carrier aggregation webcast 2012

8/10/2019 Carrier aggregation webcast 2012

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Carrier Aggregation

(one) Key Enabler for LTE-Advanced

Andreas Roessler

Technology Manager

Rohde & Schwarz America

[email protected]

Meik Kottkamp

Technology Manager

Rohde & Schwarz Germany

[email protected]


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Carrier Aggregation Key Enabler for LTE-Advanced

Nov 2012 | Andreas Roessler, Meik Kottkamp | 2

Q2/2012: 27.6 million LTE subscriptions worldwide

LTE status

LTE = 4G? No!


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IMT-Advanced LTE3GPP Rel.8

LTE-Advanced3GPP Rel.10

Transmission bandwidth (MHz) 40 / 100 MHz 20 100

Peak data rate (DL/UL) (Mbps)1000 (low mobility)

100 (high mobility)300/75 1000/500

Peak spectral

efficiency (bps/Hz)

DL (4x4/8x8) 15/- 15/- 16/30

UL (2x2/4x4) 6.75 3.758.4/16.8 (FDD)

8.1/16.1 (TDD)

Latency (ms)

User plane


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l Two or more component carriers are aggregated in LTE-Advanced

in order to support bandwidths up to 100 MHz.

l Support of contiguous and non-contiguous component carrier aggregation

(intra-band) and inter-band carrier aggregation.

l Different bandwidths per component

carrier (CC) are possible.

l Each CC limited to a max. of 110 RB

using the 3GPP Rel-8 numerology(max. 5 carriers, 20 MHz each).

l TDD: all CC have typically

same UL-DL configuration .

l Enables higher peak data ratesto meet IMT-Advanced requirements.

l NWOP: spectrum aggregation,

enabling Heterogonous Networks.

Carrier aggregation: types, motivation

Frequency band A Frequency band B



Intra-band contiguous

Intra-band non-contiguous

Inter-band

ComponentCarrier (CC)

2012 by Rohde&Schwarz


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Specification work in 3GPP RAN4, contd.

Inter-band band combinations (RAN#55)

Acronym Mode Work i temWork item

rapporteur

LTE_CA_B3_B7 FDD RP-100668 TeliaSonera

LTE_CA_B4_B17 FDD RP-111750 AT&T

LTE_CA_B4_B13 FDD RP-111678 Ericsson (Verizon)

LTE_CA_B4_B12 FDD RP-111316 Cox Communications

LTE_CA_B7_B20 FDD RP-110403 Huawei (Orange)



LTE_CA_B5_B12 FDD RP-120111 US Cellular


LTE_CA_B1_B7 FDD RP-111357 China Telecom

Acronym Mode Work itemWork item

rapporteur

LTE_CA_B3_B5 FDD RP-111603 SK Telecom

LTE_CA_B4_B7 FDD RP-111358 Rogers Wireless

LTE_CA_B3_B20 FDD RP-120372 Vodafone

LTE_CA_B8_B20 FDD RP-111213 Vodafone

LTE_CA_B11_B18 FDD RP-111634 KDDI

LTE_CA_B1_B19 FDD RP-111765 NTT DoCoMo

LTE_CA_B1_B21 FDD RP-111764 NTT DoCoMo

LTE_CA_B3_B5

with 2 uplinkFDD RP-120364 SK Telecom

LTE_CA_B3_B8 FDD RP-120388 KT


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2012 by Rohde&Schwarz

PCCSCC

Primary, secondary component carrier (PCC, SCC)

l A device capable of carrier aggregation has 1 DL primary

component carrier and 1 associated primary UL component carrier.

l

Basic linkage between DL and UL is signaled in SIB Type 2.l Configuration of primary component carrier (PCC) is UE-specific.

Downlink: cell search / selection, system information, measurement and mobility.

Uplink: access procedure on PCC, control information (PUCCH) on PCC.

Network may decide to switch PCC for a device handover procedure is used.

l Device may have one or several secondary component carriers. Secondary

Component Carriers (SCC) added in RRC_CONNECTED mode only. Symmetric carrier aggregation.

Asymmetric carrier aggregation (= most likely initial deployment scenario).

SCC PCC SCC

Downlink Uplink

SCC SCCSCCSCCSCC

PDSCH, PDCCH is optional

PDSCH and PDCCH

PUSCH only

PUSCH and PUCCH


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UE EUTRAN

Initial access and RRC connection establishmentattach request and PDN connectivity request

Authentication

NAS security

UE capabili ty procedure

AS security

RRC connection reconfiguration

Attach accept and default EPS bearer context request

Default EPS bearer context accept

Default EPS bearer setup (3GPP Rel-8)

Additional information

being submitted by a

3GPP Rel-10 device

Source: 3GPP TS 36.508 V10.0.0, section 4.5.3.3


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Carrier Aggregation capabilities of the deviceWhat frequency bands, band combination (CAand MIMO capabilities, inter-band, intra-band

contiguous and non-contiguous, bandwidth class

does the device support?

Carrier aggregation capabilities

are signaled separately for DL, UL.2012 by Rohde&Schwarz


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Bandwidth classes

l Bandwidth classes = UE (device) capabil ity.

CA Bandwidth

Class

Aggregated Transmission

Bandwidth Configuration

Maximum

number of CC

Nominal Guard

Band BWGB

A NRB,agg 100 1 0.05BWChannel(1)

B NRB,agg 100 2 FFS

C 100 < NRB,agg 200 2 0.05 max(BWChannel(1),BWChannel(2))

D 200 < NRB,agg [300] FFS FFS

E [300] < NRB,agg [400] FFS FFS

F [400] < NRB,agg [500] FFS FFS

BWChannel(1) and BWChannel(2) are channel bandwidths of two E-UTRA component carriers according to Table 5.6-1.

contiguous

Intra-band CA

non-contiguous

Intra-band CA Inter-band CA

Source: R4-122764

CA_1C CA_25A_25A CA_1A_5A25 25 1 51 AAC AA

Supported bandwidth class

E-UTRA frequncy band number


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LTE protocol stack entities impacted by carrier

aggregation

l Non-Access Stratum (NAS):

l UE is connected to the PCell.l PCell provides:

Security keys at handover.

