digitel - digital transmission
TRANSCRIPT
-
8/10/2019 Digitel - Digital Transmission
1/12
Digital Transmission(TRANS101)
-
8/10/2019 Digitel - Digital Transmission
2/12
Objectives
At the end of this module, participants should beable to:
Explain the telephone voice signal.
Calculate the DSO capacity.
Dierentiate the !"Carrier from E"Carrier System.
-
8/10/2019 Digitel - Digital Transmission
3/12
-
8/10/2019 Digitel - Digital Transmission
4/12
The Telephone Signal
$ending the signal in an analog form for long transmission and
switching purposes is not efficient.
%&pensive and huge euipments are needed to ma'e this happen.(ue to these limitations, digital transmission was developed in )*+3.
This was done by conveying multiple telegraphy sources into singletelegraph cable.
t was then patented by -estern %lectric in )/.
-
8/10/2019 Digitel - Digital Transmission
5/12
-
8/10/2019 Digitel - Digital Transmission
6/12
Sampling
This is the process of stripping the voice signal which is 4 Khz by*,000 samples per second of time.
%ach sample of signal is digitized or coded into *bit of pulses.
Total bandwidth of an analog voice in digital form is * bits & *,000samples which is euivalent to 4,000 bits per second.
-
8/10/2019 Digitel - Digital Transmission
7/12
Time Slot Multiplexing
%ach *bit of information "octet# is sent to the main line by the time
allocation. This process continues for all channels or lines "telephone lines#
which could be either 30 or /4 channels depending to what carrierstandard is used "T2arrier or %2arrier#.
-
8/10/2019 Digitel - Digital Transmission
8/12
T-Carrier System
The 5nited $tates 6ell $ystem activated the first commercial digital
carrier system in )/
%lectrical noise from hightension lines and automotive ignitionsinterfered with analog systems.
The system was designated T), with the T standing for Terrestrialto
distinguish the land transmission from satellite transmission.
T)
T/
T3
T4
T)2
-
8/10/2019 Digitel - Digital Transmission
9/12
T-Carrier
Tcarrier was designed for a fourwire twistedpair circuit,although the ($7) interface is mediumindependent.
Table T-1: orth American Digital !ierarchy: T-carrier
Digital Signal "DS#$evel
Data %ate&'-(bps
Channels "DS-)s#
*+uivalent T1s
DS-0 64 Kbps 1 1/24
DS-1 (T1) 1.544 Mbps 24 1
DS-1C (T1C) 3.152 Mbps 48 2
DS-2 (T2) 6.312 Mbps 96 4
DS-3 (T3) 44.736 Mbps 672 28
DS-4 (T4) 274.176 Mbps 4,032 168
DS-5 (T5) 400.352 Mbps 5,760 250
-
8/10/2019 Digitel - Digital Transmission
10/12
*-Carrier System
E"carrier is based on the original !"carrier digital carrier system.
E"carrier has improved certain electrical characteristics such assignaling rates, framing conventions, line coding techni#ue, and$C% techni#ue.
E"& supports '( DS"( payload channels, compared )ith !& at *+channels, and the higher E"carrier levels build on that dierence.
*-carrier$evel
Data %ate"Mbps#
umber o, &'bpsChannels
"DS-)s#
umber o, *-1s
E-1 2.048 30 1
E-2 8.448 120 4
E-3 34.368 480 16
E-4 139.268 1920 64
E-5 565.148 7680 256
-
8/10/2019 Digitel - Digital Transmission
11/12
TDM Stan.ar.s
C O U N T R Y
S A - C A A D A
E / 0 A D
/ E 1 % A 2
3 1 A C E
4 ! A 0 2
5 A $ A
M U L T I P L E X I N S T E P
1 S T ! N D " R D # T $ % T $
* +
& , 6 *
(
& , + +(
& , 7 8
(
+ , ( '
*7 9 *6 7
& , 6 *
(
& , + +
(
+ 8 (& * (' (
: , 9 *(
9 , 7 8
(
* + 6 7 + 8 (: , 9 7
(
& . : + +% b i t ; s
7 . ' & *% b i t ; s
+ + . 9 ' 7% b i t ; s
* 9 + % b i t ; s
& * ( % b i t ; s
& ( 8 % b i t ; s + + * % b i t ; s
& ' 6 . * 7 +% b i t ; s
& ' ( % b i t ; s: 7 + . 6 6 *
% b i t ; s
6 9 % b i t ; s ' 6 9 % b i t ; s
' * . ( 7 +
% b i t ; s
7 . ' & * % b i t ;
s
& . : + + % b i t ;
s
* . ( + 8 % b i t ;s
8 . + + 8 % b i t ;s
' + . ' 7 8% b i t ; s
x + x 9 x 7
x & +
x ' x +
x +
x + x +
x +x 'x :x +
x +
M U L T I P L E X I N $ I E R A R C $ Y
-
8/10/2019 Digitel - Digital Transmission
12/12
Test
-hat is the freuency range of the telephone signal8
9 300 hz to 3,400 hz
The process of conversion, transmission of telephone signal fromanalog to digital and vice versa8
9 (igital Transmission
-hat is the sampling freuency8
9 * Khz
:ow many channels are their in ($) level with %2arrier8
9 30 ch
:ow do you calculate 4 Kbps89 * bits & *,000
:ow many voice channel in a T)8
9 /4 ch