part 3. multiplexing pdh sdh
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Multiplexing
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Multiplexing
Multiplexing (also known as muxing) is a method by which multiple
analog message signals or digital data streams are combined into onesignal over a shared medium.
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Space-Division Multiplexing (SDM)-
simply implies different point-to-point wires for different channels.
Analogue stereo audio cable ( Multi pair telephone cable)
Switched star network( analog telephone access network)
Mesh network.
Wired space-division multiplexing is typically not considered as multiplexing.Space-Division Multiplexing is achieved by multiple antenna elements forming
a phased array antenna.
Multiple-Input and Multiple-Output (MIMO),
Single-Inputand Multiple-Output (SIMO)
Multiple-Input and Single-Output (MISO)
Types of Multiplexing
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Frequency-division multiplexing (FDM)
Assignment of non-overlapping frequency ranges to each user or signal ona medium. Thus, all signals are transmitted at the same time, each using
different frequencies.
A multiplexor accepts inputs and assigns frequencies to each device.
Types of Multiplexing
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Time-division multiplexing (TDM) is a type of digital (or
rarely analog) multiplexing in which two or more bit streams or signalsare transferred apparently simultaneously as sub-channels in one
communication channel, but are physically taking turns on the channel.
Types of Multiplexing
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Types of Multiplexing
The time domain is divided into several recurrent time slots of fixed
length, one for each sub-channel
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Code-division multiplexing(CDM)- is a technique in which each channel
transmits its bits as a coded channel-specific sequence of pulses. This codedtransmission typically is accomplished by transmitting a unique time-
dependent series of short pulses, which are placed within chip times within the
larger bit time.
All channels, each with a different code, can be transmitted on the same fiber and
asynchronously demultiplxed Allows numerous signals to occupy a single
transmission channel, optimizing the use of available bandwidth,
Types of Multiplexing
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Multiplexing Hierarchies and
Transport Technologies
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E1 / T1
E1 (FIRST ORDER EUROPE TRANSMISSION STANDARD)
E1 Frame Format-Frame is composed from 256 bits that are divided to 32Time Slots (TS) x 8 bits per sec
T1 Frame Format-T1 circuits operate at 1.544 Mbit/s. These circuits were
originally carried using a line code called Alternate Mark Inversion (AMI)
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2.048 Mbps SIGNAL
1 Bit Rate 2.048Mbps+-50ppm
2 Input Signal 64 kbps
3 No. of Channels 30+2
4 Bit duration 488ns
5 No. of bits per Time Slots 8
6 Time Slot duration 3.9us
7 No. of TS per frame 32
8 Frame duration 125us
9 No. of frames per multi frame 16
10 MF duration 2ms
11 Frame alignment B0011011s use n
international networks
otherwise 0
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PDH
Plesiochronous Digital Hierarchy
The PDH high capacity transmission networks are based
on a hierarchy of digital multiplexed signals: E.1 to E.4.
The basic building block is the primary rate of 2.048 Mb/s(E.1). This could be made up of 30 x 64 Kb/s voice
channels. This would then be multiplexed up to a higher
rate for high capacity transmission.
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Line coding Hierarchy
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Line coding in PDH systems
PDH Signal Line coding used as per standards
64kbps AMI (Alternate Mark Inversion)
2.048Mbps HDB3 (High Density Block 3)
8.448 Mbps HDB3 (High Density Block 3)
34.368 Mbps HDB3 (High Density Block 3)
139.364 Mbps CMI (Code Mark Inversion )
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SDH Basics
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Introduction
SDH (Synchronous Digital Hierarchy) is a standard for
telecommunications transport
Specification are written by ITU-T
First Introduced into the telecommunication networks in 1992
Based on overlaying a synchronous multiplexed signal onto a
light stream transmitted over fibre-optic cable.
SDH is also defined for use on radio relay links, satellite links,
and at electrical interfaces between equipment.
