The present application relates to the field of communications technologies, and in particular, to a method and device for sending and receiving service data.
An Optical Transport Network (OTN) includes technical specifications in an electrical layer and an optical layer, has rich Operation Administration and Maintenance (OAM), and a strong Tandem Connection Monitoring (TCM) capability and an out-of-band Forward Error Correction (FEC) capability, and can implement flexible scheduling and management of a service with high capacity. The OTN is a technology of networking, scheduling, and sending on the basis of a large granularity bandwidth. An OTN system has the following characteristics: (1) The OTN system can transparently send multiple types of service data; (2) the OTN system provides large granularity bandwidth multiplexing and cross-configuration; (3) the OTN system provides perfect performance and failure detection capability; (4) the OTN system provides the out-of-band FEC capable of bringing a coding gain of at most 6.2 dB (Bit Error Rate (BER)=10−15); (5) the OTN system provides a stronger networking and protection capability than Wavelength Division Multiplexing (WDM); and (6) the OTN system has poor capability of supporting a small bandwidth service, and in the OTN, a minimum granularity of an Optical Channel Data Unit-k (ODUk) is ODU0, and a minimum granularity of a corresponding Optical Channel Payload Unit-k (OPUk) is OPU0.
Rates corresponding to OPU0, OPU1, OPU2, and OPU3 defined in G.709 are 1.238954 Gbits/Sec, 2.488320 Gbits/Sec, 9.953280 Gbits/Se, and 39.813120 Gbits/Sec respectively.
Currently, services with client signal rates lower than 1.25 Gbits/Sec exist in large quantities and will last for a long time. With the in-depth application of the OTN, in one aspect, the OTN is expanded to a rate of 100 Gbits/Sec or higher; in the other aspect, the OTN extends to the field of a rate lower than 1.25 Gbits/Sec, and directly bears a low rate service to reduce the investment and operation and maintenance cost.
The OPUk is divided into multiple fixed sub-channels according to an agreement or a certain protocol in order to bear services of different bandwidths. For example, OPU1 may be divided into 32 slots, each slot having 119 columns to form a channel with a rate of 77.76 Mbit/S. If a rate of a service data is lower than the rate of 77.76 Mbit/S, the service data is filled until the rate of the service data is equal to the rate of 77.76 Mbit/S; if a rate of a service data is higher than the rate of 77.76 Mbit/S, multiple channels are bound to provide a bandwidth which is an integral multiple of the rate of the service data.
The method in the prior art has the following problems: The sub-channel bandwidth is fixed and must be the integral multiple of 77.76 Mbit/Sec; for smaller granularity scheduling (for example, 2 Mbit/Sec), bandwidth may be wasted or scheduling may be difficult; and the operation of changing the channel bandwidth is complex, which cannot adapt to a flexible and rapid bandwidth adjustment capability required by future data services, and cannot adapt to future services of unknown rates either.
Embodiments of the present application provide a method and device for sending and receiving service data, so as to solve the problem that a network system cannot bear a service of arbitrary rate.
The embodiments of the present application employ the following technical solutions.
A method for sending service data according to an embodiment of the present application includes:
A method for receiving service data according to an embodiment of the present application includes:
A data apparatus according to an embodiment of the present application includes:
Another data apparatus according to an embodiment of the present application includes:
Through the method and device for sending and receiving the service data according to the embodiments of the present application, the sending end can schedule each flexible data channel to the ODUk frame in the corresponding destination port according to the scheduling control information corresponding to each flexible data channel, and the receiving end can schedule each flexible data channel to the corresponding destination port according to the scheduling control information corresponding to the flexible data channel, so as to recover the service data in the flexible data channel. Since a bandwidth of the flexible data channel is variable, bearing at any rate is implemented, and a flexible and rapid bandwidth adjustment capability is provided.
To illustrate the technical solutions according to the embodiments of the present application or in the prior art more clearly, the accompanying drawings are described briefly below for the embodiments or the prior art. Apparently, the accompanying drawings in the following description are only some embodiments of the present application, and persons of ordinary skill in the art can derive other drawings from the accompanying drawings without creative efforts.
A method and device for sending service data according to embodiments of the present application are described in detail in the following with reference to the accompanying drawings.
It should be understood that the described embodiments are only part rather than all of the embodiments of the present application. On the basis of the embodiments of the present application, other embodiments derived by persons of ordinary skill in the art without creative efforts should fall within the protection scope of the present application.
As shown in
S101: Receive at least one flexible data channel to which service data is adapted.
