Name of lecture and lecturer
1
Name of lecture and lecturer
2
Analog Signal Transmission
Source Signal
Line Span
Line Attenuation
Signal & Noise
Amplifier
Signal
Regeneration
Name of lecture and lecturer
3
Digital Signal Transmission
The Solution


v
Convert all signals to digital
Employ time division multiplexing (TDM)
t Source Signal
v
v
t
Line Attenuation
Signal & Noise
t
Signal
Regeneration
Name of lecture and lecturer
4
11 000 000 000!
How to
convert speech
to a sequence
of ones and
zeros
Name of lecture and lecturer
5
Pulse Amplitude Modulation - PAM
a
t
Analog Signal
t
Sampling Signal
a
a
t Reconstruction
a = Amplitude
t = Time
Name of lecture and lecturer
6
Pulse Code Modulation - PCM
Designated to Carry Digitized Voice
(Based on 4 kHz Channels in AT&T’s FDM Hierarchy)
Step 1
Sample analog signal at 8 kHz
Results: Pulse Amplification Modulation
Step 2
Digitize PAM samples to 13 (or 14) bits and
compress to 8-bits using A-law or m-law tables
Results: Pulse Code Modulation
Transmission Requirement: 8,000 samples/second ´ 8-bits = 64 kbps = 1 octet/125 msec
a
a
00001111
00010011
00010100
t
Voice Signal
t
PAM Signal
PCM Signal
FDM = Frequency Division Multiplexing
Name of lecture and lecturer
7
Pulse Code Modulation - PCM (Cont.)
Transmit Side
Filter
Codec
XMT Filter
Encoder
(A/D)
8000 sample/sec.
Transmit
PCM
Decoder
(D/A)
8000 sample/sec.
Receive
PCM
Receive Side
RCV Filter
Analog
Digital
Name of lecture and lecturer
8
CODEC Quantizing - USA
The Formula
The North American standard for
assigning and decoding a signal’s
amplitude is m-law 255. This law
defines how many quantizing levels
are used and how they are arranged
1n (1+mc)
Fm (c) = sgn (c)
m = 255 (compression parameter)
Character Signal Binary Code *
0
0
0
0
0
0
1
0
0
0
1
1
1
1
1
0
0
1
1
1
1
1
1
0
1
0
1
1
1
1
1
0
1
1
1
1
1
1
1
1
0
0
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
1
* This is the bit pattern
transmitted for positive input
values. The left-most bit is a 0
for negative input values
Curve of m-Law Compander
127
0.875
112
96
80
m = 255
64
48
32
16
0
1/8
1/128
1/64
1/32
1/16
1/4
1/2
Normalized Output
0
Compresed And Coded Signal
1
1n (1+m)
0.750
0.625
0.500
0.375
0.250
0.125
1
Input Signal Relative Level
Name of lecture and lecturer
9
CODEC Quantizing - Europe
The European standard is the A-law and its formula is:
Ac
F (c) = sgn (c)
1 + nAc
1
1 + 1n (A)
when 0c
A
F (c) = sgn (c)
and
1 + 1n (A)
1
when
A
c1
Character Signal Binary Code *
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
0
0
0
0
0
1
1
0
1
0
0
0
0
1
1
0
0
0
0
0
0
1
0
1
1
0
0
0
0
1
0
1
0
0
0
0
0
1
0
0
1
0
0
0
0
1
0
0
0
0
0
0
0
* For positive input values. The
left-most bit is a 0 for negative
input values. Even bits
(beginning with 1 at the left) are
inverted before transmission
127
0.875
112
96
80
A = 87.6
64
48
32
16
0
1/8
1/128
1/64
1/32
1/16
1/4
Normalized Output
1
Compresed and Coded Signal
Curve of A-Law Compander
1/2
0.750
0.625
0.500
0.375
0.250
0.125
1
Input Signal Relative Level
Name of lecture and lecturer
10
Network Evolution
Analog
Switch
Analog
A/D
Switch
Digital
Switch
Analog
Digital
Digital
Analog
Switch
Analog
D/A
Switch
Digital
Switch
Name of lecture and lecturer
11
Time Division Multiplexing
For Analog Signals
Voice A
Voice B
Voice C
Codec
Codec
Codec
64 kbps
64 kbps
64 kbps
Buffer
Buffer
Buffer
A B C .... X Fr A B ....
MUX
Voice D
Voice X
Codec
Codec
64 kbps
64 kbps
2048 Kbps Clock
Buffer
Buffer
Frame
Pattern
Name of lecture and lecturer
12
Time Division Multiplexing
For Digital Signals
CH
1
2
3
4
.
.
.
.
M.
C.O
C.O
n bps
n bps
n bps
n bps
n bps
n bps
.
.
.
.
.
n bps
MUX
High-Speed
Transmission Line
(n ´m + Overhead)
n bps
MUX
n bps
.
.
.
.
.
n bps
CH
1
2
3
4.
.
.
.
.
M
Line Code
n
m
Line Speed
Overhead
USA
T1
64K
24
1.544 Mbps
8 kbps
Europe
E1
64K
31
2.048 Mbps
64 kbps
Name of lecture and lecturer
13
T1 Frame Structure
Extended Superframe Frame Format
Extended Superframe
4632 Bits
FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR FR
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Frame
193 Bits
F
CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH CH
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
192 Bits
Frame
Overhead 1 Bit
Channel
8 Bits
Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8
Name of lecture and lecturer
14
Name of lecture and lecturer
15
Plesiochronous Drop & Insert
34 Mbps
140M
LTE
140
140
34
140M
LTE
34
8 Mbps
34
34
2 Mbps
8
8
8
8
2
2
Customer
Add/Drop
operation
requires
complete
demultiplex
NG to locate
A channels
bits
Name of lecture and lecturer
16
The Add/Drop Operation
SW 1
T1
T1
AD
M
SW 2
M
AD
Fiber Optic
Ring
(622 Mbps)
ADM
New Technologies
T1
SW 3

