An extension unit of an extended pico base station based on 5G VoNR network

Abstract

The present invention provides an extension unit of an extended pico base station based on a 5G VoNR network, characterized in that it includes a high-speed interface module, a data unit processing module, a control management module, an optical port + power supply module and a clock recovery module; the high-speed interface module is connected to the data unit processing module, the data unit processing module is connected to a plurality of the optical ports + power supply modules, the optical port + power supply module is used to connect a remote unit, the control management module and the clock recovery module are arranged in the extension unit, and are connected and coordinated to control the above-mentioned other modules. In the present invention, under VoNR, the terminal resides in NR, and both voice services and data services are carried on the 5G network, which solves the problem of limited data service bandwidth caused by the EPSFallback solution; on this basis, the expansion efficiency problem of the extension unit is solved.

Description

Technical Field

[0001] The present invention relates to the field of network topology, and in particular to an extension unit of an extended pico base station based on a 5G NR (VoNR, Voice over NR, voice services are carried on 5G wireless access NR, i.e., gNB) network. Background Art

[0002] As an important station type in the 5G network era, 5G extended base stations occupy an important position in indoor coverage solutions. Compared with the distributed base stations of traditional manufacturers, they are cheaper and have higher capacity, flexible deployment, and intelligent unified management advantages compared with traditional passive DAS systems. Therefore, as a FlexORAN system that meets the requirements of 5G extended base stations, it will be one of the ideal choices for operators' 5G indoor network coverage.

[0003] Based on the current 5G network, voice service types are mainly divided into two types. One is the telecommunications-level voice service with strict QoS guarantee, such as VoNR, VoLTE; the other is the OTT voice service without QoS guarantee, such as WeChat voice, QQ voice, etc.

[0004] The 5G network continues the 4G voice solution based on the IMS (IP Multimedia System) architecture. The voice carried on the 4G network is VoLTE, and the voice carried on the 5G NR network is VoNR. VoLTE and VoNR are different access modes of IMS voice / video communication services. 3GPP has determined that 5G will continue to use the 4G voice architecture and still provide voice services based on IMS. Under the 5G SA network, there are mainly two solutions: EPS Fallback and VoNR. UE using VoNR services resides in 5G NR, and both voice and data services are carried on the 5GNR network. After completing the registration on the 5G network, it will register to the IMS network through the 5G network, and the IMS signaling will be carried on the 5G network. When the user initiates a call or receives a call termination request, a dedicated voice or video bearer is established on the 5G NR network.

[0005] EPS Fallback means that 5G NR does not support voice services. When the UE initiates or receives a voice call in 5G NR, it falls back to the 4G network through redirection or switching, and VoLTE provides voice services. When the voice call ends, the UE returns to the 5G NR network. Compared with EPS Fallback, since there is no need for a fallback process, the process is relatively simple and the connection time is shorter than EPSFallBack. The NR in VoNR needs to support not only the IMS signaling channel (SIP over NR), but also the IMS voice channel (RTP / RTCP over NR), which has high requirements for real-time performance. Therefore, other features need to be continuously improved to achieve good voice quality and low UE power consumption. Summary of the invention

[0006] The object of the present invention is to provide an extension unit of an extended pico base station based on a 5G VoNR network to solve the scalability problem based on the 5G VoNR network.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] An extension unit of an extended pico base station based on a 5G VoNR network, characterized in that it includes a high-speed interface module, a data unit processing module, a control management module, an optical port + power supply module and a clock recovery module; the high-speed interface module is connected to the data unit processing module, the data unit processing module is connected to a plurality of the optical ports + power supply modules, the optical port + power supply module is used to connect a remote unit, the control management module and the clock recovery module are arranged in the extension unit, connected to and cooperatively control the above-mentioned other modules.

[0009] The high-speed interface module is used to receive the downlink baseband data sent by the main station, and transmit it to the remote unit after branching processing; the data unit processing module sends the uplink data of the remote unit to the main station after certain combination processing; the optical port + power supply module has a built-in power supply circuit, supplies power to the remote unit through an optoelectronic hybrid cable, and supports direct cascading of expansion units; the control management module is used for O&M information separation, extraction, feedback, and current level equipment management, and the clock recovery module is used for clock recovery and distribution, data compression and decompression.

