CN1330118C - Distributed base stations and data interactive method - Google Patents

Abstract

The invention discloses a distributed base station system, which includes a baseband processing unit and more than one remote radio unit, and a main multiplexing and demultiplexing module for wavelength division multiplexing of multi-wavelength optical signals is arranged on the side of the baseband processing unit and a standby multiplexing and demultiplexing module, an optical add-drop multiplexing module is arranged on the side of each radio remote unit, and the baseband processing unit and the radio remote unit are connected through two optical fiber links in opposite directions to form a wavelength division multiplexing Ring topology network used. At the same time, a data interaction method based on a distributed base station system is disclosed, and data transmission is performed simultaneously on eastbound and westbound optical fiber links of wavelength division multiplexing rings. It not only improves the data transmission bandwidth of each remote radio unit, but also simplifies the structural design of network equipment in each system. And by adopting a new self-healing switching protection mechanism, the reliability of the network is further improved while ensuring the normal data exchange between system devices.

Description

Distributed base station system and data interaction method

technical field

The invention relates to base station networking technology in a wireless communication system, in particular to a distributed base station networking system and a data interaction method.

Background technique

With the development of the third-generation mobile communication (3G) technology, the design method of the base station tends to separate the baseband processing unit (BBU, BaseBand Unit) from the radio frequency processing unit. Remote Radio Unit (RRU) is a typical application under this design idea. It can solve problems such as difficulty in site selection of the equipment room and feeder cable loss, and improve the transmit power of the antenna port. But it also brings some new problems to be solved, one of the most important problems is the transmission networking problem between the BBU and the RRU.

The interface signal between the BBU and the RRU is an IQ signal with a relatively high rate. Generally, light is used as the medium for direct transmission. Since the IQ signal requires a relatively small transmission delay, it is not suitable to use synchronous digital series (SDH) transmission.

Refer to Figure 1, which is a schematic diagram of the distributed base station system structure of the ring networking scheme commonly used at present. Each node on the structural ring of this networking form has optical ports in two directions, and there are active optical ports on the BBU. Each RRU has an east optical port and a west optical port. The east optical port is directly or indirectly connected to the main optical port of the BBU, and the west optical port is directly or indirectly connected to the backup optical port of the BBU.

When the base station system shown in Figure 1 is working normally, in the downlink direction, the BBU will multiplex the downlink interface data in the form of electrical interface signals sent to all RRUs on the ring and convert them into optical signals of a certain wavelength through the main optical signal. RRU0 receives the downlink optical signal sent by the BBU through the eastbound optical port, restores the interface data in the form of an electrical interface signal, intercepts the downlink interface data of the node for processing, and converts the remaining data into optical signals , and forward it to the next-level RRU through the west optical port, and the subsequent RRUs complete the same function in turn until RRUn receives the downlink interface data of this RRU from the east optical port.

In the uplink direction, after RRUn converts the uplink interface data into optical signals, it sends the uplink interface data through the eastbound optical port, and RRUn-1 receives the uplink interface data sent by RRUn through the westbound optical port, and inserts the uplink interface data of the node into the uplink interface data. The uplink interface data is sent through the east optical port, and the subsequent RRUs perform the same function in turn until the BBU receives the uplink interface data of each RRU on the ring from the east optical port.

When the system fails, for example: the optical fiber between RRUn-1 and RRUn fails, the data transmission between the uplink and downlink interfaces between BBU and RRU0, ..., RRUm-1 remains unchanged, and each RRU still passes through the eastbound optical port Send and receive uplink and downlink interface data with the main optical port of BBU; but the transmission of uplink and downlink interface data between BBU and RRUm, ..., RRUn is the opposite of that before the failure, that is, each RRU sends and receives BBU backup optical port through the west optical port Uplink and downlink interface data.

Since the existing ring networking scheme needs to design a relatively complex frame structure to multiplex the data of each RRU, each RRU also needs to complete the data frame-level add/drop and multiplex functions, so that each RRU interface The function design is very complicated; in addition, since all RRUs on the ring share the bandwidth of the same wavelength for data transmission and reception, the bandwidth of each RRU needs to be limited, causing network resources to be tight and affecting data transmission speed.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a distributed base station system to solve the problems in the prior art that the functions of the RRU interface are too complicated and the data transmission bandwidth is limited.

Another object of the present invention is to provide a data interaction method based on the distributed base station system of the present invention, so as to realize normal data interaction between network devices in the system.

