CN106992838B

CN106992838B - Method and equipment for transmitting public wireless interface signal

Info

Publication number: CN106992838B
Application number: CN201610042131.5A
Authority: CN
Inventors: 向俊凌; 李兴文
Original assignee: Huawei Technologies Co Ltd
Current assignee: Hangzhou Weiyuan Network Technology Co.,Ltd.
Priority date: 2016-01-21
Filing date: 2016-01-21
Publication date: 2020-02-21
Anticipated expiration: 2036-01-21
Also published as: CN106992838A; WO2017124787A1

Abstract

The embodiment of the invention discloses a method for sending a common radio interface (CPRI) signal, which comprises the following steps: a sending device acquires the CPRI signal and acquires antenna carrier AxC container configuration information of the CPRI signal, wherein the AxC container configuration information comprises indication information of a valid AxC container; mapping valid AxC containers in the CPRI signal into virtual basic frames according to the AxC container configuration information; mapping the virtual basic frame into an optical channel data unit ODU, mapping the ODU into an optical channel transport unit OTU, and sending the OTU into an optical transmission channel. The sending equipment maps the effective AxC container in the CPRI signal to the virtual basic frame, thereby improving the utilization rate of OTN transmission bandwidth.

Description

Method and equipment for transmitting public wireless interface signal

Technical Field

The present invention relates to the field of communications, and in particular, to a method and apparatus for transmitting a public wireless interface signal.

Background

In order to realize low-cost and quick wireless network establishment under the condition of no machine room or non-ideal machine room positions, a scheme of a distributed base station is provided. The scheme adopts a Radio Remote Unit (RRU) and a baseband control Unit (BBU) to be separated by a Radio Remote Unit (RRU) technology, and the RRU and the BBU are connected through an optical fiber or a cable. In-phase/Quadrature (I/Q) data quantized by digital sampling is transmitted between the BBU and the RRU through a Common Radio Interface (CPRI).

Current CPRI signals have defined a range of rates including CPRI options 1-8 (eight rates from 614.4Mbit/s to 10137.6 Mbit/s), with rate definitions of 25Gbps and 100Gbps already in the year. How to realize the transmission of CPRI signals at low cost becomes a current research hotspot, wherein, the CPRI signals are carried through an Optical Transport Network (OTN) is one of the main schemes.

Currently, the OTN is used as a core technology of a transport network, and includes technical specifications of an electrical layer and an optical layer, and has rich OAM (Operation Administration and Maintenance), strong TCM (tandem connection Monitoring) capability and out-of-band FEC (Forward Error Correction) capability, and can implement flexible scheduling and management of a large-capacity service. As shown in fig. 1, the OTN frame is a modular structure of 4080 columns by 4 rows. Frame Alignment byte FAS (Frame Alignment Signal), among others, provides the function of Frame synchronization Alignment. OTUk (Optical Channel Transport Unit k) OH is an Optical Channel Transport Unit overhead byte, providing a network management function at the level of the Optical Channel Transport Unit. An ODUk (Optical channel data Unit k) OH provides maintenance and operation functions for Optical channel data Unit overhead bytes. The OPUk (Optical Channel Payload Unit k) OH provides a function of adapting the client signal for an Optical Channel Payload Unit overhead byte. The OPUk is an optical channel payload unit and provides a function of carrying a client signal. FEC is a forward error correction byte that provides error detection and correction functions. The coefficient k represents the supported bit rate and the different kinds of OPUk, ODUk and OTUk. k 1 means a bit rate of 2.5Gbit/s, k 2 means a bit rate of 10Gbit/s, k 3 means a bit rate of 40Gbit/s, k 4 means a bit rate of 100Gbit/s, and k flex means any bit rate.

In the prior art, a 10G bandwidth is adopted to transmit multiple CPRI signals with the same rate, so that bearer capabilities such as 6-way CPRI option 3, 3-way CPRI option 4, 3-way CPRI option 5 and the like can be provided on OTU2r (OTU2r is over-frequency OTU2 rate, OTU2r rate band FEC is 12.639Gbit/s, and OTU2 is 10.709 Gbit/s). The received CPRI signal is subjected to 8B/10B decoding processing, and then mapped into a corresponding time slot by a BMP (Bit-synchronous Mapping Procedure), and the OPU2r divides the time slot by byte and adds Mapping overhead information at a corresponding time slot overhead position. The AxC (AxC) container carrying I/Q data in the CPRI basic frame is statically configured, with a fixed rate point-to-point, and the CPRI interface is still running at a rate corresponding to the peak load and full Carrier operation even if there is idle padding or slot fragmentation in the CPRI frame. With the rapid increase of traffic, the rate of the CPRI interface is higher and higher, and the number of idle areas in the CPRI frame may be more and more. In this case, when the OTN bearer network is carrying CPRI signals, the OTN bearer network must transmit the CPRI basic frames as a whole regardless of how many valid AxC containers are carried on the CPRI basic frames, which results in bandwidth waste.

