station, and the first link is determined according to whether the IPC signal transmission is successfully transmitted through a first link in which an inter process communication (IPC) signal path among the plurality of links is activated. An interface unit for detecting a failure of a link; Failure detecting means for detecting a failure of the first link through a keep alive confirmation procedure through the first link; And And a failure processing means for performing IPC communication through a second link of the remaining links other than the first link among the plurality of links when the failure of the first link is detected. The method of claim 1, The failure detection means, And detecting a failure of the link according to whether a status report request IPC signal is received from the digital unit within a first reference period after the radio unit is initialized. The method according to claim 1 or 2, The failure detection means, In the IPC communication operation state with the digital unit, detecting a failure of the link according to whether or not the status report receiving response IPC signal is received from the digital unit within a second reference period after the status report IPC signal is transmitted. Link failure handling unit. The method of claim 1, The failure processing means, When a failure of the first link is detected in the state where the radio unit is initialized, after receiving an IPC signal from the digital unit through the second link, the IPC signal is transmitted through the second link to the digital unit. Link failure processing apparatus, characterized in that. The method of claim 1, The failure processing means, When the failure of the first link is detected in the IPC communication operation state with the digital unit, the IPC signal is transmitted through the second link to the digital unit immediately after the IPC signal path is changed to the second link. Link failure handling unit. In the method for handling a link failure of the radio unit in a base station including a radio unit (Radio unit) and a digital unit (Digital Unit), Detecting a failure of a first link having an inter process communication (IPC) path activated among a plurality of links established with the digital unit; Activating an IPC signal path of a second link among remaining links except for the first link among the plurality of links, if a failure occurs in the first link; And Performing IPC communication with the digital unit over the second link. The method of claim 6, In detecting a failure of the first link, It is determined whether an IPC signal from the digital unit is received within a first reference period after initialization of the radio unit, and when the communication operation state with the digital unit is in correspondence with the transmitted IPC signal of the radio unit within a second reference period. And determining whether a response IPC signal of the digital unit is received and detecting a failure of the first link. The method according to claim 6 or 7, Performing IPC communication with the digital unit, Transmitting a route change notification IPC signal to the digital unit through the second link; Transmitting a status report IPC signal to the digital unit via the second link; And And receiving a status report reception response IPC signal of the digital unit via the second link. The method of claim 6, Before the step of performing IPC communication with the digital unit, Receiving a status report request IPC signal of the digital unit through the second link after the path change when a failure of the first link is detected in the state where the radio unit is initialized. How to handle link failures. A separate base station including at least one radio unit for transmitting and receiving a radio signal with a terminal, and a digital unit for transmitting and receiving data with the radio unit and controlling the radio unit. The radio unit, An interface unit providing the digital unit and a plurality of common public radio interface (CPRI) interfaces; And A processor configured to select one of the plurality of CPRI interfaces to perform IPC communication with the digital unit for control, and to change the CPRI interface in a predetermined order when a failure of the CPRI interface is detected; Separate base station, characterized in that. The method of claim 10, The processor comprising: And a failure detecting means for detecting the failure according to a keep alive confirmation procedure. The method according to claim 10 or 11, wherein The processor comprising: When the IPC communication is initially set up, the base station detects the failure based on whether a status report request signal or a status report reception response signal from the digital unit is received through the IPC signal path included in the CPRI interface. .

Images