Manajemen Frekuensi dan Manajemen Mobilitas pada Teknologi Seluler ALFIN HIKMATUROKHMAN., ST.,MT S1 TEKNIK TELEKOMUNIKASI SEKOLAH TINGGI TEKNOLOGI TELEMATIKA TELKOM PURWOKERTO 2016 http://alfin.dosen.st3telkom.ac.id/profile/
Cluster • Sebuah cluster merupakan kumpulan dari beberapa sel, memiliki prinsip tidak ada penggunaan ulang kanal dalam satu cluster. Berikut ilustrasi tujuh buah sel dalam satu cluster.
Tujuh sel dalam sebuah cluster 2
• Satu cluster terdiri dari beberapa sel (K sel). K bisa berharga 3, 4,7, 9, 12 • Warna yang sama menunjukkan sel-sel co-channel yang menggunakan frekuensi yang sama
3
Parameter Geser • K pada bentuk sel heksagonal ditentukan oleh parameter geser I dan J. • Persamaan : K = I2 + IJ + J2 • Penentuan sel dengan frekuensi sama (cochannel sel) adalah sbb. :
• Pilih salah satu sel, namakan (misalnya sel A) • Tarik garis lurus sejauh I melalui salah satu sisi sel A • Berhenti di pusat sel, lalu putar 60o
• Tarik lagi garis tersebut sejauh J, berhenti di pusat sel. • Namai sel tersebut sel A. • Lakukan cara tersebut di atas melalui sisi yang lain dari sel A
pertama tadi
4
I
J
k
1
1
3
0
2
4
1
2
7
2
1
7
2
2
12
5
Ilustrasi Menentukan Sel Cochannel I 1 0 1
J 1 2 2
K 3 4 7
2
1
7
2
2
12
A A
A A A 60
A A
Alfin Hikmaturokhman, MT
6
o
Cara menentukan sel-sel co-channel dengan menggunakan rumus : K = i2+j2+ij I = arah pergerakan awal ; j = arah awal diputar 60o Contoh untuk K=7, I = 2, j = 1 Contoh untuk K=7, I = 2, j = 1
Lalui sejauh I dari sel referensi sepanjang rantai Hexagonalnya (garis lurus yang menghubungkan 2 pusat sel), lalu berputar 600 Berlawanan dengan arah jarum jam 7
7 6
2 1
5 7 6
3 4
1
2
2
1
5
3
7 6
4
2
1 7
6
5 2
1 5
7 6
3 4
3 4
2 1
5
3 4
The Cell Structure for K = 7 8
Pengulangan Frekuensi • D adalah jarak pengulangan ‘reuse distance’ • R adalah jari-jari sel heksagonal (jarak terjauh dari pusat sel ke ujung sel • K adalah kelompok sel atau cluster • Untuk sel berbentuk heksagonal : (D/R)2
=
3K
K
=
1/3 (D/R)2
D/R
=
q
K
=
1/3(q)2
R
R D
SEL A
SEL A
9
• Jarak pengulangan frekuensi ditentukan dengan • D = Jarak pengulangan (reuse distance) • R = Jari-jari terjauh sel hexagonal (jarak terjauh dari pusat sel ke ujung sel) • K = cluster • q = Dinamakan faktor pengurangan interferensi(cochannel reduction faktor) 10
2
D 3K R D 3K R q 3K q
D R
EFISIENSI SPEKTRUM Jumlah maksimum kanal yang dapat dialokasikan pada lebar pita frekuensi yang disediakan. m
Bt kanal / sel Bc . K
Bt Lebar spektrum total yang disediakan Bc Lebar pita frekuensisatu kanal K
Jumlah sel pada setiap kelompok sel
q2 q 3K K 3 C 1 C q4 I I 6 6 q 4 K
2C 3 I
m
Bt 2C Bc . 3I
kanal / sel
Kapasitas Radio Sistem Analog • • • •
Penyempitan lebar pita kanal tidak meningkatkan kapasitas radio Lebar pita per kanal 30 KHz atau 15 KHz (Modulasi FM) Nilai C/I berdasarkan test subjekivitas harus di atas 18 dB. Dalam lingkungan tanpa fading menggunakan pre dan de-emphasis C/I = 18 dB. C S 18 dB setara dengan 38 dB I N C S Pada Bc 15 KHz ; 24 dB setara dengan 38 dB I N Misalkan :
Pada Bc 30 KHz ;
Bt 20 MHz ; Bc 30 KHz 20 MHz 103 kanal per sel 2 30 KHz (63) 3 Bt 20 MHz ; Bc 15 KHz
m
m
20 MHz 2 15 KHz (251) 3
