Method and devices for transmitting client signals in optical transport network

Abstract

A method for transmitting client signals in an OTN includes: obtaining the client signals, and determining an OPUk TS in an OPUk according to the client signals; mapping the client signals to the OPUk TS in an agnostic CBR mapping mode; and adding an overhead into the OPUk, and sending the OPUk with the added overhead to the OTN. A device for transmitting client signals and a device for receiving client signals in an OTN are disclosed.

1 . A method for transmitting client signals in an Optical Transport Network, OTN, comprising:
 obtaining the client signals and determining an Optical Channel Payload Unit-k Tributary Slot (OPUk TS) in an Optical Channel Payload Unit-k (OPUk) according to the client signals;   mapping the client signals to the OPUk TS in an agnostic Constant Bit Rate (CBR) mapping mode; and   adding an overhead into the OPUk, and sending the OPUk with the added overhead to the OTN.   
   
   
       2 . The method of  claim 1 , wherein the determining of the OPUk TS in the OPUk according to the client signals comprises:
 determining the number of the OPUk TSs of the OPUk according to a type of the client signals and a bit rate of the OPUk; and   determining the OPUk TS by using the number of the OPUk TSs as a cycle.   
   
   
       3 . The method of  claim 2 , wherein the determining of the OPUk TS in the OPUk according to the client signals further comprises:
 stuffing fixed byte positions of the OPUk with invalid data so that the number of non-stuffed bytes of the OPUk is an integer multiple of the number of the OPUk TSs.   
   
   
       4 . The method of  claim 2 , wherein the determining of the OPUk TS in the OPUk according to the client signals further comprises:
 grouping the determined OPUk TSs of the OPUk, and letting the OPUk TSs in a same group constitute a channel for transmitting the client signals.   
   
   
       5 . The method of  claim 1 , wherein the mapping of the client signals to the OPUk TS in the OPUk in the agnostic CBR mapping mode comprises:
 determining the number of bytes of a first client signal according to a rate of the first client signal among the client signals and an OPUk TS rate corresponding to the first client signal;   mapping the number of the bytes of the first client signal to an overhead of the OPUk TS corresponding to the first client signal; and   mapping bytes of a client signal of this number of the bytes to the OPUk TS corresponding to the first client signal.   
   
   
       6 . The method of  claim 1 , wherein the mapping of the client signals to the OPUk TS in the OPUk in the agnostic CBR mapping mode comprises:
 mapping a first client signal among the client signals to the OPUk TS corresponding to the first client signal in the agnostic CBR mapping mode; and   mapping a second client signal among the client signals to the OPUk TS corresponding to the second client signal in a Generic Framing Procedure (GFP) mapping mode or an Asynchronous Transfer Mode (ATM) cell mapping mode.   
   
   
       7 . The method of  claim 1 , further comprising:
 adding a control identifier into the overhead added in the OPUk for at least one of the following purposes: identifying the OPUk TS corresponding to each client signal, identifying the number of OPUk TSs in the OPUk, identifying a type of the client signals mapped in the OPUk TS, and identifying a mode of mapping the client signal to the OPUk TS.   
   
   
       8 . The method of  claim 1 , wherein the client signals comprise one kind or multiple kinds of Ethernet signals, Fibre Channel signals, ODUk signals, SDH signals, Enterprise system connection signals, and Digital video broadcast signals. 
   
   
       9 . A method for receiving client signals in an Optical Transport Network (OTN) comprising:
 receiving an Optical Channel Payload Unit-k (OPUk); identifying an agnostic Constant Bit Rate (CBR) mapping mode of an Optical Channel Payload Unit-k Tributary Slot (OPUk TS) according to an overhead in the OPUk; and resolving the OPUk to obtain the OPUk TS; and   resolving the OPUk TS of the OPUk in the agnostic CBR mapping mode to obtain the client signals.   
   
