sdh and sonet
TRANSCRIPT
-
8/10/2019 Sdh and Sonet
1/40
SDH / SONET
Engr. Zain Ul Abiden Akhtar
Assistant Professor - UCET
Telecommunication Systems
&
Applications
-
8/10/2019 Sdh and Sonet
2/40
SDH/SONET
SDH/SONET, created in the mid-1980s, is
the second generation of digital hierarchy.
Whereas PDH involves a lot of overheadbecause it includes three standards
throughout the world, SDH/SONET uses
one common standard that applies tonetworks worldwide.
-
8/10/2019 Sdh and Sonet
3/40
SDH
International Telecommunication Union
(ITU) documented in standard G.707 and its
extension G.708
Uses single master clock for
synchronization.
Basic transmission rate is 155.52Mbps
-
8/10/2019 Sdh and Sonet
4/40
SDH/SONET
SONET is the American National Standards
Institute (ANSI) standard, which is part of
SDH, and it is used in North America.SDH/SONET was created to be an industry
standard for high-speed transmission over
optical fiber.It was actually part of a much bigger
standard in the works at that time
Broadband ISDN.
-
8/10/2019 Sdh and Sonet
5/40
Broadband ISDN
Two technologies were required in order to
support such applications: a transport
infrastructure (SDH/SONET) that had thesignificant bandwidth needed to support the
applications and a switching technology
(ATM)
-
8/10/2019 Sdh and Sonet
6/40
-
8/10/2019 Sdh and Sonet
7/40
SDH/SONET RING
ARCHITECTURE
-
8/10/2019 Sdh and Sonet
8/40
Ring Example
F
CB
D
E
A
SONET: Bi-Directional Line-Switched Ring (BLSR)
SDH: Multiplex Section Shared Protection Ring (MS-SPRING)
S
S
S
S
S
S
S: Service
P
P
P
P
P
P
P: Protection
Original Circuit
Protection Switch
-
8/10/2019 Sdh and Sonet
9/40
Ring Example
F
CB
D
E
A
S
S
S
S
S
S
S: Service
P
P
P
P
P
P
P: Protection
Original Circuit
Protection Switch
X
-
8/10/2019 Sdh and Sonet
10/40
SONET/SDH Dual Rings
SONET/SDH Ring
SONET/SDH Ring
Telephone
Switch
Telephone
Switch
Telephone
Switch
Telephone
Switch
Rings can be
Wrapped if aTrunk line
is Broken
-
8/10/2019 Sdh and Sonet
11/40
SDH/SONET Frame
In the case of SONET, this frame is called the
Synchronous Transport Signal (STS).
In SDH, the frame is called the Synchronous
Transport Module (STM).
The electrical side of the SONET signal is
known as the STS, and the electrical side of the
SDH is known as the STM.
The optical side of a SONET/SDH signal is
known as the Optical Carrier (OC).
-
8/10/2019 Sdh and Sonet
12/40
SDH/SONET Hierarchy
The SDH/SONET signal hierarchy deals with
Optical Carrier (OC) levels, which refer to
the optical aspect of the transmission theoptical pulse as it travels through the fibers.
These optical pulses go through electronic
muxes, and when the signal is going throughthese network elements, the bits are packaged
in a frame for transport across the fiber.
-
8/10/2019 Sdh and Sonet
13/40
The SDH/SONET Hierarchy
SONET Electr ical
Signal
Optical Signal B it Rate (Mbps) SDH
Electr ical Signal
STS-1 OC-1 51.84 N/A or STM-0
STS-3 OC-3 155.52 STM-1
STS-9 OC-9 466.56 STM-3
STS-12 OC-12 622.08 STM-4
STS-18 OC-18 933.12 STM-6
STS-24 OC-24 1244.16 STM-8
STS-36 OC-36 1866.24 STM-12STS-48 OC-48 2488.32 STM-16
STS-192 OC-192 9953.28 STM-64
STS: Synchronous
Transport Signal
OC: Optical Channel STM: Synchronous
Transfer Module
-
8/10/2019 Sdh and Sonet
14/40
Find the data rate of an STS-1 signal
Each Synchronous Transfer Signal STS-n is
composed of 8000 frames. Each frame is a
two-dimensional matrix of bytes with 9 rowsby 90 n columns.
-
8/10/2019 Sdh and Sonet
15/40
Solution
STS-1, like other STS signals, sends 8000 frames per
second. Each STS-1 frame is made of 9 by (1 90)
bytes. Each byte is made of 8 bits. The data rate is
-
8/10/2019 Sdh and Sonet
16/40
SONET Framing
-
8/10/2019 Sdh and Sonet
17/40
STM-N FRAME STRUCTURE270 x N
Columns
261 x N
Columns9 x N Columns
9Rows
= 8
bits/byte
-
8/10/2019 Sdh and Sonet
18/40
SDH Rate
ITU-T defines the frequency to be 8000 frames per
second for all levels in STM hierarchy
STM-1 Rate :
9 rows x 270 columns x 8 bits/byte x 8000 frames
per second
= 155.52 Mb/s
STM-4 Rate :
9 rows x (270 x 4) columns x 8 bits/byte x 8000 frames
per second
= 622 Mb/s
-
8/10/2019 Sdh and Sonet
19/40
Find the data rate of an STS-3 signal.