According to the first objective, a distributed base station system disclosed by the present invention includes a baseband processing unit and more than one remote radio unit, and a main multiplexer for wavelength division multiplexing of multi-wavelength optical signals is arranged on the side of the baseband processing unit. The demultiplexing module and the standby multiplexing and demultiplexing module are equipped with an optical add-drop multiplexing module including an east optical port and a west optical port on the side of each radio remote unit; the main multiplexing and demultiplexing module, The optical add-drop multiplexing module and the standby multiplexing and demultiplexing module of each remote radio unit connect the baseband processing unit and the remote radio unit to form a ring topology network through two optical fiber links in opposite directions;

The baseband processing unit converts the downlink electrical interface signals sent to each remote radio unit into optical signals of different wavelengths, and sends them to the main multiplexing and demultiplexing module and the standby multiplexing and demultiplexing module respectively;

The main multiplexing and demultiplexing module combines the downlink optical signals of different wavelengths and sends them step by step along an optical fiber link to the eastbound optical port of the optical add-drop multiplexing module on the side of each radio remote unit, and the standby multiplexing The demultiplexing module multiplexes the downlink optical signal and sends it step by step along another optical fiber link to the west optical port of the optical add-drop multiplexing module on the side of each radio remote unit;

Each optical add-drop multiplexing module takes out the optical signal of the local wavelength from the east optical port and the west optical port and sends it to the radio remote unit, and the radio remote unit converts the optical signal into an electrical interface signal;

Each radio remote unit converts the uplink electrical interface signal sent to the baseband processing unit into a local wavelength uplink optical signal, and sends it to the local optical add-drop multiplexing module;

The optical add-drop multiplexing module combines the local wavelength uplink optical signal with other wavelength optical signals received from the eastbound optical port, and then sends the uplink optical signal to the baseband processing unit through its own westbound optical port along a fiber link for backup multiplexing Demultiplexing module, optical add-drop multiplexing module combines the local wavelength uplink optical signal with other wavelength optical signals received from the westbound optical port, and then sends the uplink optical signal to the baseband through its own eastbound optical port along another optical fiber link The main multiplexing and demultiplexing module of the processing unit;

The main multiplexing and demultiplexing module and the standby multiplexing and demultiplexing module respectively demultiplex the received uplink optical signals into optical signals of different wavelengths and send them to the baseband processing unit. The baseband processing unit converts the optical signals into electrical interfaces Signal.

The main and standby multiplexing and demultiplexing modules described in the system are multiplexing and demultiplexing modules for coarse wavelength division multiplexing or multiplexing and demultiplexing modules for dense wavelength division multiplexing.

The multiplexing and demultiplexing module described in the system is a multiplexing and demultiplexing device for coarse wavelength division multiplexing or a multiplexing and demultiplexing device for dense wavelength division multiplexing; the optical add-drop multiplexing module is Optical Add-Drop Multiplexer.

The main and standby multiplexing and demultiplexing modules of the system are arranged inside or outside the baseband processing unit; the optical add-drop multiplexing module is arranged inside or outside the remote radio unit.

The optical fiber link of the system further includes at least one optical relay unit.

According to the other objective, the present invention simultaneously discloses a data interaction method for a distributed base station system, which is applied to a distributed base station system, and a multi-wavelength optical signal wave is provided on the baseband processing unit side of the distributed base station networking system. The main multiplexing and demultiplexing module and the standby multiplexing and demultiplexing module of the division multiplexing; an optical add/drop multiplexing module is arranged on the side of each remote radio unit; the main multiplexing and demultiplexing module, each radio frequency The optical add-drop multiplexing module and the standby multiplexing and demultiplexing module of the remote unit connect the baseband processing unit and the remote radio unit to form a ring topology through two optical fiber links in opposite directions;

Allocate an optical wavelength for carrying data to each remote radio unit on each optical fiber link;

The data transmission process in the downlink direction in which the baseband processing unit sends data to the remote radio unit includes:

a) The baseband processing unit converts all the downlink electrical interface signals sent to the radio remote unit into the eastbound optical signal and the westbound optical signal of the corresponding allocated wavelength, and sends them to the main multiplexing demultiplexing module and the standby multiplexing module respectively. Use the demultiplexing module;

b) The main multiplexing and demultiplexing module multiplexes all eastbound downstream optical signals and sends them to the eastbound optical port of the optical add-drop multiplexing module on the side of each radio remote unit on the ring network through a fiber link, The standby multiplexing and demultiplexing module multiplexes all westbound downstream optical signals and sends them to the westbound optical port of the optical add-drop multiplexer module on the side of each radio remote unit on the ring network through another optical fiber link;

c) The optical add-drop multiplexing module on the side of each radio remote unit takes out the downlink optical signals belonging to its own assigned wavelength from the downlink optical signals received by the eastbound optical port and westbound optical port, and sends them to the radio remote unit;

d) The radio remote unit selects one of the two downlink optical signals sent by the optical add-drop multiplexing module and converts one into an electrical interface signal for data processing;

The data transmission process in the uplink direction in which the remote radio unit sends data to the baseband processing unit includes:

a') Each radio remote unit converts the uplink electrical interface signal that needs to be sent to the baseband processing unit into an eastbound optical signal and a westbound optical signal with corresponding assigned wavelengths, and sends them to the local optical add-drop multiplexing module;

b') The optical add-drop multiplexing module combines and multiplexes the local westbound optical signal with the eastbound optical signal received from the eastbound optical port, and sends the westbound optical signal to the baseband through a fiber link from the westbound optical port. The standby multiplexing and demultiplexing module on the processing unit side transmits the local eastbound optical signal and the non-local westbound optical signal received from the westbound optical port. After multiplexing, the eastbound optical port passes through another optical fiber. The link is sent to the main multiplexing and demultiplexing module on the side of the baseband processing unit;

c') The main multiplexing and demultiplexing module and the standby multiplexing and demultiplexing module on the side of the baseband processing unit demultiplex each radio remote from the received eastbound optical signal and westbound optical signal respectively The uplink optical signal of the unit is sent to the baseband processing unit;

d') The baseband processing unit selects one of the two upstream optical signals of each radio remote unit sent by the main multiplexing and demultiplexing module and the standby multiplexing and demultiplexing module to convert it into an electrical interface signal for data processing .

