Manajemen Frekuensi dan Manajemen Mobilitas pada

Teknologi SelulerALFIN HIKMATUROKHMAN., ST.,MT

S1 TEKNIK TELEKOMUNIKASISEKOLAH TINGGI TEKNOLOGI TELEMATIKA TELKOM

PURWOKERTO 2016http://alfin.dosen.st3telkom.ac.id/profile/

Cluster

2

• Sebuah cluster merupakan kumpulan daribeberapa sel, memiliki prinsip tidak adapenggunaan ulang kanal dalam satu cluster.Berikut ilustrasi tujuh buah sel dalam satucluster.

Tujuh sel dalam sebuah cluster

3

• Satu cluster terdiri dari beberapa sel (K sel). K bisaberharga 3, 4,7, 9, 12

• Warna yang sama menunjukkan sel-sel co-channelyang menggunakan frekuensi yang sama

4

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

5

I J k

1 1 3

0 2 4

1 2 7

2 1 7

2 2 12

Alfin Hikmaturokhman, MT

http://sinauonline.org

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Ilustrasi Menentukan Sel Cochannel

I J K

1 1 3

0 2 4

1 2 7

2 1 72 2 12

A

60 o

A

A

A

A

AA

7

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

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

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The Cell Structure for K = 7

1

2

3

4

5

6

7

1

2

3

4

5

6

7

2

1

1

2

3

4

5

6

7

1

2

3

4

5

6

7

1

2

3

4

5

6

7

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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 = 3 K K = 1/3 (D/R)2

D/R = q K = 1/3(q)2

D

R

SEL ASEL A

R

• 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(co-channel reduction faktor)

R

Dq

Kq

KR

D

KR

D

3

3

3

2

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EFISIENSI SPEKTRUM

Jumlah maksimum kanal yang dapat dialokasikan pada lebar pita frekuensi

yang disediakan.

selkelompoksetiappadaselJumlahK

kanalsatufrekuensipitaLebarB

disediakanyangtotalspektrumLebarB

sel/kanalK.B

Bm

c

t

c

t

I

C

3

2K

6

q

I

C

q6

1

I

C

3

qKK3q

4

4

2

sel/kanal

I

C

3

2.B

Bm

c

t

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.

sel/kanal103

)251(3

2KHz15

MHz20m

KHz15B;MHz20B

selperkanal103

)63(3

2KHz30

MHz20m

KHz30B;MHz20B

:Misalkan

dB38N

SdengansetaradB24

I

C;KHz15BPada

dB38N

SdengansetaradB18

I

C;KHz30BPada

ct

ct

c

c

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.

• Dapat dibuat tabel sebagai berikut :

selperkanal2,258

)10(3

2KHz30

MHz20m

Lebar kanal (C/I) K D/R m

(KHz) (dB)

30 10 2,58 2,78 258,2

12 3,25 3,12 205,1

10 16 5,16 3,93 388,2

18 6,48 4,41 308,4

ALOKASI SPEKTRUM FREKUENSI

SISTEM GSM SISTEM AMPS

935 - 960 MHz

890 - 915 MHz

MS

MS

BS

824 - 851 MHz

869 - 896 MHz935 - 960 MHz

890 - 915 MHz

MS

MS

BS

935 - 960 MHz

890 - 915 MHz

Managemen Frekuensi

Manajemen Frekuensi Sistem Analog (AMPS)

A A B A B R

Arah Down Link

Frekuensi

Nomor Kanal

869 870 880 890 891,5 894 896 MHz

991 1 333 666 716 799

1023

A A B A B R

824 825 835 845 846.5 849 851

Mobile Transmit

AA B A B

Cell Site transmit

869 870 880 890 891.5 894 896

Frequency (MHz)

Frequency (MHz)

R

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Alokasi Frekuensi untuk GSM 900

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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)

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• Pada setiap kanal Absolut Radio Frequency Channel(ARFCN) antara frekuensi uplink dan downlinkdipisahkan oleh lebar pita frekuensi sebesar 45 MHzdengan 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 BTSuntuk mengirim informasi ke MS), sebesar 936 – 960 MHzyang terdiri dari 124 kanal radio GSM yang dikenal dengannama ARFCN (Absolut Radio Frequency Channel) denganmasing-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

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Frequency used

23

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Pengalokasian Kanal

Alokasi Kanal Sistem GSM

• Penentuan nomor kanal pada sistem GSM mengikuti persamaan berikut :

• 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

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

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

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2G Frequency Allocation in Indonesia

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Contd..