Very tight synchronization
 Use pointers to locate channels
Name of lecture and lecturer
17
Frame Format
1
30 or 31
64 kbps
-
31 . . . . . . . . . . . . . . . . . . 0
PCM 30
8
8
8
8
8
8
64 kbps
Voice with
CAS Signaling
Applications
Data Applications
or
CCS Signaling
30 ´ 64 kbps
Signaling (Timeslot 16)
Framing (Timeslot 0)
1.920 Mbps
0.064 Mbps
0.064 Mbps
Total, E1
2.048 Mbps
31 ´ 64 kbps
Framing (Timeslot 0)
1.984 Mbps
0.064 Mbps
Total, E1
2.048 Mbps
Name of lecture and lecturer
18
Name of lecture and lecturer
19
What is E1?
A high speed digital communications link
that enables the transmission of voice, data,
and video signals at a rate of 2.048 Mbps

Initially designed for transmission of 30 telephone
channels
 Basis for design: PCM voice digitizing using 64 kbps
for each channel
 The E1 frame consists of 32 8-bit channels (timeslots)
32 ´ 8 = 256 bits/frame
 E1 frames are transmitted at the rate of 8,000 frames/s
256 ´ 8,000 = 2,048 kbps or 2,048 Mbps
Name of lecture and lecturer
20
What is E1? (Cont.)

Serial synchronous bit stream at 2.048 Mbps
 Specifications defined in CCITT recommendations:
– G.704/G.732 Frame definition (for framing
over E1 and T1)
– G.703
Interface physical specs
(pulse mask, etc.)
– G.823
Jitter requirements
 Interface (G.703) - two alternatives
– 4-wire, balanced
120W, pulse = 3.00 volts nominal
– 4-wire, unbalanced, 2 coaxial connectors
75W, pulse = 2.37 volts nominal
Name of lecture and lecturer
21
HDB3 Coding
Alternate Mark Inversion
with
HDB3 (High Density Bipolar of Order 3)
0000 => 000V
or
B00V
So that violations
alternate polarity
1 1 0 0 0 V 0 1 1
1 1 0 0 0 0 0 0 1 1
HDB3
Code
HDB3
Decode
Name of lecture and lecturer
22
Frame Format for E1
1 Frame = 256 bits (125 ms)
Bit Rate = 2.048 kbps
Channel 0
F
1
15
Channels 1 to 15
16
Sig
17
31
Channels 17 to 31
Channel 16
Channel 0
Optional
Signaling Channel
Sync. Timing
& Control Data
Name of lecture and lecturer
23
E1/T1 Error Conditions
Principal T1/E1 Alarms
Red Alarm (FAS Loss)
Produced by a receiver to indicate that it
has lost frame alignment
Yellow Alarm (RAI)
Returned to a transmitting terminal
to report a loss of frame alignment
at the receiving terminal
Normally, a T1/E1 terminal will use the receiver’s
red alarm to request that a yellow alarm be transmitted
Name of lecture and lecturer
24
E1/T1 Error Conditions (Cont.)
Blue Alarm (AIS)
A continuous ones pattern without framing,
indicates an upstream failure
Blue (AIS)
T1/E1
MUX
Red (LOF)
T3/E3
MUX
Loss here
Yellow (RAI)
Name of lecture and lecturer
25
Principal Error Conditions
Loss of Carrier
Receive data was 0 for 31 consecutive bits
Bipolar Violation
A failure to meet the AMI T1 line code
F Bit Error
Framing bit is in error
Name of lecture and lecturer
26
Name of lecture and lecturer
27
T1 Frame Format
AT&T - 1957
CH
1
.
.
.
.
.
.
.
24
Analog
-
Analog
F
F
DS 0
DS 1
“D” Channel
Bank
8
8
8
8
8
8
CH 24 . . . . . . . . . . . . . . . . . . . . . . 1
DS 0
8 bit PCM Codes 24 ´ Channels + 1 Framing Bit = 193 bits (Overhead)
Level
Bit Rate
Circuit
DS 0
64 kbps
1
DS 1
1.544 Mbps
24
Name of lecture and lecturer
28
D4 Channel Bank
DS 1 1.544 Mbps
193 bit, 125 ms
1
8 bit
8 bit
F-bit
TS 1
TS 2 TS 3



