CN107733522B - LTE-R annular network system - Google Patents

Abstract

The invention provides an LTE-R ring network system, which comprises a BBU and a plurality of RRUs (radio remote units) connected in series; the BBU is connected with the head RRUs and the tail RRUs in the plurality of RRUs connected in series to form a loop. The LTE-R ring network system provided by the invention improves the redundancy performance of the system and greatly improves the reliability.

Description

LTE-R annular network system

Technical Field

The invention relates to a railway communication system, in particular to an LTE-R ring network system.

Background

At present, a ring connection mode is adopted between a base station (BTS) and a Base Station Controller (BSC) of a GSM-R system, so that the reliability of a wireless subsystem is improved. When a GSM-R system evolves to an LTE-R system, the network tends to be flat, a Base Station Controller (BSC) is not arranged in the system, the system is directly networked with an Evolved Packet Core (EPC) in an IP mode through a base station, and the base station is in a distributed mode.

The LTE-R system widely adopts a distributed base station, the distributed base station consists of a Base Band Unit (BBU) and a Radio Remote Unit (RRU), and the RRU can be installed in a distributed mode, so that great flexibility is brought to engineering construction, and meanwhile, the cost of supporting equipment facilities such as transmission, a direct current power supply and a house can be saved at an independent RRU station.

As shown in fig. 1, a star networking scheme and a chain networking scheme are mainly supported between a BBU and an RRU in a current LTE-R distributed base station. The star networking scheme needs more optical fiber resources, and the network reliability is higher; the chain-shaped networking scheme needs less optical fiber resources and has the lowest network reliability.

Disclosure of Invention

In order to solve the problem of low reliability of the existing LTE-R networking, the invention provides a network system to solve the technical problem.

In accordance with an aspect of the present invention, there is provided an LTE-R ring network system,

the ring network system comprises a BBU and a plurality of RRUs connected in series;

the BBU is connected with the head RRUs and the tail RRUs in the plurality of RRUs connected in series to form a loop.

Further, the BBU and the RRU connected thereto in the ring network system form one or more loops.

Further, a ring head RRU and a tail RRU in the ring network are connected to the same baseband board of the BBU.

Further, a ring head RRU and a tail RRU in the ring network are connected to different baseband boards of the BBU.

Furthermore, a BBU in the ring network and the connected RRUs form a loop, and each RRU in each loop belongs to the same logical cell.

Further, when a single point of failure occurs in an optical fiber outside the connection with the BBU in the ring network, RRUs on both sides of the optical fiber breakpoint belong to one logical cell.

Furthermore, when a single point of failure occurs in an optical fiber outside the connection with the BBU in the ring network, one logical cell is split into two logical cells with the optical fiber break point as a boundary.

Furthermore, a BBU in the ring network and connected RRUs form a loop, and each RRU in each loop belongs to a different logical cell.

The invention also provides an LTE-R ring network system, which comprises a BBU and a single RRU;

and the BBU is connected with two ports of the RRU to form a loop.

The invention provides an LTE-R ring network system, which improves the redundancy performance of the system and greatly improves the reliability of the system.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

FIG. 1 shows a prior art star and chain networking schematic;

FIG. 2 shows a ring networking schematic 1 according to an embodiment of the invention;

FIG. 3 shows a ring networking schematic 2 according to an embodiment of the invention;

FIG. 4 shows a ring networking diagram 3 according to an embodiment of the invention;

FIG. 5 shows a ring networking diagram 4 according to an embodiment of the invention;

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The LTE-R system includes a core network and a radio access network, where the radio access network includes an eNodeB, and the eNodeB adopts a distributed architecture, and is a distributed base station, and implements an IP connection with an Evolved Packet Core (EPC). The eNodeB provides radio coverage within the LTE-R network. The eNodeB includes a Base Band Unit (BBU) and a Radio Remote Unit (RRU). The BBU mainly completes functions of baseband signal processing, protocol conversion, resource scheduling and the like, and performs data interaction with a core network where the MME/S-GW is located through an S1 interface; the RRUs provide wireless coverage of the LTE-R network, different BBUs form different logical cells, and the access and wireless link transmission functions of user equipment are completed through the Uu interface. The RRU is connected to the BBU through a CPRI (common radio public interface) by using an optical fiber, the length of the optical cable can reach 10km (kilometer), and the length of the optical cable can reach 40km under the condition that the CPRI interface is provided with a high-power optical power amplifier, so that the RRU is very suitable for networking wiring along a railway. The RRUs are distributed on two sides of a railway line in a strip shape, wireless coverage on the railway is kept, and communication with a train is achieved.