The optical wavelength allocated to each remote radio unit in the method is the wavelength in the set of available wavelengths stipulated in the standard of the International Telecommunication Union.

In this method, the optical wavelengths allocated to the same remote radio unit for carrying data in the two optical fiber links are the same.

The multiplexing and demultiplexing module described in the method is a multiplexing and demultiplexing module for coarse wavelength division multiplexing or a multiplexing and demultiplexing module for dense wavelength division multiplexing.

The method between steps c) and d) further includes: the radio remote unit detects whether the two downlink optical signals sent by the add-drop multiplexing module are normal, and sends the detection result to the baseband processing unit;

Step d') specifically includes: the baseband processing unit detects whether the two upstream optical signals of each remote radio unit sent by the main multiplexing and demultiplexing module and the standby multiplexing and demultiplexing module are normal, and receives the radio remote The baseband processing unit selects a group of normal uplink and downlink optical signals, converts the uplink optical signals into electrical interface signals for data processing, and sends an instruction message to the radio remote unit to notify it to receive The selected downlink optical signal;

And the step d) specifically includes: the radio remote unit receives the instruction message sent by the baseband processing unit, selects the downlink optical signal specified in the message, converts it into an electrical interface signal, and performs data processing.

The method step d') said baseband processing unit selects a group of normal uplink and downlink optical signals and specifically includes:

d'1) If the two downlink optical signals of a remote radio unit are normal, and the two uplink optical signals of the remote radio unit on the side of the baseband processing unit are also normal, the baseband processing unit selects a group of uplink and downlink Uplink and downlink optical signals with minimum delay between data on the uplink interface;

d'2) If one or more of the two downlink optical signals of a remote radio unit and the two uplink optical signals on the side of the baseband processing unit are abnormal, the baseband processing unit is in the normal optical signal A group of uplink and downlink optical signals whose uplink and downlink transmission paths are just opposite are preferentially selected.

In this method, the uplink optical signal and radio remote unit should be selected by the baseband processing unit under different detection results according to the principle that the transmission path of the uplink and downlink optical signals is exactly the opposite, and the minimum delay between the uplink and downlink interface data is preferentially selected. The corresponding table of the downlink optical signal that should be selected is stored in the baseband processing unit;

Then in step d'1), the baseband processing unit selects a set of uplink and downlink optical signals with the smallest delay between the uplink and downlink interface data. In case of a corresponding set of uplink and downlink optical signals, the baseband processing unit measures the interface data delay value between the baseband processing unit and the remote radio unit uplink and downlink optical signals under this choice;

The baseband processing unit restores the previous downlink optical signal and turns off the other downlink optical signal, and selects a set of uplink and downlink optical signals corresponding to this case according to the corresponding table, and the baseband processing unit measures this selection. The interface data delay value between the uplink and downlink optical signals of the remote unit;

The baseband processing unit compares the measured interface data delay values under the two options, and selects a group of uplink and downlink optical signals with a smaller delay value;

Step d'2) The baseband processing unit selects a group of uplink and downlink optical signals with opposite uplink and downlink transmission paths in the normal optical signal. The process specifically includes: the baseband processing unit searches in the corresponding table and selects the A set of upstream and downstream optical signals.

In this method, the radio remote unit sends the detection result to the baseband processing unit through the network physical layer; the baseband processing unit sends an instruction message to the radio remote unit through the network physical layer.

It can be seen from the above that the distributed base station system and its data interaction method provided by the present invention use the wavelength division multiplexing technology to set the main device for multi-wavelength optical signal wavelength division multiplexing on the baseband processing unit side. The multiplexing and demultiplexing module and the standby multiplexing and demultiplexing module are equipped with an optical add-drop multiplexing module on the side of each radio remote unit, and the BBU and RRU are connected to form a wavelength division multiplexing through two optical fiber links in opposite directions. The ring networking structure used greatly improves the data transmission bandwidth of each RRU, and at the same time simplifies the structural design of the network equipment in each system, reduces the cost of the network equipment, and improves the data transmission speed. In the process of data interaction, using the characteristics of the ring network technology, data transmission is carried out simultaneously on the eastbound and westbound optical fiber links of the WDM ring, and by adopting a new self-healing switching protection mechanism, between the guarantee system equipment At the same time of normal data exchange, the reliability of the network is further improved.

