Download - DMRC SDH theory
SDH Theory
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ISO 9001:2008
What is SDH?
SDH = Synchronous Digital Hierarchy It is a transport network
synchronous fully standardized with high bandwidth for synchronous and asynchronous signals
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ISO 9001:2008
for future broadband signals and new services with standardized network management capabilities with traffic protection with a flexible multiplexing structure
direct access to tributaries cross-connections without de-multiplexing
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ISO 9001:2008
Digital Transmission System
Regenerator recreates the signal.
Multiplexer (MUX) Multiplexer combines data from
several lines and transmits itover a higher-capacity data link.
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No signal
60 km
R
60 km
Regenerator
MUX MUX
ISO 9001:2008
Multiplexer Naming Conventions
Terminal Multiplexer (TM) All traffic is terminated here. m: aggregate level n: lowest tributary level
Add-Drop Multiplexer (ADM) Part of the traffic is terminated. Part of the traffic goes transparently
through.5
TMm/n
aggregate
tribu taries
ADM
m/n
aggregateaggregate
tributaries
ISO 9001:2008
Digital Cross-connect (DXC m/n)
No traffic is terminated. Cross-connection matrix
connects tributary signals of one aggregate to another aggregate.
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PDHMUX
PDHMUX
PDHMUX
PDHMUX
DDF
SDHCross-Connect
ISO 9001:2008
PDH Bit Rates & HIERARCHY
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E1
E0
E2
E3
E4plesiochronous
plesiochronous
plesiochronous
synchronous
ISO 9001:2008
SDH Bit Rates & HIERARCHY
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STM1
STM4
STM16
STM64
ISO 9001:2008
PDH vs. SDH — Add & Drop Function
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ADM STM-1STM-1
Six TMs needed to drop E1
One ADM is enough to drop E1.
TM TM
TMTM
TMTM
E3
E3
E3
E2
E2
E1
E1
E1
E4 E4
E1 (2.048 kbit/s)
E2
2/1 2/1
3/23/2
4/3 4/3
PDH
SDH
ISO 9001:2008
STM-1 Frame
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2430 bytes/frame × 8 bit/byte × 8000 frame/s = 155.52 Mbit/s
transmitted from top to bottom and left to right
ISO 9001:2008
SDH Multiplexing Structure (ETSI)
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Pointer processing
Multiplexing
Aligning
Mapping
VC-4STM-N
× N
× 3× 1
× 3
× 7
139 264 kbit/s
44 736 kbit/s34 368 kbit/s
6312 kbit/s
2048 kbit/s
1544 kbit/s
AUG AU-4
TUG-3
TUG-2
TU-3
TU-2
TU-12
VC-2
VC-3
VC-12
VC-11
C-4
C-3
C-2
C-12
C-11
× 1
C-n Container-n
× 1
C Container
VC Virtual Container
TU Tributary Unit
TUG Tributary Unit Group
AU Administrator Unit
AUG Administrator Unit Group
ISO 9001:2008
PDH over SDH Container (C)
basic payload unit
Virtual Container (VC) C + POH (path overhead)
Tributary Unit (TU) VC + pointer The pointer indicates the
start of the VC and allows dynamic alignment of the VC within the TU frame.
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2 Mbit/s plesiochronous stream
Justification bytes
C12
Path OverheadVC12
Container
POH
TU PointerTU12
Virtual Container
ISO 9001:2008
KLM Coordinates
A U -4 po in te rs
M S O H
P ayloadV C -4 (H O -V C )
R S O H
VC-4 POH
VC-12
VC-12
K
L
TU12-1 TU12-2 TU12-3
TUG3-1 TUG3-2 TUG3-3
TUG2-6
TUG2-7
TUG2-5
TUG2-4
TUG2-3
TUG2-1
TUG2-2
TUG-3 number (values 1-3)TUG-2 number (values 1-7)TU-12 number (values 1-3)
KLM: 271KLM: 152 KLM: 300
VC-3
ISO 9001:2008
Termination of Sections
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Path
Multiplexing Sections Multiplexing Sections
Regenerator Sections
TM TM
ISO 9001:2008
Regenerator
Regenerates the optical signal.
