Download - SDH TRAINING VOL1
The Synchronous Digital Hierarchy (SDH) (Vol.1)
SAR ISC S&T100 TELE 0005
ITU-T Recommendations
– G.707 Bitrates
– G.708 Signal Structure (NNI)
– G.709 Synchronous Multiplex Structure
– G.703 Electrical characteristic
– G.957 Optical interface characteristic
SDH Multiplexing Components
• Containers – C
• Path Overheads -POH
• Virtual Containers – VC
• Pointers
• Tributary Units – TU
• Tributary Unit Groups – TUG
• Administrative Units – AU
• Administrative Unit Groups – AUG
• Multiplexer Section Overhead – MSOH
• Regenerator Section Overhead - RSOH
SDH BIT RATES
• Synchronous Transport Modules (STM)
• STM-1: 155.520 Mbit/s
• STM-4: 622.080 Mbit/s
• STM-16: 2,488.320 Mbit/s
• STM-64: 9,953.280 Mbit/s
• STM-256: 39.81312 Gbits/s
Multiplexing PDH to SDH
E1, T1, E3, T2,T3, E4 can be directly
multiplexed/ de multiplexed to/from any
higher order bit rates.
STM 1
• 63x E1 or
• 3x E3 or 3x T3
• 84x T1 or
• 1x E4 or
• 21x T2 or
combinations
SDH EQUIPMENTS
Terminal Mux –TM
Add Drop Mux – ADM
Regenerators
Digital Cross Connects DX
SDH PATHS
• End to end of a Bandwidth( Circuits)
• Goes through different Network Elements
• Lower order Path
• Higher Order Path
SDH SECTIONS
Regenerator Section
Multiplex Section
Multiplex and Regenerator Sections
Multiplexing of E1
• E1=2.048 Mbps(+ 50 ppm)
• 32x8bit in 125 micro sec
• 32x1Bytes in 125 micro sec
• 32 Bytes in 125 micro sec
Multiplexing of E1
• Container for Multiplexing E1 = C12
• C12 = 34 Bytes/ 125 micro sec
• 16 bits of Stuffing
Virtual Container 12 (VC12)
• =C12+ 1 Byte(LPOH)
• Using 1 Byte LPOH, 4 different Bytes are send in 500 Micro sec Multi frame
• LPOH Bytes are V5, J2, N2 and K4
Mapping of 2Mbps into STM – N
LPOH
LPOH…
LPOH…
Tributary Unit 12 (TU12)
• TU12= VC12+ 1Byte TU Pointer• Pointer points the position of V5 Byte(Start of VC12)• Pointers mapped in 500 micro sec multi frame• Pointer Bytes are V1, V2, V3 and V4.• V1 and V2 used for Pointers• TU12= 36 Byte/125 micro sec• 9x4 matrix, each cell 1 byte=64kbps• TU12 is denoted as “M” in bandwidth configurations
Mapping of 2Mbps into STM – N
Mapping VC12 into TU12
TU Pointer
TU12 Multi frame
TU12 Multi frame
TU12 Multi frame
Tributary Unit Group 2 (TUG2)
• Multiplexing 3 x TU12
• Byte interleaved
• 108 Bytes/125 micro sec
• 9x12 Matrix, each cell 1 byte=64kbps
• TUG2 is denoted as “L”
• Each “L” contains 3 “M”
Mapping of 2Mbps into STM – N
Mapping TU12’s into TUG2’s
SDH Multiplexing Structure
Tributary Unit Group 3 (TUG3)
• Multiplexing 7 x TUG2 + 18 Stuffing Bytes
• Byte interleaved.
• 774 Bytes / 125 micro sec
• 9 x 86 Matrix, each cell 1 byte=64kbps
• TUG3 is denoted as “K”
• Each “K” Contains 7 “L”
Mapping of 2Mbps into STM – N
Virtual Container 4 (VC4)
• Multiplexing 3 x TUG3 + 18 stuffing Bytes + 9 Bytes Higher Order Path Overhead(HPOH)
• 2349 Bytes/ 125 micro sec
• 9x261 Matrix, each cell 1 byte=64kbps
VC4 Frame structure
VC4 Path Over Head (HPOH)
HPOH….
HPOH…
HPOH…
Administrative Unit 4 (AU4)
• VC4 + 9Byte AU Pointer
• AU pointer points the Start Position of VC4 in the Frame (i.e. Position of J1 Byte in the frame)
• AU4= 2358 Bytes/ 125 micro sec
• AU4 is denoted as “J”
• Each “J” contains 3 “K”
Administrative Unit 4 (AU4)
AU-Pointer
Administrative Unit Group (AUG)
• AUG1 Contains 1 AU4, 1x J Leads STM1
• AUG4 Contains 4 x AUG1’s, 4x J Leads STM4
• AUG16 Contains 4 x AUG4’s,16 x J Leads STM16
• AUG64 Contains 4 x AUG16’s, 64 x J Leads STM64
Synchronous Transport Module1
• AUG1+ 45 Bytes MSOH + 27 Bytes RSOH
• 2430 Bytes/ 125 micro sec
• 155.52 Mbps
• 9x270 Matrix
SDH Multiplexing Structure
SDH Multiplexing Structure…
STM1 Section Overheads
Mapping E3/T3(DS3)
SDH ALARMS
What Next?
• Protection• Bandwidth Configuration-Provisioning• Structure of SDH Equipments