5G millimeter wave small base station three-sector cascade networking system

Abstract

The invention relates to the technical field of wireless communication, in particular to a 5G millimeter wave small base station three-sector cascade networking system, which comprises a switch and three 5G millimeter wave small base stations, and is characterized in that each base station comprises an external optical fiber port and a cascade optical fiber port; each base station covers a range of 120 degrees; the switch is sequentially connected with the three base stations through optical fibers; when the cascade optical fiber port of any base station receives the uplink flow, the base station forwards the uplink flow to the switch or other base stations through the external optical fiber port; when an external optical fiber port of any base station receives downlink flow, if the destination address of the message is the base station, the message is uploaded to an application layer for processing; and if the message destination address of the downlink flow is not the base station, forwarding the message destination address to the base station through a cascade optical fiber port. According to the technical scheme, the three 5G millimeter wave small base stations are used for cascading networking, the three-sector coverage problem is solved, the structure of the small base stations does not need to be modified, additional wiring cost does not need to be increased, deployment is flexible, and the deployment cost is low.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and in particular to a 5G millimeter wave small base station three-sector cascade networking system. Background Art

[0002] In the 4G era, the main hardware components of a base station are BBU (baseband processing unit), RRU (radio remote unit) and antenna (antenna, feeder) system. Usually, the standard configuration of a macro base station is 3 sectors. The main reason is that experts have calculated that the 3-antenna method, each covering 120°, has the highest cost-effectiveness and the best effect. Therefore, there is a design of a base station with 3 coverage areas (three sectors).

[0003] In the 5G era, in order to pursue higher transmission speeds and lower network latency, the cellular industry began to look for new frequency bands. High frequency bands in the spectrum above 24GHz are considered to have the potential to support large bandwidths and high data rates, and are ideal for increasing wireless network capacity. These high frequency bands are generally referred to as millimeter waves (mmWave). However, due to the high propagation loss of millimeter waves and the fact that signals are easily blocked by the human body, building materials, and leaves, the coverage of macro base stations is far less extensive than that of 4G base stations, so new distributed 5G millimeter wave small base station solutions have emerged.

[0004] These 5G millimeter wave small base stations have advantages such as low price and can meet the needs of users in densely populated urban areas through high-density deployment. Generally, as a supplementary solution to macro base stations, 5G millimeter wave small base stations are designed as an integrated structure, that is, all hardware modules including antennas are integrated. Its characteristic is that the coverage radius of signal transmission is small, which is suitable for scenarios with small-scale precise coverage.

[0005] In actual use scenarios, such as in urban CBD parks, 5G millimeter wave small base stations still require a 360-degree coverage solution. However, due to the small coverage radius of 5G millimeter wave small base stations, the three-sector coverage problem cannot be solved. If three independent small base stations are used directly to solve the coverage problem, the deployment cost will increase due to the need to pull additional optical fiber lines and occupy more optical switch ports. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a 5G millimeter wave small base station three-sector cascade networking system to solve the problem in the prior art that when 5G millimeter wave small base stations perform three-sector coverage, the optical switch ports occupy a large number and the deployment cost is high.

[0007] According to a first aspect of an embodiment of the present invention, a 5G millimeter wave small base station three-sector cascade networking system is provided, including:

[0008] Switch, first 5G millimeter wave small base station, second 5G millimeter wave small base station and third 5G millimeter wave small base station; 5G millimeter wave small base stations all include external optical fiber ports and cascade optical fiber ports; each 5G millimeter wave small base station covers a 120° range;

[0009] The switch is connected to the external optical fiber port of the first 5G millimeter wave small base station, the cascade optical fiber port of the first 5G millimeter wave small base station is connected to the external optical fiber port of the second 5G millimeter wave small base station, and the cascade optical fiber port of the second 5G millimeter wave small base station is connected to the external optical fiber port of the third 5G millimeter wave small base station;