Disclosure of Invention

In view of this, embodiments of the present invention provide a method and a device for transmitting a public radio interface signal, which can solve the problem of bandwidth waste in an OTN carrying CPRI signals.

In a first aspect, an embodiment of the present invention provides a method for sending a public radio interface CPRI signal, including: a sending device acquires the CPRI signal and acquires antenna carrier AxC container configuration information of the CPRI signal, wherein the AxC container configuration information comprises indication information of a valid AxC container; mapping valid AxC containers in the CPRI signal into virtual basic frames according to the AxC container configuration information; mapping the virtual basic frame into an optical channel data unit ODU, mapping the ODU into an optical channel transport unit OTU, and sending the OTU into an optical transmission channel.

The sending equipment maps the effective AxC container in the CPRI signal to the virtual basic frame according to the AxC container configuration information, thereby improving the utilization rate of OTN transmission bandwidth.

With reference to the implementation manner of the first aspect, in a first possible implementation manner of the first aspect, the indication information of the valid AxC container includes: the column width of the effective AxC containers, the starting column position of the effective AxC containers, and the total length column number of the effective AxC containers.

Optionally, the indication information of the valid AxC container is used to identify the valid AxC container in the CPRI signal, and may further include an indication identifier, for example, to identify which are valid AxC containers and which are invalid AxC containers in the overhead indication corresponding to the AxC container. Optionally, the AxC container configuration information may also contain position information or indication information of invalid AxC containers.

The effective AxC in the CPRI signal can be extracted according to the indication information of the effective AxC container, and the utilization rate of OTN transmission bandwidth for bearing the CPRI signal can be improved.

With reference to the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, a frame structure of the virtual basic frame is the same as a frame structure of the CPRI basic frame.

Alternatively, the frame structure of the virtual basic frame may also be the same as that of the CPRI superframe.

In a second aspect, an embodiment of the present invention provides a method for receiving a public radio interface CPRI signal, where the method includes: receiving, by a receiving device, an optical channel transport unit OTU from an optical transmission channel, and demapping the OTU to obtain an optical channel data unit ODU; de-mapping the ODU to obtain a virtual basic frame; demapping an effective antenna carrier AxC container of the CPRI signal from the virtual basic frame, and restoring the effective AxC container of the CPRI signal to the CPRI signal according to AxC container configuration information of the CPRI signal, wherein the AxC container configuration information includes indication information of the effective AxC container.

The receiving device de-maps the effective AxC container from the virtual basic frame, and recovers the effective AxC container to the CPRI signal according to the AxC container configuration information of the CPRI signal, thereby improving the utilization rate of OTN transmission bandwidth.

With reference to the implementation manner of the second aspect, in a first possible implementation manner of the second aspect, the indication information of the valid AxC container includes: the column width of the effective AxC containers, the starting column position of the effective AxC containers, and the total length column number of the effective AxC containers.

With reference to the second aspect or the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, a frame structure of the virtual basic frame is the same as a frame structure of the CPRI basic frame.

In a third aspect, an embodiment of the present invention provides an optical transport network OTN device, where the OTN device includes: an obtaining module, configured to obtain a CPRI signal and obtain antenna carrier AxC container configuration information of the CPRI signal, where the AxC container configuration information includes indication information of a valid AxC container; a mapping module, configured to map a valid AxC container in the CPRI signal into a virtual basic frame according to the AxC container configuration information; the mapping module is configured to map the virtual basic frame into an optical channel data unit ODU, map the ODU into an optical channel transport unit OTU, and send the OTU to an optical transmission channel.

With reference to the implementation manner of the third aspect, in a first possible implementation manner of the third aspect, the indication information of the valid AxC container includes: the column width of the effective AxC containers, the starting column position of the effective AxC containers, and the total length column number of the effective AxC containers.

With reference to the third aspect or the first possible implementation manner of the third aspect, in a second possible implementation manner of the third aspect, a frame structure of the virtual basic frame is the same as a frame structure of the CPRI basic frame.

In a fourth aspect, an embodiment of the present invention provides an optical transport network OTN device, including: a receiving module, configured to receive an optical channel transport unit OTU from an optical transmission channel; a demapping module, configured to demap the OTU to obtain an optical channel data unit ODU; de-mapping the ODU to obtain a virtual basic frame; demapping an effective antenna carrier AxC container of a CPRI signal from the virtual basic frame, and restoring the effective AxC container of the CPRI signal to the CPRI signal according to AxC container configuration information of the CPRI signal, wherein the AxC container configuration information includes indication information of the effective AxC container.

With reference to the implementation manner of the fourth aspect, in a first possible implementation manner of the fourth aspect, the indication information of the valid AxC container includes: the column width of the effective AxC containers, the starting column position of the effective AxC containers, and the total length column number of the effective AxC containers.

With reference to the fourth aspect or the first possible implementation manner of the fourth aspect, in a second possible implementation manner of the fourth aspect, a frame structure of the virtual basic frame is the same as a frame structure of the CPRI basic frame.

