Huawei - 40G
OTN (Optical Transport Network) :- An Optical Transport Network
(OTN) is composed of a set of Optical Network Elements connected by
optical fiber links, able to provide functionality of transport,
multiplexing, routing, management, supervision and survivability of
client signals. Benefits over SDH and SONET : Ultra capacity with
high accuracy, Terabit/second per fibre via DWDM lines Service
transparency for client signals Asynchronous mapping, powerful FEC
function, predigest network design and reduce the cost Compared
with traditional WDM : Enhanced OAM & networking functionality
for all services Dynamically electrical/optical layer grooming OTN
Network layers & interface structure: The optical transport
module-n (OTM-n) is the information structure used to support OTN
interfaces.
As shown in the figure above, the OTM-n.m (n 1) is composed of
OTSn, OMSn, OCh, OTUk/OTUkV, and ODUk. n indicates the number of
the maximum wavelength supported by the interface in case of the
minimum bit rate supported by the wavelength. When n is 0, it
indicates one wavelength.m indicates the bit rate or bit rate set
supported by the interface.r indicates the reduced function.
OTM-0.m need not label r, because one wavelength indicates the
reduced function. OTM-nr.m and OTM-0.m is composed of OPSn, OChr,
OTUk/OTUkV, and ODUk. The information structure that supports the
OTN interface is called OTM-n, that is, the optical transport
module-n. The OTM-n includes two structures: OTM with full
functionality OTM-n.m, OTM with reduced functionality OTM-0.m and
OTM-nr.m.
OPUk: Optical channel Payload Unit-k ODUk: Optical channel Data
Unit-k OTUk: completely standardized Optical channel Transport
Unit-k OTUkV: functionally standardized Optical channel Transport
Unit-k OCh: Optical Channel with full functionality OChr: Optical
Channel with reduced functionality OMS: Optical Multiplex Section
OTS: Optical Transmission Section OPS: Optical Physical Section
OTM: Optical Transport Module
n represents the maximum number of wavelengths that can be
supported at the lowest bit rate supported on the wavelength,
m=1,2,3,12,23,123 OTS_OH, OMS_OH, OCh_OH and COMMS OH information
fields are contained within the OOS OSCOptical Supervisory Channel
used to transmit OOS The figure on shows the composition of the
OTM-n.m signals of the OTM interface with complete function. The
OTM-n.m is composed of up to n multiplexing wavelengths and OTM
overhead signals that support the non-associated overhead, m can be
1, 2, 3, 12, 23, or 123.m=1 indicates the signals are OTU1/OTU1V.
m=2: indicate the signals are OTU2/OTU2V. m=3 indicates the signals
are OTU3/OTU3V. m=12 indicates partial signals are OTU1/OTU1V and
partial signals are OTU2/OTU2V. m=23 indicates partial signals are
OTU 2/OTU2V and partial signals are OTU3/OTU3V. m=123 indicates
partial signals are OTU 1/OTU1V, partial signals are OTU2/OTU2V,
and partial signals are OTU3/OTU3V. The physical optical feature
specifications of OTM-n.m signals are determined by the suppliers.
The recommendations do not have specific specifications. The
optical layer signal OCh is composed of OCh payload and OCh
overhead. After the OCh is modulated to the OCC, multiple OCC time
division multiplexes (TDM) constitute the OCG-n.m unit. OMSn
payload and OMSn overhead constitute the OMU-n.m. OTSn payload and
OTSn overhead constitute the OTM-n.m unit. The overhead and generic
management information of the optical layer units constitute the
OTM overhead signal (OOS), which is transmitted by 1-channel
independent OSC in the non-associated overhead. The overhead of
electrical layer units such as OPUk, ODUk, and OTUk are the
associated channel overheads, which are transmitted together with
the payload.
OTN Interface Structure: Reduced Functionality
Mapping & Multiplexing:
OTUk -> OTMOTU1[v]
OTU2[v]
OTU3[v]
OTU4[v]
Optical-Layer Overheads :
TTI: Trail trace identifier BDI-O: Backward defect indication
overhead BDI-P: Backward defect indication payload PMI-P: Payload
missing indicationFDI-O: Frontward defection indication
overheadFDI-P: Frontward defection indication payloadOCI: Open
connection indication
The OMS overhead is used to support the maintenance and
operation function of the optical MS, and is terminated at the OMU
signal assembly and dissemble places, including:FDI-P: Transmit
OMSn payload signal status to the downstream direction.FDI-O:
Transmit OMSn overhead signal status to the downstream
direction.BDI-P: Transmit the OMSn payload signal invalidity status
detected from the OMSn terminal sink function to the
upstream.BDI-O: Transmit the OMSn overhead signal invalidity status
detected from the OMSn terminal sink function to the upstream.PMI:
Transmit the information with a OCCp containing optical channel
signal information at the upstream of OMS signal source terminal to
the downstream, to suppress subsequent reporting of signal
invalidity status.The OCh overhead is used to support the
maintenance function of the fault management in the optical
channel, and is terminated at the OCh signal assembly and dissemble
places, including:FDI-P: Transmit OCh payload signal status to the
downstream direction.FDI-O: Transmit OCh overhead signal status to
the downstream direction.OCI: It is the OCh open connection
indication. The OCI is the signal sent to the downstream. It
indicates that the matrix connection is opened when the upstream
delivers the management commands in the connection function. Then,
at the OCh terminal point, detect that the OCh signal loss status
may be related to the open matrix.
Hardware Description: There are three types of network element
that are being used in Bharti 40G Expressway network . OSN 3800 OSN
8800 T32 for OPTICAL OSN 8800 T64 for Electrical
OSN 3800 : (OLA /ILA)
Major card that are being used in Bharti Expressway Network.1-
OAU1 (Optical Amplifier Unit )2- ST2 (optical supervisory channel
board)3- PIU (Power Interface Unit)4- AUX (System Auxiliary
Interface Board )5- FAN (FAN Unit)6- SCC (System Control &
Communication Unit)7- DFIU (Bidirectional Fiber Line Interface
Unit)
Slot assignment :
U2000 View :
OAU1 : (optical Amplifier Unit ) : Type description of the OAU1
board Basic function of OAU : Amplifies the input optical signals
in C band. The totalwavelengths range from 1529 nm to 1561 nm.
Supports the system to transmit services over different fiber
spanswithout electrical regeneration.
Gain Adjustment : The OAU100 continuously adjusts the gain from
16 dB to 25.5 dBbased on the input optical power. The OAU101/OAU102
continuously adjusts the gain from 20 dB to31 dB based on the input
optical power. The OAU103 continuously adjusts the gain from 24 dB
to 36 dB basedon the input optical power. The OAU105 continuously
adjusts the gain from 23 dB to 34 dB basedon the input optical
power. The OAU106 continuously adjusts the gain from 16 dB to 23 dB
basedon the input optical power.
Online optical performance monitoring: Provides an in-service
monitoring port (MON). This port connects to an optical spectrum
analyzer or spectrum analyzer unit to monitor the spectrum and
optical performance of the multiplexed signal without affecting
traffic.
OSN 8800 T32 (Optical)