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Advantages of SDH
A reduction in the amount of equipment and an increase in
network reliability.
The provision of overhead and payload bytes the overhead
bytes permitting management of the payload bytes on an
individual basis and facilitating centralized fault sectionalization
The definition of a synchronous multiplexing format for carrying
lower-level digital signals (such as 2 Mbit/s, 34 Mbit/s, 140Mbit/s) which greatly simplifies the interface to digital switches,
digital cross-connects, and add-drop multiplexers.
The availability of a set of generic standards, which enable multi-
vendor interoperability.
The definition of a flexible architecture capable of
accommodating future applications, with a variety of
transmission rates.
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SDH Signal
The basic format of an SDH signal allows it to carry manydifferent services in its Virtual Container (VC) because it is
bandwidth-flexible.
This capability allows for such things as the transmission of
high-speed packet-switched services, ATM, contribution
video, and distribution video. However, SDH still permits
transport and networking at the 2 Mbit/s, 34 Mbit/s, and 140
Mbit/s levels, accommodating the existing digital hierarchy
signals.
In addition, SDH supports the transport of signals based onthe 1.5 Mbit/s hierarchy.
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PDH Bit Rates
SignalDigital Bit
RateChannels
E0 64Kbit/s One 64Kbit/s
E1 2.048Mbit/s 32 E0
E2 8.448Mbit/s 128 E0
E3 34.368Mbit/s 16 E1
E4 139.264Mbit/s 64 E1
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SDH Bit Rates
Signal Digital Bit Rate Channels
STM-0 51.84 Mbit/s 21 E1
STM-1 155.52 Mbit/s 63 E1 or 1E4
STM-4 622.08 Mbit/s 256 E1 or 4 E4
STM-16 or
2.4Gbps2488.32 Mbit/s
1008 E1 or
16 E4
STM-64 or10 Gbps
9953.28 Mbit/s 4032 E1 or64 E4
STM-256 or
40Gbps39813.12Mbit/s
16128 E1 or
256 E4
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Flexibility of SDH
2 Mbit/s
140 Mbit/s
34 Mbit/s
8 Mbit/s
1.5 Mbit/s
6 Mbit/s
45 Mbit/s
STS-1 (OC-1) 52 Mbit/s
STM-1 STS-3 (OC-3) 155 Mbit/s
STM-64 STS-192 (OC-192) 10 Gbit/s
STM-16 STS-48 (OC-48) 2.5 Gbit/s
STM-4 STS-12 (OC-12) 622 Mbit/s
PDH ETSI
PDH USA
SONET USA
SDH ITU-T
STM-0 52 Mbit/s
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All SDH Mappings
STM-N
AU-3 VC-3 C3
VC-3TU-3TUG-3
C-4VC-4AU-4AUG
AUG
AUG
C2
C12
C11
TUG-2 VC-2TU-2
VC-12TU-12
VC-11TU-11
STM-0
ATM 2.144 M
E4 139.264 M
ATM 1.6 M
ATM 149.760M
ATM 48.384 M
ATM 6.874M
E3 34.368 MT3 44.736 M
T2 6.312 M
E1 2.048 M
T1 1.544 M
* 3
*7
* 3
*7
* 4
* 3
* Pointer ProcessingMultiplexingAligning
Mapping
AUG Administrative Unit GroupAU Administrative UnitTUG Tributary Unit GroupTU Tributary UnitVC Virtual ContainerC Container
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STM-1 Frame Structure
MSOH
RSOH
AU pointer
Payload
1
3
5
9
9 rows
N 9 N 261
N 270 columns
SOH: Section OverheadAU: Administration Unit RSOH: Repeater Section Overhead
MSOH: Multiplexer Section Overhead
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STM-1 Frame Structure
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Virtual Container Size
SDH Digital Bit Rate Size of VC
VC-11 1.728 Mbit/s9 rows,
3 columns
VC-12 2.304 Mbit/s 9 rows,4 columns
VC-2 6.912 Mbit/s9 rows,
12 columns
VC-3 48.96 Mbit/s 9 rows,85 columns
VC-4 150.336 Mbit/s9 rows,
261 columns
f l d
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Position of VC-4 in Payload Area
2mbps C12 (32+2)--------------VC 12 (34+1)-------TU 12 (35+1)----
TUG 2 ((9*4) X 3=108)-
TUG3[9*{(12*7)+2}=774]-
(Stuffing Bytes) Path Overhead byte Pointer Byte 3 X TU12 7 X TUG 2
VC-4 [9*{86+86+86+3)]=9*261=2349)- AU-4 -STM-1
3 X TUG 3 POH+2 Stuffing byte
STM 1 f
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STM-1 frame structure
Section
Overhead
SOH STM-1 has 9 (different) columns of transport overhead !