27

900M

1800M

Penetration loss

DCS1800 Distance

UMTS frequency bands

• In telecommunications, UMTS frequencybands are the radio spectrum frequenciesdesignated for the operation of the UniversalMobile 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 HimachalPradesh.

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.

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Frequency Planning

Example at Band 40 TDD

https://www.cellmapper.net/arfcn

Mobility Management

• Handover is a key technology of mobilecommunication system and make continuedconversation possible.

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Purposes of HO

• A major characteristic in the mobilecommunications: Mobility of the UE

• l As a key component of the mobilecommunication system, the cell has a limitedcoverage area.

• l The primary function of the handover is toprovide the continuous service for the movingUEs in the coverage of the network.

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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 Intra-

frequency cells or Inter-

frequency 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.

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BSC BSC

CA1 CA2 CA3CB1 CB2 CB3

HO

HO

HOHOHO

MSC

Ilustrasi kontinyuitas layanan

RNC

NodeB 2NodeB 1

Soft Handover

3/11/2016 44

Soft handoff : Selama proses handoff MS terhubung ke dua atau tiga

BTS

BSC

Menggunakan

Rake receiver

Down-link

BTS BTS MS

Daerah soft handoff MSC

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.

Untuk mengantisifasi adanya SHO dalam disain

jaringan jumlah kanalnya yang disediakan dilebihi

35 % dari yang diasumsikan

Make before Break

3/11/2016 45

Lanjutan soft-handoff

Up-link

BSC

BTS BTS

Daerah soft handoff

MSC

RNC (WFMR)

NodeB

Softer Handover

3/11/2016 47

BSC

Sektor A

Sektor B

Sektor C

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.

BTS

Hard Handover

RNC

NodeB 2NodeB 1

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Hard handoff

WCDMA to WCDMA handoff melibatkan dua carrier ( bisa berbeda

operator ) sering disebut D to D handoff.

F1 F1+n

50

Serv BTS

Neighbor BTS Neighbor BTS Neighbor BTS Neighbor BTS

Serv BTS

Page 51

Three Steps of Handover

• 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

Decision

Execute

Measurement

LTE Handover PrinciplesOnly 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

S-GW + P-GW

MME

Source eNB

Target eNB

MME MME MME

= Data in radio

= Signalling in radio= GTP tunnel

= GTP signalling

= S1 signalling

= X2 signalling

Before handoverHandover

preparationRadio handover

Late path

switching

S-GW + P-

GW

S-GW + P-GW S-GW + P-GW

X2

Handover PreparationUE Source Target MME GW

1. Measurement control

2. Measurement report

3. HO

decision

4. HO request

5. Admission control

6. HO request ack.

1. The source eNB configures the UE measurement procedures with MEASUREMENT CONTROL

2. UE is triggered to send MEASUREMENT REPORT to the source eNB. It can be event triggered or periodic

3. Source eNB makes handover decision based on UE report + load and service information

4. The source eNB issues a HANDOVER

REQUEST to the target eNB

5. Target eNB performs admission control

6. Target eNB sends the HANDOVER

REQUEST ACKNOWLEDGE to the source eNB

Handover ExecutionUE Source Target MME GW

7. HO command

8. Status transfer

Forward packets to

target

Buffer packets

from source

9. Synchronization

10. UL allocation and timing advance

11. Handover confirm

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

Presentation /

Author / Date

Handover Completion

UE 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

12.Target eNB sends a PATH SWITCHmessage to MME to inform that the UE has changed cell

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 ACKmessage

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 eNBcan release radio and C-plane related resources associated to the UE context

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