02_RA41202EN15GLA1_LTE_EPS_Overview.pdf

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RA4120-15a

NokiaEDU LTE RPESS LTE – EPS Overview

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© Nokia Solutions and Networks 2016

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Copyright and confidentiality The contents of this document are proprietary and confidential property of Nokia Solutions and Networks. This document is provided subject to confidentiality obligations of the applicable agreement(s). This document is intended for use of Nokia Solutions and Networks customers and collaborators only for the purpose for which this document is submitted by Nokia Solutions and Networks. No part of this document may be reproduced or made available to the public or to any third party in any form or means without the prior written permission of Nokia Solutions and Networks. This document is to be used by properly trained professional personnel. Any use of the contents in this document is limited strictly to the use(s) specifically created in the applicable agreement(s) under which the document is submitted. The user of this document may voluntarily provide suggestions, comments or other feedback to Nokia Solutions and Networks in respect of the contents of this document ("Feedback"). Such Feedback may be

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used in Nokia Solutions and Networks products and related specifications or other documentation. Accordingly, if the user of this document gives Nokia Solutions and Networks feedback on the contents of this document, Nokia Solutions and Networks may freely use, disclose, reproduce, license, distribute and otherwise commercialize the feedback in any Nokia Solutions and Networks product, technology, service, specification or other documentation. Nokia Solutions and Networks operates a policy of ongoing development. Nokia Solutions and Networks reserves the right to make changes and improvements to any of the products and/or services described in this document or withdraw this document at any time without prior notice. The contents of this document are provided "as is". Except as required by applicable law, no warranties of any kind, either express or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular

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purpose, are made in relation to the accuracy, reliability or contents of this document. NOKIA SOLUTIONS AND NETWORKS SHALL NOT BE RESPONSIBLE IN ANY EVENT FOR ERRORS IN THIS DOCUMENT or for any loss of data or income or any special, incidental, consequential, indirect or direct damages howsoever caused, that might arise from the use of this document or any contents of this document. This document and the product(s) it describes are protected by copyright according to the applicable laws. Nokia is a registered trademark of Nokia Corporation. Other product and company names mentioned herein may be trademarks or trade names of their respective owners. © Nokia Solutions and Networks 2016

© Nokia Solutionsand Networks 2016

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Index          

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LTE/EPC Overview LTE Air Interface Air Interface Overheads RRM overview LTE Link Budget Radio Planning – Coverage Planning Cell Range Radio Planning – Capacity LTE Performance Simulations Nokia LTE Solution Initial Parameters Planning

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Module Objectives After completing this module, the participant will be able to: •List the LTE/SAE main requirements

•Underline the LTE/SAE key features •Describe the LTE Network Architecture •List the key functionalities of the evolved NB •Describe the protocol stack implemented on EUTRAN interfaces •Identify the LTE Terminals categories •LTE Advanced features

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Module Contents • LTE Requirements • LTE Key Features • LTE Standardization • LTE Architecture • Evolved NB functionalities • EUTRAN Interfaces • LTE Terminals • LTE Advanced

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LTE/SAE Requirements Summary 1. • •

Simplify the RAN: - Reduce the number of different types of RAN nodes, and their complexity. - Minimize the number of RAN interface types.

2.

Increase throughput: Peak data rates of UL/DL 50/300 Mbps (R8)

3.

Reduce latency (prerequisite for CS replacement).

4.

Improve spectrum efficiency: Capacity 2-4 x higher than with Release 6 HSPA

5.

Frequency flexibility & bandwidth scalability: Frequency Refarming

6.

Migrate to a PS only domain in the core network: CSFB, SRVCC

7.

Provide efficient support for a variety of different services. Traditional CS services will be supported via VoIP, etc: EPS bearers for IMS based Voice

8.

Minimise the presence of single points of failure in the network above the eNBs S1-Flex interface

9.

Support for inter-working with existing 3G system & non-3GPP specified systems.

10.

Operation in FDD & TDD modes

11.

Improved terminal power efficiency

A more detailed list of the requirements and objectives for LTE can be found in TR 25.913.