   
       10 . The method of  claim 9 , wherein the resolving of the OPUk TS of the OPUk in the agnostic CBR mapping mode to obtain the client signals comprises:
 resolving the overhead to obtain the number of bytes of corresponding client signals, and resolving out clock information of the corresponding client signals according to the number of the bytes; and   demapping the client signals in the OPUk TS of the OPUk according to the resolved number of the bytes and the clock information of the client signals, and recovering the client signals.   
   
   
       11 . A device for transmitting client signals in an Optical Transport Network (OTN) comprising:
 a client signal obtaining unit adapted to obtain the client signals;   a determining unit adapted to determine an Optical Channel Payload Unit-k Tributary Slot (OPUk TS) in an Optical Channel Payload Unit-k (OPUk) according to the client signals;   a mapping unit adapted to map the client signals to the determined OPUk TS in the OPUk in an agnostic Constant Bit Rate (CBR) mapping mode;   an adding unit adapted to add an overhead into the OPUk; and   a sending unit adapted to send the OPUk with the added overhead to the OTN.   
   
   
       12 . The device of  claim 11 , wherein the determining unit further comprises:
 a unit for determining the number of OPUk TSs, adapted to determine the number of the OPUk TSs of the OPUk according to a type of the client signal and a bit rate of the OPUk; and   an OPUk TS setting unit adapted to determine the OPUk TS according to the number of the OPUk TSs.   
   
   
       13 . The device of  claim 12 , wherein the determining unit further comprises at least one of the following units:
 a stuffing unit adapted to: stuff fixed byte positions of the OPUk with invalid data so that the number of non-stuffed bytes of the OPUk is an integer multiple of the number of the OPUk TSs; and   a grouping unit adapted to: group the determined OPUk TSs of the OPUk, and let the OPUk TSs in a same group constitute a channel for transmitting the client signals.   
   
   
       14 . The device of  claim 11 , wherein the mapping unit comprises:
 a unit for determining the number of bytes of a client signal adapted to determine the number of bytes of a first client signal according to a rate of the first client signal among the client signals and an OPUk TS rate corresponding to the first client signal;   a unit for mapping the number of bytes adapted to map the number of the bytes of the first client signal to an overhead of the OPUk TS corresponding to the first client signal; and   a unit for mapping bytes of a client signal adapted to map the client signal of the number of the bytes to the OPUk TS corresponding to the first client signal.   
   
   
       15 . The device of  claim 11 , wherein the mapping unit comprises a hybrid mapping unit, adapted to:
 map a first client signal among the client signals to the OPUk TS corresponding to the first client signal in the agnostic CBR mapping mode; and   map a second client signal among the client signals to the OPUk TS corresponding to the second client signal in a Generic Framing Procedure (GFP) mapping mode or an Asynchronous Transfer Mode (ATM) cell mapping mode.   
   
   
       16 . The device of  claim 11 , further comprising:
 an OPUk constructing unit, adapted to: add a control identifier into the overhead added in the OPUk for at least one of the following purposes: identifying the OPUk TS corresponding to each client signal, identifying the number of OPUk TSs in the OPUk, identifying a type of the client signals mapped in the OPUk TS, and identifying a mode of mapping the client signal to the OPUk TS.   
   
   
       17 . A device for receiving client signals in an Optical Transport Network (OTN) comprising:
 a receiving unit adapted to receive an Optical Channel Payload Unit-k (OPUk);   a first resolving unit adapted to: identify an agnostic Constant Bit Rate (CBR) mapping mode of an Optical Channel Payload Unit-k Tributary Slot (OPUk TS) according to an overhead in the OPUk, and resolve the OPUk to obtain the OPUk TS; and   a second resolving unit, adapted to resolve the OPUk TS of the OPUk in the agnostic CBR mapping mode to obtain the client signals.   
   
   
       18 . The device of  claim 17 , wherein the second resolving unit comprises:
 a unit for resolving the number of bytes of a client signal adapted to: resolve the overhead to obtain the number of bytes of corresponding client signals, and resolve out clock information of the corresponding client signals according to the number of the bytes; and   a client signal resolving unit adapted to demap the client signals in the OPUk TS of the OPUk according to the resolved number of the bytes and the clock information of the client signals, and recover the client signals.