[0010] The position of the extension unit in the network topology includes a primary cascade and a secondary cascade, the primary cascade configuration principle includes a configuration principle based on a star topology networking single-mode (NR) scenario and a configuration principle based on a star topology networking multi-mode (NR+LTE-FDD) scenario, and the secondary cascade configuration principle includes a configuration principle based on a chain topology networking single-mode (NR) scenario and a configuration principle based on a chain topology networking multi-mode (NR+LTE) scenario;

[0011] The configuration principles in the single-mode (NR) scenario based on star topology networking are as follows: each EU corresponds to one logical cell and supports a maximum of 8 RRUs (Remote Radio Units); each EU must be connected to a full single-mode RRU; the EU is connected to the fronthaul acceleration card configured on the BBU (Base Band Unit), and the maximum distance from the BBU is no more than 5 km; the maximum distance between the EU and the connected RRU is no more than 500 meters;

[0012] The configuration principles in the scenario of multi-mode (NR+LTE-FDD) based on star topology networking are as follows: each EU corresponds to one logical cell and supports a maximum of 8 RRUs; each EU must be connected to a full multi-mode RRU; the maximum distance between the EU connected to the fronthaul acceleration card configured on the BBU and the BBU is no more than 5km; the maximum distance between the EU and the connected RRU is no more than 500 meters;

[0013] The configuration principles in the single-mode (NR) scenario based on the chain topology network are as follows: each EU corresponds to 1 logical cell, and supports a maximum of 8 RRU file names; each EU must be connected to a full single-mode RRU; 2 secondary cascade EUs are supported; the maximum distance between the EU connected to the fronthaul acceleration card configured on the BBU and the BBU is no more than 5km; the maximum distance between the first-level cascade EU and the connected RRU is no more than 500 meters; the maximum distance between the second-level cascade EU and the connected RRU is no more than 500 meters;

[0014] The configuration principles in the chain topology networking multi-mode (NR+LTE) scenario are as follows: each EU corresponds to one logical cell and supports a maximum of 8 RRUs; each EU must be connected to a full multi-mode RRU; 2 secondary cascaded EUs are supported; the maximum distance between the EU connected to the fronthaul acceleration card configured on the BBU and the BBU is no more than 5km; the maximum distance between the first-level cascaded EU and the connected RRU is no more than 500 meters; the maximum distance between the second-level cascaded EU and the connected RRU is no more than 500 meters.

[0015] The extension unit is used in conjunction with the BBU and RRU to achieve communication between the BBU and the RRU, and is used for 5G NR indoor coverage in related segmented application scenarios to achieve the following functions:

[0016] Option 7-2 splitting is used between the BBU and the downlink baseband data sent by the BBU is received and sent to the RRU after splitting.

[0017] Option 8 splitting is adopted between the RRU, the uplink baseband data sent by the RRU is received, and the data is sent to the BBU after combining.

[0018] To handle the splitting of the same EU cell and the RF / baseband merging between multiple RRUs corresponding to the same cell, an optical-electric composite cable is used to supply power to the RRU.

[0019] The brief 5G VoNR process is as follows:

[0020] First, an RRC connection is established between the UE (User Equipment) and the gNB. Then, the 5GC establishes a service quality flow Qosflow to carry SIP signaling, and the 5GC initiates a PDU Session Resource Setup request to the gNB base station, and the gNB establishes a DRB bearer, namely, a 5QI5 bearer. Subsequently, the UE and the IMS conduct a SIP session negotiation for voice services, such as encoding mode, IP address, port number, and called party related information. After the SIP session negotiation is successful, the 5GC establishes a QoSFlow to carry RTP and RTCP data flows, and the 5GC initiates a PDU Session Resource Modify request to the gNB, and the gNB establishes a DRB bearer 5QI1. Finally, the UE releases the QosFlow and DRB bearer.