8 bit
8 bit
TS 24
Voice sent as 8-bit codes
Signaling by having the 8th bit (every 8th frame)
indicate loop open or loop closed
Framing based on placing a 12-bit pattern in the
framing bit (193rd bit)
Name of lecture and lecturer
29
T1 Frame Structure
Extended Superframe Format
Frame
Number
Fe
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
0
193
386
579
772
965
1158
1351
1544
1737
1930
2123
2316
2509
2702
2895
3088
3281
3474
3667
3860
4053
4246
4439
Bit use in Each
Channel
F Bit
Bit
Number
FDL
CRC
m
C1
m
0
m
C2
m
0
m
C3
m
1
m
C4
m
0
m
C5
m
1
m
C6
m
1
Traffic
1-8
1-8
1-8
1-8
1-8
1-7
1-8
1-8
1-8
1-8
1-8
1-7
1-8
1-8
1-8
1-8
1-8
1-7
1-8
1-8
1-8
1-8
1-8
1-7
Robbed Bit
Signaling
Signaling
8
A
8
B
8
C
8
D
Name of lecture and lecturer
30
Line Code - Bipolar, 50% RTZ


To guarantee 0 DC element on the line, bipolar is used
To eliminate high frequency components that can
interfere with other transmissions, digital services
utilize 50% duty cycle, known as:
Alternate Mark Inversion (AMI)
(Mark = Logic “1”)
Bit 1
0
Bit 2
1
Bit 3
1
Bit 4
0
+
0V
-
Name of lecture and lecturer
31
Bipolar Violations
1
+3 Volts
0
0
-3 Volts
1
BPV
1
One Error
Name of lecture and lecturer
32
T1 Standard
ANSI T1.403 - 1989

Line Rate
1.544 MHz

Cable Length
6.000 ft max.

Pulse Amplitude
2.7 to 3.3 V

Maximum Successive Zeros
15

Receive Attenuation
15 to 22.5 dB

Line Build Out
0.0, 7.5, 15 dB
Name of lecture and lecturer
33
T1 Summary









Serial Synchronous Bits Stream at 1.544 Mbps
Timeslot
8 bits
24 Timeslots
8 ´ 24 = 192 bits
Frame
24 T.S. + 1 Framing Bit = 192 + 1 = 193 bits
Sampling Rate
8.000 samples/sec
T1 Bit Stream
8.000 Frames (192 bits/frame + 1 bit/frame) =
1.536 Mbps + 0.008 Mbps (framing) =
1.544 Mbps
Line Code
AMI (50% Duty Cycle) or B8ZS (for clear channel)
Synchronization From Line
Interface
4-wire, Balanced, 100 W, RJ-45 Connector (or dB-15)
Name of lecture and lecturer
34
SDH/SONET
Synchronous Digital Hierarchy
Synchronous Optical Network

Developed as a result of PDH inability to cater for
new digital data transmission requirements

Evolved as a joint world-wide standardization effort
(ITU-T&ANSI)

Few differences still exist between European (ETSI)
SDH and North-American (ANSI) SONET