103 kanal / sel
Kapasitas Radio Sistem Digital • Untuk mencapai kualitas yang sama, sistem digital membutuhkan C/I lebih rendah dibanding sistem analog. • Harga C/I sistem digital kurang lebih 10 - 12 dB untuk lebar kanal 30 KHz dan 16 - 18 dB untuk lebar kanal 10 KHz. m
20 MHz 258,2 kanal per sel 2 30 KHz (10) 3
• Dapat dibuat tabel sebagai berikut : Lebar kanal (C/I)
K
D/R
m
(KHz)
(dB)
30
10 12
2,58 3,25
2,78 3,12
258,2 205,1
10
16 18
5,16 6,48
3,93 4,41
388,2 308,4
ALOKASI SPEKTRUM FREKUENSI
SISTEM AMPS
SISTEM GSM
935 - 960 MHz
869 - 896 MHz
935 - 960 MHz
935 - 960 MHz
MS
MS
890 - 915 MHz
824 - 851 MHz
890 - 915 MHz
890 - 915 MHz
MS BS
MS BS
Managemen Frekuensi Manajemen Frekuensi Sistem Analog (AMPS) M obile Transmit Frequency (M Hz) 851 R
B
A
B
A
A
849
846.5
845
835
825
824
Cell Site transmit Frequency (M Hz)
A
896 R
B
A
B
A
894
891.5
890
880
870
869
Arah Down Link
Frekuensi
869
A
A Nomor Kanal
991
880
870
1 1023
890
A
B 333
666
894
891,5
B 716
896
R 799
MHz
Alokasi Frekuensi untuk GSM 900
16
17
ALOKASI KANAL GSM UNTUK OPERATOR DI INDONESIA SATELINDO
: 890 – 900 MHz (10 MHz)
TELKOMSEL
: 900 – 907 MHz (7.5 MHz)
EXCELCOMINDO
: 907.5 – 915 MHz (7.5 MHz)
19
• Pada setiap kanal Absolut Radio Frequency Channel (ARFCN) antara frekuensi uplink dan downlink dipisahkan oleh lebar pita frekuensi sebesar 45 MHz dengan tujuan untuk menghindari interferensi
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Alokasi frekuensi GSM berada pada 890 – 960 MHz. Uplink (spektrum frekuensi pembawa yang digunakan MS untuk mengirim informasi ke BTS) sebesar 890 – 915 MHz Downlink (spektrum frekuensi pembawa yang digunakan BTS untuk mengirim informasi ke MS), sebesar 936 – 960 MHz yang terdiri dari 124 kanal radio GSM yang dikenal dengan nama ARFCN (Absolut Radio Frequency Channel) dengan masing-masing kanal memiliki lebar pita 200 KHz
Satu kanal pada GSM terdiri dari 8 time slot yang mempunyai lebar band 200 KHz. Jumlah Kanal pada sistem GSM 124 Kanal. Kanal No 1 dg frekuensi pancar utk Tx- Mobil 890,20 MHz dan untuk Tx-RBS 935,20 MHz. Kanal No. 124 dg frekuensi pancar utk untuk Tx-mobil 914,80 MHz dan untuk Tx-RBS 959,80 MHz 21
Frequency used
23
Pengalokasian Kanal Alokasi Kanal Sistem GSM • Penentuan nomor kanal pada sistem GSM mengikuti persamaan berikut : Uplink
:
Fu
=
890,2 + 0,2 * (N-1) MHz
Downlink
:
Fd
=
935,2 + 0,2 * (N-1) MHz
Fu
=
Frekuensi uplink
Fd
=
Frekuensi downlink
N
=
1, 2, 3, …, 124
• Jumlah kanal yang tersedia adalah : 124 kanal Contoh : • Kanal 1
:
Uplink : 890,2
Downlink : 935,2 MHz
• Kanal 2
:
Uplink : 890,4
Downlink : 935,4 MHz …….
• Kanal 124
:
Uplink : 914,8
Downlink : 959,8 MHz 24
TD ref • • • • • • • • •
Untuk mengetahui frekuensi yang sedang digunakan oleh MS berdasarkan kanal yang sedang ditempati dapat diperoleh dari rumus3) : Pada GSM900 adalah: Frekuensi uplink: Fu(n) = 890 + 0.2 n Frekuensi downlink: Fd(n) = Fu(n) + 45 Dengan n adalah nomor kanal pada range 51 ≤ n ≤ 87 Pada DCS1800 adalah: Frekuensi uplink: Fu(n) = 1710,2 + 0.2 x (n-512) Frekuensi downlink: Fd(n) = Fu(n) + 45 Dengan n adalah nomor kanal pada range 575 ≤ n ≤ 836
25
2G Frequency Allocation in Indonesia
26
Contd..