[0021] The 5G VoNR application strategy can be divided into three stages: EPS Fallback stage, EPS Fallback and VoNR coexistence stage, and VoNR stage; specifically, it includes the following contents:

[0022] Set switches in 5G network equipment: VoNR feature switch and policy switch to implement the above three stages:

[0023] 1) EPS Fallback stage: Turn off the VoNR function switch, and all 5G voice services adopt the EPS Fallback solution;

[0024] 2) EPS Fallback and VoNR coexistence stage:

[0025] Turn on the VoNR function switch and the policy switch. According to the policy, VoNR or EPS Fallback solution is adopted. If the policy requirements are met, NR executes the VoNR process, otherwise the EPS Fallback process is executed.

[0026] 3) VoNR stage: Turn on the VoNR function switch and turn off the policy switch. In this stage, all terminals support VoNR by default, and all 5G voice services execute the VoNR process. Set the switches in sequence according to the stage of the evolution process: VoNR function switch off → VoNR function switch on, and the policy switch on;

[0027] At present, all domestic operators are in the EPSFallback stage, so the VoNR function switch is turned off. When the following conditions are met, operators have the ability to carry out VoNR services: the existing IMS network elements, 5GC network elements, and NR already support VoNR; there are commercial terminals that support VoNR; the existing NR meets the coverage requirements of voice services; when it is decided to gradually enable VoNR, on the basis of completing the existing network test, starting from the 5GNR with higher coverage, gradually enable the VoNR function of the existing 5GNR, and turn on the policy switch at the same time. NR triggers the VoNR or EPSFallback process according to the policy, and enters the EPSFallback and VoNR coexistence stage. When it is assumed that all terminals support VoNR, turn off the policy switch on NR, and all terminal voice services execute the VoNR process and enter the VoNR stage.

[0028] FlexEz-EU is a data extension unit as one of the network elements in the FlexEz-RAN 5G NR extended pico base station solution. It needs to be used in conjunction with the BBU and RRU to achieve communication between the BBU and RRU, and is used for 5GNR indoor coverage in related segmented application scenarios.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] Under VoNR, the terminal resides in NR, and both voice and data services are carried on the 5G network, solving the problem of limited data service bandwidth caused by the EPSFallback solution. When the mobile terminal in a call moves to an area with poor NR signal coverage, it can also initiate coverage-based switching to achieve interoperability with 4G, switch to 4G and continue to provide services with VoLTE, avoiding service problems caused by coverage reasons. On this basis, the expansion efficiency problem of the expansion unit is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the hardware framework of the expansion unit of the present invention;

[0032] Figure 2 This is a schematic diagram of the topological position of the first-level cascade of FlexEz-EU of the present invention in the 5G NR network;

[0033] Figure 3 This is a schematic diagram of the topological position of the FlexEz-EU two-level cascade in the 5G NR network of the present invention. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] Example

[0036] An extension unit of an extended pico base station based on a 5G VoNR network, characterized in that it includes a high-speed interface module, a data unit processing module, a control management module, an optical port + power supply module and a clock recovery module; the high-speed interface module is connected to the data unit processing module, the data unit processing module is connected to a plurality of the optical ports + power supply modules, the optical port + power supply module is used to connect a remote unit, the control management module and the clock recovery module are arranged in the extension unit, connected to and cooperatively control the above-mentioned other modules.

[0037] The high-speed interface module is used to receive the downlink baseband data sent by the main station, and transmit it to the remote unit after branching processing; the data unit processing module sends the uplink data of the remote unit to the main station after certain combination processing; the optical port + power supply module has a built-in power supply circuit, supplies power to the remote unit through an optoelectronic hybrid cable, and supports direct cascading of expansion units; the control management module is used for O&M information separation, extraction, feedback, and current level equipment management, and the clock recovery module is used for clock recovery and distribution, data compression and decompression.