[0010] When the cascaded optical fiber port of any 5G millimeter wave small base station receives uplink traffic, this base station forwards the uplink traffic to the switch or other 5G millimeter wave small base station through the external optical fiber port;

[0011] When the external optical fiber port of any 5G millimeter wave small base station receives downlink traffic, if the destination address of the message of the downlink traffic is this base station, the downlink traffic is sent to the application layer for processing;

[0012] When the external optical fiber port of the first 5G millimeter wave small base station or the second 5G millimeter wave small base station receives downlink traffic, if the destination address of the message of the downlink traffic is not this base station, the downlink traffic will be forwarded to other 5G millimeter wave small base stations through the cascade optical fiber port.

[0013] Preferably, the 5G millimeter wave small base station three-sector cascade networking system further includes:

[0014] When the air interface of any 5G millimeter wave small base station receives uplink traffic sent by a smart terminal, the uplink traffic is forwarded to a switch or other 5G millimeter wave small base station through the external optical fiber port.

[0015] Preferably, each 5G millimeter wave small base station has a Mac table corresponding to the base station;

[0016] When the air interface of any 5G millimeter wave small base station receives the uplink traffic sent by the smart terminal, the uplink traffic is processed according to the 3GPP protocol rules, and the header is encapsulated, and the processed uplink traffic is forwarded to the switch or other 5G millimeter wave small base station through the external optical fiber port; the source Mac address of the header encapsulation is the Mac of the external optical fiber port of this base station;

[0017] When the cascaded optical fiber port of any 5G millimeter wave small base station receives uplink traffic, this base station learns the source Mac address of the uplink traffic into the Mac table of this base station;

[0018] When the external optical fiber port of any 5G millimeter wave small base station receives downlink traffic, if the destination Mac address of the message of the downlink traffic is the Mac address of this base station in the Mac table, the downlink traffic is sent to the application layer for processing;

[0019] When the external optical fiber port of the first 5G millimeter wave small base station or the second 5G millimeter wave small base station receives downlink traffic, if the destination Mac address of the message of the downlink traffic is the Mac address of other base stations in the Mac table, the downlink traffic is forwarded to other 5G millimeter wave small base stations through the cascade optical fiber port.

[0020] Preferably, when the external optical fiber port of the first 5G millimeter wave small base station receives downlink traffic, if the destination Mac address of the message of the downlink traffic does not exist in the Mac table, the downlink traffic is discarded.

[0021] Preferably, when the external optical fiber port of any 5G millimeter wave small base station receives multicast or broadcast message traffic, the multicast or broadcast message traffic is sent to the application layer for processing;

[0022] When the external optical fiber port of the first 5G millimeter wave small base station or the second 5G millimeter wave small base station receives multicast or broadcast message traffic, the multicast or broadcast message traffic is copied; and the copied multicast or broadcast message traffic is forwarded to other 5G millimeter wave small base stations through the cascade optical fiber port.

[0023] Preferably, after the 5G millimeter wave small base station sends the downlink traffic to the application layer for processing, this base station strips the header encapsulation of the downlink traffic according to the 3GPP protocol rules, and sends the processed downlink traffic to the smart terminal via the air interface.

[0024] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0025] It can be understood that the technical solution shown in the present invention provides a 5G millimeter wave small base station three-sector cascade networking system, including a switch and three 5G millimeter wave small base stations, each base station includes an external optical fiber port and a cascade optical fiber port; each 5G millimeter wave small base station covers a 120° range; the switch is connected to the three base stations in sequence through optical fibers; when the cascade optical fiber port of any base station receives uplink traffic, this base station forwards the uplink traffic to the switch or other base stations through the external optical fiber port; when the external optical fiber port of any base station receives downlink traffic, if the destination address of the message is this base station, it is sent to the application layer for processing; if the destination address of the message of the downlink traffic is not this base station, it is forwarded to the base station through the cascade optical fiber port. The technical solution shown in the present invention uses three 5G millimeter wave small base stations for cascade networking, which solves the three-sector coverage problem, does not require modifying the structure of the small base station, and does not require additional wiring costs, and is flexible to deploy and has low deployment costs.