RS overhead is 3 rows * 9 columns
Pointer overhead is 1 row * 9 columns
MS overhead is 5 rows * 9 columns
SPE is 9 rows * 261 columns
270 columns
RSOH
MSOH
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TX END
TX END
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RX END
RX END
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Section Overhead
The STS-1 overhead consists of 3 rows of section overhead
frame sync (A1, A2) section trace (J0) error control (B1)
section orderwire (E1) Embedded Operations Channel (Di)
6 rows of line overhead
pointer and pointer action (Hi) error control (B2) Automatic Protection Switching signaling (Ki) Data Channel (Di) Synchronization Status Message (S1) Far End Block Error (M0) line orderwire (E2)
A1 A2 J0
B1 E1 F1
D1 D2 D3
H1 H2 H3
B2 K1 K2
D4 D5 D6
D7 D8 D9
D10 D11 D12
S1 M0 E2
section
overhead
line
overhead
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SDH Mapping
S i
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SDH Pointers
SDH provides payload pointers to permit differences in thephase and frequency of the Virtual Containers (VC-N) with
respect to the STM-N frame. Lower-order pointers are also
provided to permit phase differences between VC-1/VC-2 and
the higher-order VC-3/VC-4.
On a frame-by-frame basis, the payload pointer indicates the
offset between the VC payload and the STM-N frame by
identifying the location of the first byte of the VC in the
payload. In other words, the VC is allowed to float within
the STM-1 frame capacity.
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SDH need to be highly reliable (five nines)
Down-time should be minimal (less than 50 msec)
So systems must repair themselves (no time for manual intervention)
Upon detection of a failure (dLOS, dLOF, high BER)
the network must reroute traffic (protection switching)from working channel to protection channel
The Network Element that detects the failure (tail-end NE)initiates the protection switching
The head-end NE must change forwarding or to send duplicate traffic
Protection switching is unidirectionalProtection switching may be revertive (automatically revert to working channel)
Head End Tail-End
working channel
protection channel
SDH Protection
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How does it work?
Head-end and tail-end NEs have bridges (muxes)
Head-end and tail-end NEs maintain bidirectional signaling channel
Signaling is contained in K1 and K2 bytes ofprotection channel
K1 tail-end status and requests K2 head-end status
Head-End Bridge Tail-End Bridge
working channel
protection channel signaling channel
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Linear 1+1 protection
Simplest form of protection
Can be at OC-n level (different physical fibers)
or at STM/VC level (called Sub Network Connection Protection)
or end-to-end path (called trail protection)
channel A
channel B
Head-End BridgeTail-End Bridge
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Linear 1:1 protection
Head-end bridge usually sends data on working channel
When tail-end detects failure it signals (using K1) to head-end
working channel
protection channel
extra traffic
Head-End BridgeTail-End Bridge
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Linear 1:N protection
In order to save BW
we allocate 1 protection channel for every N working channels
working channels
protection channel
Head-End BridgeTail-End Bridge
T fib F fib i
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Two fiber vs. Four-fiber rings
Four-fiber ringsfully redundant at OC level
can support bidirectional routing at line layerTwo-fiber rings
support unidirectional routing at line layer
2 fibers in opposite directions
U idi ti l Bidi ti l
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Unidirectional vs. Bidirectional
Unidirectional routing
working channel B-A same direction (e.g. clockwise) as A-Bmanagement simplicity: A-B and B-A can occupy same timeslotsInefficient: waste in ring BW and excessive delay in one direction
A
BA-B
B-A
A
B
B-A
A-B
C
B-C
C-B
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High transmission rates Transmission rates up to 40Gbit/s can be achieved in modern SDH
systems. SDH is therefore the most suitable technology for backbones,which can be considered as being the super highways in todaystelecommunications networks.
