Difference between revisions of "OpenBTS: Kalibrasi"

From OnnoWiki
Jump to navigation Jump to search
 
(20 intermediate revisions by the same user not shown)
Line 87: Line 87:
 
===Scanning 900===
 
===Scanning 900===
  
−
Menjalankan  
+
Untuk Clock 64MHz Menjalankan  
  
 
  cd /usr/local/src/kal-v0.4.1/src/
 
  cd /usr/local/src/kal-v0.4.1/src/
 
  ./kal -s 900 -F 64000000 -b GSM900
 
  ./kal -s 900 -F 64000000 -b GSM900
 +
 +
Untuk Clock 52MHz Menjalankan
 +
 +
cd /usr/local/src/kal-v0.4.1/src/
 +
./kal -s 900 -F 52000000 -b GSM900 -vv
  
 
Hasil
 
Hasil
  
 +
FPGA clock : 52000000
 +
Decimation : 192
 +
Sample rate: 270833.343750
 
  kal: Scanning for GSM-900 base stations.
 
  kal: Scanning for GSM-900 base stations.
 +
channel detect threshold: 9458.928125
 
  GSM-900:
 
  GSM-900:
 +
chan: 36 (942.2MHz + 423Hz) power: 194131.34
 +
chan: 37 (942.4MHz + 428Hz) power: 50474.90
 +
chan: 38 (942.6MHz + 412Hz) power: 50189.51
 +
chan: 39 (942.8MHz + 397Hz) power: 14175.00
 +
chan: 40 (943.0MHz + 483Hz) power: 38742.63
 +
chan: 41 (943.2MHz + 510Hz) power: 50648.68
 +
chan: 61 (947.2MHz + 503Hz) power: 73085.29
 +
chan: 62 (947.4MHz + 490Hz) power: 18121.82
 +
chan: 66 (948.2MHz + 512Hz) power: 16138.32
 +
chan: 68 (948.6MHz + 491Hz) power: 18167.35
 +
chan: 113 (957.6MHz + 548Hz) power: 24349.49
 +
chan: 114 (957.8MHz + 493Hz) power: 11841.20
 +
chan: 115 (958.0MHz + 520Hz) power: 20344.80
 +
chan: 119 (958.8MHz + 505Hz) power: 31772.62
 +
chan: 120 (959.0MHz + 535Hz) power: 10510.76
 +
chan: 123 (959.6MHz + 565Hz) power: 18004.66
  
 
===Scanning 850===
 
===Scanning 850===
Line 121: Line 146:
 