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Module Contents • LTE Requirements • LTE Key Features • LTE Standardization

• LTE Architecture • Evolved NB functionalities • EUTRAN Interfaces • LTE Terminals • LTE Advanced

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LTE Radio Interface Key Features LTE Radio Access Network (EUTRAN)

Evolved Packet Core (EPC) SAE-GW MME

eNode-B

Serving GW

PDN GW

Packet Data Network

LTE Radio Interface Key Features • Retransmission Handling (HARQ/ARQ) • Spectrum Flexibility • FDD & TDD modes • Multi-Antenna Transmission • Frequency and time Domain scheduling • Uplink (UL) Power Control

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EUTRAN Key Features LTE Radio Access Network (EUTRAN)


eNode-B

Serving GW

PDN GW

Packet Data Network

EUTRAN Key Features: • Evolved NodeB • IP transport layer • UL/DL resource scheduling • QoS Awareness • Self-configuration

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EUTRAN Key Features Evolved NodeB • No RNC is provided anymore • The evolved Node Bs take over all radio management functionality. • This will make radio management faster and hopefully the network architecture simpler IP transport layer • EUTRAN exclusively uses IP as transport layer UL/DL resource scheduling • In UMTS physical resources are either shared or dedicated • Evolved Node B handles all physical resource via a scheduler and assigns them dynamically to users and channels • This provides greater flexibility than the older system QoS awareness • The scheduler must handle and distinguish different quality of service classes • Otherwise real time services would not be possible via EUTRAN • The system provides the possibility for differentiated services Self configuration • Currently under investigation • Possibility to let Evolved Node Bs configure themselves • It will not completely substitute the manual configuration and optimization.

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EPC Key Features LTE Radio Access Network (EUTRAN)


eNode-B

Serving GW

PDN GW

Packet Data Network

EPC Key Features: • IP transport layer • QoS Awareness • Packet Switched Domain only • 3GPP (GTP) or IETF (MIPv6) option • Prepare to connect to non-3GPP access networks

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EPC Key Features IP transport layer • EUTRAN exclusively uses IP as transport layer QoS awareness • The scheduler must handle and distinguish different quality of service classes • Otherwise real time services would not be possible via EUTRAN • The system provides the possibility for differentiated services Packet Switched Domain only • No circuit switched domain is provided • If CS applications are required, they must be implemented via IP • Only one mobility management for the UE in LTE. 3GPP (GTP) or IETF (MIPv6) option • The EPC can be based either on 3GPP GTP protocols (similar to PS domain in UMTS/GPRS) or on IETF Mobile IPv6 (MIPv6) Non-3GPP access • The EPC will be prepared also to be used by non-3GPP access networks (e.g. LAN, WLAN, WiMAX, etc.) • This will provide true convergence of different packet radio access system

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Module Contents • LTE Requirements • LTE Key Features • LTE Standardization • LTE Architecture • Evolved NB functionalities • EUTRAN Interfaces

• LTE Terminals • LTE Advanced

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LTE = Long Term Evolution • Next step for GSM/WCDMA/HSPA and CDMA

A true global roaming technology

• Peak data rates of 300 Mbps / 50 Mbps (R8)

Enhanced consumer experience

• Low latency 10-20 ms

• Scalable bandwidth of 1.4 – 20 MHz (R8)

Easy to introduce on any frequency band

• OFDM technology • Flat, scalable IP based

Decreased cost / GB

architecture 14

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Schedule for 3GPP releases

• Next step for

A true global roaming technology

GSM/WCDMA/HSPA and cdma2000 Specification:

HSPA+ LTE Studies

Rel. 5

Rel. 6

Rel. 7

2003

2005

HSDPA IMS

3GPP Rel. 99/4 2000

•

HSUPA MBMS WLAN IW

UMTS/ WCDMA

LTE-A studies

LTE-A

Rel. 9

Rel. 10

LTE & EPC

2007

Rel. 8 2008

2009

2011

year

LTE have been developed by the same standardization organization. The target has been simple multimode implementation and backwards compatibility. HSPA and LTE have in common: – Sampling rate using the same clocking frequency – Same kind of Turbo coding The harmonization of these parameters is important as sampling and Turbo decoding are typically done on hardware due to high processing requirements. WiMAX and LTE do not have such harmonization.