Tracking area for Tracking Area Updates (TAUs).

l SCell(s) is only considered as (an) additional transmission resources.

l Carrier aggregation is transparent to higher layers:

l Packet Data Convergence Protocol (PDCP).

l Radio Link Control (RLC) like Rel-8, except higher data rate support.

lUEs are configured to handle SCells on RRC (3GPP TS 36.331).

l SCells are (de-)activated by MAC control elements (3GPP TS

36.321).


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RRCConnectionReconfiguration message

SCellIndex-r10

= 1, 2, , 7

maximum

4 SCells

Source: 3GPP TS 36.331 V10.5.0

UE-specific information; DL: cross-carrier

scheduling, CSI-RS configuration, PDSCH

UL: PUSCH, uplink power control, CQI, SRS

DL: bandwidth, antennas, MBSFN subframeconfiguration, PHICH configuration, PDSCH

configuration, TDD config (if TD-LTE SCell)

UL: bandwidth, carrier frequency, additional

spectrum emission, P-Max, power control info,

uplink channel configuration (PRACH, PUSCH)


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Activation / Deactivation of SCellsMedium Access Control (MAC) layer, basic rules

l Activated SCell:

l If activation in subframe n, then from subframe n+8 on availability of:

PDCCH (UL grants and DL assignments), SRS, CSI reports, CSI measurements

( n+8), power headroom reporting, SCell deactivation timer is started.

l Deactivated SCell:

l If deactivation in subframe n, then operation is stopped in subframe n+8.

l Activation / Deactivation MAC control element

(8-bit bitmap) (de-)activates one or more SCells.

l Automatic deactivation by timer (if no data or

PDCCH msg. are received for a certain period).

l In case of RRC reconfiguration:

Including mobility control information (i.e. a handover) all SCells = deactivated.

Without mobility control info added SCells = deactivated and remaining SCells =

unchanged status.

l Mechanism for UE power saving. PCells can never be deactivated.

sCellDeactivationTimer-r10:

2n radio frames with n = 1, 2, , 7, inf


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Cross-carrier scheduling

l Main motivation for cross carrier scheduling: Interference

management for HetNet (eICIC); load balancing.

l

Cross carrier scheduling is optional to a UE.l Activated by RRC signaling, if not activated no CIF is present.

l Component carriers are numbered, Primary Component Carrier (PCC) is

always cell index 0.

l Scheduling on a component carrier is only possible from ONE component,

independent if cross-carrier scheduling is ON or OFF:

l If cross carrier-scheduling active, UE needs to be informed about PDSCH

start on component carrier RRC signaling.

PDCCH

PDSCH

Component

Carrier #1

Component

Carrier #2

Component

Carrier #5

not possible,

transmission

can only be

scheduled by

one CC

PDCCH

PDCCH

PDSCH start

signaled by RRC

PCFICHFrequency

Time


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Carrier Aggregation Key Enabler for LTE-AdvancedNov 2012 | Andreas Roessler, Meik Kottkamp | 14

Outline: Carrier aggregation (one) Key Enabler

for LTE-Advanced

l Part I Technological background.

l Part II Test&Measurement aspects, demonstrations.

l Part III Summary.


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Outline: Carrier aggregation (one) Key Enabler

for LTE-Advanced

l Part I Technological background.

l Part II Test&Measurement aspects, demonstrations.

l Part III Summary.


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Summary, conclusion & outlook

l Carrier aggregation: to overcome spectrum crunch and to supporthigher data rates (IMT-Advanced requirements).

l Most demanded feature out of the LTE-Advanced feature set;

chipset / handset design implication:l Increased receiver complexity driven by # of carrier (and antennas).

l CA is transparent to higher layers (PDCP, RLC). Parameterization on RRC,activation by MAC, MAC is multiplexing entity.

l

One PHY layer per component carrier impact on uplink power control, BSR,PHR, TADV; Impact due to cross-carrier scheduling.

l Challenges on RF front-end: wideband PAs, tunable antennas, flexibleswitches.

l Outlook: CA enhancements in 3GPP Rel-11 and Rel-12.

l Timing Advanced Groups (TAG) will be introduced, allowing random accessprocess also on Secondary Component Carrier.

l TDD: different UL-DL configuration per carrier if in a different frequency band.

l Rel-12: new carrier might be introduced, not backward compatible.


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Thank you for your attention!

Carrier Aggregation

(one) Key Enabler for LTE-Advanced


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Specification work in 3GPP RAN4Intra-band contiguous and non-contiguous band combination (RAN#55)

l Intra-band contiguous. l Intra-band non-contiguous.

Acronym Mode Work i temWork item

rapporteur

LTE_CA-B7 FDD RP-111356 China Telecom

LTE_CA_B25 FDD Sprint-Nextel

LTE_CA_B38 TDD CMCC

LTE_CA_B38 TDD RP-110862 Huawei(CMCC)

LTE_CA_B41 TDD RP-120249 Clearwire

Acronym Mode Work itemWork item

rapporteur

LTE_CA_NC_B3 FDD RP-120383 SK Telecom

LTE_CA_NC_B25 FDD RP-120336 Sprint-Nextel

carrier aggregation webcast 2012

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