In a fifth aspect, an embodiment of the present invention provides an OTN system, including: the device comprises a sending device and a receiving device, wherein the sending device is used for acquiring a CPRI signal and acquiring antenna carrier AxC container configuration information of the CPRI signal, and the AxC container configuration information comprises indication information of a valid AxC container; mapping valid AxC containers of the CPRI signal into virtual basic frames according to the AxC container configuration information; mapping the virtual basic frame into an optical channel data unit ODU, mapping the ODU into an optical channel transport unit OTU, and sending the OTU into an optical transmission channel. The receiving device is configured to receive an optical channel transport unit OTU from an optical transmission channel, and perform demapping on the OTU to obtain an optical channel data unit ODU; de-mapping the ODU to obtain a virtual basic frame; demapping an effective antenna carrier AxC container of the CPRI signal from the virtual basic frame, and restoring the effective AxC container of the CPRI signal to the CPRI signal according to AxC container configuration information of the CPRI signal, wherein the AxC container configuration information includes indication information of the effective AxC container.

In a sixth aspect, an embodiment of the present invention provides an OTN device, including: the main control board executes a pre-configured program code, and controls any one or more single boards among the branch board, the cross board and the circuit board to execute the method according to any one of the possible implementation manners of the first aspect and the first aspect.

In a seventh aspect, an embodiment of the present invention provides an OTN device, including: the main control board executes a pre-configured program code, and controls any one or more single boards of the branch board, the cross board and the circuit board to execute the method according to the second aspect and any one of the possible implementation manners of the second aspect.

The technical scheme provided by the embodiment of the invention can be applied to the application scene of the CPRI signal front-end feedback. The generating equipment maps the effective AxC container to the virtual basic frame according to the AxC container configuration information of the CPRI signal, thereby improving the utilization rate of OTN transmission bandwidth.

Drawings

The drawings used in describing the background and embodiments will now be briefly described.

Fig. 1 is a schematic structural diagram of an OTN frame in the prior art;

fig. 2 is a schematic structural diagram of a network architecture according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a prior art method for processing an OTN-bearing CPRI signal;

fig. 4 is a schematic structural diagram of a CPRI data frame according to an embodiment of the present invention;

fig. 5 is an exemplary flowchart of a method for CPRI signaling according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a frame format of a CPRI signal according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a virtual basic frame according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a virtual basic frame according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a clock tracking method according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a phase-locked loop according to an embodiment of the present invention;

fig. 11 is a schematic diagram of a CPRI signal mapping process according to an embodiment of the present invention;

fig. 12 is a schematic diagram of a frame format of a CPRI signal according to an embodiment of the present invention;

fig. 13 is a schematic structural diagram of a virtual basic frame according to an embodiment of the present invention;

fig. 14 is a schematic structural diagram of a virtual basic frame according to an embodiment of the present invention;

fig. 15 is a schematic diagram of a CPRI signal mapping process according to an embodiment of the present invention;

fig. 16 is an exemplary flowchart of a method for receiving a CPRI signal according to an embodiment of the present invention;

fig. 17 is a schematic structural diagram of a transmitting device according to an embodiment of the present invention;

fig. 18 is a schematic structural diagram of a receiving device according to an embodiment of the present invention;

fig. 19 is a schematic structural diagram of an OTN system provided in an embodiment of the present invention;

fig. 20 is a schematic structural diagram of an OTN device according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The method, the device and the system for sending and receiving the CPRI signal provided by the embodiment of the invention can be applied to the scene of the front-end back transmission of the CPRI signal. Fig. 2 is a schematic structural diagram of a network architecture according to an embodiment of the present invention. As shown in fig. 2, the network architecture includes the radio devices of the distributed base stations, BBU and RRU, and further includes OTN devices. In particular, the OTN devices may include a transponder Tranponder and a Muxponder. The BBU, the RRU and the OTN equipment can be controlled in a unified way through the controller. In particular, the controller may be an SDN (Software Defined Network) controller. The BBU and the RRU are connected through one or more OTN devices, and CPRI signals transmitted between the BBU and the RRU can be carried and transmitted through one or more OTN devices. For example, when the BBU is used as a sending end, a CPRI signal sent by the BBU is received by the RRU after passing through one or more OTN devices; or when the RRU is used as the sending end, the CPRI signal sent by the RRU is received by the BBU after passing through one or more OTN devices.

Fig. 3 is a schematic diagram of a processing method for carrying CPRI signals through an OTN in the prior art. For CPRI option 1 and CPRI option 2, mapping into the OPU0 by means of Generic Mapping Procedure (GMP); for CPRI option 3, mapping is performed in the OPU1 in a GMP manner; and for the CPRI options 4-8, mapping the CPRI options into the OPUflex in a bit synchronization mapping mode. Then, the multiple lower-order OPU0, OPU1, and OPUflex are mapped into the higher-order OPUk in a GMP manner, and ODUk and OTUk overhead are added, and finally transmitted through the OTUk. For bit stream transparent transmission, each CPRI signal is first mapped to OPU0, OPU1, or OPUflex at a lower order by encapsulation and then mapped to OPUk at a higher order. In the process of mapping CPRI options 1-6 to low-order OPU0, OPU1, or OPUflex, there is a serious waste of bandwidth because the payload regions of OPU0, OPU1, or OPUflex are not fully utilized.