Simplified add & drop function Compared with the older PDH systems, it is much easier to extract and
insert low-bit rate channels from or into the high-speed bit streams inSDH. It is no longer necessary to de multiplex and then re multiplexthe plesiochronous structure, a complex and costly procedure at thebest of the times.
High availability and capacity matching With SDH, network providers can react quickly and easily to the
requirements of their customers. For example, leased lines can beswitched in a matter of minutes. The network provider can usestandardized network elements that can be controlled and monitoredfrom the central location by means of a telecommunication networkmanagement (TMN) system.
Advantages of SDH
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Reliability Modern SDH networks include various automatic back-up and repair
mechanisms to cope with system faults. Failure of a link or an networkelement does not lead to failure of the entire network which could bea financial disaster for the network provider.
These back-up circuits are also monitored by a management system.
Future-proof platform for new services
Right now, SDH is the ideal platform for services ranging from POTS,ISDN and mobile radio through to data communications (LAN, WAN,etc.), and it is able to handle the very latest services, such as video ondemand and digital video broadcasting via ATM that are graduallyestablished.
Interconnection SDH makes it much easier to setup gateways between different
network providers and to SONET systems. The SDH interfaces areglobally standardized, making it possible to combine networkelements from different manufacturers into a network. The result is areduction in equipment costs as compared with PDH.
Advantages of SDH
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SDHPointers & Overheads
Objective
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Objective
Regenerator Section Overhead
Multiplex Section Overhead
Path Overhead
Pointers
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STM-1 Frame Format
9 Rows
Administrative Unit
Capacity of the
Virtual Container
+
Pointers
12
3
4
5
6
7
8
9
RegeneratorSectionOverhead
MultiplexSection
Overhead
H3H1 H2Pointers
STM-1 = 270 Columns (2430 bytes)
H1H1H1 H2 H2H2H3 H3H3
Frame =125s Frame = 125sFrame =125s
Overhead width = 9 columns
Regenerator Section Overhead RSOH
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A1 A1 A1 A2 A2 A2 J0
B1 E1 F1
D1 D2 D3
Regenerator
Section
Regenerator Section Overhead - RSOH
Regenerator Section Overhead RSOH
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Regenerator Section Overhead - RSOH
A1 A2 J0B1 E1 F1
D1 D2 D3
Framing (A1,A2)
Start of the STM-1 frame
A1, A2 The Frame Alignment Word
is used to recognize the beginningof an STM-N frame
A1: 1111 0110 = F6 (HEX)
A2: 0010 1000 = 28 (HEX)
Section Trace or Future Growth (J0)
J0 carries section trace message.
Path Trace. It is used to give a path through an
SDH Network a "Name". This message (Name)
enables the receiver to check the continuity of its
connection with the desired transmitter
Local Orderwire (E1)
Channel for voice communications between any
two NEs. Engineering Orderwire (EOW). It can
be used to transmit speech signals between
Regenerator Sections for operating andmaintenance purposes
Section User Channel (F1)
A 64kb/s user channel.