27
DCS1800 Distance
Penetration loss
900M
1800M
UMTS frequency bands • In telecommunications, UMTS frequency bands are the radio spectrum frequencies designated for the operation of the Universal Mobile Telecommunications System (UMTS) / High-Speed Downlink Packet Access (HSDPA) / High-Speed Uplink Packet Access (HSUPA) / HSPA+ / system for mobile phones.
UARFCN • Carrier frequencies are designated by a UTRA Absolute Radio Frequency Channel Number . • The value of the UARFCN in the IMT2000 (International Mobile Telephony 2000) is defined as: UARFCN = 5 x Frequency (MHz).
The 2100 Band • UMTS works on 2100 band in India. • Range = 1920-1980 MHz Uplink 2110-2170 MHz Downlink • UARFCN Range = 9612 - 9888 Upilink 10562 - 10838 Downlink • Bandwidth = 60 MHz. • Frequency required per channel = 5MHz. Courtesy :Wikipedia
Calculating UARFCNs • Total number of UARFCNs = 276. • The frequency increases with a step of 0.2 MHz. • So UARFCN 9612 means 9612/5= 1922.4 MHz, UARFCN 9613 means 9613/5=1922.6 MHz and UARFCN 9888 means 9888/5= 1977.6 MHz. • These UARFCNs are also known as center frequencies. • To find the actual channel we’ve to add another 2.5 MHz at either side of this center frequency. • E.g.: The first channel in 2100 and will be 1920-1925 MHz based around UARFCN 9612 i.e. 1922.4 MHz.
Frequencies Used in India
This is the frequency band on which BSNL 3G network currently works, in Himachal Pradesh.
3G • The UARFCN channel number is calculated according to it's frequency. If no offset is used, the frequency is simply multiplied by 5 to get the UARFCN (ex: 2132.8 MHZ * 5 = UARFCN 10664) If an offset is used the offset must be first subtracted from the frequency. 34
Frequency Planning
Example at Band 40 TDD https://www.cellmapper.net/arfcn
Mobility Management
• Handover is a key technology of mobile communication system and make continued conversation possible.
http://alfin.dosen.st3telkom.ac.id/profile/
37
Purposes of HO • A major characteristic in the mobile communications: Mobility of the UE • l As a key component of the mobile communication system, the cell has a limited coverage area. • l The primary function of the handover is to provide the continuous service for the moving UEs in the coverage of the network. http://alfin.dosen.st3telkom.ac.id/profile/
38
The Categories of Handover •
•
•
According to the signaling characters: – Soft handover (softer handover) – Hard handover According to the properties of source cell and target cell – Intra-frequency handover – Inter-frequency handover – Inter-mode handover (FDD <-> TDD) – Inter-system handover (UMTS <-> GSM/CDMA2000) According to the purpose of handover – Based on Coverage – Based on Load (Optional) – Based on mobility of UE (Optional) – Based on Service (Optional)
The Characters of Different Handovers Comparison between soft handover and hard handover:
Item
Soft Handover
Hard Handover
The numbers of RL in active set after handover
Several
One
Interruption during handover
No
Yes
The frequencies of cells
Only happened in Intra-frequency cells
Can be happened in Intrafrequency cells or Interfrequency cells
The Characters of Different Handovers •
Comparison between soft handover and softer handover: – During softer handover, the uplink signaling are combined in NodeB by maximum ratio combination, but during soft handover they are combined in RNC by selection combination. – Compare to later one, the maximum ration combination can get more gain. So the performance of maximum ration combination is better.
– Since softer handover is completed in NodeB, it do not consume transport resource of Iub.
Ilustrasi kontinyuitas layanan MSC
BSC
CA1
BSC
CA2
CB1
CA3
HO HO
HO
CB3
CB2
HO
HO
42
Soft Handover RNC
NodeB 1
NodeB 2
Make before Break
Soft handoff : Selama proses handoff MS terhubung ke dua atau tiga BTS BSC
MSC
Daerah soft handoff
Down-link
BTS Untuk mengantisifasi adanya SHO dalam disain jaringan jumlah kanalnya yang disediakan dilebihi 35 % dari yang diasumsikan
3/11/2016
MS Menggunakan Rake receiver
BTS Dimungkinkan dapat menerima WC yang berbeda, karena di dalam Rake Rec terdapat finger yang masing-masing dapat berfungsi sbg penerima sendiri2. Kalau dalam GSM tidak mungkin dipasang Rake Rec karena Bwnya sempit shg tdk mungkin untuk mengumpulkan signal-signal yang terpecah.
