LTE ADV ANC ED - CARRIER AGGRE GATION/media/white papers/mobile... · LTE ADV ANC ED - CARRIER AGGRE GATION Introduction and Implications for Mobile Device Testing June 2013 Rev

LTE AdvAncEd - cArriEr AggrEgATion Introduction and Implications for Mobile Device TestingJune 2013

Rev. B 06/13

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LTE AdvAncEd - cArriEr AggrEgATion Introduction and Implications for Mobile Device Testing

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Why Carrier Aggregation? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

What is Carrier Aggregation? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Carrier Aggregation Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Impacts of Carrier Aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

The Impact of Carrier Aggregation on the RRC Layer . . . . . . . . . . . . . . . . . . 6

UE Capability Transfer Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Measurement Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

RRC Connection Reconfiguration Procedure . . . . . . . . . . . . . . . . . . . . . 8

Handover and RRC Connection Reestablishment Procedures . . . . . . . 8

The Impact of Carrier Aggregation on the MAC Sub-Layer . . . . . . . . . . . . . 9

SCell Activation and Deactivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

SCell and PCell Data Scheduling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

The Impact of Carrier Aggregation on the PHY Layer . . . . . . . . . . . . . . . . 10

Cross-Carrier Scheduling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Channel Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Downlink Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Timing Advance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Testing Carrier Aggregation In Mobile Devices . . . . . . . . . . . . . . . . . . . . . . . . 12

Functional Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Acceptance Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Conformance Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Service Provider Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Test Solutions for Carrier Aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

CS8 Mobile Device Tester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

VR5 Channel Emulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

LTE Advanced - Carrier AggregationIntroduction and Implications for Mobile Device Testing

1 • SPIREnT WHITE PAPER

InTRoDUCTIon

LTE-Advanced was introduced to meet the world’s demand for faster data delivery and

increased coverage . LTE-Advanced target parameters are defined in the 3GPP’s

TR 36 .9131 document, but high-level requirements include:

• Peak Downlink throughput: 1 Gbps

• Peak Uplink throughput: 500 Mbps

• Peak Downlink spectrum efficiency: 30 b/s/Hz

• Peak Uplink spectrum efficiency: 15 b/s/Hz

• Improve cell edge throughput

A quick calculation shows that both the uplink and downlink require more than 20 MHz

of bandwidth to achieve these targets . However, finding sufficient contiguous spectrum

is usually not an option for those deploying LTE & LTE-Advanced .

The term “spectrum fragmentation” is one that is often used to describe the large

number of spectral bands expected to be used for LTE deployments around the

world, which is an issue with respect to global roaming . Spectrum fragmentation also

describes the lack of contiguous bands for deploying the high data rates required by

advanced wireless services .

As an example, Figure 1 depicts one LTE network operator’s holdings in a top-tier city .

note that this operator’s holdings in the region amount to 50 MHz of spectrum, but a

single contiguous 20-MHz band cannot be constructed from the available holdings .

1 3GPP TR 36 .913: “Requirements for further advancements for Evolved Universal Terrestrial Radio Access (E-UTRA) (LTE-Advanced)”

Figure 1 - One operator’s spectral holdings in a major city.

This problem is universal, and is addressed in 3GPP Release 10 by the concept of carrier aggregation .

1850 1870 1890 1910 1930 1950 1970 1990

SPIREnT WHITE PAPER • 2


WHY CARRIER AGGREGATIon?

Carrier aggregation enables high data rates by aggregating multiple Release 8 carriers

to support transmission bandwidths of up to 100 MHz . This approach provides the

following advantages:

• Backward compatibility with release 8 and 9 capabilities

• Dynamic scheduling over different carriers to mitigate varying channel

conditions

• Higher throughput rates

• A practical solution for the LTE spectrum fragmentation issue

Having the flexibility to schedule data across multiple carriers to the same device

provides spatial and frequency diversity, allowing for more reliable communication to

the mobile . Also, with cross carrier scheduling, all carriers can be managed by one cell .

This introduces a new option for managing Inter Cell Interference Coordination (ICIC) .

It should be noted that the strategy driving the LTE-Advanced feature set is meant to

address the need for increased flexibility in network planning and data scheduling .

Carrier aggregation is just one part of the holistic implementation of that strategy; other

aspects include modulation, spatial multiplexing and Transport Block Size (TBS) .



WHAT IS CARRIER AGGREGATIon?