User Channel. It is used to transmit data
and speech for service and maintenance
Bit Error Monitoring
Bit Error Monitoring. The B1 Byte contains the
result of the parity check of the previous STM
frame, before scrambling of the actual STM
frame. This check is carried out with a Bit
Interleaved Parity check (BIP-8).
Data communication channel (DCC_R)
Provides a single 192 kb/s channel for
Management .
This channel is used to transmit managementinformation via the STM-N frames
Regenerator Section Overhead RSOH
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Regenerator Section Overhead - RSOH
1st row = Unscrambled bytes. Their contents should therefore be monitored
X = Bytes reserved for national use
D = Bytes depending on the medium (satellite, radio relay system, ...)The Regenerator Section OverHead uses the first three rows & nine columns in the STM-1 frame
A1, A2 The Frame Alignment Word is used to recognize the beginning of an STM-N frame
A1: 1111 0110 = F6 (HEX)
A2: 0010 1000 = 28 (HEX)
J0: Path Trace. It is used to give a path through an SDH Network a "Name". This message (Name)
enables the receiver to check the continuity of its connection with the desired transmitter
B1: Bit Error Monitoring. The B1 Byte contains the result of the parity check of the previous STMframe, before scrambling of the actual STM frame. This check is carried out with a Bit Interleaved
Parity check (BIP-8).
E1 Engineering Orderwire (EOW). It can be used to transmit speech signals between Regenerator
Sections for operating and maintenance purposes
F1 User Channel. It is used to transmit data and speech for service and maintenance
D1 to D3 Data Communication Channel at 192 kbit/s (DCCR). This channel is used to transmit
management information via the STM-N frames
Multiplex Section Overhead - MSOH
http://en.wikipedia.org/wiki/BIP-8http://en.wikipedia.org/wiki/File:Regenerator_Section_OverHead_in_the_STM-1_frame.jpghttp://en.wikipedia.org/wiki/BIP-8http://en.wikipedia.org/wiki/BIP-8http://en.wikipedia.org/wiki/BIP-8 -
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B2 B2 B2 K1 K2
D4 D5 D6
D7 D8 D9
D10 D11 D12
S1 M1 E2
Multiplex
Section
Multiplex Section Overhead MSOH
Multiplex Section Overhead MSOH
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B2 K1 K2
D4 D5 D6
D7 D8 D9
D10 D11 D12S1 M1 E2
Line BIP-24 (B2)
Bit interleaved Parity-24 (BIP-
24) is used for multiplex
section error monitoring. The
B2 Bytes contains the result of theparity check of the previous STM
frame, except the RSOH, before
scrambling of the actual STM
frame. This check is carried out
with a Bit Interleaved Parity check
(BIP24)
Multiplex Section Overhead - MSOH
Data Communication Channel
(DCC-M)Provides a single 576 kb/s channel
for ManagementAutomatic Protection Switch (APS)
(K1,K2)
Used for APS signaling
K2 (Bit6,7,8) MS_RDI: Multiplex Section
Remote Defect Indication (former
MS_FERF: Multiplex Section Far End
Receive Failure)
Synchronization status or Future growth (S1)
5-8 bits of the byte defines
Synchronous status message.
0000 Quality unknown
0010 G.811 10-11/day frequency drift 0100 G.812T transit 10-9 /day frequency drift
1000 G.812L local 2*10-8/day frequency drift
1011 G.813 5*10-7/day frequency drift
1111 Not to be used for synchronization
Line Remote Error Indicator (M1)
Remote error indication. Conveys the
BIP-24 error count back to the source
MS_REI: Multiplex Section Remote
Error Indicator, number of interleaved
bits which have been detected to be
erroneous in the received B2 bytes.