[0026] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0028] Figure 1 It is a schematic block diagram of a 5G millimeter wave small base station three-sector cascade networking system according to an exemplary embodiment. DETAILED DESCRIPTION

[0029] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0030] In one embodiment, Figure 1 is a schematic block diagram of a 5G millimeter wave small base station three-sector cascade networking system according to an exemplary embodiment, see Figure 1 , providing a 5G millimeter wave small base station three-sector cascade networking system, including:

[0031] Switches, the first 5G millimeter wave small base station (in Figure 1 In the figure, represented by base station A), the second 5G millimeter wave small base station (in Figure 1 ) and the third 5G millimeter wave small base station (represented by base station B in Figure 1 In the figure, it is represented by base station C); 5G millimeter wave small base stations all include an external optical fiber port (SFP0) and a cascade optical fiber port (SFP1); each 5G millimeter wave small base station covers a range of 120°.

[0032] The switch is connected to the external optical fiber port of the first 5G millimeter wave small base station, the cascade optical fiber port of the first 5G millimeter wave small base station is connected to the external optical fiber port of the second 5G millimeter wave small base station, and the cascade optical fiber port of the second 5G millimeter wave small base station is connected to the external optical fiber port of the third 5G millimeter wave small base station. The cascade optical fiber port of the third 5G millimeter wave small base station is not connected.

[0033] When the cascaded optical fiber port of any 5G millimeter wave small base station receives uplink traffic, this base station forwards the uplink traffic to the switch or other 5G millimeter wave small base station through the external optical fiber port.

[0034] For example, when the first 5G millimeter wave small base station receives uplink traffic from the cascade fiber optic interface, it is forwarded to the switch through the external fiber optic port; when the second 5G millimeter wave small base station receives uplink traffic from the cascade fiber optic interface, it is forwarded to the first 5G millimeter wave small base station through the external fiber optic port; since the cascade fiber optic interface of the third 5G millimeter wave small base station is not connected, it will not receive uplink traffic from the cascade fiber optic interface.

[0035] When the external optical fiber port of any 5G millimeter wave small base station receives downlink traffic, if the destination address of the message of the downlink traffic is this base station, the downlink traffic will be sent to the application layer for processing; when the external optical fiber port of the first 5G millimeter wave small base station or the second 5G millimeter wave small base station receives downlink traffic, if the destination address of the message of the downlink traffic is not this base station, the downlink traffic will be forwarded to other 5G millimeter wave small base stations through the cascade optical fiber port.

[0036] For example, when the first 5G millimeter wave small base station receives downlink traffic from the external optical fiber port, the base station first determines that the destination address of the message of the downlink traffic is the first 5G millimeter wave small base station. If so, the downlink traffic is sent to the application layer for processing. If not, the downlink traffic is forwarded to the second 5G millimeter wave small base station connected to it through the cascade optical fiber port; the second 5G millimeter wave small base station also determines that the destination address of the message of the downlink traffic is the second 5G millimeter wave small base station. If not, it is forwarded again to the third 5G millimeter wave small base station connected to it through the cascade optical fiber port.

[0037] It can be understood that the technical solution shown in the present invention provides a 5G millimeter wave small base station three-sector cascade networking system, including a switch and three 5G millimeter wave small base stations, each base station includes an external optical fiber port and a cascade optical fiber port; the switch is connected to the three base stations in sequence through optical fibers; when the cascade optical fiber port of any base station receives uplink traffic, this base station forwards the uplink traffic to the switch or other base stations through the external optical fiber port; when the external optical fiber port of any base station receives downlink traffic, if the destination address of the message is this base station, it is sent to the application layer for processing; if the destination address of the message of the downlink traffic is not this base station, it is forwarded to the base station through the cascade optical fiber port. The technical solution shown in the present invention uses three 5G millimeter wave small base stations for cascade networking, which solves the three-sector coverage problem, does not require modifying the structure of the small base station, and does not require additional wiring costs. It is flexible to deploy and has low deployment costs.

