DMRC Synchronous Digital Hierarchy (SDH Theory) Presentation

1. SDH Theory
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2. 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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3.  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
ISO 9001:2008
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4. Digital Transmission System
ISO 9001:2008
 Regenerator
 recreates the signal.
 Multiplexer (MUX)
 Multiplexer combines data from
several lines and transmits it
over a higher-capacity data link.
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Regenerator
No signal
60 km
R
60 km
MUX MUX

5. Multiplexer Naming Conventions
 Terminal Multiplexer (TM)
ISO 9001:2008
 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.
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TM
m/n
aggregate
tributaries
ADM
m/n
aggregate aggregate
tributaries

6. Digital Cross-connect (DXC m/n)
ISO 9001:2008
 No traffic is terminated.
 Cross-connection matrix
connects tributary
signals of one aggregate
to another aggregate.
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PDH
MUX
PDH
MUX
PDH
MUX
PDH
MUX
DDF
SDH
Cross-Connect

7. PDH Bit Rates & HIERARCHY
ISO 9001:2008
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E1
E0
E2
E3
E4
plesiochronous
plesiochronous
plesiochronous
synchronous

8. SDH Bit Rates & HIERARCHY
ISO 9001:2008
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STM1
STM4
STM16
STM64

9. PDH vs. SDH — Add & Drop Function
E 3
E 3
E 3
E 2
E 4 E 4
TM TM
4 / 3 4 / 3
TM E 2
TM
3 / 2 E 2
PDH
E 1
3 / 2
E 1
E 1
2 / 1 2 / 1
ISO 9001:2008
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STM-1 ADM STM-1
Six TMs needed
to drop E1
One ADM is
enough to drop E1.
TM TM
E 1 ( 2 . 0 4 8 k b i t / s )
SDH

10. 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

11. SDH Multiplexing Structure (ETSI)
ISO 9001:2008
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× N
STM-N VC-4
Pointer processing
Multiplexing
Aligning
Mapping
× 3
× 1
× 3
× 7
139 264 kbit/s
44 736 kbit/s
34 368 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-3
VC-2
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

12. TU Pointer TU12
Path Overhead VC12
Justification bytes
C12
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
POH
Container
Virtual Container

13. TUG3-1 TUG3-2 TUG3-3
VC-3
ISO 9001:2008
KLM Coordinates
A U - 4 p o i n t e r s
M S O H
P a y l o a d
V C - 4 ( H O - V C )
R S O H
V
C-
4
P
OH VC-12
VC-12
K
L
TU12-1 TU12-2 TU12-3
TUG2-1
TUG2-2
TUG2-3
TUG2-4
TUG2-5
TUG2-6
TUG2-7
TUG-3 number (values 1-3)
TUG-2 number (values 1-7)
TU-12 number (values 1-3)
KLM: 152 KLM: 271 KLM: 300

14. Termination of Sections
Regenerator Sections
TM TM
Multiplexing Sections Multiplexing Sections
ISO 9001:2008
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Path

15. STM-N STM-N
ISO 9001:2008
Regenerator
 Regenerates the optical signal.
 Terminates RSOH.
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REG

16. Terminal Multiplexer
 Terminates RSOH and MSOH.
 May terminate HOP and LOP overhead.
 Multiplexes/maps tributary signals.
 Includes timing and management functions.
ISO 9001:2008
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TM
STM-N
or
PDH
STM-M

17. Add/drop Multiplexer
STM-M STM-M
ADM
 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.
ISO 9001:2008
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STM-N or PDH

18. STM-M DXC STM-M
STM-N or PDH
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.

19. SDH Overhead
 Overheads carry information for monitoring, maintaining
and controlling the operation of network.
ISO 9001:2008
 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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9 260
POH
RSOH
POINTER
MSOH
270
3
5
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20. 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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21. 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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22. 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
ISO 9001:2008
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23. 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
ISO 9001:2008
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24. 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

25. ISO 9001:2008
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26. Any Questions?
ISO 9001:2008

27. THANK YOU
ISO 9001:2008