Description of drawings

FIG. 1 is a schematic diagram of an existing distributed base station system adopting a ring networking structure;

FIG. 2 is a schematic structural diagram of a distributed base station system according to an embodiment of the present invention;

3 is a schematic diagram of data transmission and reception of OADM on the RRU side in an embodiment of the present invention;

Fig. 4 is a schematic diagram of optical fiber link self-healing switching when the second case occurs in the embodiment of the present invention;

Fig. 5 is a schematic diagram of fiber link self-healing switching when the third case occurs in the embodiment of the present invention;

Fig. 6 is a schematic diagram of optical fiber link self-healing switching when the fourth situation occurs in the embodiment of the present invention;

Fig. 7 is a schematic diagram of optical fiber link self-healing switching when the fifth situation occurs in the embodiment of the present invention;

Fig. 8 is a schematic diagram of optical fiber link self-healing switching when the sixth situation occurs in the embodiment of the present invention;

FIG. 9 is a schematic diagram of fiber link self-healing switching when the seventh situation occurs according to the embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

The scheme of the present invention adopts a ring networking structure, utilizes wavelength division multiplexing technology, and sets a main multiplexing and demultiplexing module and a standby multiplexing and demultiplexing module for multi-wavelength optical signal wavelength division multiplexing on the side of the baseband processing unit, An optical add-drop multiplexing module is installed on the side of each radio remote unit, and the BBU and RRU are connected to form a wavelength division multiplexing ring through two optical fiber links in opposite directions. And by rationally arranging the data transmission path between the BBU and the RRU, the wavelength used for data transmission by each RRU is reasonably allocated. While solving the problem of limited data transmission bandwidth, the structure of each network device in the system is simplified, and the reliability of the network is guaranteed by using the ring network technology and the new self-healing switching protection mechanism.

Because the Coarse Wavelength Division Multiplexing (CWDM, Coarse Wavelength Division Multiplexing) technology is a kind of optical transmission technology widely used in the near future, it can improve the utilization rate of the optical fiber at a relatively low cost, so the CWDM ring network technology is used in this embodiment Networking of RRUs.

The structure of the distributed base station system in this embodiment is shown in FIG. 2 . On the BBU side, there are two multiplexer/demultiplexers (MUX/DMUX) for multiplexing and demultiplexing optical signals of each wavelength, among which MUX/DMUX0 is the active module and MUX/DMUX1 is the standby module . On the RRU side, an optical add-drop multiplexer (OADM) is provided to realize the optical add-drop multiplex function of the relevant wavelength. There are two pairs of optical ports on each OADM, one pair of optical ports is directly or indirectly connected to MUX/DMUX0, mainly used for data transmission and reception with MUX/DMUX0, and the other pair of optical ports is directly or indirectly connected to MUX/DMUX1, mainly Used to send and receive data with MUX/DMUX1. MUX/DMUX0, MUX/DMUX1 and the two pairs of optical ports of the OADM on the RRU side are connected through two optical fiber links in the clockwise direction represented by the solid line and in the counterclockwise direction represented by the dotted line in Figure 2.

In the embodiment of the present invention, it is stipulated that the data transmission direction from the BBU to the RRU is the downlink direction; the data transmission direction from the RRU to the BBU is the uplink direction. The direction in which OADM is directly or indirectly connected to the active MUX/DMUX is east; the direction in which OADM is directly or indirectly connected to standby MUX/DMUX is west. The pair of optical ports directly or indirectly connected to MUX/DMUX0 on the OADM are east optical ports; the pair of optical ports directly or indirectly connected to MUX/DMUX1 are west optical ports.

The electrical interface signals for realizing data interaction between the BBU and RRU0, RRU1, ... RRUn in the distributed base station system are IF0, IF1, ..., IFn respectively. Among them, IF0 is used for RRU0, IF1 is used for RRU1, and so on, IFn is used for RRUn. When it is necessary to perform data transmission on the CWDM ring, the downlink and uplink electrical interface signals IF between the BBU and RRU that need to be sent are first converted into optical signals of corresponding wavelengths on the BBU and RRU sides; The optical signal is recovered out of the IF.

Therefore, for each RRU, two wavelengths are assigned to it from the available wavelength set {λ0, λ1, ..., λn) of the CWDM ring network specified in the International Telecommunications Union (ITU-T) standard, and the RRU One of the wavelengths is used for eastbound and westbound transmission carried in the clockwise fiber optic link, and the other wavelength is used for westbound and eastbound transmission carried in the counterclockwise fiber optic link. data.

The specific allocation of each RRU wavelength in this embodiment is shown in Table 1:

RRU0 RRU1 ... RRUn RRU receives eastbound and sends westbound λ0' λ1' ... λn' RRU receives westbound and sends eastbound λ0" λ1" ... λn"

Table 1

Since the RRU's eastbound westbound transmission and the RRU's westbound eastbound transmission are transmitted through different optical fiber links, the same wavelength can be allocated for the same RRU's eastbound westbound transmission and westbound eastbound transmission, that is, In 1, for any RRUx (x=0, 1, ..., n), λx'=λx" can be set. And the available wavelength set is in one-to-one correspondence with the RRU east-bound and west-bound wavelength set, and can be used at the same time There is a one-to-one correspondence between the wavelength set and the RRU's westbound and eastbound transmit wavelength set.