[0038] It should be noted that the 5G millimeter wave small base station three-sector cascade networking system also includes:

[0039] When the air interface of any 5G millimeter wave small base station receives uplink traffic sent by a smart terminal, the uplink traffic is forwarded to a switch or other 5G millimeter wave small base station through the external optical fiber port.

[0040] In practice, when a three-sector cascaded networking system of 5G millimeter wave small base stations is built, 360° coverage can be achieved. Therefore, other smart terminals can be connected to any 5G millimeter wave small base station. For example, when a smart terminal is connected to a third 5G millimeter wave small base station, the smart terminal registers to the third 5G millimeter wave small base station and sends uplink traffic to the air interface of the third 5G millimeter wave small base station. The third 5G millimeter wave small base station then forwards the uplink traffic to the second 5G millimeter wave small base station through the external optical fiber port, and finally forwards it to the switch through the forwarding of the second 5G millimeter wave small base station and the first 5G millimeter wave small base station.

[0041] In another embodiment, it should be noted that, based on the previous embodiment, each 5G millimeter wave small base station has a Mac table corresponding to the base station.

[0042] When the air interface of any 5G millimeter wave small base station receives uplink traffic sent by a smart terminal, the uplink traffic is processed according to the 3GPP protocol rules, and the header is encapsulated, and the processed uplink traffic is forwarded to the switch or other 5G millimeter wave small base station through the external optical fiber port; the source Mac address of the header encapsulation is the Mac of the external optical fiber port of this base station.

[0043] When the cascaded optical fiber port of any 5G millimeter wave small base station receives uplink traffic, this base station learns the source Mac address of the uplink traffic into the Mac table of this base station, and then forwards the uplink traffic to the switch or other 5G millimeter wave small base station through the external optical fiber port.

[0044] When the external optical fiber port of any 5G millimeter wave small base station receives downlink traffic, if the destination Mac address of the message of the downlink traffic is the Mac address of this base station in the Mac table, the downlink traffic will be sent to the application layer for processing.

[0045] When the external optical fiber port of the first 5G millimeter wave small base station or the second 5G millimeter wave small base station receives downlink traffic, if the destination Mac address of the message of the downlink traffic is the Mac address of other base stations in the Mac table, the downlink traffic is forwarded to other 5G millimeter wave small base stations through the cascade optical fiber port.

[0046] In specific practice, in the technical solution of this embodiment, DPDK is used on each base station to take over the external fiber optic port (SFP0 port) and the cascade fiber optic port (SFP1 port). Each port has its own Mac table, which can learn the Mac from the received upstream traffic message and update it to the Mac table, and perform corresponding processing based on the message Mac.

[0047] It should be noted that when the external optical fiber port of the first 5G millimeter wave small base station receives downlink traffic, if the destination Mac address of the message of the downlink traffic does not exist in the Mac table, the downlink traffic is discarded.

[0048] In actual applications, the uplink traffic processing flow is as follows: the smart terminal (UE) selects the base station with the best signal to access according to its location. Assuming that the smart terminal is successfully registered with the third 5G millimeter wave small base station (base station C), the smart terminal starts to send uplink traffic, and the third 5G millimeter wave small base station receives the uplink traffic of the terminal from the air interface.

[0049] The third 5G millimeter wave small base station processes the user uplink traffic according to the 3GPP protocol, then encapsulates the GTPU header and sends the user message from the external optical fiber port SFP0. The source Mac address of the header is the Mac of the external optical fiber port SFP0 network port of the third 5G millimeter wave small base station.