(former MS_FEBE: Multiplexing Section
Far End Block Errored)
Orderwire (E2)
Order-wire channel for voice and
Data communication between two
NEs
Multiplex Section Overhead - MSOH
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Multiplex Section Overhead - MSOH
B2 : Bit Error Monitoring. The B2 Bytes contains the result of the parity check of the previous STM frame,
except the RSOH, before scrambling of the actual STM frame. This check is carried out with a Bit Interleaved
Parity check (BIP24)
K1, K2 Automatic Protection Switching (APS). In case of a failure, the STM frames can be routed new withthe help of the K1, K2 Bytes through the SDH Network. Assigned to the multiplexing section protection (MSP)
protocol
K2 (Bit6,7,8) MS_RDI: Multiplex Section Remote Defect Indication (former MS_FERF: Multiplex Section Far
End Receive Failure)
D4 to D12 Data Communication Channel at 576 kbit/s (DCCM). (See also D1-D3 in RSOH above)
S1 (Bit 5 - 8) Synchronization quality level:
0000 Quality unknown
0010 G.811 10-11/day frequency drift0100 G.812T transit 10-9 /day frequency drift
1000 G.812L local 2*10-8/day frequency drift
1011 G.813 5*10-7/day frequency drift
1111 Not to be used for synchronization
E2 Engineering Orderwire (EOW). Same function as E1 in RSOH
M1 MS_REI: Multiplex Section Remote Error Indicator, number of interleaved bits which have been detected
to be erroneous in the received B2 bytes. (former MS_FEBE: Multiplexing Section Far End Block Errored)Z1, Z2 Spare bytes
K1 d K2 A t ti P t ti S it hi (APS
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K1 and K2 - Automatic Protection Switching (APS
channel) bytes
These two bytes are used for MSP (Multiplex Section Protection) signaling between multiplex
level entities for bi-directional automatic protection switching and for communicating Alarm
Indication Signal (AIS) and Remote Defect Indication (RDI) conditions.
K1 Byte K2 ByteBits 1-4 Type of request Bits 1-4 Selects channel number
1111 Lock out of Protection Bit 5 Indication of architecture
1110 Forced Switch 0 1+1
1101 Signal Fail High Priority 1 1:n1100 Signal Fail Low Priority Bits 6-8 Indicate mode of operation
1011 Signal Degrade High Priority 111 MS-AIS
1010 Signal Degrade Low Priority 110 MS-RDI
1001 (not used) 101 Provisioned mode is bi-directional
1000 Manual Switch 100 Provisioned mode is unidirectional
0111 (not used) 011 Future use
0110 Wait-to-Restore 010 Future use0101 (not used) 001 Future use
0100 Exercise 000 Future use
0011 (not used)
0010 Reverse Request
0001 Do Not Revert
0000 No Request
Bits 5-8 Indicate the number of the channel requested
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J1
B3
C2
G1
F2
H4
F3
K3
N1
Higher Order Path Overhead HPOH(VC-4 / VC-3)
Path
Overhead
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J1B3
C2
G1F2
H4
F3K3
N1
Path Signal Label (C2)
Indicates the type of payload in
AU This byte specifies whether
the virtual container is equippedor not
and the mapping type in the
respective virtual container
Path Trace (J1)
J1 byte carries the trace
information at path level
Path BIP-8 (B3)
Path error monitoring
Path Status (G1)
Provides status and performance information
back to the remote end This byte is used to
convey the path
terminating status and performance back to
the originating path
terminating equipment. Therefore the bi-
directional path in itsentirety can be monitored, from either end of
the path
Indicator byte (H4)
Carries multiframe informationPath User Channel (F2)
User data channel at path level
Path User Channel (F3)
User data channel at path levelBits 1-4 are allocated for APS.
Bits 5-8 are for future use.
Tandem Connection (N1)IEC for tandem connection
monitoring at TCM source.
Higher Order Path Overhead HPOH(VC-4 / VC-3)
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Lower Order Path Overhead POH(VC-11 / VC-12)
VC-12 VC-11
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Lower Order Path Overhead - POH
V5
J2
N2
K4
Signal Label and parity check
Path Trace (J2)
J2 byte carries the trace
information at lower order path
level
Tandem Connection (N2)
IEC for tandem connection
monitoring at TCM source.