•

• •

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Module Contents • LTE Requirements • LTE Key Features

• LTE Standardization • LTE Architecture • Evolved NB functionalities • EUTRAN Interfaces • LTE Terminals • LTE Advanced

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Network Architecture Evolution HSPA

Direct tunnel

I-HSPA

LTE

HSPA R6

HSPA R7

HSPA R7

LTE R8

GGSN

GGSN

GGSN

SAE GW

SGSN RNC Node B (NB)

SGSN

SGSN

MME/SGSN

RNC Node B (NB)

Node B + RNC Functionality

- Flat architecture: single network element in user plane in radio network and core network

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Evolved Node B (eNB) User plane Control Plane


SAE: System Architecture Evolution SAE GW: Serving Gateway +PDN Gateway

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Evolved Packet System (EPS) Architecture - Subsystems • The EPS architecture goal is to optimize the system for packet data transfer. • There are no circuit switched components. The EPS architecture is made up of: – EPC: Evolved Packet Core, also referred as SAE – eUTRAN: Radio Access Network, also referred as LTE EPS Architecture LTE or eUTRAN

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SAE or EPC

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•

EPC provides access to external packet IP networks and performs a number of CN related functions (e.g. QoS, security, mobility and terminal context management) for idle and active terminals

•

eUTRAN performs all radio interface related functions


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LTE/SAE Network Elements Main references to architecture in 3GPP specs.: TS23.401,TS23.402,TS36.300

Evolved UTRAN (E-UTRAN)

Evolved Packet Core (EPC) HSS

eNB

Mobility Management Entity

Policy & Charging Rule Function

S6a

MME

X2

S10

S7

Rx+ PCRF

S11 S5/S8

S1-U LTE-Uu

LTE-UE

Evolved Node B (eNB)

SGi

PDN Serving Gateway

PDN Gateway SAE Gateway

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• LTE Standardization • LTE Architecture • Evolved NB functionalities • EUTRAN Interfaces • LTE Terminals • LTE Advanced

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Evolved Node B (eNB) eNB Functions Inter-cell RRM: HO, load balancing between cells Radio Bearer Control: setup , modifications and release of Radio Resources Connection Mgt. Control: UE State Management, MME-UE Connection Radio Admission Control eNode B Meas. collection and evaluation Dynamic Resource Allocation (Scheduler) IP Header Compression/ de-compression Access Layer Security: ciphering and integrity protection on the radio interface

• Only network element defined as part of eUTRAN. • Replaces the old Node B / RNC combination from 3G. • Terminates the complete radio interface including physical layer. • Provides all radio management functions • To enable efficient inter-cell radio management for cells not attached to the same eNB, there is a inter-eNB interface X2 specified. It will allow to coordinate inter-eNB handovers without direct involvement of EPC during this process.

MME Selection at Attach of the UE User Data Routing to the SAE GW Transmission of Paging Msg coming from MME Transmission of Broadcast Info (e.g. System info, MBMS) 21

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Module Contents • LTE Requirements • LTE Key Features • LTE Standardization • LTE Architecture • Evolved NB functionalities • EUTRAN Interfaces • LTE Terminals • LTE Advanced

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LTE Radio Interface & the X2 Interface (E)-RRC

• • • •

User PDUs .. User PDUs

PDCP RLC

TS 36.300

MAC

eNB

LTE-L1 (FDD/TDD-OFDMA/SC-FDMA)

• •

LTE-Uu

X2-CP (Control Plane)

•

X2-UP (User Plane) User PDUs

TS 36.423 TS 36.422 TS 36.421

LTE-Uu interface Air interface of LTE Based on OFDMA in DL & SC-FDMA in UL FDD & TDD duplex methods Scalable bandwidth: 1.4MHz - 20 MHz

X2-AP

GTP-U

SCTP

UDP

IP

IP

L1/L2

L1/L2

X2 TS 36.424

X2 interface Inter eNB interface X2AP: special signaling protocol (Application Part) Functionalities: – In inter- eNB HO to facilitate Handover and provide data forwarding. – In RRM to provide e.g. load information to neighboring eNBs to facilitate interference management. – Logical interface: doesn’t need direct site-tosite connection, i.e. can be routed via CN as well

TS 36.421

TS 36.420

eNB 23

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S1-MME & S1-U Interfaces S1 interface is divided into two parts:

S1-MME (Control Plane)

S1-MME interface

• Control Plane interface between eNB & MME

NAS Protocols

• S1AP:S1 Application Protocol

TS 36.413

S1-AP

• MME & UE will exchange NAS signaling via eNB

TS 36.412

SCTP

through this interface ( i.e. authentication, tracking area updates)

IP

S1-U (User Plane)

maximum of 16 MME. (LTE2, RL20) S1-U interface

•

User plane interface between eNB & Serving Gateway.

TS 36.411

L1/L2

• S1 Flex: an eNB is allowed to connect to a

•

MME

User PDUs

eNB

GTP-U TS 36.414

UDP

Pure user data interface (U=User plane)

Serving Gateway

IP TS 36.411

L1/L2

TS 36.410

LTE4: Multi-Operator Core Network (MO-CN): An eNB can be connected simultaneously to the different Evolved Packet Cores (EPCs) of different operators, and shared by them.