Perhaps the most significant feature of LTE-Advanced, carrier aggregation provides

the means to enable wider transmission bandwidths not previously supported in 3GPP

Release 8 or 9 . Carrier aggregation allows expansion of effective bandwidth delivered

to a user terminal through simultaneous utilization of radio resources across multiple

carriers; the multiple carriers are aggregated to form an overall larger bandwidth .

Carrier aggregation permits the LTE radio interface to be configured with up to five

“component carriers” of any bandwidth . Release 10 initially limits the number of

carriers to two . Uplink and downlink may be independently configured, but the number

of uplink carriers must be less than or equal to the number of downlink carriers .

Each component carrier is equivalent to a Release 8 or Release 9 carrier . Three types

of carrier aggregation are defined: inter-band aggregation, contiguous intra-band

aggregation and non-contiguous intra-band aggregation .

Inter-Band Carrier Aggregation

Intra-Band Carrier Aggregation (Contiguous)

Intra-Band Carrier Aggregation(non-Contiguous)

The mobile is connected to a primary cell (PCell) and one or more secondary cells

(SCells) . The mobile establishes an RRC connection only to the primary cell and will only

transmit PUCCH (uplink control information) to the primary cell . The SCell(s) transmit

PDCCH and PDSCH (downlink control and data) and receives the PUSCH (uplink data) .

SCells may optionally not use the PDCCH if a feature called cross-carrier scheduling is

supported by both the UE and the network; cross-carrier scheduling is a process where

scheduling for all the bearers are managed by one of them, namely the PCell bearer .

This reserves the SCell traffic “pipes” for data only .

In terms of network architecture, the main layers impacted by carrier aggregation are

the RRC, MAC and PHY layers . The core network, PDCP and RLC are not impacted by

carrier aggregation; in fact, from the perspective of the user plane, the aggregated

carrier is a single bearer just like any other .



IMPACTS oF CARRIER AGGREGATIon

While the concept of carrier aggregation is simple, the feature has significant impact

on transceivers . Mobile device developers implementing carrier aggregation need to

consider impacts on the Radio Resource Control (RRC), Medium Access Control (MAC) and

PHY layers as well as receiver design . From the device point of view, the user plane and

layers above RRC are not impacted .

UEs are classified according to their carrier aggregation aggregate bandwidths as

shown in Table 1 . Release 10 includes provisions for six classes but has only fully

defined three of them (A, B, and C) . Table 1 lists the definition of each class by the

number of Component Carriers (CC) supported as well the aggregated resource blocks

(nRB,agg

) and aggregate bandwidth (BWagg

) .

Table 1 - Carrier aggregation bandwidth classes

Carrier Aggregation

Bandwidth ClassAggregated Transmission Bandwidth Configuration

Maximum Number of Component Carriers (CC)

A n ≤ 100 1

B n ≤ 100 2

C 100 ≤ n ≤ 200 2

D 200 ≤ n ≤ [300] Under study

E [300] ≤ n ≤ [400] Under study

F [400] ≤ n ≤ [500] Under study

• PCell: The primary cell where the UE establishes the RRC connection and where PUCCH is used

• SCell: Secondary cell(s) that the UE could be monitoring for downlink assignment and using to transmit uplink data

• The serving cell(s): The PCell and one or more SCells, if configured for a UE supporting carrier aggregation

• Aggregated channel bandwidth: The cumulative channel bandwidth for all the carriers

• Cross-carrier scheduling: Scheduling information for an SCell is transmitted over PDCCH of the PCell

CARRIER AGGREGATIon TERMInoLoGY



As of Release 10, a UE should be able to indicate which bands it supports and should

be able to report on its carrier aggregation capability for each band . Table 2 and Table 3

show intra-band continuous carrier aggregation capabilities and inter-band capabilities

defined in the Release 10 specification .

