Mobilné systémy 3. generácie UMTS -...

Mobilné systémy 3. generácie UMTS

Ing. Matúš Turcsány, PhD.

turcsany@ktl.elf.stuba.sk

KTL FEI STU2009

Prehľad prednášok• UMTS

• HSDPA, EUL

• HSPA evolution

• LTE

• LTE-Advanced

Nasadené technológie• GSM worldwide (~ 720 networks)

– EDGE almost worldwide (~ 300 networks)

• UMTS (~ 300 networks)– HSDPA (~ 290 networks)– EUL (~ 90 networks)

• CDMA2000 (~ 250 networks)– EV-DO Rel.0 (~ 90 networks)– EV-DO Rev.A (~ 10 networks)

• FLASH-OFDM– USA, Slovakia

• Mobile WiMAX– South Korea (WiBro)– Sprint (2008)

IEEE 802.16

proprietary

3GPP2

3GPP

Dnešné možnosti• GSM/GPRS/EDGE

– mainly voice oriented service– downlink up to 300 kbps– uplink up to 200 kbps

• UMTS/HSDPA/EUL– higher voice capacity– UMTS DL/UL 384 kbps– HSDPA up to 28 Mbps– EUL up to 5,8 Mbps

• FLASH-OFDM– pure IP architecture– DL up to 5,3 Mbps– UL up to 1,8 Mbps

• CDMA2000 EV-DO– packet services only– DL up to 3,1 Mbps– UL up to 1,8 Mbps

• WiBro / Mobile WiMAX– packet services only– DL up to 3 / 10 Mbps– UL up to 1,2 / 2,5 Mbps

Prečo UMTS?

Prečo UMTS?

Prečo UMTS?

Evolúcia štandardov

GSM GPRS EDGE UMTS HSDPA EUL LTE

IS-95 CDMA2000 EV-DO rel.0 UMBEV-DO rev.A

FLASH-OFDM

802.16a (WiMAX) 802.16e (Mobile WiMAX)

3GPP

3GPP2

IEEE

Evolúcia štandardov

GSM GPRS EDGE UMTS HSDPA EUL LTE

EDGE EvoVoice evo

HSPA+

LTE-Advanced

IMT-2000

3GPP

3GPP spec. list

www.3gpp.org

Architektúra

RNC

MSC

HLR VLR AuC EIR

GMSC PSTN

RNC

SGSN

GGSN

Internet

IuB

Iur

IuCS

IuPS

UTRAN

Node B

UEMS

Node BBTSRNCBSC

UMTSGSM

Roadmap

Rel.99/4 Rel.5 Rel.6 Rel.7

HSPA+WCDMA HSPA+EULHSDPA

Rel.8

Latency (ms)

14

5.8

~50

42

12

~30

28

12

~30

14.4

0.384

~75

0.384

0.384

~150

UL Mbit/s

DL Mbit/s

HSPA+

Rel.9

168

24

~30

3GPP releases

MIMO, 64QAM,16QAM UL DC Comb

LTE

QPSK 16QAM multicode

3G – voice or data?Relative Network Load – RNC level

1

5

11

3

7

9

13

15

62843628466284962

Jan07

Mar07

May07

Jul07

Sep07

Nov07

Jan08

Mar08

May08

July08

Sep08

Nov08

Jan09

Packet data

Voice

Data is surpassing voice on 3G since 2 years

128 HSDPA networks50% at 3,6 Mbps

marginal 7,2 Mbps share310 HSDPA devices

221 HSPA networks> 30% at 7,2 Mbps55 EUL networks

800 HSPA devices

Rádiová prístupová sieť- UTRAN

• Komponenty– Node B– RNC

• Multiplexná technika– CDMA

• Duplexný mód– FDD– TDD

Funkcie Node B• Air interface Transmission / Reception• Modulation / Demodulation• CDMA Physical Channel coding• Micro Diversity (Soft Handover)• Error Handling• Closed loop power control