[0050] The cascade fiber port SFP1 of the second 5G millimeter wave small base station receives the user uplink traffic forwarded from the third 5G millimeter wave small base station. The second 5G millimeter wave small base station learns the source Mac address of the uplink traffic message into its own Mac table. After the learning is completed, the uplink traffic is forwarded from the external fiber port SFP0.

[0051] The cascade fiber port SFP1 of the first 5G millimeter wave small base station receives the user uplink traffic forwarded from the second 5G millimeter wave small base station. The first 5G millimeter wave small base station learns the source Mac address of the uplink traffic message into its own Mac table. After the learning is completed, the uplink traffic is forwarded from the external fiber port SFP0 to the switch or router device.

[0052] The flow of downstream traffic processing is as follows:

[0053] The first 5G millimeter wave small base station's external optical fiber port SFP0 receives the user's downlink traffic from the switch or router device. The first 5G millimeter wave small base station first determines that it is not the Mac of the external optical fiber port SPF0 based on the destination Mac of the traffic message, and then finds that the Mac exists in the Mac table, so it forwards the user's downlink traffic from the cascade optical fiber port SFP1.

[0054] The external optical fiber port SFP0 of the second 5G millimeter wave small base station receives the user downlink traffic forwarded from the first 5G millimeter wave small base station. The second 5G millimeter wave small base station first determines that it is not the Mac of the external optical fiber port SPF0 according to the destination Mac of the traffic message, and then finds that the Mac exists in the Mac table, so it continues to forward the user downlink traffic from the cascade optical fiber port SFP1.

[0055] The external optical fiber port SFP0 of the third 5G millimeter wave small base station receives the user downlink traffic forwarded from the second 5G millimeter wave small base station. The third 5G millimeter wave small base station determines that it is the Mac of the external optical fiber port SPF0 based on the destination Mac of the traffic message, and therefore sends the traffic message to the application layer for processing.

[0056] It should be noted that after the 5G millimeter wave small base station sends the downlink traffic to the application layer for processing, this base station strips the GTPU header of the downlink traffic according to the 3GPP protocol rules, and sends the processed downlink traffic to the smart terminal through the air interface.

[0057] It should be noted that the above two embodiments can execute the following operation process when receiving multicast or broadcast message traffic:

[0058] When the external optical fiber port of any 5G millimeter wave small base station receives multicast or broadcast message traffic, the multicast or broadcast message traffic is sent to the application layer for processing; when the external optical fiber port of the first 5G millimeter wave small base station or the second 5G millimeter wave small base station receives multicast or broadcast message traffic, the multicast or broadcast message traffic is copied; the copied multicast or broadcast message traffic is forwarded to other 5G millimeter wave small base stations through the cascade optical fiber port.

[0059] It is understandable that the 5G millimeter wave small base station three-sector cascade networking system shown in the present invention has the following advantages compared with the prior art: First, by using three 5G millimeter wave small base stations in cascade networking, the three-sector coverage problem can be solved without modifying the structure of the small base station or increasing the wiring cost. Compared with ordinary base stations, the present invention realizes the automatic identification and forwarding of messages between multiple base stations by adding a set of Mac table mechanisms. The code changes are small but bring many advantages.

[0060] The 5G millimeter wave small base station three-sector cascade networking system provided by the present invention can be applied to the mobile communication network of the CBD industrial park. Each small base station covers a 120° range. After the three small base stations are cascaded and networked, they can provide users with 360° signal coverage. It is easy to operate and maintain, reducing the operation and maintenance costs. Only one optical fiber line needs to be connected to one of the three base stations, reducing the cost of wiring and the like.