Table 2 - Release 10 carrier aggregation capabilities - contiguous intra-band

Table 3 - Release 10 carrier aggregation capabilities - inter-band

CA Operating / Channel bandwidth

CA Configuration

E-UTRA Band

1.4 MHz

3 MHz

5 MHz

10 MHz

15 MHz

20 MHz

Maximum Aggregated Bandwidth

[MHz]

Bandwidth Combination

Set

CA_1A-5A1 Yes

20 05 Yes

CA_1A-18A1 Yes Yes Yes Yes

18 Yes Yes Yes


35 019 Yes Yes Yes


21 Yes Yes Yes

CA_2A-17A2 Yes Yes

20 017 Yes Yes

CA_2A-29A2 Yes Yes

29 Yes Yes Yes

CA_3A-5A

3 Yes Yes Yes30 0

5 Yes Yes3 Yes

20 15 Yes Yes

CA_3A-7A3 Yes Yes Yes Yes7 Yes Yes Yes

CA_3A-8A

3 Yes Yes Yes30 0

8 Yes Yes3 Yes

20 18 Yes Yes


20 Yes Yes


12 Yes Yes


13 Yes

CA_4A-17A4 Yes Yes

20 017 Yes Yes

CA_7A-20A7 Yes Yes Yes

20 Yes Yes

CA_11A-18A11 Yes Yes

Yes Yes Yes

CA Configuration / NRB_agg

CA Configuration

E-UTRA Band

50RB+100RB (10 MHz + 20 MHz)

75RB+75RB (15 MHz + 15 MHz)

75RB+100RB (15MHz + 20 MHz)

100RB+100RB (20 MHz + 20 MHz)

Maximum Aggregated Bandwidth

[MHz]

Bandwidth Combination

Set

CA_1C 1 Yes Yes 40 0CA_7C 7 Yes YesCA_38C 38 Yes YesCA_40C 40 Yes Yes Yes 40 0CA_41C 41 Yes Yes Yes Yes 40 0

It is important to note that there is work in progress to support different band

combinations in addition to the ones listed above .



The ImpacT of carrIer aggregaTIon on The rrc Layer

RRC signaling has been modified to support carrier aggregation messaging and

procedures . The following summarizes impacts to the RRC layer . Further details are

outlined in the 3GPP’s RRC protocol specification2 and UE radio access specification3 .

The four most significant changes are to:

• UE capability transfer procedure

• Measurement events

• RRC connection reconfiguration

• Handover and RRC connection reestablishment procedures

UE Capability Transfer Procedure

Carrier aggregation requires the addition of new Information Elements (IEs) . These

enable the communication of the UE’s carrier aggregation capability, and include:

• UE category:

– Table 4 lists UE categories as of Release 10 . Categories 6-8 imply carrier aggregation support . It is worth noting that categories 6 and 7 do not offer any improvement in downlink throughput over category 5 . They offer different configurations that can achieve the same throughput without relying on contiguous 20 MHz bandwidth .

Table 4 - UE categories

3GPP Release

User Equipment Category

Maximum L1 Data Rate Downlink

Maximum Number of DL MIMO layers

Maximum L1 Data Rate

Uplink

Release 8 Category 1 10 .3 Mbits/s 1 5 .2 Mbit/s





Release 10 Category 6 301 .5 Mbits/s 2 or 4 51 .0 Mbit/s

Release 10 Category 7 301 .5 Mbits/s 2 or 4 102 .0 Mbit/s


2 3GPP TS 36 .331: “Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification”

3 3GPP TS 36 .306: “Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio access capabilities”



• Supported Band Combination

– Indicates which band(s) and bandwidth class(es) support carrier aggregation .

• Cross-Carrier Scheduling

– Defines whether the UE supports cross-carrier scheduling operation .

• Simultaneous PUCCH and PUSCH transmission

– If the UE indicates support of carrier aggregation in the uplink, the UE supports simultaneous transmission of PUCCH and PUSCH across any uplink component carriers which the UE can aggregate .

• Multi-cluster PUSCH

– If the UE indicates support of carrier aggregation in the uplink, then the UE supports PUSCH transmissions over non-contiguous resource blocks across any UL component carriers which the UE can aggregate .

• Event A6 support

– Indicates that the UE supports enabling and triggering measurement event A6 related to a SCell . Event A6 is described in the next section (Measurement Events) of this document .

• SCell addition within the Handover to E-UTRAn

– Indicates that the UE can support an E-UTRAn handover directly into carrier aggregation mode .

Further details can be found in the 3GPP’s specification for UE radio access

capabilities4 .

Measurement Events

Measurement procedures and capabilities are used by the network to manage

network resources and perform different mobility procedures . Measurement event

A6 is introduced as an optional UE capability in release 10 to enable the addition and

removal of SCells . In Release 10, Events A3 and A5 are specific to PCells .