In the embodiment, a BBU and a plurality of RRUs form a loop, the RRUs in the loop are connected through optical fibers, and the RRUs are connected with the BBU through CPRI interfaces. In the embodiment, a set of BBU with 6 sets of RRUs to form 2 loops is taken as an example for illustration, but the embodiment is not limited to a set of BBU with only 6 sets of RRUs to form 2 loops, and 1 loop or more than 1 loop for a set of BBU with 7 sets of BBU with more than 2 loops can be applied to the present invention.

A plurality of RRUs are sequentially arranged on a railway line: a first RRU1, a second RRU2, a third RRU3, a fourth RRU4, a fifth RRU5, a sixth RRU 6; simultaneously arranging a BBU; the BBU, a first RRU1, a second RRU2 and a third RRU3 which are connected in series form a first loop, and the BBU, a fourth RRU4, a fifth RRU5 and a sixth RRU6 which are connected in series form a second loop.

Each RRU is provided with an input port and an output port, and the input port and the output port realize cascade connection between the RRUs. As shown in fig. 2 or 3, in the RRU cascade connection, one end (non-cascade end) of the head RRU, i.e., RRU1, and one end (non-cascade end) of the tail RRU, i.e., RRU3, are free ends; as a head RRU connected in series, that is, one end (non-cascaded end) of RRU4 and a tail RRU connected in series, that is, one end (non-cascaded end) of RRU6 is a free end, the free end is connected to a CPRI optical port in the BBU, an input port and an output port of the middle RRU2 are respectively connected to an output port of RRU1 and an input port of RRU3, and an input port and an output port of the middle RRU5 are respectively connected to an output port of RRU4 and an input port of RRU6, thereby implementing a ring-shaped network.

When any one of the optical fiber single points of the labels 1-8 has a fault, the RRUs on one side or two sides of the breakpoint can perform data transmission with the BBU through the optical fiber on the side without the fault, the RRU transmitting signals are not influenced, wireless coverage is performed, and the network is further ensured to provide normal communication services.

As shown in fig. 2, 2 loops are formed between RRUs connected to a BBU and the BBU, and a loop head RRU (RRU1 and RRU4) and a loop tail RRU (RRU3 and RRU6) of each loop are both connected to a baseband board, when the baseband board normally works, and a single point fault occurs in an optical fiber connected between the BBU and the RRU, data transmission between the RRUs and the BBU is not affected, and a network can provide a normal communication service, but once the baseband board fails, a railway section covered by the RRUs 1 to RR6 loses wireless signal coverage, thereby causing a large-area coverage blind area and affecting the network to provide a normal communication service.

Fig. 2 improves reliability to a certain extent compared with star networking and chain networking, but weak links still exist. In order to further improve the reliability of the network, the invention proposes a network system shown in fig. 3, as shown in fig. 3, two baseband boards are configured for BBU: the base band board 1 and the base band board 2, the loop head RRU (RRU1 and RRU4) of each loop is connected with the base band board 1, the loop tail RRU (RRU3 and RRU6) is connected with the base band board 2, when the base band board 1 or the base band board 2 breaks down, the RRU still can transmit data with the BBU through the loop tail or the loop head, and the network is not influenced to provide normal communication service.