Had to accommodate older PDH systems that are still
operating
Name of lecture and lecturer
35
The Hierarchical Network
Transport
Tier 1
-Core
Network
Tier 2
-Metro/
Regional
Network
High Capacity
Network
Core Network
Trunk
Network
Switching
Trunk
Network
Regional
Area
Junction
Network
Large
Urban
Area
Metro
Area
Rural
Area
Tier 3
-Local/
Network/
Junction
Urban
Area
Access
Network
Local
Network
Distribution
Network
RC
PC
CPE
PC
CPE
RC
Name of lecture and lecturer
36
The Transmission Equipment
Hierarchy
PDH
Core, Backbone
Trunk, Long
Distance
565 Mbps Fiber
140 Mbps Fiber
140 Mbps Radio
34/14 Mbps Multiplex
Regional, Urban,
Metropolitan
140 Mbps Fiber
34 Mbps Fiber
34 Mbps Radio
34/140 Multiplex
2/34 Mbps Multiplex
SDH
140M
2.5G
´4
Equivalent
Capacity
622M
34M
´4
Local Junction,
Access
Access
8 Mbps Fiber
4 ´ 2M Radio
2M Radio
2/8 Multiplex
Flex Mux
Primary Multiplexer
Channel Bank
Access Multiplexer
155M
8M
´4
2.5 Gbps OLS
2.5 Gbps ADM
155M Radio
4/4 DXC
2.5 Gbps OLS
2.5 Gbps ADM
622M OLS
622M ADM
155M Radio
4/3/1 DXC
622M OLS
622M ADM
155M ADM
2M
2M
64K
Name of lecture and lecturer
37
SDH/SONET Bit Rates
Information Structure
Rate
SDH
51.84 Mbps
SONET
STS-1 (OC-1)
155.52 Mbps
STM-1
STS-3 (OC-3)
622.08 Mbps
STM-4
STS-12 (OC-12)
2.48 Gbps
STM-16
STS-48 (OC-48)
10 Gbps
STM-64
STS-192 (OC-192)
Name of lecture and lecturer
38
The “SDH” Add/Drop Operation
SW 1
E1
E1
AD
M
SW 2
M
AD
Fiber Optic
SDH Ring
(622 Mbps)
Cut
New Technologies
ADM
E1
SW 3

Very tight synchronization
(very few slips)
 Uses pointers to locate channels
Name of lecture and lecturer
39
The STS-1 Frame (52 Mbps)
90 columns
8 bits
9 rows
SONET
Overhead
3 columns
(3 rows for
Section
Overhead
6 rows for
Line
Overhead)
SONET Payload (SPE)
9 rows x 87 columns
Path Overhead
125 microseconds
Name of lecture and lecturer
40
The STM-1 Frame (155 Mbps)
270 Columns (bytes)
1
9
270
1
2
Regenerator
Section Overhead
3
STM-1 Payload
5
6
7
9 rows
4
Multiplex Section
Overhead
8
9
Frame Period = 125 ms
Name of lecture and lecturer
41
VC-4/AU-4 Mapping to STM-1 Frame
STM-1 Frame
Multiplexing
Function
MSOH
AU-4 PTR
AU-4 (AU-G)
Aligning
Function
VC-4 POH
RSOH
VC-4
Mapping
Function
Name of lecture and lecturer
42
STM-1 Structure
VC-4 Payload
SOH
Seat on the Carriage = Tugs
Name of lecture and lecturer
43
Populating the Seats in the Carriage
TUG2 Seats
One Large
Passenger

VC2
Three Smaller
Passengers

3 ´ VC12
Four Even Smaller
Passengers

4 ´ VC11
Name of lecture and lecturer
44
STM-N Frame Structure
270 ´ N Columns (bytes)
9´N
261 ´ N
1
Section Overhead
SOH
3
Administrative Unit Pointer(s)
STM-N Payload
5
9 rows
4
Section Overhead
SOH
9
Name of lecture and lecturer
45
STM-Nc - Concatenated Frame
Structure
270 ´ N Columns (bytes)
10 ´ N
260 ´ N
1
Section Overhead
SOH
3
Concatenation Indication
5
STM-N Payload
9 rows
4
Section Overhead
SOH
9
Payload Overhead. N ´ 1 Columns.
One Column - Real Payload Overhead.
Others - Fixed Stuff
Name of lecture and lecturer
46
Multiplexing of N AUGs into STM-N
1
1
261
9
RSOH
1
1
261
9
#1
#N
AUG
AUG
123....N123....N
123....N123....N
MSOH
Nx9
123....N
N x 261
STM-N
Name of lecture and lecturer
47
STM-1 SOH
9 rows
9 bytes
A2
J0
A1
A1
A1
A2
A2
B1
D
D
E1
D
F1
D1
D
D
D2
D
D3
*
*
RSOH
Administrative Unit Pointer(s)
K1
K2
D4
D5
D6
D7
D8
D9
10
D11
D12
B2
B2
B2
S1
M1
MSOH
E2
Bytes reserved for national use
*
Unscrambled bytes. Therefore care should be taken with
their content
D Media dependent bytes
Name of lecture and lecturer
48
Ring In Interoffice Application
HUB
DCS
DS-3s
Wire
Center
Fiber 1
Fiber 2
DS-3s
Wire
Center
SONET
ADM
SONET
ADM
SONET
ADM
DS-3s
Wire
Center
OC-N
SONET
ADM
DS-3s/ Wire
DS-1 Center
OC-N
CUT
Name of lecture and lecturer
49
Network Management
SW 1
E1
E1
AD
M
SW 2
M
AD
Fiber Optic
SDH Ring
(622 Mbps)
ADM
E1
New Technologies