Table 5 describes events A3, A5 and A6 .

Table 5 - Measurement events related to carrier aggregation

Event Relevant Cell Description

A3 PCell neighbor becomes amount of offset better than PCell

A5 PCellPCell becomes worse than absolute threshold1 AnD neighbor becomes better than another absolute threshold2

A6 SCell neighbor becomes amount of offset better than SCell

4 3GPP TS 36 .306: “Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio access capabilities”



RRC Connection Reconfiguration Procedure

The RRC Connection Reconfiguration procedure is introduced to modify an established

connection configuration . With the introduction of carrier aggregation the addition or

removal of SCells is handled by this procedure . It is important to note that:

• This procedure can only add an SCell after Access Stratum (AS) security has been activated .

• SCell(s) can be changed using the RRCConnectionReconfiguration .

• ScellDeactivationTimer information is signaled to the mobile .

– This IE indicates how many frames of inactivity on an SCell should cause the UE to remove that SCell . More details are available in the 3GPP’s TS 36 .331 document .

– not including this IE will set the timer to infinity .

Handover and RRC Connection Reestablishment Procedures

The introduction of carrier aggregation does not directly impact handover and RRC

connection reestablishment procedures . However, it should be noted that all SCells are

released by the UE upon RRC reestablishment due to Radio Link failure or handover .

Release 10 allows for direct E-UTRAn handover in carrier aggregation mode if the UE

supports it .



The ImpacT of carrIer aggregaTIon on The mac Sub-Layer

MAC procedures (e .g . power headroom reports, retransmissions, TTI bundling semi-

persistent scheduling, etc .) are modified to support carrier aggregation . Details

are best described in the Release 10 version of the 3GPP’s TS 36 .321 MAC protocol

specification5 .

Two major areas are significantly impacted and warrant special attention:

• SCell activation and deactivation

• MAC scheduling over multiple carriers

SCell Activation and Deactivation

As was discussed earlier, RRC Connection reconfiguration is used to add or remove

SCells . once a cell is added, it must be activated by the MAC layer .

With Release 10, one formerly reserved value for the Logical Channel ID (LCID) is added

to the list of valid values used for MAC control element activation and deactivation:

LCID= 11011 is used by the UE to activate or deactivate the reception of SCells . PCells

cannot be deactivated . More details are available in section 5 .13 of 3GPP TS 36 .3215 .

SCell and PCell Data Scheduling

From the user plane perspective, the main change made to the MAC to support carrier

aggregation the enabling of scheduling on multiple component carriers as shown in

Figure 2 .

Each component carrier has a unique HARQ entity and independent HARQ processes .

For each component carrier one or two code-words may be generated depending on the

transmission mode . Figure 2 shows the changes introduced by carrier aggregation to

the MAC layer scheduling and HARQ process .

5 3GPP TS 36 .321: “Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access Control (MAC) protocol specification”



THE IMPACT oF CARRIER AGGREGATIon on THE PHY LAYER

With the introduction of the secondary cell, two major points become noteworthy:

• The PUCCH is only transmitted on primary cells . To provide information about other carriers, the Carrier Indicator Field (CIF) is provided in the Uplink Control Information (UCI) header .

• The PDCCH may optionally not be transmitted (on the SCell) if cross-carrier scheduling is enabled . In this case the Downlink Control Information (DCI) header includes a CIF that identifies the intended carrier .

Figure 2 - Downlink Data Link layer (L2) structures in Release 8 (left) and Release 10 (right)6

ROHC

Security

Segm.ARQ etc

Multiplexing UE1

ROHC

Security

Segm.ARQ etc

Scheduling / Priority Handling

Radio Bearers

Logical Channels

PDCP

RLC

MAC

…

…

…

Transport Channels

HARQ

ROHC

Security

Segm.ARQ etc

Multiplexing UE1

DL-SCHon CC1

ROHC

Security

Segm.ARQ etc

DL-SCHon CCx

HARQ HARQ

PDCP

RLC

MAC

…

…

…

…

Release 8 Release 10

6 3GPP TS 36 .300: “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access network (E-UTRAn); overall description; Stage 2”



Cross-Carrier Scheduling

Release 10 introduces an optional UE capability which allows for scheduling all carriers

via one carrier’s PDCCH . Enacting all scheduling on the PCell reserves SCells for user

data, minimizing SCell control channel overhead . It also enables coordinated scheduling

of data across multiple carriers, which in turn enables efficient network planning .