Specifically, the CPRI data frame is defined based on a frame cycle structure of a Universal mobile telecommunications System Terrestrial Radio Access (UTRA) air interface. The UTRA air interface includes 15 slots in a frame period of 10ms, each slot includes 2560 power control periods, also called 2560 segments (Chips), and the rate is 2560Chips 15/10ms — 3.84 Mcps. As shown in fig. 4, the CPRI data frame also defines a CPRI 10ms frame, where the CPRI 10ms frame includes 150 superframes, each superframe includes 256 basic frames, the basic frame rate is 3,840,000 frames per second, and 150 × 256/10ms is 3.84 Mfps. A basic frame contains 16 words, each word being transmitted from left to right, top to bottom. As shown in table 1, # Z is used to index the hyper frame number, # X is used to index the basic frame number, # W is used to index the word number, # Y is used to index the control word number, and # B is used to index the bit number.

TABLE 1

Each word in the CPRI basic frame contains Y bytes, with Y being related to the rate option of the CPRI. For example, 1 time reference rate: 491.52Mbps x 1, one word contains 1 byte; 2 times reference rate: 491.52Mbps x 2, one word contains 2 bytes; 4 times reference rate: 491.52Mbps x4, one word contains 4 bytes. As shown in table 2, the CPRI basic frame includes 1 control word and 15 data words, the control word is used to represent interface control information and overhead information, and the data word is used to carry I/Q data.

TABLE 2

1x491.52(Mbps) rate CPRI basic frame structure

4x491.52(Mbps) rate CPRI basic frame structure

Wherein the I/Q data carried in the data word is a digitized representation of the antenna carrier, and the I/Q data carrying one antenna carrier becomes an AxC container (AxC container). The mapping rule of the AxC container in the CPRI basic frame is as follows: each AxC container is sent as one block; overlapping AxC containers are not allowed, i.e. there cannot be data overlap between different AxC containers.

In the embodiment of the invention, the CPRI signal is carried through the OTN. And the OTN sending terminal equipment maps the CPRI signal to be carried into the virtual basic frame according to the AxC container configuration information. Specifically, the AxC container configuration information includes valid AxC container indication information in the CPRI signal, and may include the column width of the valid AxC containers in the CPRI signal, the starting column position of the valid AxC containers, the total length column number of the valid AxC containers, and so on. The frame structure of the virtual basic frame may be the same as that of the CPRI basic frame, or may be the same as that of the CPRI super frame. The valid AxC container may be mapped into a virtual basic frame according to the valid AxC container indication information of the CPRI signal, while the wireless AxC container in the CPRI signal may not be mapped into a virtual basic frame. Further, the virtual basic frame mapped with the valid AxC container is mapped into the ODU and/or OTU. Because the effective AxC container in the CPRI signal is mapped to the virtual basic frame, the OTN can not need to carry and transmit the ineffective AxC container, thereby improving the utilization rate of the OTN transmission bandwidth.

Fig. 5 is an exemplary flowchart of a method for CPRI signaling according to an embodiment of the present invention. As shown in fig. 5, the method may be performed by an OTN device, and includes the following steps:

s501: a sending device acquires a CPRI signal and acquires AxC container configuration information for the CPRI signal, the AxC container configuration information including information indicative of valid AxC containers.

Specifically, the sending device may be an OTN device, and the sending device may receive a CPRI signal from the BBU or the RRU. The frame structure of the CPRI signal may include a CPRI basic frame or a CPRI super frame, and the like. The AxC container configuration information may be configured in advance on the transmitting device and the receiving device, or may be configured on only one device, for example, the transmitting device, and the transmitting device transmits the configured AxC container configuration information to the receiving device. The AxC container configuration information can also be collected from the radio equipment BBU and the RRU by the SDN controller and then sent to the OTN devices of the corresponding sending end and receiving end.

Alternatively, the indication information of the valid AxC container is used to indicate the valid AxC container in the CPRI signal, and may be the position information of the valid AxC container, and may include, for example, the column width of the valid AxC container in the CPRI signal, the starting column position of the valid AxC container, the total length column number of the valid AxC container, and the like. Optionally, the indication information of the valid AxC container may further include indication identifiers, for example, which are valid AxC containers and which are invalid AxC containers are identified in the overhead indication corresponding to the AxC container. Optionally, the AxC container configuration information may also contain position information or indication information of invalid AxC containers.

Assume two paths of current CPRI signals to be carried, CPRI #0 and CPRI # 1. Fig. 6 shows frame formats of CPRI #0 and CPRI #1 signals, where the rate of CPRI #0 is 1.22Gbps and the rate of CPRI #1 is 2.45 Gbps. The AxC container configuration information for CPRI #0 includes: the column width of the effective AxC container is 8 bits, the starting column position of the effective AxC container is 18 th column, and the total length of the effective AxC container is 13 columns. The AxC container configuration information of CPRI #1 includes: the column width of the effective AxC container is 16 bits, the starting column position of the effective AxC container is the 14 th column, and the total length of the effective AxC container is 17 columns.