For the downlink direction of data: on the BBU side, according to the wavelength allocation principle in Table 1, the BBU simultaneously converts the electrical interface signal IF downlink to each RRU into two downlink optical signals with wavelengths λ' and λ", and sends them to Enter MUX/DMUX0 and MUX/DMUX1.

Taking the xth RRU as an example, a) BBU simultaneously converts the electrical interface signal IFx downlink to RRUx (x=0, 1, ..., n) into two channels with wavelengths λx' and λx" Downlink optical signals are sent to MUX/DMUX0 and MUX/DMUX1 respectively.

b) MUX/DMUX0 as the main module combines all the east-bound optical signals λ0', λ1',..., λn' together and sends them to the clockwise optical fiber link of the CWDM ring; as a backup The MUX/DMUX1 of the module multiplexes all westward downstream optical signals λ0", λ1", ..., λn" and sends them to the counterclockwise optical fiber link of the CWDM ring.

c) When the downlink optical signal reaches the RRUx side, as shown in Figure 3, the OADMx on the RRUx side takes out its own downlink optical signal λx' from the east optical port, and takes out its own downlink optical signal λx" from the west into RRUx.

d) RRUx selects one downlink optical signal from λx’ and λx” for photoelectric conversion, and restores the IFx electrical interface signal.

For the upstream direction of data: a') On the RRUx side, the RRUx simultaneously converts the upstream electrical interface signal IFx sent to the BBU into two upstream optical signals with wavelengths λx' and λx" and sends them to OADMx.

b') As shown in Figure 3, OADMx combines the uplink optical signal λx" with the optical signals λ0", λ1", ..., λx-1" of all wavelengths received from the local westbound optical port except the downlink λx", λx+1", ..., λn" are multiplexed and sent to the counterclockwise optical fiber link of the CWDM ring from the east optical port; at the same time, OADMx divides the uplink optical signal λx' with the received Optical signals λ0', λ1', ..., λx-1', λx+1', ..., λn' of all wavelengths other than λx' are multiplexed and sent to the clockwise optical fiber of the CWDM ring from the west port link.

c') When the uplink optical signal arrives at the BBU side, MUX/DMUX0 decomposes the uplink optical signal received from the counterclockwise optical fiber link into n wavelengths respectively λ0", λ1", ..., λn" +1 optical signal is sent to the BBU; MUX/DMUX1 decomposes the uplink optical signal it receives from the clockwise optical fiber link into n+1 wavelengths of λ0', λ1',..., λn' The optical signal of the road is sent to the BBU.

d') The BBU selects one of each pair of uplink optical signals λx" and λx' for photoelectric conversion, and recovers the uplink IFx electrical interface signal of the RRUx corresponding to the signal for processing.

During the working process of the distributed base station networking system of the present invention described above, the BBU needs to select one optical signal from the two upstream optical signals λx' and λx" of each RRUx to restore the uplink electrical interface signal IFx; each RRUx It is necessary to select one optical signal from the two downstream optical signals λx' and λx" to restore to the downstream electrical interface signal IFx.

In order to ensure the best transmission effect, this embodiment requires the BBU and RRU to follow the following two constraints when selecting optical signals:

1. The transmission delay of uplink interface data between BBU and RRUx (x=0, 1, ..., n) is as consistent as possible with the transmission delay of downlink interface data between BBU and RRUx, which is expressed as transmission The path is just the opposite.

2. The transmission delay of uplink interface data between BBU and RRUx (x=0, 1, . . . , n) and the transmission delay of downlink interface data between BBU and RRU are as small as possible.

The priority of condition 1 is higher than that of condition 2, that is, condition 1 must be satisfied first, and then condition 2 must be satisfied on the basis of condition 1.

According to the above two constraints, the optical signal selection scheme of the BBU and RRU formulated in this embodiment is shown in Table 2.

The BBU detects two uplink optical signals RRUx detects two downlink optical signals Uplink optical signal selected by BBU Downlink optical signal selected by RRUx λx' λx" λx' λx" 1 normal normal normal normal Choose the path with the least delay 2 Fault normal normal -- λx" λx' 3 -- normal normal Fault λx" λx' 4 normal Fault -- normal λx' λ” 5 normal -- Fault normal λx' λx" 6 normal Fault normal Fault λx' λx' 7 Fault normal Fault normal λx" λx"

Table 2

And save the optical signal selection scheme shown in Table 2 in the BBU, when the BBU and RRU select the optical signal, specifically include the following process:

On the BBU side, the BBU detects whether λ0', λ1', ..., λn' and λ0", λ1", ..., λn" of the uplink optical signal are normal.

On the RRU side, each RRUx detects whether the downlink optical signals λx' and λx" are normal, and reports the detection results to the BBU through the physical layer or other methods.