Channel Quality

Downlink channel quality is measured by the UE and reported to the base-station in

the Uplink Control Information (UCI) . The UCI field includes a CIF that indicates which

component carrier is being referenced . This is used in the case when cross-carrier

scheduling is enabled .

Uplink channel quality is measured by the base-station using Sounding Reference

Symbols (SRS) transmitted by the UE . As of Release 10, an optional capability allows

the UE to transmit SRS on secondary cells as well as primary cells .

Downlink Monitoring

Release 8 introduced the Radio Link Failure procedure . This procedure remains the

same with the introduction of carrier aggregation . The only clarification made in the

specification is that Radio Link Failure is only triggered by the UE upon failure of the

PCell, and is not triggered by failure of a SCell . Upon radio link reestablishment, all

SCells are deleted from the UE’s list of serving cells .

Timing Advance

Timing advance is a method in which a base-station requests that a mobile adjusts its

uplink timing (relative to downlink time) in order to mitigate the effect of propagation

delay . In carrier aggregation, only a single timing advance value is used by the

E-UTRAn; this value is applied to all carriers .



TESTInG CARRIER AGGREGATIon In MoBILE DEVICES

Carrier aggregation introduces new considerations for device design verification .

Additional RF testing and characterization is required, as is functional testing to verify

carrier-aggregation-specific features of the design, such as the ability of the mobile to

manage multiple data streams from multiple carriers . The following sections describe

some of these types of testing .

FUnCTIonAL TESTS

Functional tests are targeted at testing specific sub-features or procedures introduced

to the specifications to support carrier aggregation . They cover RRC, MAC, PHY layers

and Radio Resource Management (RRM) .

one example of a functional test introduced by carrier aggregation is verification of

the SCell deactivation MAC timer . A network that supports carrier aggregation must

configure each mobile with a deactivation timer . This timer tells the mobile when to

stop monitoring an SCell . To verify that a mobile being tested has stopped monitoring

an SCell, a test should schedule data on the SCell after the timer has expired . By

monitoring the behavior of the mobile, the tester or automated test can verify whether

or not the mobile has behaved properly with respect to the timer . The following table

lists additional examples of functional tests:

Test Focus Example of Test Areas

RRC - SCell addition and removal - Event A6 support - Radio link failure procedures - Handover procedures including SCell addition - Backward compatibility between carrier aggregation and Release 8 and 9 procedures

MAC and Physical Layer

- Decoding MAC control element to activate, deactivate the SCell - Deactivation of SCell based on the SCellDeactivation Timer - Deactivation of SCell because of radio link failure - Deactivation of SCell because of mobility procedures - Reception of downlink data from 2 component carriers - Decoding of carrier indication field for cross-carrier scheduling - Link quality monitoring and reporting for PCells and all SCells configured - Verification of Sounding Reference Signals (SRS) on PCell and SCells

Radio Resource Management

- SCell addition and activation - SCell removal and deactivation - Handover from PCell + SCell to a second PCell - Handover from PCell to PCell + SCell (If supported by the UE)



performance TeSTS

Performance tests are system tests that are intended to characterize the RF and end-

to-end performance of a mobile under different scenarios and channel conditions . The

introduction of additional carriers provides new methods to reach target throughput

numbers, mainly by maintaining multiple streams from different carriers . This has a

direct impact on the mobile’s performance, since throughput is now dependent on other

factors; each carrier will experience different channel conditions (especially in the case

of inter-band aggregation) and loading . Examples of performance test cases:

• Evaluation of uplink and downlink throughput when the E-UTRAn is scheduling over one carrier vs . two carriers (with separate sets of channel conditions)

• Impact of cross-carrier scheduling on throughput performance

• Impact of channel quality reporting on the mobile’s performance

accepTance TeSTIng

Acceptance testing can be divided into two main groups: Conformance Testing and

Service Provider Testing .

Conformance Testing

These are tests mandated by standards bodies for device certification, in this case

3GPP, GCF and PTCRB . All mobile equipment must pass these tests before being

commercially deployed . Test specifications 36 .521 and 37 .571 list different carrier

aggregation test cases testing different aspects of carrier aggregation .

Service Provider Testing

These are tests that are developed by wireless service providers to validate whether

mobiles that are carrier aggregation capable are fit to be deployed in their specific

networks . They are typically a combination of conformance and operator-defined

performance test cases .