In the ring networks shown in fig. 2 and 3, a BBU and RRUs connected to the BBU form a loop, each RRU in each loop may belong to the same logical cell, and when a single point fault occurs in an optical fiber outside a connection with the BBU in the ring network, RRUs on both sides of a fiber break point may belong to one logical cell or may belong to different logical cells. Taking a loop formed by the RRU1, the RRU2, and the RRU3 as an example, when a single-point fiber fault occurs at reference numeral 2, the RRU1, the RRU2, and the RRU3 loop network becomes a chain network, one chain includes the RRU1, and the other chain includes the RRU2 and the RRU3, and the two chains may belong to the same logical cell or different logical cells; when a single point of failure occurs at reference numeral 3, the ring networking of the RRU1, the RRU2, and the RRU3 becomes a chain networking, one chain includes the RRU1 and the RRU2, and the other chain includes the RRU3, and the two chains may belong to the same logical cell or different logical cells.

In the ring network shown in fig. 2 and 3, the BBU and the connected RRUs form a loop, and each RRU in each loop may also belong to a different logical cell.

In the ring network shown in fig. 4 and 5, a BBU is connected with two ports of a single RRU to form a loop.

In the ring network shown in fig. 4 and 5, when any one of the optical fibers of reference numbers 1-2 has a single point failure, the RRU can perform data transmission with the BBU through the optical fiber on the side where the failure has not occurred, and does not affect the RRU transmission signal, and performs wireless coverage, thereby ensuring that the network provides normal communication service.

As shown in fig. 4, two ports of the RRU are connected to a baseband board of the BBU, when the baseband board normally works and a single point fault occurs in an optical fiber connected between the BBU and the RRU, data transmission between the RRU and the BBU is not affected, and the network can provide a normal communication service.

As shown in fig. 5, two base band plates are configured for BBU: the RRU comprises a baseband board 1 and a baseband board 2, wherein one port of the RRU is connected with the baseband board 1, the other port of the RRU is connected with the baseband board 2, when the baseband board 1 or the baseband board 2 breaks down, the RRU can still transmit data with the BBU through one port of the two ports, and the network is not influenced to provide normal communication service.

It should be noted that: the above examples are only for illustrating the technical solutions of the present invention, and are not limited thereto. The various devices in the system are not necessarily in direct electrical contact with each other, but rather the description is merely intended to represent logical relationships. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (3)

1. An LTE-R ring network system, characterized in that,

the ring network system comprises a BBU and a plurality of RRUs connected in series;

the BBU is connected with head RRUs and tail RRUs in the plurality of RRUs connected in series to form a loop;

the BBU and the RRU connected in the ring network system form more than one loop;

a head RRU and a tail RRU in the ring network are connected to different baseband boards of the BBU;

two base band plates are configured for the BBU: the base band board 1 and the base band board 2, 2 loops are formed between RRUs connected with the BBU and the BBU, the loop head RRU of each loop is connected with the base band board 1, the loop tail RRU is connected with the base band board 2, and when the base band board 1 or the base band board 2 breaks down, the RRU still can transmit data with the BBU through the loop tail or the loop head;

a loop formed by one BBU and the connected RRUs in the ring network, wherein each RRU in each loop belongs to the same logic cell;

when a single-point fault occurs to an optical fiber outside the connection part of the optical fiber and the BBU in the ring network, RRUs on two sides of the optical fiber breakpoint belong to a logic cell.

2. The LTE-R ring network system of claim 1,

when a single-point fault occurs to an optical fiber outside the connection part of the optical fiber and the BBU in the ring network, one logic cell is split into two logic cells by taking the optical fiber breakpoint as a boundary.

3. An LTE-R ring network system, characterized in that,

the ring network system comprises a BBU and a plurality of RRUs connected in series;

the BBU is connected with head RRUs and tail RRUs in the plurality of RRUs connected in series to form a loop;

the BBU and the RRU connected in the ring network system form more than one loop;

a head RRU and a tail RRU in the ring network are connected to different baseband boards of the BBU;

two base band plates are configured for the BBU: the base band board 1 and the base band board 2, 2 loops are formed between RRUs connected with the BBU and the BBU, the loop head RRU of each loop is connected with the base band board 1, the loop tail RRU is connected with the base band board 2, and when the base band board 1 or the base band board 2 breaks down, the RRU still can transmit data with the BBU through the loop tail or the loop head;

and a loop formed by one BBU and the connected RRUs in the ring network, wherein each RRU in each loop belongs to different logic cells.

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