  overruns: 0
 
  overruns: 0
 
  not found: 0
 
  not found: 0
 +
 +
 +
==Kalkulasi Kalibrasi==
 +
 +
Misalnya kita menggunakan BTS pada channel 47 untuk kalibrasi
 +
 +
./kal -F 52000000 -c 47
 +
 +
Hasil
 +
 +
kal: Calculating clock frequency offset.
 +
Using GSM-900 channel 47 (944.4MHz)
 +
average [min, max] (range, stddev)
 +
+ 501Hz [479, 524] (45, 13.227342)
 +
overruns: 0
 +
not found: 0
 +
 +
 +
Misalnya kita menggunakan BTS pada channel 61 untuk kalibrasi
 +
 +
./kal -F 52000000 -c 61
 +
 +
Hasil
 +
 +
kal: Calculating clock frequency offset.
 +
Using GSM-900 channel 61 (947.2MHz)
 +
average [min, max] (range, stddev)
 +
+ 494Hz [481, 504] (23, 6.454695)
 +
overruns: 0
 +
not found: 0
 +
 +
 +
==Proses Kalibrasi==
 +
 +
===Ukur===
 +
 +
Gunakan Kalibrate untuk mengukur offset frekuensi, misalnya pada channel 52
 +
 +
./kal -f 945400000
 +
 +
Misalnya hasilnya adalah
 +
 +
kal: Calculating clock frequency offset.
 +
Using GSM-900 channel 52 (945.4MHz)
 +
average [min, max] (range, stddev)
 +
+ 498Hz [429, 555] (126, 32.384548)
 +
overruns: 0
 +
not found: 165
 +
 +
===Hitung Offset===
 +
 +
Hitung dengan asumsi
 +
 +
* Frekuensi Clock  20MHz
 +
* Kanal 52 atau frekuensi 945.4MHz
 +
* Offset hasil pengukuran + 500Hz
 +
 +
Maka clock 20MHz harus di offset sebesar
 +
 +
-500Hz/945.4MHz*20MHz=-10.6 Hz
 +
 +
Tepatnya menjadi
 +
 +
19,999,990 Hz
 +
 +
===Set Ulang ClockTamer===
 +
 +
Set ulang OSC pada ClockTamer menggunakan
 +
 +
sudo screen /dev/ttyACM0 115200,cs8,-ixon,-ixoff
 +
 +
Beberapa pilihan setting
 +
 +
SET,,OSC,19999991
 +
SET,,OSC,19999990
 +
SET,,OSC,19999989
 +
STE
 +
 +
===Scan Ulang Frekuensi===
 +
 +
Hasilnya harus lebih baik
 +
 +
cd /usr/local/src/kal-v0.4.1/src
 +
./kal -s 900 -F 52000000 -b GSM900 -vv
 +
 +
Semoga hasilnya memperoleh offset yang lebih baik, seperti
 +
 +
FPGA clock : 52000000
 +
Decimation : 192
 +
Sample rate: 270833.343750
 +
kal: Scanning for GSM-900 base stations.
 +
channel detect threshold: 6922.106769
 +
GSM-900:
 +
chan: 36 (942.2MHz -  34Hz) power: 192896.03
 +
chan: 37 (942.4MHz -  30Hz) power: 48710.69
 +
chan: 38 (942.6MHz -  13Hz) power: 31109.57
 +
chan: 64 (947.8MHz +  68Hz) power: 15319.56
 +
chan: 66 (948.2MHz +  65Hz) power: 14363.92
 +
chan: 109 (956.8MHz +  2Hz) power: 12547.61
 +
chan: 112 (957.4MHz -  88Hz) power: 10748.52
 +
chan: 113 (957.6MHz +  42Hz) power: 22609.95
 +
chan: 114 (957.8MHz +  36Hz) power: 18037.21
 +
chan: 115 (958.0MHz +  61Hz) power: 15508.45
 +
chan: 116 (958.2MHz +  80Hz) power: 10971.88
 +
chan: 119 (958.8MHz +  65Hz) power: 24555.23
 +
chan: 123 (959.6MHz +  25Hz) power: 16705.38
  
 
==Referensi==
 
==Referensi==
Line 134: Line 265:
  
 
* [[OpenBTS]]
 
* [[OpenBTS]]
 +
* [[OpenBTS: Arsitektur secara umum]]
  
 
===Persiapan===
 
===Persiapan===
Line 143: Line 275:
 
* [[USRP: Instalasi Board]]
 
* [[USRP: Instalasi Board]]
 
* [[OpenBTS: GIT Source Code]]
 
* [[OpenBTS: GIT Source Code]]
 +
* [[USRP: Rangkaian Board USRP]]
 +
* [[OpenBTS: Tethr untuk Bencana Alam]]
  
 
===OpenBTS 2.6===
 
===OpenBTS 2.6===
Line 148: Line 282:
 
* [[GNURadio]]
 
* [[GNURadio]]
 
* [[GNURadio: Ubuntu Install]]
 
* [[GNURadio: Ubuntu Install]]
−
* [[GNURadio: Ubuntu Install GNURadio 3.4.2]]
+
* [[GNURadio: Menggunakan UHD]]
 +
* [[GNURadio: Ubuntu Install GNURadio 3.4.2]] '''RECOMMENDED'''
 +
* [[GNURadio: Ubuntu Install GNURadio 3.4.2 Clock 52MHz]] '''RECOMMENDED'''
 
* [[GNURadio: Contoh Aplikasi]]
 
* [[GNURadio: Contoh Aplikasi]]
 
* [[GNURadio: Spectrum Analizer GSM]]
 