The processing done by the BBU includes the following 7 situations according to Table 2:

1. If the BBU detects that the uplink optical signals λx' and λx" of the RRUx are normal, and the RRUx detects that the downlink optical signals λx' and λx" are also normal, then the BBU and the RRUx select a set of transmission delay between the uplink and downlink interface data. When the smallest transmission path, the specific process includes:

a. The BBU turns off the downlink λx" optical signal. According to the third optical signal selection principle in Table 2, the BBU selects the uplink λx" optical signal, and the RRUx selects the downlink λx' optical signal. The BBU measures the uplink and downlink between the BBU and RRUx Data transmission delay, set this value as T0.

b. The BBU restores the downlink λx" optical signal, and then the BBU turns off the downlink λx' optical signal. According to the fifth optical signal selection principle in Table 2, the BBU selects the uplink λx' optical signal, and the RRUx selects the downlink λx" optical signal, and the BBU measures The transmission delay from the BBU to the RRUx is set as T1, and the BBU recovers the downlink λx' optical signal.

c. The BBU compares T0 and T1. When T0≤T1, the BBU selects the uplink λx" optical signal, and the BBU sends an instruction message to the RRUx through the physical layer to notify the RRUx to select the downlink λx' optical signal; when T0>T1, the BBU The uplink λx' optical signal is selected, and the BBU sends an instruction message to the RRUx through the physical layer to notify the RRUx to select the downlink λx" optical signal.

2. As shown in Figure 4, the BBU detects that the uplink optical signal λx" is normal, but the uplink optical signal λx' is faulty, and the RRUx detects that the downlink optical signal λx' is normal. After the BBU receives the detection result reported by the RRU, the downlink optical signal is ignored. Whether λx" is normal, by looking up Table 2, the BBU will select the uplink optical signal λx", and send an instruction message to the RRUx to inform the RRUx to select the uplink optical signal λx'.

3. As shown in Figure 5, the RRUx detects that the downlink optical signal λx' is normal, but the downlink optical signal λx" is faulty, and the BBU detects that the uplink optical signal λx" is normal. After the BBU receives the detection result reported by the RRU, the uplink optical signal is ignored. Whether λx' is normal, by looking up Table 2, the BBU selects the uplink optical signal λx", and sends an instruction message to the RRUx to notify the RRUx to select the uplink optical signal λx'.

4. As shown in Figure 6, the BBU detects that the uplink optical signal λx' is normal, but the uplink optical signal λx" is faulty, and the RRUx detects that the downlink optical signal λx" is normal. After receiving the detection result reported by the RRU, the BBU ignores the downlink optical signal Whether λx' is normal, by looking up Table 2, the BBU selects the uplink optical signal λx', and sends an instruction message to the RRUx to notify the RRUx to select the uplink optical signal λx".

5. As shown in Figure 7, the RRUx detects that the downlink optical signal λx" is normal, but the downlink optical signal λx' is faulty, and the BUB detects that the uplink optical signal λx' is normal. After receiving the detection result reported by the RRU, the BBU checks Table 2 , regardless of whether the uplink optical signal λx" is normal or not, the BBU selects the uplink optical signal λx', and sends an instruction message to the RRUx to notify the RRUx to select the uplink optical signal λx".

6. As shown in Figure 8, the BBU detects that the uplink optical signal λx' is normal, but the uplink optical signal λx" is faulty, and the RRUx detects that the downlink optical signal λx' is normal but the downlink optical signal λx" is faulty, and the BBU receives the detection reported by the RRU After the result, the BBU selects the uplink optical signal λx' by looking up Table 2, and sends an instruction message to the RRUx to notify the RRUx to select the uplink optical signal λx'.

7. As shown in Figure 9, the BBU detects that the uplink optical signal λx" is normal, but the uplink optical signal λx' is faulty, and the RRUx detects that the downlink optical signal λx" is normal, but the downlink optical signal λx' is faulty, and the BBU receives a report from the RRU After the detection result, by looking up Table 2, the BBU selects the uplink optical signal λx", and sends an instruction message to the RRUx to notify the RRUx to select the uplink optical signal λx".

In addition, in order to increase the data transmission distance, an optical relay unit such as an optical power amplifier can be added to the optical fiber link. In the case of a distributed base station with many RRU sites, dense wavelength division multiplexing (DWDM) MUX/DMUX can be used on the BBU side, and the DWDM technology capable of multiplexing more wavelengths can be used to replace the CWDM technology in the above embodiment. The multiplexing and demultiplexing module of the present invention can be arranged inside or outside the baseband processing unit; the optical add/drop multiplexing module can also be arranged inside or outside the remote radio unit.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (13)

1, a kind of distributed base station system, include baseband processing unit and more than one Remote Radio Unit, it is characterized in that, be provided with in the baseband processing unit side and be used for the main of multiple wavelength optical signal wavelength division multiplexing, be provided with in each Remote Radio Unit side and comprise east orientation Guang Kou and west OADM module to the light mouth with multiplexing and demultiplexing module and standby multiplexing and demultiplexing module; Main OADM module and standby multiplexing and demultiplexing module with multiplexing and demultiplexing module, each Remote Radio Unit connects into the ring topology net by two opposite optical fiber links of direction with baseband processing unit and Remote Radio Unit;