TEST SoLUTIonS FoR CARRIER AGGREGATIon

Carrier Aggregation functionality will be deployed across Mobile Device/Chipset &

LTE network Infrastructure . Spirent offers test solutions available today, for Carrier

Aggregation testing in following test areas:

• R10 LTE Chipset & Devices

• LTE network Infrastructure

• Service Quality of Experience



CS8 Mobile Device Tester

CS8 Mobile Device Tester is multi technology network emulator solution that provides

Carrier Aggregation test capability for R10 LTE Chipset & Devices . CS8 is the only

“single box for two independent carriers with up to 4x2 MIMo for Carrier Aggregation

(CA) with independent fading”, with support for multiple band combinations . CS8

Hardware is 4x2 MIMo ready, for future deployments of Carrier Aggregation . Key

benefits of CS8 Device Tester for Carrier Aggregation:

• Configurable physical layer, MAC and RRC

• Configurable MAC scheduler

• Inter and Intra Band carrier aggregation

• Cross carrier scheduling

• SISo, 2x2 MIMo, 4x2 MIMo (with fading)

• Logging capability to analyze functional aspects of RRC/MAC/PHY layers

Single Box for Two Independent Carriers with up to 4x2 MIMo

VR5 Channel Emulator

Spirent also offers the market leading channel emulator, VR5, with the ability to support

up to 8 simultaneous RF channels with different MIMo configurations up to 6GHz .

With scalable bandwidth support up to 100 MHz, the VR5 can be used for Carrier

Aggregation testing of both LTE chipset & network infrastructure testing .



ConCLUSIon

Recognizing the looming spectrum shortage and the need to boost LTE speeds,

operators on a global scale are shifting gears to ensure their LTE networks will be

compatible with LTE-3GPP Release 10, LTE-Advanced . Carrier aggregation has been

specified by 3GPP as the method for addressing the wireless industry’s requirement for

greater spectrum utilization and faster data delivery .

By enabling RRC connections with multiple cells at low protocol layers, this Release

10 feature creates wide-band bearers for delivery of higher data rates . With the

challenge of combining relatively disparate contiguous and non-contiguous bands of

spectrum into a single logical channel, comes the guarantee of significant complexity

in development and testing . When considering the various types of carrier aggregation

and the possible combinations, it is not difficult to imagine the numerous test cases

and scenarios that will need to be addressed .

This paper was produced to provide an overview of carrier aggregation, the impacts

of implementation on relevant protocol layers and a discussion on how implementing

carrier aggregation affects the requirements for mobile device testing during

development . With years of experience of bringing real-world network and radio

channel conditions into the lab, Spirent is well positioned to support device developers

in addressing the challenges of carrier aggregation implementation .



ACRonYMS

The following is a list of all acronyms/abbreviations used in this document:

3GPP 3rd Generation Partnership Project

AS Access Stratum

CC Component Carrier

CIF Carrier Indicator Field

DCI Downlink Control Information

E-UTRA Evolved UMTS Terrestrial Radio Access

E-UTRAn Evolved UMTS Terrestrial Radio Access network

EV-Do EVolution - Data only

GCF Global Certification Forum

HARQ Hybrid Automatic-Repeat-Request

HSDPA High-Speed Downlink Packet Access

HSUPA High-Speed Uplink Packet Access

IE Information Element

LCID Logical Channel Identifier

LTE Long-Term Evolution

MAC Medium Access Control

PCell Primary Cell

PDCCH Physical Downlink Control Channel

PDCP Packet Data Convergence Protocol

PDSCH Physical Downlink Shared Channel

PHY PHYsical layer

PTCRB (pseudo-acronym; previously stood for PCS Type Certification Review Board)

PUCCH Physical Uplink Control Channel

PUSCH Physical Uplink Shared Channel

RF Radio Frequency

RRC Radio Resource Control

RRM Radio Resource Management

SCell Secondary Cell

SRS Sounding Reference Signal

TBS Transport Block Size

UCI Uplink Control Information

UE User Equipment

UMTS Universal Mobile Telecommunications System

Documents

LTE ADV ANC ED - CARRIER AGGRE GATION/media/white papers/mobile... · LTE ADV ANC ED - CARRIER AGGRE GATION Introduction and Implications for Mobile Device Testing June 2013 Rev