S502: mapping valid AxC containers in the CPRI signal into virtual basic frames according to AxC container configuration information.

Specifically, the valid AxC containers of the two signals can be extracted respectively according to the valid AxC container indication information of the two signals, including, for example, the column width, the starting column position, and the total length column number of the valid AxC containers.

Before mapping the valid AxC container of the CPRI signal to the virtual basic frame, the virtual basic frame is constructed first. Specifically, the virtual basic frame may be constructed in the following two ways:

the first method is as follows: and constructing according to the ODU rate of the physical port carrying the CPRI signal. Specifically, the structure of the virtual basic frame may be the same as that of the CPRI basic frame, and includes 16 words, each of which includes m bytes. Where m is related to the ODU rate carrying the CPRI signal, for example, when the CPRI signal is carried by the ODU1, m takes a value of 4. The relationship between the value of m and the ODU rate is shown in table 3, and it should be noted that m may have other values as the ODU rate changes.

TABLE 3

ODUk	ODU Rate	m
			ODU1	2.498Gb/s	4
ODU2	10.037Gb/s	20
			ODU3	40.319Gb/s	80
ODU4	104.794Gb/s	200
			ODUCn	n*104.794Gb/s	n*200

The second method comprises the following steps: and constructing a virtual basic frame according to the total number of the effective AxC containers in each path of CPRI signal to be carried. Specifically, the sending device obtains the n value of each path of CPRI signal to be carried according to the column width and total length column number of the effective AxC container in the obtained AxC container configuration information. The value of n of each CPRI signal may be the total number of the valid AxC containers of the CPRI signal, and may be represented by the product of the column width of the valid AxC containers and the total column number. The n value of each path of CPRI signal is the sum of the n values of each path of CPRI signal. For example, the n value of the CPRI #0 signal is 13 columns × 8 bits, the n value of the CPRI #1 signal is 17 columns × 16 bits, and the n values of the two signals are the sum of 13 columns × 8 bits and 17 columns × 16 bits.

Optionally, a virtual basic frame may be constructed in advance on the sending device according to the ODU rate of the physical port, and then adjusted according to the total number of the effective AxC containers of the CPRI signal to be carried. If the calculated n value of each path of CPRI signal is larger than the bearing capacity of the current virtual basic frame, a new physical port can be added, and a new virtual basic frame is reconstructed, namely the m value of the virtual basic frame is added; if the calculated n value of each path of CPRI signal is smaller than the capacity of the current virtual basic frame, the physical port can be reduced, namely the m value of the virtual basic frame is reduced. The m value of the virtual basic frame is the same as the m value of the ODU carrying the virtual basic frame.

Assuming that the physical port of the ODU1 is used to carry the two CPRI signals, the structure of the virtual basic frame is as shown in fig. 7. In fig. 7, the m value of the virtual basic frame corresponding to the ODU1 is 4, the first two columns of the virtual basic frame may be control words of the virtual basic frame, and the definition of the control words of the virtual basic frame may be the same as that of the CPRI basic frame.

Fig. 8 is a schematic structural diagram for mapping two signals of CPRI #0 and CPRI #1 to a virtual basic frame as shown in fig. 7. In addition to mapping the valid AxC containers of the two signals into virtual basic frames, the control words of the two signals may also be mapped into virtual basic frames. Specifically, in the process of mapping the effective AxC containers of the two signals to the virtual basic frame, the virtual basic frame tracks the clock of the CPRI signal to be carried, and the effective AxC containers and the control words in the CPRI basic frame are mapped to the virtual basic frame in a synchronous mapping manner. As shown in fig. 9, the clock of one of the CPRI signals can be tracked as a reference clock, and the clock of the other CPRI signal can be based on the reference clock. In the mapping process, alignment may be performed in units of columns.

The specific implementation process of tracking the clock to be loaded with the CPRI signal by the virtual basic frame is as follows: and recovering a clock signal from the line CPRI signal, sending the recovered clock signal of the CPRI signal into a phase-locked loop, and after the clock signal is successfully locked, stably outputting the clock signal of the virtual basic frame by the phase-locked loop. At this time, the clock signal of the virtual basic frame and the clock signal of the CPRI signal are synchronized, and this process is clock tracking. Specifically, fig. 10 is a schematic structural diagram of a phase-locked loop, which includes a phase detector, a loop filter, a voltage-controlled oscillator, a frequency divider, and the like. The working principle of the phase-locked loop is consistent with that of the prior art, and the description is omitted here.

S503: mapping the virtual basic frame into an ODU, mapping the ODU into an OTU, and sending the OTU to an optical transmission channel.