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Module Contents • LTE Requirements

• LTE Key Features • LTE Standardization • LTE Architecture • Evolved NB functionalities • EUTRAN Interfaces • LTE Terminals • LTE Advanced

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LTE UE Categories Downlink UE Category

3GPP Release

Peak rate in Maximum number Mbps of DL-SCH transport DL / UL block bits received within a TTI (Note)

1 2 3 4 5 6

4

7

4 5

8 9

6

10 7

4 4

Uplink

Maximum number of bits of a DL-SCH Total number of soft transport block channel bits received within a TTI

Maximum number of supported layers for spatial multiplexing in DL

Maximum number Maximum number of UL-SCH transport of bits of an UL-SCH block bits transport block transmitted within a transmitted within a TTI TTI

Support for 64QAM in UL

Total layer 2 buffer sizes

150 000

8 8 8 8 8

10 / 5

10296

10296

250368

1

5160

5160

No

50 / 25

51024

51024

1237248

2

25456

25456

No

700 000

50 / 100

102048

75376

1237248

2

51024

51024

No

1 400 000

150 / 50

150752

75376

1827072

2

51024

51024

No

1 900 000

300 / 75

299552

149776

3667200

4

75376

75376

Yes

3 500 000

10

300 / 50

301504

51024

51024

No

3 300 000

4

102048 (UL MIMO)

51024

No

3 800 000

8

1497760

149776

Yes

42 200 000

51024

51024

No

4 800 000

102048 (UL MIMO)

51024

No

5 200 000

10

300 / 100

301504

10

3000 / 1500

2998560

11

450 / 50

452256

11

450 / 100

452256

75376 (2 layers) 149776 (4 layers) 75376 (2 layers) 149776 (4 layers) 299856 75376 (2 layers) 149776 (4 layers) 75376 (2 layers) 149776 (4 layers)

3654144 3654144 35982720 5481216 5481216

2 4 2

2 4 2 4

NOTE: In carrier aggregation operation, the DL-SCH processing capability can be shared by the UE with that of MCH received from a serving cell. If the total eNB scheduling for DL-SCH and an MCH in one serving cell at a given TTI is larger than the defined processing capability, the prioritization between DL-SCH and MCH is left up to UE implementation. NOTE: Rel 8 = [1 .. 5], Rel 10 = [6 .. 8], Rel 11 = [9 .. 10] A UE Cat 9 transmits Rel 11  UE category 9 + Rel 10 transmits Cat 6  UE Cat 9 + Rel 8 transmits Cat 4 NOTE: A UE indicating category 10 shall also indicate category 7 and 4. A UE indicating category 9 shall also indicate category 6 and 4. A UE indicating category 8 shall also indicate category 5.

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Power Class 1 2

Tx Power (dBm) [+30] [+27]

Tolerance (dB)

3 4

+23 [+21]

+/-2 dB

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LTE: What is new? • new network architecture: – More functionality in the base

- new radio transmission schemes: • OFDMA in DL • SC-FDMA in UL • MIMO Multiple Antenna Technology - New radio protocol architecture: • Complexity reduction • Focus on shared channel operation, no dedicated channels anymore

station (eNodeB) – Focus on PS domain – Flat architecture (2-nodes) – All-IP

• Important for Radio Planning – Frequency Reuse 1 ▪ No need for Frequency Planning

– No need to define neighbor lists in LTE

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• LTE Standardization • LTE Architecture • Evolved NB functionalities • EUTRAN Interfaces

• LTE Advanced

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LTE becomes LTE-Advanced with 3GPP Rel 10 LTE-Advanced Goals Meet and exceed capabilities requested for IMT-Advanced

LTE-A fulfills or exceeds the requirements of IMT-Advanced defined by ITU

Meet 3GPP operators’ requirements for LTE evolution Enhance macro network performance

Mobility

Enable efficient use of small cells More Bandwidth available Able to achieve higher data rates ( up to 1 Gbps in downlink for stationary users)

Data rates

Enhance the coverage by increasing data rates on the cell edge Backward compatibility

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System Performance Requirements • Peak data rate - 1 Gbps data rate will be achieved by 4-by-4 MIMO and transmission bandwidth wider than approximately 70 MHz • Peak spectrum efficiency - DL: Rel. 8 LTE satisfies IMT-Advanced requirement

- UL: Need to double from Release 8 to satisfy IMT-Advanced requirement

Rel. 8 LTE Peak data rate Peak spectrum efficiency [bps/Hz]