[0038] The position of the extension unit in the network topology includes a primary cascade and a secondary cascade, the primary cascade configuration principle includes a configuration principle based on a star topology networking single-mode (NR) scenario and a configuration principle based on a star topology networking multi-mode (NR+LTE-FDD) scenario, and the secondary cascade configuration principle includes a configuration principle based on a chain topology networking single-mode (NR) scenario and a configuration principle based on a chain topology networking multi-mode (NR+LTE) scenario;

[0039] The configuration principles in the single-mode (NR) scenario based on star topology networking are as follows: each EU corresponds to one logical cell and supports a maximum of 8 RRUs (Remote Radio Units); each EU must be connected to a full single-mode RRU; the EU is connected to the fronthaul acceleration card configured on the BBU (Base Band Unit), and the maximum distance from the BBU is no more than 5 km; the maximum distance between the EU and the connected RRU is no more than 500 meters;

[0040] The configuration principles in the scenario of multi-mode (NR+LTE-FDD) based on star topology networking are as follows: each EU corresponds to one logical cell and supports a maximum of 8 RRUs; each EU must be connected to a full multi-mode RRU; the maximum distance between the EU connected to the fronthaul acceleration card configured on the BBU and the BBU is no more than 5km; the maximum distance between the EU and the connected RRU is no more than 500 meters;

[0041] The configuration principles in the single-mode (NR) scenario based on the chain topology network are as follows: each EU corresponds to 1 logical cell, and supports a maximum of 8 RRU file names; each EU must be connected to a full single-mode RRU; 2 secondary cascade EUs are supported; the maximum distance between the EU connected to the fronthaul acceleration card configured on the BBU and the BBU is no more than 5km; the maximum distance between the first-level cascade EU and the connected RRU is no more than 500 meters; the maximum distance between the second-level cascade EU and the connected RRU is no more than 500 meters;

[0042] The configuration principles in the chain topology networking multi-mode (NR+LTE) scenario are as follows: each EU corresponds to one logical cell and supports a maximum of 8 RRUs; each EU must be connected to a full multi-mode RRU; 2 secondary cascaded EUs are supported; the maximum distance between the EU connected to the fronthaul acceleration card configured on the BBU and the BBU is no more than 5km; the maximum distance between the first-level cascaded EU and the connected RRU is no more than 500 meters; the maximum distance between the second-level cascaded EU and the connected RRU is no more than 500 meters.

[0043] The extension unit is used in conjunction with the BBU and RRU to achieve communication between the BBU and the RRU, and is used for 5G NR indoor coverage in related segmented application scenarios to achieve the following functions:

[0044] Option 7-2 splitting is used between the BBU and the downlink baseband data sent by the BBU is received and sent to the RRU after splitting.

[0045] Option 8 splitting is adopted between the RRU, the uplink baseband data sent by the RRU is received, and the data is sent to the BBU after combining.

[0046] To handle the splitting of the same EU cell and the RF / baseband merging between multiple RRUs corresponding to the same cell, an optical-electric composite cable is used to supply power to the RRU.

[0047] The brief 5G VoNR process is as follows:

[0048] First, an RRC connection is established between the UE (User Equipment) and the gNB. Then, the 5GC establishes a service quality flow Qosflow to carry SIP signaling, and the 5GC initiates a PDU Session Resource Setup request to the gNB base station, and the gNB establishes a DRB bearer, namely, a 5QI5 bearer. Subsequently, the UE and the IMS conduct a SIP session negotiation for voice services, such as encoding mode, IP address, port number, and called party related information. After the SIP session negotiation is successful, the 5GC establishes a QoSFlow to carry RTP and RTCP data flows, and the 5GC initiates a PDU Session Resource Modify request to the gNB, and the gNB establishes a DRB bearer 5QI1. Finally, the UE releases the QosFlow and DRB bearer.

[0049] The 5G VoNR application strategy can be divided into three stages: EPS Fallback stage, EPS Fallback and VoNR coexistence stage, and VoNR stage; specifically, it includes the following contents:

[0050] Set switches in 5G network equipment: VoNR feature switch and policy switch to implement the above three stages:

[0051] 1) EPS Fallback stage: Turn off the VoNR function switch, and all 5G voice services adopt the EPS Fallback solution;

[0052] 2) EPS Fallback and VoNR coexistence stage:

[0053] Turn on the VoNR function switch and the policy switch. According to the policy, VoNR or EPS Fallback solution is adopted. If the policy requirements are met, NR executes the VoNR process, otherwise the EPS Fallback process is executed.