* [[GNURadio: Spectrum Analizer GSM]]
 
* [[GNURadio: Mengubah board RFX1800 menjadi RFX900]]
 
* [[GNURadio: Mengubah board RFX1800 menjadi RFX900]]
 
* [[GNURadio: Programming Untuk Pemula]]
 
* [[GNURadio: Programming Untuk Pemula]]
−
* [[OpenBTS: Ubuntu Install]]
+
* [[OpenBTS: Ubuntu Install]] '''RECOMMENDED'''
−
* [[OpenBTS: Konfigurasi]]
+
* [[OpenBTS: Ubuntu Install OpenBTS 2.6 Clock 52MHz]] '''RECOMMENDED'''
 +
* [[OpenBTS: Konfigurasi]] '''RECOMMENDED'''
 
* [[OpenBTS: Kalibrasi]]
 
* [[OpenBTS: Kalibrasi]]
−
* [[OpenBTS: Konfigurasi Asterisk untuk OpenBTS]]
+
* [[OpenBTS: Konfigurasi Asterisk untuk OpenBTS]] '''RECOMMENDED'''
 
* [[OpenBTS: Menjalankan smqueue]]
 
* [[OpenBTS: Menjalankan smqueue]]
−
* [[OpenBTS: Mengoperasikan BTS]]
+
* [[OpenBTS: Mengoperasikan BTS]] '''RECOMMENDED'''
 
* [[OpenBTS: Tampilan di Nokia saat pakai OpenBTS]]
 
* [[OpenBTS: Tampilan di Nokia saat pakai OpenBTS]]
 
* [[OpenBTS: Operasi 1800 MHz]]
 
* [[OpenBTS: Operasi 1800 MHz]]
Line 169: Line 306:
 
===OpenBTS 2.8===
 
===OpenBTS 2.8===
  
−
* [[GNURadio: Ubuntu 11.10 Install]] '''*NOT RECOMMENED*'''
+
* [[GNURadio: Ubuntu 11.10 Install]] ''NOT RECOMMENED''
−
* [[GNURadio: Ubuntu 11.10 instalasi menggunakan Repo]] '''NOT RECOMMENDED'''
+
* [[GNURadio: Ubuntu 11.10 instalasi menggunakan Repo]] ''NOT RECOMMENDED''
 +
* [[GNURadio: Download GNURadio]]
 +
* [[GNURadio: Install UHD]]
 
* [[GNURadio: Ubuntu 11.10 Instal GNURadio 3.3.0]]
 
* [[GNURadio: Ubuntu 11.10 Instal GNURadio 3.3.0]]
−
* [[GNURadio: Ubuntu 11.10 Instal GNURadio 3.4.2]]
+
* [[GNURadio: Ubuntu 11.10 Instal GNURadio 3.4.2]] '''RECOMMENDED'''
−
* [[GNURadio: Ubuntu 11.10 Install dari GIT GNURadio]]
+
* [[GNURadio: Ubuntu 12.04 Instal GNURadio 3.4.2]] '''RECOMMENDED'''
 +
* [[GNURadio: Ubuntu 11.10 Instal GNURadio 3.5.0]] ''NOT RECOMMENDED''
 +
* [[GNURadio: Ubuntu 11.10 Instal GNURadio 3.5.3.2]] ''NOT RECOMMENDED''
 +
* [[GNURadio: Ubuntu 11.10 Instal GNURadio 3.6.0]] ''NOT RECOMMENDED''
 +
* [[GNURadio: Ubuntu 11.10 Install dari GIT GNURadio]] ''NOT RECOMMENDED''
 +
* [[GNURadio: Ubuntu 11.10 cek USRP Daughter Board]]
 +
* [[GNURadio: UHD]] ''NOT RECOMMENDED''
 +
* [[GNURadio: UHD Image]] ''NOT RECOMMENDED''
 +
* [[GNURadio: UHD burn EEPROM RFX Board di USRP1]] ''NOT RECOMMENDED''
 +
* [[GNURadio: UHD Identifikasi Device]]
 
* [[OpenBTS: Ubuntu 11.10 Install]]
 