The service data may enter the flexible data channel after being encapsulated, and may be encapsulated by Gigabit Passive Optical Network (GPON), Generic Framing Procedure-Transparent (GFP-T), Generic Framing Procedure-Framing (GFP-F), Generic Mapping Procedure (GMP), High-Level Data Link Control (HDLC), or other self-defined methods. The service data may also be transparently transmitted directly. The service data may be Synchronous Transmission Module level n (STM-N), Optical Channel Transport Unit k (OTUk), Fiber Channel (FC), or any client-defined data stream.
The flexible data channel is a physical carrier for bearing the service data, and may transmit the service data only or transmit the service data and a flexible data channel overhead at the same time.
S102: Schedule the at least one flexible data channel to an ODUk frame in a corresponding destination port respectively according to scheduling control information corresponding to the at least one flexible data channel.
The scheduling control information may be carried in an ODUk data frame or may be statically configured on a data apparatus used for performing a scheduling operation.
S103: Send the ODUk frame to a destination address through an OTN line after completing construction of the ODUk frame.
Through the method for sending the service data according to the embodiment of the present application, each flexible data channel can be scheduled to the ODUk frame in the corresponding destination port according to the scheduling control information corresponding to each flexible data channel, so that the receiving end can schedule each flexible data channel to the corresponding destination port according to the scheduling control information corresponding to the flexible data channel, and recover the service data in the flexible data channel. Since a bandwidth of the flexible data channel is variable, bearing at any rate is implemented, and a flexible and rapid bandwidth adjustment capability is provided.
As shown in
S201: Receive an ODUk frame that includes at least one flexible data channel.
S202: Schedule the at least one flexible data channel to a corresponding destination port according to scheduling control information corresponding to the at least one flexible data channel.
S203: Recover service data in the at least one flexible data channel from the destination port.
Through the method for receiving the service data according to the embodiment of the present application, the receiving end can schedule each flexible data channel to the corresponding destination port according to the scheduling control information corresponding to the flexible data channel, so as to recover the service data in the flexible data channel. Since a bandwidth of the flexible data channel is variable, bearing at any rate is implemented, and a flexible and rapid bandwidth adjustment capability is provided.
The embodiments of the present application are described in detail in the following by taking service data transmission based on an OTN as an example.
S301: Adapt service data to a corresponding flexible data channel.
In the embodiment of the present application, a location and a bandwidth of each flexible data channel may be determined according to requirements, for example, a rate requirement and/or a bandwidth allocation policy of the service data. The size of each flexible data channel may be adjusted according to actual requirements. For example, the channels may be divided with the same bandwidth or different bandwidths.
Generally, at least one flexible data channel exists. Since the bandwidths of the flexible data channels may be inconsistent, the service data with different rate and different bandwidth requirements may be adapted to appropriate flexible data channels according to actual situations.
When the service data is adapted to each flexible data channel, a channel overhead may be added in each flexible data channel. For example, channel management information relevant to the service data may be added in each flexible data channel, or information, such as error or check, of the service data obtained after the service data is detected may be added in each flexible data channel.
After the service data is adapted to each flexible data channel, the service data in each flexible data channel may be encapsulated, for example, by GPON, GFP-T, GFP-F, GMP, HDLC, or other self-defined methods. Alternatively, the service data in each flexible data channel may be transparently transmitted directly without being encapsulated.
S302: Receive the flexible data channel to which the service data is adapted.
The received flexible data channels may be directly sent through a branch or may be sent through an ODUk virtual frame in the branch. As shown in
The ODUk frame sent in Port 1 includes TC1 and TC3. In this embodiment, the flexible data channel TC2 needs to be sent to the ODUk frame sent in Port 1.
S303: Generate a scheduling control table according to scheduling control information corresponding to the flexible data channel.
The scheduling control information may include port information and channel information. The port information includes a source port corresponding to the flexible data channel and a destination port corresponding to the source port. The channel information includes a channel definition field in the source port corresponding to the flexible data channel and a channel definition field in the corresponding destination port. The channel definition field includes a channel start time and a channel length, or a channel start time and a channel end time. The channel start time and the channel length or the channel start time and the channel end time can define a location of the corresponding flexible data channel in the ODUk frame. The channel information may further include an identifier (ID) of each flexible data channel.
The scheduling control information of the flexible data channel may be statically configured on a data apparatus used for performing scheduling control, or may be carried in the ODUk frame sent in Port 1. Moreover, the port information or channel information may be allocated and carried in the ODUk frame sent in Port 1, or may be statically configured on the data apparatus used for performing scheduling control. If the scheduling control information is carried in the ODUk frame, a main node selected in a network may configure the scheduling control information, and other nodes only need to select scheduling control information belonging to them from the scheduling control information carried in the ODUk frame, so as to control the scheduling of the flexible data channel.