After the downlink electrical interface signal that baseband processing unit will send to each Remote Radio Unit is converted to wavelength optical signals, send into main respectively with multiplexing and demultiplexing module and standby multiplexing and demultiplexing module;

Main with the multiplexing and demultiplexing module downlink optical signal of different wave length is closed the east orientation light mouth that is sent to the OADM module of each Remote Radio Unit side behind the ripple along an optical fiber link step by step, standby multiplexing and demultiplexing module is closed behind the ripple downlink optical signal along another optical fiber link and is sent to the west of OADM module of each Remote Radio Unit side step by step to the light mouth;

Each OADM module is sent into Remote Radio Unit from east orientation Guang Kou and west to the light signal that the light mouth takes out local wavelength, and Remote Radio Unit is converted to electrical interface signals with light signal;

After the up electrical interface signals that each Remote Radio Unit will send to baseband processing unit is converted to local wavelength uplink optical signal, send into local OADM module;

OADM module closes behind the ripple local wavelength uplink optical signal and other wavelength light signal that receives from east orientation light mouth by self west and along an optical fiber link uplink optical signal is sent to the standby multiplexing and demultiplexing module of baseband processing unit to the light mouth, and OADM module is with local wavelength uplink optical signal and the main multiplexing and demultiplexing module of using that along another optical fiber link uplink optical signal is sent to baseband processing unit from the west after other wavelength light signal that the light mouth receives closes ripple by self east orientation light mouth;

The main uplink optical signal demultiplexing that will receive separately respectively with multiplexing and demultiplexing module and standby multiplexing and demultiplexing module is to send into baseband processing unit behind the different wave length light signal, and baseband processing unit is converted to electrical interface signals with light signal.

2, system according to claim 1 is characterized in that, described primary and backup multiplexing and demultiplexing module is the multiplexing and demultiplexing module that is used for the multiplexing and demultiplexing module of Coarse Wavelength Division Multiplexing or is used for dense wave division multipurpose.

3, system according to claim 1 is characterized in that, described multiplexing and demultiplexing module is the multiplexer and demultiplexer that is used for the multiplexer and demultiplexer of Coarse Wavelength Division Multiplexing or is used for dense wave division multipurpose; Described OADM module is an optical add/drop multiplexer.

4, system according to claim 1 is characterized in that, it is inner or outside that described primary and backup multiplexing and demultiplexing module is arranged on baseband processing unit; It is inner or outside that described OADM module is arranged on Remote Radio Unit.

5, system according to claim 1 is characterized in that, further comprises at least one optical relay unit on the described optical fiber link.

6, a kind of data interactive method of distributed base station system, be applied in the distributed base station system, it is characterized in that, be provided with in the baseband processing unit side of distributed base station group network system and be used for the main of multiple wavelength optical signal wavelength division multiplexing with multiplexing and demultiplexing module and standby multiplexing and demultiplexing module; Be provided with OADM module in each Remote Radio Unit side; By two opposite optical fiber links of direction baseband processing unit and Remote Radio Unit are connected into ring topology by main OADM module and standby multiplexing and demultiplexing module with multiplexing and demultiplexing module, each Remote Radio Unit;

For each Remote Radio Unit on every optical fiber link distributes an optical wavelength that is used to carry data;

Comprise to the data transmission procedure that Remote Radio Unit sends the down direction of data at baseband processing unit:

A) described baseband processing unit is sent into east orientation downlink optical signal and west that all downlink electrical interface signals that mail to Remote Radio Unit are converted to corresponding distribution wavelength main with multiplexing and demultiplexing module and standby multiplexing and demultiplexing module respectively to downlink optical signal;

B) mainly with the multiplexing and demultiplexing module all east orientation downlink optical signals are closed the multiplexing back of ripple and be sent to the east orientation light mouth of each Remote Radio Unit sidelight add-drop multiplexing module on the looped network by an optical fiber link, standby multiplexing and demultiplexing module is closed all west that ripple is multiplexing afterwards to be sent to the west of each Remote Radio Unit sidelight add-drop multiplexing module on the looped network to the light mouth by another optical fiber link to downlink optical signal;

C) OADM module of each Remote Radio Unit side takes out respectively to belong to the downlink optical signal that the light mouth is received with the west from east orientation Guang Kou and self distributes the downlink optical signal of wavelength to send into Remote Radio Unit;

D) Remote Radio Unit selects one the tunnel to be converted to electrical interface signals and to carry out data processing from the two-way downlink optical signal that OADM module is sent into;

Comprise to the data transmission procedure that baseband processing unit sends the up direction of data at Remote Radio Unit:

A ') each Remote Radio Unit is converted to corresponding distribution wavelength east orientation uplink optical signal and the western OADM module of sending into this locality to uplink optical signal respectively with the up electrical interface signals that needs mail to baseband processing unit;