[0054] 3) VoNR stage: Turn on the VoNR function switch and turn off the policy switch. In this stage, all terminals support VoNR by default, and all 5G voice services execute the VoNR process. Set the switches in sequence according to the stage of the evolution process: VoNR function switch off → VoNR function switch on, and the policy switch on;

[0055] At present, all domestic operators are in the EPSFallback stage, so the VoNR function switch is turned off. When the following conditions are met, operators have the ability to carry out VoNR services: the existing IMS network elements, 5GC network elements, and NR already support VoNR; there are commercial terminals that support VoNR; the existing NR meets the coverage requirements of voice services; when it is decided to gradually enable VoNR, on the basis of completing the existing network test, starting from the 5GNR with higher coverage, gradually enable the VoNR function of the existing 5GNR, and turn on the policy switch at the same time. NR triggers the VoNR or EPSFallback process according to the policy, and enters the EPSFallback and VoNR coexistence stage. When it is assumed that all terminals support VoNR, turn off the policy switch on NR, and all terminal voice services execute the VoNR process and enter the VoNR stage.

[0056] FlexEz-EU is a data extension unit as one of the network elements in the FlexEz-RAN 5G NR extended pico base station solution. It needs to be used in conjunction with the BBU and RRU to achieve communication between the BBU and RRU, and is used for 5GNR indoor coverage in related segmented application scenarios.

[0057] Port Description:

[0058] 25G optical interface: used for data transmission between the expansion unit and the BBU, and for cascading between expansion units;

[0059] Spare 10G optical port + power supply: reserved interface, 10G optical transmission interface, with power supply function;

[0060] 10G optical port + power supply (0-7): Transmission interface between the expansion unit and the RRU, transmitting signals and power supply through a hybrid optical-electrical cable.