* [[OpenBTS: Ubuntu 11.10 Install]]
−
* [[OpenBTS: 2.8 dari SVN Install]] '''RECOMMENDED'''
+
* [[OpenBTS: dari GIT ttsou]]
−
* [[OpenBTS: 2.8 Instalasi Real Time Asterisk]]
+
* [[OpenBTS: 2.8 dari SVN Install]]
 +
* [[OpenBTS: 2.8 dari SVN Install Clock 52MHz]] '''RECOMMENDED'''
 +
* [[OpenBTS: 2.8 dari SVN Install Clock 52MHz dengan UHD tanpa GNURadio]] ''NOT RECOMMENDED''
 +
* [[OpenBTS: 2.8 Edit User di sqlite3.db]] '''RECOMMEND'''
 +
* [[OpenBTS: Yate Softswitch]] '''RECOMMENDED'''
 +
* [[OpenBTS: Yate Config Test]]
 +
* [[OpenBTS: 2.8 Instalasi Real Time Asterisk]] '''RECOMMENDED'''
 +
* [[OpenBTS: 2.8 Menjalankan]] '''RECOMMENDED'''
 
* [[OpenBTS: 2.8 Konfigurasi]]
 
* [[OpenBTS: 2.8 Konfigurasi]]
 +
* [[OpenBTS: 2.8 Konfigurasi Subscriber Registery]]
 
* [[OpenBTS: Database SQLite]]
 
* [[OpenBTS: Database SQLite]]
 +
 +
===Multi OpenBTS 2.8===
 +
 +
* [[OpenBTS: Pola Multi OpenBTS]] '''RECOMMENDED'''
 +
* [[Multi OpenBTS: Catatan Konfigurasi]] '''RECOMMENDED'''
  
 
===Ettus E110===
 
===Ettus E110===
  
 
* [[OpenBTS: E110 Cara Login]]
 
* [[OpenBTS: E110 Cara Login]]
−
* [[OpenBTS: E110 Install Image di MicroSD]]
+
* [[OpenBTS: E110 Install Image di MicroSD]] '''*RECOMMENDED*'''
 
* [[OpenBTS: E110 Cek Daughter Board]]
 
* [[OpenBTS: E110 Cek Daughter Board]]
 
* [[OpenBTS: E110 Mengubah Master Clock]]
 
* [[OpenBTS: E110 Mengubah Master Clock]]
Line 189: Line 350:
 
* [[OpenBTS: E110 Bekerja dengan opkg]]
 
* [[OpenBTS: E110 Bekerja dengan opkg]]
 
* [[OpenBTS: E110 GNURadio]]
 
* [[OpenBTS: E110 GNURadio]]
 +
* [[OpenBTS: E110 Compile UHD]] '''*RECOMMENDED*'''
 +
* [[OpenBTS: E110 UHD burn EEPROM RFX Board]] '''*RECOMMENDED*'''
 +
* [[OpenBTS: E110 Install UHD Image]] '''*RECOMMENDED*'''
 
* [[OpenBTS: E110 Instalasi OpenBTS]]
 
* [[OpenBTS: E110 Instalasi OpenBTS]]
−
* [[OpenBTS: E110 Instalasi OpenBTS 2.6]] '''*NOT RECOMMENDED*'''
+
* [[OpenBTS: E110 Instalasi OpenBTS 2.6]] ''NOT RECOMMENDED''
 +
* [[OpenBTS: E110 Instalasi OpenBTS 2.8 untuk MultiBTS]] '''*RECOMMENDED*'''
 +
 
 +
===GPRS===
 +
 
 +
* [[OpenBTS: GPRS]]
 +
 
 +
===Power Amplifier===
 +
 
 +
* [[Driver 900MHz]]
 +
* [[Power Amplifier 900MHz]]
 +
* [[Duplexer]]
  
 
===Lain Lain===
 
===Lain Lain===
  
 +
* [[OpenBTS: Materi Magang di ICTWATCH]]
 +
* [[OpenBTS: Seminar Outline]]
 +
* [[OpenBTS: Workshop Outline]]
 
* [[Membuat Base Station GSM Open Source]]
 
* [[Membuat Base Station GSM Open Source]]
 
* [[Teknologi Selular]]
 
* [[Teknologi Selular]]
Line 209: Line 387:
 
* [[Siapa Bilang OpenBTS Ilegal?]]
 