Terminates RSOH.
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REG
STM-N STM-N
ISO 9001:2008
Terminal Multiplexer
Terminates RSOH and MSOH.
May terminate HOP and LOP overhead.
Multiplexes/maps tributary signals.
Includes timing and management functions.16
TMSTM-N
orPDH
STM-M
ISO 9001:2008
Add/drop Multiplexer
Terminates RSOH and MSOH. May terminate HOP and LOP overhead. Includes connection function between the two aggregates. Multiplexes/maps tributary signals. Includes a connection function for allocation of TUs within the STM frame. Includes timing and management functions.
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STM-N or PDH
STM-MSTM-M
ADM
ISO 9001:2008
Cross-connect
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• Terminates RSOH and MSOH.
• Includes connection function between the aggregates.
• Can have tributary ports, for which it may terminate HOP and LOP overhead.
• Includes timing and management functions.
STM-N or PDH
STM-MSTM-M DXC
ISO 9001:2008
SDH Overhead Overheads carry information for monitoring, maintaining
and controlling the operation of network. Overhead types
POH for end-to-end monitoring of payload signal (VC-12, VC-3 and VC-4) Block errors, far end alarms, trace and payload type
SOH is used for monitoring of signal between SDH equipment. RSOH: block errors, trace MSOH: block errors, synchronization, and far-end alarms
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POH
RSOH
MSOH
POINTER
9 260
270
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5
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ISO 9001:2008
RSOH
A1, A2 framing patterns (F6H), (28H) J0 regenerator section Trail Trace Identifier (TTI) B1 BIP-8 parity byte E1 RS orderwire channel (service telephone) F1 user (network operator) data channel D1, D2, D3 regenerator section Data Communication Channel
(DCCR) NU1, NU2, NU3, NU4 bytes reserved for national use R1, R2, R3, R4, R5, R6 media specific bytes (e.g. radio link) U1, U2, U3, U4 bytes with no defined use
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ISO 9001:2008
MSOH
B2 BIP-24 parity bytes K1, K2 Automatic Protection Switching (APS) channel, D4 to D12 multiplex section Data Communication Channel (DCCM) S1 synchronization status M1 Remote Error Indication (REI) E2 MS orderwire channel (service telephone) NU5, NU6 bytes reserved for national use U5 to U26 bytes with no defined use Z12, Z13, Z21, Z22 bytes with no defined use
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ISO 9001:2008
Functions of POH (Path Overhead)* Parity check (B3, V5/BIP-2 calculated by terminating point)
* Alarm and performance information (V5, G1)
* Structure of VC (Signal label C2)
* Multi-frame indication for TUs (H4)
* User communication channel-between path elements (F2, F3)• Identification of path source (path trace J1, J2)
Functions and characteristics of the individual elements
1) The Administrative Unit (AU)
* Is shaped if a pointer is allocated to the VC formed at last
* Clock justification through positive –zero-negative stuffing in the AU pointer area
* Byte by byte stuffing
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ISO 9001:2008
2) The container (C)
* Basic packaging unit for tributary signals (PDH)
* Synchronous to STM-1
* Bit rate adaptation is done via a positive stuffing procedure
* Adaptation of synchronous tributaries by fixed stuffing bits
* Bit by bit stuffing
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ISO 9001:2008
3) The virtual container (VC)
* Formation of the container by adding of POH (Path Overhead)
* Transport as a unit through the network (SDH)
* A VC containing several VCs has also same pointer area
4) The Tributary Unit (TU)
* Is formed by adding pointer to
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5) Tributary Unit Group (TUG) * Combines several TUs for new VC
ISO 9001:2008
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ISO 9001:2008
Any Questions?
ISO 9001:2008
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