[0061] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only preferred examples of the invention and are not intended to limit the present invention. Without departing from the novel spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An extension unit of an extended pico base station based on a 5GVoNR network, It is characterized in that It includes a high-speed interface module, a data unit processing module, a control management module, an optical port + power supply module and a clock recovery module; the high-speed interface module is connected to the data unit processing module, the data unit processing module is connected to multiple optical ports + power supply modules, the optical port + power supply module is used to connect to a remote unit, the control management module and the clock recovery module are arranged in an extension unit, the control management module and the clock recovery module are respectively connected to and collaboratively control the high-speed interface module, the data unit processing module and the optical port + power supply module; the high-speed interface module is used to receive the downlink baseband data sent by the master station, and transmit it to the remote unit after branching; the data unit processing module transmits the uplink data of the remote unit to the remote unit; After certain combining processing, it is sent to the main station; the optical port + power supply module has a built-in power supply circuit, which supplies power to the remote unit through an optical-electrical hybrid cable, and supports direct cascading of the expansion unit; the control management module is used for O&M information separation, extraction, feedback, and current level equipment management, and the clock recovery module is used for clock recovery and distribution, data compression and decompression; the position of the expansion unit in the network topology includes primary cascading and secondary cascading, the primary cascading configuration principle includes the configuration principle based on the star topology networking single-mode scenario and the configuration principle based on the star topology networking multi-mode scenario, and the secondary cascading configuration principle includes the configuration principle based on the chain topology networking single-mode scenario and the configuration principle based on the chain topology networking multi-mode scenario; The configuration principles in the single-mode scenario based on the star topology network are as follows: each data expansion unit corresponds to one logical cell and supports a maximum of 8 RF remote units; each data expansion unit must be connected to a full single-mode RF remote unit; the data expansion unit is connected to the fronthaul acceleration card configured on the baseband processing unit, and the maximum distance from the baseband processing unit is no more than 5km; the maximum distance between the data expansion unit and the connected RF remote unit is no more than 500 meters; The configuration principles in the multi-mode scenario based on the star topology network are as follows: each data expansion unit corresponds to one logical cell and supports a maximum of 8 RF remote units; each data expansion unit must be connected to a full multi-mode RF remote unit; the maximum distance between the data expansion unit connected to the fronthaul acceleration card configured on the baseband processing unit and the baseband processing unit is no more than 5km; the maximum distance between the data expansion unit and the connected RF remote unit is no more than 500 meters; The configuration principles in the single-mode scenario based on the chain topology network are as follows: each data expansion unit corresponds to one logical cell, and supports a maximum of 8 RF remote unit file names; each data expansion unit must be connected to a full single-mode RF remote unit; supports 2 secondary cascaded data expansion units; the data expansion unit connected to the fronthaul acceleration card configured on the baseband processing unit is no more than 5km away from the baseband processing unit; the maximum distance between the primary cascaded data expansion unit and the connected RF remote unit is no more than 500 meters; the maximum distance between the secondary cascaded data expansion unit and the connected RF remote unit is no more than 500 meters; The configuration principles in the multi-mode scenario based on the chain topology network are as follows: each data expansion unit corresponds to one logical cell, and supports a maximum of 8 RF remote units; each data expansion unit must be connected to a full multi-mode RF remote unit; supports 2 secondary cascaded data expansion units; the maximum distance between the data expansion unit connected to the fronthaul acceleration card configured on the baseband processing unit and the baseband processing unit is no more than 5km; the maximum distance between the primary cascaded data expansion unit and the connected RF remote unit is no more than 500 meters; the maximum distance between the secondary cascaded data expansion unit and the connected RF remote unit is no more than 500 meters; the brief process of 5GVoNR is as follows: First, an RRC connection is established between the user equipment and the gNB. Then, the 5GC establishes a service quality flow Qosflow to carry SIP signaling. The 5GC initiates a PDUSessionResourceSetup request to the gNB base station, and the gNB establishes a DRB bearer, namely, a 5QI5 bearer. Then, the UE and the IMS conduct a SIP session negotiation for voice services. After the SIP session negotiation is successful, 5GC establishes QoSFlow to carry RTP and RTCP data flows, 5GC initiates PDUSessionResourceModify request to gNB, and gNB establishes DRB bearer 5QI1; finally, UE releases QoSFlow and DRB bearer; the application strategy of 5GVoNR can be divided into three stages: EPSFallback stage, EPSFallback and VoNR coexistence stage and VoNR stage; specifically includes the following contents: Set switches in 5G network equipment: VoNR feature switch and policy switch to implement the above three stages: 1) EPSFallback stage: Turn off the VoNR function switch, and all 5G voice services adopt the EPSFallback solution; 2) EPSFallback and VoNR coexistence stage: Turn on the VoNR function switch and the policy switch. According to the policy, decide whether to use the VoNR or EPSFallback solution. If the policy requirements are met, NR executes the VoNR process, otherwise the EPSFallback process is executed. 3) VoNR stage: Turn on the VoNR function switch and turn off the policy switch. In this stage, all terminals support VoNR by default, and all 5G voice services execute the VoNR process. Set the switches in sequence according to the stage of the evolution process: VoNR function switch off → VoNR function switch on, and the policy switch on; Operators have the ability to carry out VoNR services when the following conditions are met: existing IMS network elements, 5GC network elements, and NR all support VoNR; commercial terminals that support VoNR are available; existing NR meets the coverage requirements for voice services; when deciding to gradually enable VoNR, on the basis of completing the existing network test, starting from 5GNR with higher coverage, gradually enable the VoNR function of the existing 5GNR, and turn on the policy switch at the same time. NR triggers the VoNR or EPSFallback process according to the policy and enters the coexistence stage of EPSFallback and VoNR. When it is assumed that all terminals support VoNR, turn off the policy switch on NR, and all terminal voice services execute the VoNR process and enter the VoNR stage.

2. The extension unit of the extended pico base station based on the 5GVoNR network according to claim 1, Features: The extension unit is used in conjunction with the baseband processing unit and the radio frequency remote unit to realize communication between the baseband processing unit and the radio frequency remote unit, and is used for 5GNR indoor coverage of relevant segmented application scenarios to realize the following functions: Option 7-2 splitting mode is adopted between the baseband processing unit, the downlink baseband data sent by the baseband processing unit is received, and the downlink baseband data is sent to the RF remote unit after branching processing; Option 8 segmentation is used between the RF remote unit to receive the uplink baseband data sent by the RF remote unit, and then send it to the baseband processing unit after combining. The photoelectric composite cable is used to supply power to the radio frequency remote unit for processing the splitting of the same cell of the data expansion unit and the RF / baseband merging between multiple radio frequency remote units corresponding to the same cell.

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