* [[Siapa Bilang OpenBTS Ilegal?]]
 
* [[OpenBTS: Catatan MNC dan MCC Indonesia]]
 
* [[OpenBTS: Catatan MNC dan MCC Indonesia]]
 +
* [[OpenBTS: Catatan MNC dan MCC COOL]]
 
* [[OpenBTS : Alokasi Frekuensi Operator GSM Indonesia]]
 
* [[OpenBTS : Alokasi Frekuensi Operator GSM Indonesia]]
 +
* [[GSM: Daftar Channel Frekuensi]]
  
 
===Catatan Sejarah===
 
===Catatan Sejarah===
Line 216: Line 396:
 
* [[OpenBTS: Daftar Workshop atau Seminar yang pernah dilakukan]]
 
* [[OpenBTS: Daftar Workshop atau Seminar yang pernah dilakukan]]
 
* [[OpenBTS: Daftar Artikel di Media]]
 
* [[OpenBTS: Daftar Artikel di Media]]
 +
 +
===Dokumentasi Video===
 +
 +
* http://youtu.be/8ogOcUSpINU (1/6)
 +
* http://youtu.be/F5d7HGuhppk (2/6)
 +
* http://youtu.be/90Jgq6bOgrQ (3/6)
 +
* http://youtu.be/cNkx_qNqdfc (4/6)
 +
* http://youtu.be/6LCuoeI57ak (5/6)
 +
* http://youtu.be/-dEqcHoIlYk (6/6)
  
 
[[Category: Wireless]]
 
[[Category: Wireless]]
 
[[Category: Selular]]
 
[[Category: Selular]]

Latest revision as of 07:23, 14 August 2012

Sumber: http://gnuradio.org/redmine/wiki/1/OpenBTSClockCalibration


Jika kita tidak mempunyai peralatan lab yang baik dan kita ingin mengetahui akurasi clock USRP, kita dapat menggunakan aplikasi Kalibrator (Copyright (c) 2009 Joshua Lackey, Alexander Chemeris). Tentunya kita tidak mungkin memperoleh hasil yang baik seperti hi-tech lab, tapi cukup lah untuk mengetahui error kalibrasi clock yang ada.

Download

Download dari 

http://thre.at/kalibrate/kal-v0.4.1.tar.bz2
git clone https://github.com/ttsou/kalibrate-uhd kalibrate-uhd

Compile

cp kal-v0.4.1.tar.bz2 /usr/local/src/
cd /usr/local/src
tar jxvf kal-v0.4.1.tar.bz2 
cd /usr/local/src/kal-v0.4.1
./bootstrap && CXXFLAGS='-W -Wall -O3' ./configure && make

Menjalankan

cd /usr/local/src/kal-v0.4.1/src/
./kal -h

Hasil 

kalibrate v0.4.1, Copyright (c) 2010, Joshua Lackey

Usage:
	GSM Base Station Scan:
		kal <-s band indicator> [options]

	Clock Offset Calculation:
		kal <-f frequency | -c channel> [options]

Where options are:
	-s	band to scan (GSM850, GSM900, EGSM, DCS, PCS) 
	-f	frequency of nearby GSM base station
	-c	channel of nearby GSM base station
	-b	band indicator (GSM850, GSM900, EGSM, DCS, PCS)
	-R	side A (0) or B (1), defaults to B
	-A	antenna TX/RX (0) or RX2 (1), defaults to RX2
	-g	gain as % of range, defaults to 45%
	-F	FPGA master clock frequency, defaults to 52MHz
	-v	verbose
	-D	enable debug messages
	-h	help