B ') OADM module with the west of this locality to uplink optical signal and east orientation downlink optical signal beyond this locality that receives from east orientation light mouth close ripple multiplexing after, send by the standby multiplexing and demultiplexing module of an optical fiber link from the west to the light mouth to the baseband processing unit side, with the east orientation uplink optical signal of this locality with from the west to the west beyond this locality that the light mouth receives to downlink optical signal close ripple multiplexing after, send with the multiplexing and demultiplexing module to the main of baseband processing unit side by another optical fiber link from east orientation light mouth;

C ') the baseband processing unit side main with multiplexing and demultiplexing module and standby multiplexing and demultiplexing module respectively from the east orientation uplink optical signal received and western to uplink optical signal demultiplexing send into baseband processing unit after going out the uplink optical signal of each Remote Radio Unit;

D ') baseband processing unit selection one tunnel from the two-way uplink optical signal of main each Remote Radio Unit of being sent into multiplexing and demultiplexing module and standby multiplexing and demultiplexing module is converted to electrical interface signals and carries out data processing.

7, method according to claim 6 is characterized in that, described optical wavelength of distributing for each Remote Radio Unit is the concentrated wavelength of stipulating in International Telecommunications Union's standard of wavelength available.

8, method according to claim 6 is characterized in that, the optical wavelength that is used to carry data for same Remote Radio Unit in two optical fiber links for it distributed is identical.

9, method according to claim 6 is characterized in that, described multiplexing and demultiplexing module is the multiplexing and demultiplexing module that is used for the multiplexing and demultiplexing module of Coarse Wavelength Division Multiplexing or is used for dense wave division multipurpose.

10, method according to claim 6 is characterized in that, step c) and d) between further comprise: whether Remote Radio Unit detects the two-way downlink optical signal that add-drop multiplexing module sends into normal, and testing result is sent to baseband processing unit;

Steps d ') specifically comprise: whether baseband processing unit detection master is normal with the two-way uplink optical signal of each Remote Radio Unit that multiplexing and demultiplexing module and standby multiplexing and demultiplexing module are sent into, and the testing result sent of received RF extension unit, baseband processing unit is selected one group of normal up-downgoing light signal, uplink optical signal wherein is converted to the laggard line data processing of electrical interface signals, and, notify it to receive selected downlink optical signal to this Remote Radio Unit transmission instruction message;

And described step d) specifically comprises: Remote Radio Unit receives the described instruction message that baseband processing unit sends, and specified downlink optical signal is converted to the laggard line data processing of electrical interface signals in the selection message.

11, method according to claim 10 is characterized in that, steps d ') described baseband processing unit selects one group of normal up-downgoing light signal specifically to comprise:

D ' 1) if the two-way downlink optical signal of a Remote Radio Unit all normally, and this Remote Radio Unit is also all normal at the two-way uplink optical signal of baseband processing unit side, and then baseband processing unit is therefrom selected the minimum uplink and downlink light signal of time-delay between one group of downlink and uplink interfaces data;

D ' 2) if the two-way downlink optical signal of a Remote Radio Unit and in the two-way uplink optical signal of baseband processing unit side, have the light signal more than a road or a tunnel undesired, then baseband processing unit is preferential in normal light signal would select one group of uplink and downlink light signal that the up-downgoing transmission path is just in time opposite.

12, method according to claim 11, it is characterized in that, just in time opposite according to up-downgoing optical signal transmission path in advance, and therefrom preferentially select the principle of time-delay minimum between the downlink and uplink interfaces data to be provided with under the different testing result situations, the correspondence table of the downlink optical signal that uplink optical signal that baseband processing unit should be selected and Remote Radio Unit should be selected is kept in the baseband processing unit;

Steps d ' 1 then) described baseband processing unit selects therefrom that the minimum uplink and downlink light signal process of time-delay specifically comprises between one group of downlink and uplink interfaces data: baseband processing unit turn-offs one road downlink optical signal, select one group of corresponding in such cases uplink and downlink light signal according to correspondence table, baseband processing unit is measured under this kind selection, and baseband processing unit is to the interface data delay value between the Remote Radio Unit uplink and downlink light signal;

Baseband processing unit recovers last road downlink optical signal and turn-offs another road downlink optical signal, select one group of corresponding in such cases uplink and downlink light signal according to correspondence table, baseband processing unit is measured under this kind selection, and baseband processing unit is to the interface data delay value between the Remote Radio Unit uplink and downlink light signal;

The interface data delay value that records under two kinds of selections of baseband processing unit comparison is selected one group of less uplink and downlink light signal of delay value;

Steps d ' 2) described baseband processing unit selects one group of just in time opposite uplink and downlink light signal process of up-downgoing transmission path specifically to comprise in normal light signal: one group of uplink and downlink light signal that baseband processing unit is searched in correspondence table and selection and present case are mated.

13, method according to claim 10 is characterized in that, described Remote Radio Unit sends testing result by network physical course baseband processing unit; Described baseband processing unit sends instruction message by network physical course Remote Radio Unit.

Images