The scheduling control table generated according to the scheduling control information is shown in Table 1. Herein, the flexible data channel is defined by the channel start time and the channel end time.
Referring to
The scheduling control table may further include two fields, that is, storage location and frame count. For example, the storage location may be an OPUk payload area, and the frame count is the number of sent frames. Moreover, the channel information may further include a channel quantity indication field and other check information. The channel quantity indication field is used to represent the total number of the flexible data channels and may also be used to check the channel information.
S304: Schedule each flexible data channel to an OPUk payload area of ODUk in the destination port j according to the scheduling control table.
In this embodiment, an OPU1 with a rate of 2.48832 Gbits/Sec may be adopted. In this manner, an overhead of the OPU1 is reserved and not used.
S305: Carry the channel information in the OPUk payload area.
The channel information may include the channel quantity indication field and the channel definition field. As shown in
As shown in
Definitely, the channel information may also be reserved in a scheduling apparatus as statically configured information, or the port information may also be carried in the ODUk frame to send. The sequence of S305 and S304 is not limited to the foregoing sequence, and S305 and S304 may be performed simultaneously.
S306: Generate a corresponding ODUk data frame.
In order to be compatible with a transmission structure of the ODU1, necessary format conversion further needs to be performed on the service data, and spare OPU1 payload needs to be filled, so as to generate an ODU1 data frame.
S307: Schedule the generated ODUk frame to an OTU line card and add an OTUk overhead, so as to generate an OTUk frame.
S308: Transmit the generated OTUk frame in an OTN.
In this embodiment, the channel information is transmitted through the OPU1 payload, the length of the channel information is variable, and correctness of the channel information can be ensured by methods such as repeated transmission and check. After receiving the data frame, a receiving end may directly obtain complete channel information from the OPU1 payload at one time, so as to generate the corresponding scheduling control table according to the channel information and the port information, schedule each flexible data channel to a destination port, and recover the service data in each flexible data channel. Moreover, the receiving end may also reschedule the flexible data channel in the received ODUk frame and forward the ODUk frame to other destinations. It can be seen from
In the implementation of the embodiment of the present application, if a certain flexible data channel has an error in the process of sending the service data, the corresponding flexible data channel is filled with an ID, so as to prevent the error from propagating, and facilitate apparatus detection and alarm processing at a receiving end.
In this embodiment, multiple flexible data channels and corresponding channel information and/or port information are carried in the OPUk payload, and all the channel information and/or port information can be transmitted through the OPUk frame, so that bearing at any rate in the OTh is implemented, and a flexible and rapid bandwidth adjustment capability is provided. The method is suitable for rapid rate adjustment of the flexible data channel, and may ensure that an adjustment rate is consistent with a frequency of an OTU frame.
Moreover, in the embodiment of the present application, the flexible data channel in the OPUk can bear an OTUn frame of a lower rate, where n<k. For example, the flexible data channel in an OPU3 can bear an OTU1 frame or an OTU2 frame. Therefore, in the embodiment of the present application, a small bandwidth service or a bandwidth of any rate can be borne.
Different from Embodiment 3, in this embodiment, flexible data channels are scheduled in different ODUk frames.
As shown in
A scheduling control table 2 may be generated according to scheduling control information configured statically or scheduling control information carried in the ODUk frame sent by the source port 1.
Each flexible data channel can be scheduled to an OPUk payload in a corresponding destination port according to Table 2. For other steps of sending service data, reference may be made to Embodiment 1.
Moreover, in
In this embodiment, a small bandwidth service or a bandwidth of any rate may be borne through the multiple flexible data channels in the ODUk frame.
Different from Embodiment 1, in this embodiment, a signaling channel is established in an OPUk overhead to transmit scheduling control information, and specifically, to transmit channel information and/or port information.
The channel information and/or the port information is transmitted after being encapsulated by, for example, HDLC or GFP. A receiving end may perform decapsulation and obtain complete channel information and/or port information.
In this embodiment, correctness of the channel information and/or the port information is ensured through the signaling channel, and in the method of this embodiment, an OPUk payload bandwidth is not occupied, thereby increasing a utilization rate of bandwidths.
The present application is not limited to this embodiment, and the channel information and/or the port information may also be transmitted directly through more than one OPUk sub-frame in the OPUk overhead. In this method, the OPUk payload bandwidth is not occupied, and the channel information and/or the port information does not need to be encapsulated and decapsulated, so the process is simple.