Scanning 1800

Menjalankan 

cd /usr/local/src/kal-v0.4.1/src/
./kal -s 1800 -F 64000000 -b DCS

Hasil 

kal: Scanning for DCS-1800 base stations.
DCS-1800:
 	chan: 513 (1805.4MHz + 14.952kHz)	power: 5336.89 
	chan: 514 (1805.6MHz + 14.954kHz)	power: 1927.35
	chan: 517 (1806.2MHz + 14.952kHz)	power: 3715.71
	chan: 518 (1806.4MHz + 14.983kHz)	power: 1717.65
	chan: 519 (1806.6MHz + 14.969kHz)	power: 5159.38
	chan: 520 (1806.8MHz + 14.951kHz)	power: 2017.03
	chan: 542 (1811.2MHz + 15.092kHz)	power: 4554.77
	chan: 544 (1811.6MHz + 15.084kHz)	power: 3730.97
	chan: 569 (1816.6MHz + 15.181kHz)	power: 6196.37
	chan: 570 (1816.8MHz + 15.172kHz)	power: 1924.81
	chan: 613 (1825.4MHz + 15.237kHz)	power: 15746.19
	chan: 614 (1825.6MHz + 15.242kHz)	power: 6683.53
	chan: 616 (1826.0MHz + 15.260kHz)	power: 12953.63
	chan: 617 (1826.2MHz + 15.248kHz)	power: 4816.39
	chan: 620 (1826.8MHz + 15.224kHz)	power: 4274.58
	chan: 625 (1827.8MHz + 15.268kHz)	power: 3613.13
	chan: 626 (1828.0MHz + 15.313kHz)	power: 1926.56
	chan: 627 (1828.2MHz + 15.274kHz)	power: 3536.15
	chan: 628 (1828.4MHz + 15.267kHz)	power: 2346.39
	chan: 629 (1828.6MHz + 15.288kHz)	power: 7923.44
 	chan: 632 (1829.2MHz + 15.316kHz)	power: 5417.85
 	chan: 633 (1829.4MHz + 15.312kHz)	power: 2652.96
   	chan: 689 (1840.6MHz + 15.602kHz)	power: 3734.25
 	chan: 692 (1841.2MHz + 15.587kHz)	power: 11674.51
	chan: 693 (1841.4MHz + 15.586kHz)	power: 5294.69

Scanning 900

Untuk Clock 64MHz Menjalankan 

cd /usr/local/src/kal-v0.4.1/src/
./kal -s 900 -F 64000000 -b GSM900

Untuk Clock 52MHz Menjalankan 

cd /usr/local/src/kal-v0.4.1/src/
./kal -s 900 -F 52000000 -b GSM900 -vv

Hasil 

FPGA clock : 52000000
Decimation : 192
Sample rate: 270833.343750
kal: Scanning for GSM-900 base stations.
channel detect threshold: 9458.928125
GSM-900:
	chan: 36 (942.2MHz + 423Hz)	power: 194131.34 
	chan: 37 (942.4MHz + 428Hz)	power: 50474.90
	chan: 38 (942.6MHz + 412Hz)	power: 50189.51
	chan: 39 (942.8MHz + 397Hz)	power: 14175.00
	chan: 40 (943.0MHz + 483Hz)	power: 38742.63
	chan: 41 (943.2MHz + 510Hz)	power: 50648.68
	chan: 61 (947.2MHz + 503Hz)	power: 73085.29
	chan: 62 (947.4MHz + 490Hz)	power: 18121.82
	chan: 66 (948.2MHz + 512Hz)	power: 16138.32
	chan: 68 (948.6MHz + 491Hz)	power: 18167.35
	chan: 113 (957.6MHz + 548Hz)	power: 24349.49
	chan: 114 (957.8MHz + 493Hz)	power: 11841.20
	chan: 115 (958.0MHz + 520Hz)	power: 20344.80
	chan: 119 (958.8MHz + 505Hz)	power: 31772.62
	chan: 120 (959.0MHz + 535Hz)	power: 10510.76
	chan: 123 (959.6MHz + 565Hz)	power: 18004.66