As shown in fig. 11, specifically, the virtual basic frame may be mapped into a payload slot of the ODU1 by means of BMP or BGMP (Bit-synchronous general mapping procedure). Optionally, mapping overhead information, for example, a payload type indication, may be added to the overhead of the ODU1, so as to indicate a mapping manner for mapping the CPRI signal to the ODU 1. Specifically, the payload type indication may be a PT bit indicating that the valid AxC container of the CPRI signal is mapped into the ODU1, and the idle slot (i.e., the invalid AxC container) is not mapped into the ODU 1. In the process of demapping from the ODU1, the receiving device needs to report the payload type indication to the controller, so as to implement the monitoring and warning function.

After the virtual basic frame is mapped to the ODU1, OTU overhead may be added to the ODU1 to form an OTU1, and the OTU1 carrying the CPRI signal is sent out.

In the embodiment of the present invention, multiple CPRI signals may be carried through multiple physical ports. Specifically, a virtual basic frame is constructed according to the ODU rate of each physical port. In i ODUs (i is a positive integer greater than or equal to 2) carrying multiple CPRI signals, the m value of each ODU is m₁，m₂，…，m_iAnd the m value of the constructed virtual basic frame is m₁+m₂…+m_i. As shown in fig. 12, the CPRI signal to be carried includes three paths, CPRI #0, CPRI #1 and CPRI #4, and the frame format is similar to that of fig. 6. The valid AxC container configuration information for CPRI #0 and CPRI #1 can be seen at step S501. The valid AxC container configuration information for CPRI #4 includes: the column width of the effective AxC container is 32 bits, the starting column position of the effective AxC container is the 24 th column, and the total length of the effective AxC is 9 columns. Assuming that two ODUs 1 are used to carry the 3 CPRI signals, the structure of the virtual basic frame is as shown in fig. 13. Virtual corresponding to two ODU1 pathsThe pseudo basic frame m is 8, and the first two columns of the virtual basic frame can be control words. As shown in fig. 14, the process of mapping the three CPRI signals to the virtual basic frame is similar to the process of mapping the two CPRI signals to the virtual basic frame, and is not described herein again.

After the valid AxC container and control word of the CPRI signal are mapped to the virtual basic frame, the virtual basic frame is mapped to the ODUXn. Wherein, X represents a reference rate which can be 100Gb/s, 10Gb/s or 25Gb/s, etc., and n is a positive integer. For example, the ODUCn indicates an ODU carrying container of n × 100G, and adopts a variable frame structure of n × 4 rows × 3824 columns. In this embodiment, the ODUXn is composed of two ODU1 paths, the reference rate is 2.498Gb/s, and n is 2. As shown in fig. 15, the virtual basic frame is mapped into the ODUXn by BMP or BGMP, and then the ODUXn is mapped into two OTUs 1. Optionally, the ODUXn may also be mapped into one OTUXn, where the OTUXn is formed by two OTUs 1.

In the embodiment of the invention, the sending equipment maps the effective AxC container of the CPRI signal to the virtual basic frame according to the AxC container configuration information, thereby improving the utilization rate of OTN transmission bandwidth.

Fig. 16 is an exemplary flowchart of a method for receiving a CPRI signal according to an embodiment of the present invention. As shown in fig. 16, the method may be performed by an OTN device, and includes the following steps:

s601: the receiving device receives an optical channel transport unit OTU from an optical transmission channel, and demaps the OTU to obtain an optical channel data unit ODU.

For example, the receiving device receives the OTU1 in the embodiment of fig. 5 from the optical transmission channel, and demaps the OTU1 to obtain the ODU 1.

S602: and de-mapping the ODU to obtain a virtual basic frame.

For example, the ODU1 is demapped to obtain a virtual basic frame. The structure and the construction process of the virtual basic frame can refer to the embodiment shown in fig. 5, and are not described herein again. The virtual basic frame demapped from the ODU may carry the valid AxC container of the CPRI signal.

S603: and demapping the virtual basic frame to obtain a valid AxC container of the CPRI signal, and restoring the valid AxC container of the CPRI signal to the CPRI signal according to AxC container configuration information of the CPRI signal, wherein the AxC container configuration information includes indication information of the valid AxC container.

The AxC container configuration information includes information indicative of valid AxC containers in the CPRI signal, and may include the column width of valid AxC containers in the CPRI signal, the starting column position of valid AxC containers, the total length column number of valid AxC containers, and the like. In the process of restoring the valid AxC container to the CPRI signal, the empty time slots may also be filled in locations in the CPRI signal other than the valid AxC container and the control word. The recovered CPRI signals may include CPRI #0, CPRI #1, and the like.

In the embodiment of the invention, the receiving equipment demaps the effective AxC container of the CPRI signal from the virtual basic frame, and recovers the CPRI signal according to the AxC container configuration information, thereby improving the utilization rate of OTN transmission bandwidth.

Fig. 17 is a schematic structural diagram of a sending device according to an embodiment of the present invention. As shown in fig. 17, the sending device may be an OTN device, including: an acquisition module 171, a mapping module 172, and a sending module 173.

