telephone system by : warsun najib. telepon system concept telephone network is often called as pstn...
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Telephone SystemBy : Warsun Najib
Telepon System Concept Telephone network is often called as PSTN (Public Switch
Telephone Network) Telephone Device Central Office (CO)
suatu istilah untuk menggambarkan pusat jaringan telepon (dalam suatu kota). Tugasnya menyediakan daya untuk telepon, me-routing panggilan, merekam tagihan telepon, dsb.
Trunk (E1) Link/kabel between CO to other CO
Local Loop Pasangan kabel telepon yang terhubung antara central office dan pesawat telepon rumah (kantor).
Switch Perangkat yang me-route komunikasi ke bagian (tempat) yang lain.
Pada awalnya, switch terbuat dari banyak switch-switch mekanik Saat ini, mayoritas switch adalah elektronis, bahkan digital. Digital switches lebih reliable, dan menawarkan banyak keuntungan
Distribution Network MDF Rumah Kabel
Telephone Set
Standby : Hoook switch is on position 1, Idc from CO does not come, Ringing signal (ac) can activate Bell
Busy : Switch is off-hook (hook-switvh on position 2),
Hibrid•Pemisah mic dengan speaker•Penekan nada samping
Dialer
Mic
Speaker
Bell
Hook Switch
1
2
H D
Telephone : Off-Hook / Busy
Side Tone
Dialing System DTMF (Dual tone multi frequency) Rotary Switch
Dual Tone Multi-frequency
11 22 33
44 55 66
77 88 99
##00**
Baris 1 [697 Hz]
Baris 2[770 Hz]
Baris 3[852 Hz]
Baris 4[941 Hz]
Kolom 1[1209 Hz]
Kolom 2[1336 Hz]
Kolom 3[1477 Hz]
Periode T > 100 ms depend on how fast finger push the button (normally 250 ms)
Digit ‘1’ Digit ‘6’
T T
i(t)
t
DTMF
space
7
6
5
4
3
21
0
89
Dialing : Rotary Switch
‘1’ one stop pulse
‘2’ two stop pulse
‘3’ three stop pulse
…
‘0’ ten stop pulse
T/3 T :100 ms ≥ 4T
‘3’ ‘2'
i(t)
t
space
Dial a numberOff-hook
0
Rotary switch dialing system
Subscriber link signal (Link Voltage)
Volt
100
50
0
-50
-100
-150
On-hook Off-hook
Dialing pulse
voice
Bell, ringing voltage
20 Hz, 90 Vrms, 2 s on, 3 s off
Incoming
Outgoing
1-2 V
ingoing
0,5-1 VΔv: 48 V
ΔI: 18 mA
I:16-20 mA,
6-8 V
48 V
register
Switching Device
Controller
trunk
SLIC
Pengisyaratan
SLIC
SLIC
trunk
Pengisyaratan
Switching Element
Controller can be :
•Sentralized
•Distributed at signaling and switcing Device
SLIC : Subscriber Line Interface Circuit
To/from other CO
Central Office
Switching SystemStep By Step,
Each digit activates directly one switching-level, except the last 2 digit usually connected to 2-dimension switch
3054
3 0 5 4
Call Finder
Switch level 1
Switch level 2
Switch level 3
Switch level 4
Illustration of Call Switching
Common Control Each digit of dialed number is first stored
in a register at CO, then if the destination number is not busy, call is routed to the phone.
Caller lift handset / off hook
CO find the available link
Get a link
CO send dial-tone to caller
Caller dial the destination number
Switching Process of Telephone Call
Yes
No
CO make switching process
Is dialed numberfree (not busy) ?
CO send:•Ringing signal to dialed phone•Ringing tone to caller phone(tuut – tuut…..)
CO send busy tone to caller phone
Call dropCalled phoneOff hook
Call success
yes no
yes
No
Voice SignalingNama Signal Kegunaan
Off-hook Memberitahu CO bahwa user
ingin melakukan panggilan
Dial tone Memberitahu user bahwa CO
sudah siap melayani (ready)
Ringback tone Memberitahu user bahwa
telepon tertuju sedang
berdering
Ringing voltage Tegangan tertentu yang
dikirim untuk membunyikan
bel
Busy signal Memberitahu user bahwa
telepon tertuju sedang sibuk
On-hook Memberitahu CO bahwa user
Nama Signal Kegunaan
Off-hook Memberitahu CO bahwa user
ingin melakukan panggilan
Dial tone Memberitahu user bahwa CO
sudah siap melayani (ready)
Ringback tone Memberitahu user bahwa
telepon tertuju sedang
berdering
Ringing voltage Tegangan tertentu yang
dikirim untuk membunyikan
bel
Busy signal Memberitahu user bahwa
telepon tertuju sedang sibuk
On-hook Memberitahu CO bahwa user
CO
Private Branch eXchange
.
.
.
Common Subscriber
PBX90XXXX
m ext-link
.
.
.
Operator
n main link
2201
2202
1302
PBX is categorized: PMBX private manual branch exchange
Both intern and extern call is handled by an operator PABX-private automatic branch exchange
Intern call is automatic Extern call
Automatic if the device has DID (direct inward dialing) Via operator If device does not have DID
If n >1 (link between co-pbx) User call via one number if PABX has hunting system User can call via n different number if PABX doesn’t have
hunting system.
Advantage of PBX Cost Probability of success call
Numbering System Open System Close System
Network from CO to Subscriber
LE
-
MDFCCP CCP
DPDP
DPPBX
Primary network
Secondary network
MDF 2000 pairs
CCP 50 pairs
DP:10 pairs
MDF,CCP,DP are in a form of cable switching terminal
Network Between LE
LE LE LE
Toll Central
Toll Central
Toll Central
Regional Central
LE LE LE
Toll Central
Toll Central
Toll Central
Regional Central
yk1 yk2 yk3
One local area