For the solution of this embodiment, reference may be made to
Through the method of this embodiment, a bandwidth occupation rate of the channel information and/or the port information in the OPUk payload may be reduced, and a bandwidth adjustment rate may be increased.
Moreover, in the embodiment of the present application, the channel information and/or the port information may also be encapsulated by, for example, HDLC or GFP in a Generic Communication Channel (GCC) of an OTUk overhead and then transmitted. The receiving end may recover the complete channel information and/or port information after receiving a data frame, generate a scheduling control table according to the channel information and/or the port information, and schedule flexible data channels in each port, so as to obtain service data in the corresponding flexible data channel.
The method for sending and receiving the service data according to the embodiments of the present application can be used not only in an OTN system but also in other systems with an M×N block frame structure, such as Synchronous Digital Hierarchy/MultiService Transport Platform/Synchronous Optical Network (SDH/MSTP/SONET). For the methods for dividing the flexible data channel and generating, sending or receiving the service data, reference may be made to the foregoing embodiments.
As shown in
a receiving unit 101, configured to receive at least one flexible data channel to which service data is adapted;
a scheduling unit 102, configured to schedule the at least one flexible data channel to an ODUk frame in a corresponding destination port respectively according to scheduling control information corresponding to the at least one flexible data channel; and
a sending unit 103, configured to send the ODUk frame to a destination address through an OTN line after completing construction of the ODUk frame.
On the basis of the foregoing solution, as shown in
The control table generation module 1021 is configured to generate a scheduling control table according to the scheduling control information corresponding to the at least one the flexible data channel.
The search module 1022 is configured to search for the destination port corresponding to the at least one flexible data channel and search for a channel definition field in the corresponding destination port from the scheduling control table generated by the control table generation module 1021.
The channel scheduling module 1023 is configured to schedule the at least one flexible data channel to the corresponding destination port respectively according to information found by the search module 1022.
As shown in
a receiving unit 121, configured to receive an ODUk frame that includes at least one flexible data channel;
a scheduling unit 122, configured to schedule the at least one flexible data channel to a corresponding destination port according to scheduling control information corresponding to the at least one flexible data channel; and
a recovery unit 123, configured to recover service data in the at least one flexible data channel from the destination port.
On the basis of the foregoing solution, the scheduling unit 122 may include a control table generation module, a search module, and a channel scheduling module. For a schematic structural diagram of the scheduling unit 122, reference may be made to the schematic structural diagram of the scheduling unit 102 shown in
The control table generation module is configured to generate a scheduling control table according to the scheduling control information corresponding to the at least one the flexible data channel.
The search module is configured to search for the destination port corresponding to the at least one flexible data channel and search for a channel definition field in the corresponding destination port from the scheduling control table generated by the control table generation module. The channel scheduling module is configured to schedule the at least one flexible data channel to the corresponding destination port respectively according to information found by the search module.
For the data apparatuses in the foregoing embodiments, the scheduling control information includes port information and channel information. The port information includes a source port corresponding to the at least one flexible data channel and a destination port corresponding to the source port. The channel information includes a channel definition field in the source port corresponding to the at least one flexible data channel and a channel definition field in the corresponding destination port. The channel definition field includes a channel start time and a channel length, or a channel start time and a channel end time.
The scheduling control information may be carried in an ODUk data frame or may be statically configured on the data apparatus.
The device for sending and receiving the service data according to the embodiments of the present application may complete the sending and receiving of the service data in combination with the embodiments of the method for sending and receiving the service data.
Through the device for sending and receiving the service data according to the embodiments of the present application, the sending end may schedule each flexible data channel to the ODUk frame in the corresponding destination port according to the scheduling control information corresponding to each flexible data channel, and the receiving end may schedule each flexible data channel to the corresponding destination port according to the scheduling control information corresponding to the flexible data channel, so as to recover the service data in the flexible data channel. Since a bandwidth of the flexible data channel is variable, bearing at any rate is implemented, and a flexible and rapid bandwidth adjustment capability is provided.
The above descriptions are merely exemplary embodiments of the present application, but the protection scope of the present application is not limited thereto. Any change or replacement readily made by persons skilled in the art within the technical scope disclosed by the present application should fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.
Number | Date | Country | Kind |
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200910131493.1 | Apr 2009 | CN | national |
This application is a continuation of International Application No. PCT/CN2010/071490, filed on Apr. 1, 2010, which claims priority to Chinese Patent Application No. 200910131493.1, filed on Apr. 1, 2009, both of which are hereby incorporated by reference in their entireties.
Number | Date | Country | |
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Parent | PCT/CN2010/071490 | Apr 2010 | US |
Child | 13226232 | US |