Scanning 850

Menjalankan 

cd /usr/local/src/kal-v0.4.1/src/
./kal -s 850 -F 64000000

Hasil

Scanning Channel

Menjalankan 

cd /usr/local/src/kal-v0.4.1/src/
./kal -c 513 -F 64000000 -b DCS

Hasil 

kal: Calculating clock frequency offset.
Using DCS-1800 channel 513 (1805.4MHz)
average		[min, max]	(range, stddev)
+ 17.109kHz		[17087, 17136]	(50, 14.080007)
overruns: 0
not found: 0


Kalkulasi Kalibrasi

Misalnya kita menggunakan BTS pada channel 47 untuk kalibrasi 

./kal -F 52000000 -c 47

Hasil 

kal: Calculating clock frequency offset.
Using GSM-900 channel 47 (944.4MHz)
average		[min, max]	(range, stddev)
+ 501Hz		[479, 524]	(45, 13.227342)
overruns: 0
not found: 0


Misalnya kita menggunakan BTS pada channel 61 untuk kalibrasi 

./kal -F 52000000 -c 61

Hasil 

kal: Calculating clock frequency offset.
Using GSM-900 channel 61 (947.2MHz)
average		[min, max]	(range, stddev)
+ 494Hz		[481, 504]	(23, 6.454695)
overruns: 0
not found: 0


Proses Kalibrasi

Ukur

Gunakan Kalibrate untuk mengukur offset frekuensi, misalnya pada channel 52 

./kal -f 945400000

Misalnya hasilnya adalah 

kal: Calculating clock frequency offset.
Using GSM-900 channel 52 (945.4MHz)
average		[min, max]	(range, stddev)
+ 498Hz		[429, 555]	(126, 32.384548)
overruns: 0
not found: 165

Hitung Offset

Hitung dengan asumsi

  • Frekuensi Clock 20MHz
  • Kanal 52 atau frekuensi 945.4MHz
  • Offset hasil pengukuran + 500Hz

Maka clock 20MHz harus di offset sebesar 

-500Hz/945.4MHz*20MHz=-10.6 Hz

Tepatnya menjadi 

19,999,990 Hz

Set Ulang ClockTamer

Set ulang OSC pada ClockTamer menggunakan 

sudo screen /dev/ttyACM0 115200,cs8,-ixon,-ixoff

Beberapa pilihan setting 

SET,,OSC,19999991
SET,,OSC,19999990
SET,,OSC,19999989
STE

Scan Ulang Frekuensi

Hasilnya harus lebih baik 

cd /usr/local/src/kal-v0.4.1/src
./kal -s 900 -F 52000000 -b GSM900 -vv

Semoga hasilnya memperoleh offset yang lebih baik, seperti 

FPGA clock : 52000000
Decimation : 192
Sample rate: 270833.343750
kal: Scanning for GSM-900 base stations.
channel detect threshold: 6922.106769
GSM-900:
	chan: 36 (942.2MHz -  34Hz)	power: 192896.03
	chan: 37 (942.4MHz -  30Hz)	power: 48710.69
	chan: 38 (942.6MHz -  13Hz)	power: 31109.57
	chan: 64 (947.8MHz +  68Hz)	power: 15319.56
	chan: 66 (948.2MHz +  65Hz)	power: 14363.92
	chan: 109 (956.8MHz +   2Hz)	power: 12547.61
	chan: 112 (957.4MHz -  88Hz)	power: 10748.52
	chan: 113 (957.6MHz +  42Hz)	power: 22609.95
	chan: 114 (957.8MHz +  36Hz)	power: 18037.21
	chan: 115 (958.0MHz +  61Hz)	power: 15508.45
	chan: 116 (958.2MHz +  80Hz)	power: 10971.88
	chan: 119 (958.8MHz +  65Hz)	power: 24555.23
	chan: 123 (959.6MHz +  25Hz)	power: 16705.38

Referensi

Pranala Menarik

Persiapan

OpenBTS 2.6

OpenBTS 2.8

Multi OpenBTS 2.8

Ettus E110

GPRS

Power Amplifier

Lain Lain

Catatan Legal dan Pendukung

Catatan Sejarah

Dokumentasi Video

Retrieved from "https://onnocenter.or.id/wiki/index.php?title=OpenBTS:_Kalibrasi&oldid=34199"