Solution
STS-3, like other STS signals, sends 8000 frames per
second. Each STS-3 frame is made of 9 by (3 90) bytes.Each byte is made of 8 bits. The data rate is
-
8/10/2019 Sdh and Sonet
20/40
Duration of an STS frame
What is the duration of an STS-1 frame? STS-3 frame?
STS-n frame?
SolutionIn SONET, 8000 frames are sent per second. This means
that the duration of an STS-1, STS-3, or STS-n frame is the
same and equal to 1/8000 s, or125 s.
What is the user data rate of an STS-1 frame (without
considering the overheads)?
-
8/10/2019 Sdh and Sonet
21/40
A SONET System
STS Mux/Demux beginning & end points
Regenerator repeater that regenerates the optical signals
Add/drop mux
add signals into a given path or remove a desired signalfrom a path
-
8/10/2019 Sdh and Sonet
22/40
An Example of a SONET Network
Section optical link connecting 2 neighbor devices
Line portion of a network between 2 muxes
Path - end to end portion of the network between 2 STS muxes
-
8/10/2019 Sdh and Sonet
23/40
SONET/SDH Reference Model
Path Layer (close to OSI layer 3 Network)
Line Layer (close to OSI layer 2 Data Link)
Section Layer (close to OSI layer 2 Data Link)
Photonic Layer (close to OSI layer 1 Physical)
-
8/10/2019 Sdh and Sonet
24/40
Manages end-to-end connection, Monitoring and
management of user connection.
-Also responsible for the movement of signalfrom its optical source to its optical destination
-Transformation of signals
-STS mux provides path layer functions
Path Layer
-
8/10/2019 Sdh and Sonet
25/40
Multiplexing of several path-layer connection
among nodes, Protection and Fault
Management.- STS mux and add/drop mux provide line
layer functions
Line Layer
-
8/10/2019 Sdh and Sonet
26/40
-Responsible for the movement of a signal
across a physical section
-Framing, error control
Section Layer
-
8/10/2019 Sdh and Sonet
27/40
Defines all the transmission requirements
of signals.
-Specs for optical fiber channel, sensitivityof the receiver
Photonic Layer
-
8/10/2019 Sdh and Sonet
28/40
Device-Layer Relationship in SONET
-
8/10/2019 Sdh and Sonet
29/40
STS-1 Frame Overhead
SPE
Synchronous
Payload Envelope
- Contains user
data
Path overhead
- end-to-end
tracking
information
-
8/10/2019 Sdh and Sonet
30/40
Mapping
Is the procedure through which signals are packed
inside an SDH frame
PDH signal passes through the following steps
before emerging as an SDH Signal
Container (C-X)
Virtual Container (VC-X)
Tributary Unit (TU-X)
Tributary Unit Group (TUG-X)
Administrative Unit (AU-4)
STM Signal
-
8/10/2019 Sdh and Sonet
31/40
How 2 Mb signals are mapped into an SDH stream?
C-12
VC-12
2 Mb/Sec
Container
Virtual Container
Path Overhead (POH)
-
8/10/2019 Sdh and Sonet
32/40
How 2 Mb signals are mapped into an SDH stream?
VC-12
STM-1/4/16
Payload
Pointer
SOHSOH
270
9
TU
(Tributary Unit)
-
8/10/2019 Sdh and Sonet
33/40
Formation of Synchronous Signal
Pointer
Phase relation betweenvirtual container (payload)and subordinate frame
Plesiochronous signal
Path overhead
Additional information forend-to-end monitoring
Tributary
unit (TU)
Virtual
container
(VC)
Container
(C)
Synchronous Signal
-
8/10/2019 Sdh and Sonet
34/40
MAPPING OF PDH SIGNAL INTO
SDH SIGNAL
-
8/10/2019 Sdh and Sonet
35/40
SDH Elements
-
8/10/2019 Sdh and Sonet
36/40
SDH Multiplexing
-
8/10/2019 Sdh and Sonet
37/40
PDH attributes scheme carry into different
containers. Note that first digit of lowest level
container is 1 and the second digit indicates
whether it contains 1.5 Mbps (C11) or 2Mbps
(C12).
The container and its path overhead collectively
form virtual container VC. The VC and its pointerare known as Tributary Unit (TU) if VC carries a
lower order tributaries. The largest VC in an STM-
1 frame is known as Administrative Unit (AU).
-
8/10/2019 Sdh and Sonet
38/40
SDH Network Elements
Path Ter minating E lement
These are the end point devices where the lower
speed channels enter and leave the SDH Network.These are known as Path Leveldevices.
Digital Cross Connect
These devices can x-connect at the STM leveldown to individual E1 streams. So an E1 stream
on one STM trunk could be x-connected to
another STM trunk.
-
8/10/2019 Sdh and Sonet
39/40
SDH Network Elements
Regenerator
Is a device that regenerates the signal.
Add/Dr op M ul tiplexer
The Add/Drop mux has the ability to breakout
and insert low speed channels into an STM
stream.
-
8/10/2019 Sdh and Sonet
40/40
SDH Network Elements