[0061] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0062] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0063] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0064] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0065] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0066] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0067] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0069] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A 5G millimeter wave small base station three-sector cascade networking system, characterized in that: include: Switch, first 5G millimeter wave small base station, second 5G millimeter wave small base station and third 5G millimeter wave small base station; 5G millimeter wave small base stations all include external optical fiber ports and cascade optical fiber ports; each 5G millimeter wave small base station covers a 120° range; The switch is connected to the external optical fiber port of the first 5G millimeter wave small base station, the cascade optical fiber port of the first 5G millimeter wave small base station is connected to the external optical fiber port of the second 5G millimeter wave small base station, and the cascade optical fiber port of the second 5G millimeter wave small base station is connected to the external optical fiber port of the third 5G millimeter wave small base station; When the cascaded optical fiber port of any 5G millimeter wave small base station receives uplink traffic, this base station forwards the uplink traffic to the switch or other 5G millimeter wave small base station through the external optical fiber port; When the external optical fiber port of any 5G millimeter wave small base station receives downlink traffic, if the destination address of the message of the downlink traffic is this base station, the downlink traffic is sent to the application layer for processing; When the external optical fiber port of the first 5G millimeter wave small base station or the second 5G millimeter wave small base station receives downlink traffic, if the destination address of the message of the downlink traffic is not this base station, the downlink traffic will be forwarded to other 5G millimeter wave small base stations through the cascade optical fiber port.

2. The 5G millimeter wave small base station three-sector cascade networking system according to claim 1 is characterized in that: Also includes: When the air interface of any 5G millimeter wave small base station receives uplink traffic sent by a smart terminal, the uplink traffic is forwarded to a switch or other 5G millimeter wave small base station through the external optical fiber port.

3. The 5G millimeter wave small base station three-sector cascade networking system according to claim 2 is characterized in that: Each 5G millimeter wave small base station has a Mac table corresponding to the base station; When the air interface of any 5G millimeter wave small base station receives uplink traffic sent by a smart terminal, it processes the uplink traffic according to the 3GPP protocol rules, performs header encapsulation, and forwards the processed uplink traffic to a switch or other 5G millimeter wave small base station through the external optical fiber port; The source Mac address encapsulated in the header is the Mac of the external optical fiber port of this base station; When the cascaded optical fiber port of any 5G millimeter wave small base station receives uplink traffic, this base station learns the source Mac address of the uplink traffic into the Mac table of this base station; When the external optical fiber port of any 5G millimeter wave small base station receives downlink traffic, if the destination Mac address of the message of the downlink traffic is the Mac address of this base station in the Mac table, the downlink traffic is sent to the application layer for processing; When the external optical fiber port of the first 5G millimeter wave small base station or the second 5G millimeter wave small base station receives downlink traffic, if the destination Mac address of the message of the downlink traffic is the Mac address of other base stations in the Mac table, the downlink traffic is forwarded to other 5G millimeter wave small base stations through the cascade optical fiber port.

4. The 5G millimeter wave small base station three-sector cascade networking system according to claim 3 is characterized in that: When the external optical fiber port of the first 5G millimeter wave small base station receives downlink traffic, if the destination Mac address of the message of the downlink traffic does not exist in the Mac table, the downlink traffic is discarded.

5. The 5G millimeter wave small base station three-sector cascade networking system according to claim 2 is characterized in that: When the external optical fiber port of any 5G millimeter wave small base station receives multicast or broadcast message traffic, the multicast or broadcast message traffic is sent to the application layer for processing; When the external optical fiber port of the first 5G millimeter wave small base station or the second 5G millimeter wave small base station receives multicast or broadcast message traffic, the multicast or broadcast message traffic is copied; and the copied multicast or broadcast message traffic is forwarded to other 5G millimeter wave small base stations through the cascade optical fiber port.

6. The 5G millimeter wave small base station three-sector cascade networking system according to claim 3 is characterized in that: After the 5G millimeter wave small base station sends the downlink traffic to the application layer for processing, this base station strips the header encapsulation of the downlink traffic according to the 3GPP protocol rules and sends the processed downlink traffic to the smart terminal via the air interface.

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