SW 3
Embedded overhead channels (EOC) for
management messages
 Uses standard communications protocols
Name of lecture and lecturer
50
SDH Standards

G.651
Multimode Fiber Specification

G.652
Single Mode Fiber Specification

G.700
Framework of the G.700, 800, 900 Rec.

G.701
Vocabulary of Terms

G.702
Digital Hierarchy Bit Rates

G.703
Physical/Electrical Characteristics Interfaces

G.704
Synchronous Frame Structures Primary & Secondary Levels

G.705
Characteristics - Terminate Digital Links on a Digital Exchange

G.707
Network Node Interface for SDH Incl. Multiplexing Structure

G.774.04
SDH Management for SNC Protection for the NE

G.780
Vocabulary of Terms for SDH Networks and Equipment

G.781
Structure & Rec. for Multiplexing Equipment for the SDH
Name of lecture and lecturer
51
SDH Standards (Cont.)

G.783
Characteristics of SDH Equipment Functional Blocks

G.784
SDH Management

G.803
Architectures of Transport Networks Based on SDH

G.825
Control of Jitter & Wander in Digital Nets based on SDH

G.826
Error Performance Parameters and Objectives

G.831
Management Capabilities of Transport Nets based on SDH

G.832
SDH Elements on PDH Networks: Frames and Multiplexing

G.841
SDH Protection: Rings and Other Architectures

G.957
Physical Parameters for SDH Optical Interface

G.958
Provides overall Requirements for Optical Interfaces

ITU-R
Architectures & Functional Aspects of Radio Relay for SDH

O.SDH
Equipment to Assess Error Performance on SDH Interface
Name of lecture and lecturer
52
ANSI Standards
Phase I

T1.105
– Byte interleaved multiplexing format
– Line rates for STS - 1, 3, 9, 12, 18, 24, 36 and 48
– Mappings for DS0, DS1, DS2, DS3
– Monitoring mechanisms for section, line and path
structures
– 192 kbps and 576 kbps DCC

T1.106 - This is an associated standard that establishes
the optical parameters for the SONET standards. Single
mode fiber is defined as the standard optical
transmission medium

T1.107 - Digital hierarchy format specification
Name of lecture and lecturer
53
ANSI Standards (Cont.)
Phase II

T1.105R1
– SONET format clarification and enhancements
– Timing and synchronization enhancements
– Automatic protection switching (APS)
– Seven-layer protocol stack for DCC and embedded
operations channels
– Mapping of DS4 (139 Mbps) signal into STS-3c

T1.117 - Optical parameters for short-haul (2 km)
multimode fiber cable

T1.102-199X - Electrical specifications for STS-1 and
STS-3 signals
Name of lecture and lecturer
54
ANSI Standards (Cont.)
Phase III

T1.105.01-1994 - Protection for two & four fiber bidirectional
line switched SONET rings
 T1.105.05-1994 - Tandem connection overhead layer for SONET
 T1.105.03-1994 - Jitter for SONET and SONET-PDH
 T1.119-1994 - Management of SONET NE, OSI compliant interface
 T1.204 - OAM&P lower layer protocols for TMN interfaces
 T1.208 - OAM&P upper layer protocols for TMN interfaces
 T1.214 - OAM&P network model for interfaces between OS & NE
 T1.215 - OAM&P fault management messages for OS & NE
 T1.229 - OAM&P performance management messages for OS & NE
 T1.231 - Layer 1 in-service transmission performance monitoring
Name of lecture and lecturer
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