An obtaining module 171, configured to obtain a CPRI signal and obtain antenna carrier AxC container configuration information of the CPRI signal, where the AxC container configuration information includes indication information of a valid AxC container; a mapping module, configured to map a valid AxC container in the CPRI signal into a virtual basic frame according to the AxC container configuration information;

the mapping module 172 is configured to map the virtual basic frame into an optical channel data unit ODU, and map the ODU into an optical channel transport unit OTU;

and a sending module 173, configured to send the OTU to an optical transmission channel.

Optionally, the indication of valid AxC containers comprises: the column width of the effective AxC containers, the starting column position of the effective AxC containers, and the total length column number of the effective AxC containers.

Optionally, a frame structure of the virtual basic frame is the same as a frame structure of the CPRI basic frame.

Optionally, the sending device further includes a constructing module, configured to construct the virtual basic frame according to the column width and total length column number of the effective AxC container before mapping the effective AxC container of the CPRI signal into the virtual basic frame.

Optionally, a one-to-one correspondence exists between a number of bytes contained in each word in the virtual basic frame and a rate of the ODU signal.

Fig. 18 is a schematic structural diagram of a receiving device according to an embodiment of the present invention. As shown in fig. 18, the receiving device may be an OTN device, including: a receiving module 181 and a demapping module 182.

A receiving module 181, configured to receive an optical channel transport unit OTU from an optical transmission channel;

a demapping module 182, configured to demap the OTU to obtain an optical channel data unit ODU; de-mapping the ODU to obtain a virtual basic frame; and demapping the virtual basic frame to obtain an effective antenna carrier AxC container of the CPRI signal, and restoring the effective AxC container of the CPRI signal to the CPRI signal according to AxC container configuration information of the CPRI signal, wherein the AxC container configuration information includes indication information of the effective AxC container.

Optionally, the indication of the valid AxC container comprises: the column width of the effective AxC containers, the starting column position of the effective AxC containers, and the total length column number of the effective AxC containers.

Optionally, the demapping module 182 is further configured to demap the control word of the CPRI signal from the virtual basic frame.

Optionally, the receiving device further comprises a filling module for filling free time slots in areas outside the valid AxC container and the control word.

Fig. 19 is a schematic structural diagram of an OTN system according to an embodiment of the present invention. As shown in fig. 19, the system includes: a transmitting device 191 and a receiving device 192. The sending device 191 and the receiving device 192 may be OTN devices.

A sending device 191 configured to acquire a CPRI signal and acquire antenna carrier AxC container configuration information of the CPRI signal, where the AxC container configuration information includes indication information of a valid AxC container; mapping valid AxC containers in the CPRI signal into virtual basic frames according to the AxC container configuration information; mapping the virtual basic frame into an optical channel data unit ODU, mapping the ODU into an optical channel transport unit OTU, and sending the OTU into an optical transmission channel.

Receiving device 192, configured to receive an optical channel transport unit OTU from an optical transmission channel, and perform demapping on the OTU to obtain an optical channel data unit ODU; de-mapping the ODU to obtain a virtual basic frame; demapping an effective antenna carrier AxC container of the CPRI signal from the virtual basic frame, and restoring the effective AxC container of the CPRI signal to the CPRI signal according to AxC container configuration information of the CPRI signal, wherein the AxC container configuration information includes indication information of the effective AxC container.

In the embodiment of the present invention, the sending device maps the effective AxC container in the CPRI signal to the virtual basic frame according to the AxC container configuration information, and the receiving device demaps the effective AxC container of the CPRI signal from the virtual basic frame, and recovers the CPRI signal according to the AxC container configuration information, thereby improving the utilization rate of the OTN transmission bandwidth.

Fig. 20 is a schematic structural diagram of an OTN device 200 according to an embodiment of the present invention. As shown in fig. 20, the OTN device 200 includes a main control board 201, an OTN line card 202, a cross board 203, and an OTN line card 204. The traffic may be transmitted in a direction from the client side to the line side, and also from the line side to the client side. The traffic transmitted or received by the client side is called client side traffic, and the traffic received or transmitted by the line side is called wavelength division side traffic. The business processing flows in the two directions are reverse processes, and the direction from the client side to the line side is taken as an example in this embodiment to explain:

the main control board 201 is connected to the OTN branch circuit board 202, the cross board 203, and the OTN circuit board 204 through a bus or directly, and performs a control and management function on the OTN branch circuit board 202, the cross board 203, and the OTN circuit board 204.

And the OTN branch board 202 completes the encapsulation mapping of the customer service. The client service includes a plurality of service types, such as ATM (Asynchronous Transfer Mode) service, SDH (Synchronous digital hierarchy) service, ethernet service, CPRI service, storage service, and the like. Specifically, the tributary board 202 is configured to receive a client service from a client side, encapsulate and map the received client service to an ODU (Optical Channel data unit) signal, and add a corresponding OTN management monitoring overhead. On the OTN tributary board 202, the ODU signal may be a low-order ODU signal, such as ODU0, ODU1, ODU2, ODU3, ODUflex, and the like, and the OTN management monitoring overhead may be an ODU overhead. And for different types of client services, different ways are adopted for encapsulation and mapping into different ODU signals.