44
Lanjutan soft-handoff
BSC
MSC
Up-link
BTS
BTS Daerah soft handoff
3/11/2016
45
Softer Handover RNC (WFMR)
NodeB
Softer handoff : pengalihan layanan dari satu sektor ke sektor lain dalam satu cell. Arah down-link sama dengan soft handoff sedang arah up-link proses seleksi terjadi di BTS. Sektor B
BSC
BTS
Sektor A
3/11/2016
Sektor C
47
Hard Handover RNC
NodeB 1
NodeB 2
Hard handoff WCDMA to WCDMA handoff melibatkan dua carrier ( bisa berbeda operator ) sering disebut D to D handoff.
F1 F1+n
49
Neighbor BTS
Neighbor BTS
Serv BTS
Neighbor BTS
Neighbor BTS
Serv BTS
50
Three Steps of Handover •
Measurement
Decision
•
•
Execute
Page 51
Measurement – Measurement control – Measurement execution and the result processing – The measurement report – Mainly accomplished by UE Decision – Based on Measurement – The application and distribution of resource – Mainly accomplished by RRM in RNC Execution – The process of signaling – Support the failure drawback – Measurement control refresh
LTE Handover Principles Only hard handovers in LTE (no soft handovers) – Lossless • Packets are forwarded from the source to the target
– Network-controlled • Target cell is selected by the network, not by the UE • Handover control in E-UTRAN (not in packet core)
– UE-assisted • Measurements are made and reported by the UE to the network
– Late path switch • Only once the handover is successful, the packet core is involved
Handover Procedure Before handover S-GW + P-GW MME
Source eNB
Handover preparation S-GW + PGW MME
Target eNB
= Data in radio = Signalling in radio = GTP tunnel = GTP signalling
Radio handover S-GW + P-GW MME
X2
= S1 signalling = X2 signalling
Late path switching S-GW + P-GW MME
1.
Handover Preparation The source eNB configures the UE measurement procedures with
UE
Source Target
MME
MEASUREMENT CONTROL
2. UE is triggered to send MEASUREMENT REPORT to the source
3.
4. 5. 6.
eNB. It can be event triggered or periodic Source eNB makes handover decision based on UE report + load and service information The source eNB issues a HANDOVER REQUEST to the target eNB Target eNB performs admission control Target eNB sends the HANDOVER REQUEST ACKNOWLEDGE to the source eNB
1. Measurement control 2. Measurement report 3. HO decision 4. HO request
5. Admission control 6. HO request ack.
GW
Handover Execution
7. Source eNB generates the HANDOVER COMMAND towards UE Source eNB starts forwarding packets to target eNB
8. Source eNB sends status information to target eNB 9. UE performs the final synchronisation to target eNB and accesses the cell via RACH procedure DL pre-synchronisation is obtained during cell identification and measurements
10.Target eNB gives the uplink allocation and timing advance information 11.UE sends HANDOVER CONFIRM to target eNB Target eNB can begin to send data to UE
UE
Source
Target
MME
7. HO command Forward packets to target 8. Status transfer
9. Synchronization
Buffer packets from source
10. UL allocation and timing advance
11. Handover confirm
GW
Handover Completion 12.Target eNB sends a PATH SWITCH message to MME to inform that the UE has changed cell UE 13.MME sends a USER PLANE UPDATE REQUEST message to Serving Gateway 14.Serving Gateway switches the downlink data path to the target side 15.Serving Gateway sends a USER PLANE UPDATE RESPONSE message to MME 16.MME confirms the PATH SWITCH message with the PATH SWITCH ACK message 17.By sending RELEASE RESOURCE the target eNB informs success of handover to source eNB and triggers the release of resources 18.Upon reception of the RELEASE RESOURCE message, the source eNB can release radio and C-plane related resources associated to the UE context Presentation /
Source Target
MME
GW
12. Path switch request 13. User plane update request 14. Switch downlink path
15. User plane update response 16. Path switch request ack. 17. Release resources 18. Release resources
Handover Measurement Procedure
eNodeB sends Measurement control to UE giving Reporting thresholds
UE identifies others cell ids (Physical Cell ID - PCI -) from Synchronization Signal
UE measures other cells’ signal from Reference Signals (RS)
When the reporting threshold condition is fulfilled, UE sends Handover measurements to eNodeB
POWER POINT SYNDROME
60
TERIMA KASIH