Funkcie RNC• Radio Resource Control• Admission Control• Channel Allocation• Power Control Settings• Handover Control• Macro Diversity (Soft Handover)• Ciphering• Segmentation / Reassembly• Broadcast Signaling• Open Loop Power Control

Duplexný mód• Frequency division duplex

+ symetric traffic (e.g. voice)+ higher average power

=> less Node Bs- higher complexity (HW)- channel measurements must be reported

• Time division duplex+ asymetric traffic (data)+ channel measurements are precise

- lower average power- strict synchronization needed- higher delays

FDD TDD

CDMA• Interference limited system• Sequences selection is crucial• Power control needed• Soft handover possible

• 5 MHz channel• 3,84 Mchip/s

Soft handover

Importance of Soft Handover

• Graphs show probability of excessive interference in neighbouring cell

• Active set size of 4 was agreed as mandatory for UEs

Why power control?• NEAR – FAR effect

– High interference between users & cell breathing

Power control

Choose throughput

Evaluate radio conditions

Required cell power

• Circuit switched services are guaranteed• Packet switched services are best effort

Power control• Open loop

– initial access to the network

• Closed loop– INNER loop

• Guarantee link quality (keep desired SIR)• 1500 times per second (Hz)

– OUTER loop• Minimize transmit power by setting SIR target for inner loop• Estimate SIR target based on BLER

Air interface protocol model

Channel concept

what type of data

how and with which type of characteristics

define the exact physical characteristics

BCCH, PCCH, DCCH, CCCH,DTCH, CTCH, …

BCH, PCH, RACH, FACH,DSCH, HS-DSCH, DCH, …

SCH, CPICH, PDSCH, HS-PDSCH,DPDCH, DPCCH, PRACH, …

new for UMTS, not in GSM/GPRS

Logical channels• Control channels

– Common (P2M)– Dedicated (P2P)

• Traffic channels– Common– Dedicated

Transport channels• Common channels

• Dedicated channel– DCH (UL & DL)

Physical channels• Synchronization• Pilot• Paging• Dedicated Physical Data Channel• Dedicated Physical Control Channel• High Speed Physical Downlink Shared Channel• …

Channels

downlink

uplink

Channel structure - UL

Channel structure - UL

Channel structure - DL

Channel structure - DL

Fyzická vrstva - DL

Channel Coding

Fyzická vrstva - DL

Spreading - UL

Modulation - UL

( )( ) ( )

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛−

⎟⎟⎠

⎞⎜⎜⎝

⎛++⎟⎟

⎠

⎞⎜⎜⎝

⎛−

=20

41

1cos41sin

CC

CCC

Tt

Tt

Tt

Tt

Tt

tRC

απ

απααπ

root-raised cosine (RRC) with roll-off α =0.22

RRCF impulse response

6 4 2 0 2 40.4

0.2

0

0.2

0.4

0.6

0.8

1

1.2

0

1

RRCF t( )

1− 1

t

normalized Tc = 1 (Tc = 26,042 μs)

Spreading - DL

Modulation - DL

( )( ) ( )

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛−

⎟⎟⎠

⎞⎜⎜⎝

⎛++⎟⎟

⎠

⎞⎜⎜⎝

⎛−

=20

41

1cos41sin

CC

CCC

Tt

Tt

Tt

Tt

Tt

tRC

απ

απααπ

root-raised cosine (RRC) with roll-off α =0.22

Codes

OVSF

Scrambling codes - UL(long code)

Scrambling - DL

Spreading & scrambling

Received signal

Detection

I = number of fingers of RAKE receiver

Measurements

Limiting factors• Downlink is power limited

• Uplink is interference limited

Common channels

Dedicated channels

max Node B power

Intercell interference

Intracell interference

max noise level

Power dynamics

Pnom

PCCH

100 ms

Services & RABs

Services & RABs• New service: Video Call

64/128/384PS Best Effort57CS Streaming64CS video call

12,2CS voiceRate [kbps]RAB type