And the cross board 203 completes full cross connection of the branch circuit board and the circuit board, and realizes flexible cross scheduling of the ODU signals. Specifically, the cross board can transmit the ODU signal from any one of the branch circuit boards to any one of the circuit boards, or transmit the OTU signal from any one of the circuit boards to any one of the circuit boards, and can also transmit the client signal from any one of the branch circuit boards to any one of the branch circuit boards.

The OTN board 204 forms the ODU signal into an OTU (Optical Channel Transport Unit) signal and sends the OTU signal to a line side. Before the ODU signal is formed into an OTU signal, the OTN line board 204 may multiplex the lower-order multiplexed ODU signal into the higher-order ODU signal. And then adding corresponding OTN management monitoring overhead to the higher-order ODU signal to form an OTU signal and sending the OTU signal to an optical transmission channel at the line side. On the OTN circuit board, the higher-order ODU signal may be an ODU1, an ODU2, an ODU3, an ODU4, and the like, and the OTN management monitoring overhead may be OTU overhead.

The main control board 201 may execute a pre-configured program code, and control any one or more single boards of the OTN branch board 202, the cross board 203, and the OTN circuit board 204 to complete the following functions: acquiring a CPRI signal and acquiring antenna carrier AxC container configuration information of the CPRI signal, wherein the AxC container configuration information comprises indication information of a valid AxC container; mapping valid AxC containers in the CPRI signal into virtual basic frames according to the AxC container configuration information; mapping the virtual basic frame into an optical channel data unit ODU, mapping the ODU into an optical channel transport unit OTU, and sending the OTU into an optical transmission channel.

The OTN device of the embodiment of the present invention may be further configured to perform the method steps of the embodiments shown in fig. 5 and fig. 16.

As will be appreciated by one of ordinary skill in the art, various aspects of the invention, or possible implementations of various aspects, may be embodied as a system, method, or computer program product. Accordingly, aspects of the present invention, or possible implementations of aspects, may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit," module "or" system. Furthermore, aspects of the invention, or possible implementations of aspects, may take the form of a computer program product, which refers to computer-readable program code stored in a computer-readable medium.

The above description is only a few embodiments of the present invention, and those skilled in the art can make various modifications or alterations to the present invention without departing from the spirit and scope of the present invention as disclosed in the specification.

Claims

1. A method of transmitting a public radio interface CPRI signal, the method comprising:

a sending device acquires the CPRI signal and acquires antenna carrier AxC container configuration information of the CPRI signal, wherein the AxC container configuration information comprises indication information of a valid AxC container;

mapping the valid AxC containers of the CPRI signals to a virtual basic frame according to the AxC container configuration information, wherein the virtual basic frame is constructed according to the total number of the valid AxC containers in each path of CPRI signals to be loaded;

mapping the virtual basic frame into an optical channel data unit ODU, mapping the ODU into an optical channel transport unit OTU, and sending the OTU into an optical transmission channel.

2. A method according to claim 1 wherein the information indicative of a valid AxC container comprises:

the column width of the effective AxC containers, the starting column position of the effective AxC containers, and the total length column number of the effective AxC containers.

3. The method of claim 1, wherein mapping the valid AxC container of the CPRI signal into a virtual basic frame further comprises:

constructing the virtual basic frame according to the column width and total length column number of the effective AxC container.

4. The method of claim 1, wherein the method further comprises:

mapping a control word of the CPRI signal into the virtual basic frame.

5. The method of any of claims 1-4, wherein there is a one-to-one correspondence between a number of bytes contained in each word in the virtual basic frame and a rate of the ODU signal.

6. An optical transport network, OTN, device, the OTN device comprising:

an obtaining module, configured to obtain a common radio interface CPRI signal and obtain antenna carrier AxC container configuration information of the CPRI signal, where the AxC container configuration information includes indication information of a valid AxC container;

a mapping module, configured to map the valid AxC containers of the CPRI signals to virtual basic frames according to the AxC container configuration information, where the virtual basic frames are constructed according to the total number of the valid AxC containers in each path of CPRI signals to be carried;

the mapping module is configured to map the virtual basic frame into an optical channel data unit ODU, map the ODU into an optical channel transport unit OTU,

and the sending module is used for sending the OTU to an optical transmission channel.

7. The OTN device of claim 6, wherein the indication of the valid AxC container comprises:

8. The OTN device of claim 6, wherein the OTN device further comprises a build module,

the constructing module is configured to construct the virtual basic frame according to the column width and the total length column number of the effective AxC container before mapping the effective AxC container of the CPRI signal into the virtual basic frame.

9. The OTN device of claim 6, wherein the mapping module is further to:

mapping a control word of the CPRI signal into the virtual basic frame.

10. The OTN device of any one of claims 6 to 9, wherein there is a one-to-one correspondence between a number of bytes contained in each word in the virtual basic frame and a rate of the ODU signal.