Carries APS information at
lower order path level
RS Al
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RS Alarms
RS alarms are those, which can be reported evenby a pure Regenerator
(who has privilege of opening (interpreting & rewriting) onlyRSOH)
LOS (Los s of Signal)
based on whole RSOH
LOF (Los s of Frame)
based on A1, A2 bytes
TIM (Trace Identi f ier Mismatch)
based on J0 byte
SF (Signal Fail)
based on B1 byte
SD (Sign al Degrade)
based on B1 byte
D3D2D1
F1E1B1
J0A2A1
RSOH
bytes
Note: The order in which the alarms are written is important,
as we will see later while discussing Alarm masking
MS Alarms
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MS Alarms
MS alarms are those, which can be reported by a Add-Drop Multiplexer, i r respect ive of
cross-connect configuration
(who has privilege of opening (interpreting & rewriting) RSOH, MSOH, AU pointers plus
opening HOPOH(s) / TU Pointers / LOPOH(s) depending upon cross-connect configuration)
AIS (Alarm Indicat ion Signal)
reportedbased on K2 byte -- bits 6,7,8
SF (Signal Fail)based on B2 bytes
SD (Sign al Degrade)
based on B2 bytes
RDI (Remo te Defect Ind icat ion )
based on K2 byte -- bits 6,7,8
MSOH
bytes
K2K1B2
D6D5D4
D9D8D7
E2M1S1
D12D11D10
Note 1: The order in which the alarms are written is important, we will see later while discussing Alarm
masking
Note 2: MS-AIS is also called Line-AIS or AIS on STM port
MS-RDI is also called Line-RDI or RDI on STM port
HP / LP Alarms
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HP / LP Alarms
HP / LP alarms are those, which can be reported by a Add-Drop Multiplexer, having
HO / HO & LO object(LO object => LOcross-connect)
(who has privilege of opening (interpreting & rewriting) RSOH, MSOH, AU Pointers plusat leastinterpreting HOPOH(s) / opening (interpreting & rewriting) RSOH, MSOH, AU
Pointers, HOPOH(s), TU Pointers plusat leastinterpreting LOPOH(s)
depending upon cross-connect configuration)
HP-AIS reportedbased on H1, H2 bytes
HP-LOP (Los s of Pointer)based on H1, H2 bytes
HP-UNEQ (unequipped)based on C2 byte
HP-TIM based on J1 byte
HP-SF based on B3 byte
HP-SDbased on B3 byte
HP-RDIbased on G1 byte -- bit 5
Note 1: Same as before
Note 2: HP-Alarm is also
called AU-Alarm
or Alarm on AU
LP-Alarm is also
called TU-Alarm
or Alarm on TU
K3
F3
H4
F2
G1
C2
B3
J1
N1
H
O
PO
H
b
y
te
s
H1, H2, H3 AU
Pointer bytes
HP / LP Al ( td )
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HP / LP Alarms (contd.)
LP-AIS reportedbased on V1, V2 bytes
LP-LOP based on V1, V2 bytes
LOM (Loss o f Mult i f rame)based on H4 byte bits 7,8
HP-PLM / SLM (Payload / Signal Label Mismatch )
based on C2 byte
LP-UNEQ based on V5 byte bits 5,6,7
LP-TIM based on J2 byte
LP-SF based on V5 byte bits 1,2
LP-SDbased on V5 byte bits 1,2
LP-RDIbased on V5 byte -- bit 8
LP-PLM / SLM based on V5 byte bits 5,6,7
Note 1: Same as before
Note 2: Whole of this slide assumes
TU2/TU12/TU11 for LP. If there
is TU3 with AU4 mapping, then
also it is LP but Pointers & POH
bytes will be like HO
K4
N2J2
V5
LOPOH bytes
V1, V2, V3 TU
Pointer bytes
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Thanks
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