LTE-Advanced

IMT-Advanced

DL

300 Mbps

1 Gbps

UL

75 Mbps

500 Mbps

DL

15

30

15

UL

3.75

15

6.75

1 Gbps(*)

*“100 Mbps for high mobility and 1 Gbps for low mobility

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LTE-Advanced: First features standardized in 3GPP Release10 Key aspects in 3GPP Rel.10 Carrier Aggregation

….. Carrier1 Carrier2

8x

MIMO

Carrier n

4x

• Carrier Bandwidth extension by carrier aggregation • Downlink: Up to 100 MHz bandwidth with 2 Release 8 carriers from different frequency bands • Uplink: Only single band carrier aggregation • New codebook for downlink (DL) 8TX MIMO

Coordinated Multipoint

• Feedback enhancements for DL 2TX/4TX Multiuser MIMO • 2TX/4TX Uplink Single/Multiuser MIMO • Coordinated multipoint transmission (CoMP), also known as cooperative system • Receiving transmission from multiple sectors (not necessary visible for UE)

Relaying

• Single Relay Node architecture based on self-backhauling eNB • Simple intercell interference coordination in time domain • Enhancements for office Femto handovers

Heterogeneous networks

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Support wider bandwidth Carrier aggregation to achieve wider bandwidth Support of spectrum aggregation  Peak data rate, spectrum flexibility Advanced MIMO techniques Extension to up to 8-layer transmission in downlink Introduction of single-user MIMO up to 4-layer transmission in uplink  Peak data rate, capacity, cell-edge user throughput Coordinated multipoint transmission and reception (CoMP) CoMP transmission in downlink CoMP reception in uplink  Cell-edge user throughput, coverage, deployment flexibility Further reduction of delay AS/NAS parallel processing for reduction of C-Plane delay Relaying Type 1 relays create a separate cell and appear as Rel. 8 LTE eNB to Rel. 8 LTE UEs Coverage, cost effective deployment

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Bandwidth Extension by Carrier Aggregation

Key aspects in 3GPP Rel.10

Carrier Aggregation


8x

MIMO

Carrier n

4x



up to 100 MHz

 Flexible component carrier aggregation  different frequency bands  asymmetric in UL/DL

Component Carrier (LTE rel. 8 Carrier)

Mobility


20 MHz

10 MHz

Aggregated BW: 30MHz 20 MHz

20 MHz

in June 2009

Relaying

20 MHz

20 MHz

20 MHz

Aggregated BW: 5x20MHz = 100MHz

300Mbps 300Mbps 300Mbps

300Mbps

300Mbps

Heterogeneous networks 1.5Gbps

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Carrier Aggregation (CA) - High peak data rate of 1 Gbps in downlink and 500 Mbps in uplink can be achieved with bandwidth extension from 20 MHz up to 100 MHz. - Backwards compatibility to Release 8 by combining N Release 8 component carriers to N x LTE bandwidth, for example 5 x 20 MHz = 100 MHz - Old LTE terminals use one carrier, new ones all N

LTE-Advanced maximum bandwidth

Rel’8 BW

Rel’8 BW

Rel’8 BW

Rel’8 BW

Rel’8 BW

Carrier 1

Carrier 2

Carrier 3

Carrier 4

Carrier 5

Both contiguous and non-contiguous CA is supported offering improved spectrum flexibility (e.g. for refarming).

CA also offers opportunities for autonomous interference management schemes – especially relevant for heterogeneous networks.

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Brief description • Carrier Aggregation functionality for three Component Carriers (3CC) provides means to aggregate three downlink carriers configured on three overlapped cells that operate in separate bands. This feature is activated for the UEs that have such CA capability on board that match with bands where CA operates in the network. Improving the user perceived downlink throughput (both peak and instantaneous) is the primary design target of this feature. • Both LTE1804 and LTE1836 allow to aggregate up to 60 MHz spectrum. • LTE1836 is a TDD counterpart of FDD LTE1804.

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LTE1804 DL Carrier Aggregation 3CC 60 MHz (1/2)

CA capable UE

CA non-capable UE

35

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CA principles: • Every cell called Component Carrier (CC) is logically combined with additional cells serving the same site sector • Primary Cell (PCell) serves both UL and DL traffic (GBR and non-GBR) • Secondary Cells (SCells) serve DL non-GBR traffic only • If configured so, every carrier can play a PCell role • All cells handle CA and non-CA UEs simultaneously • CA for UL traffic is not available yet

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LTE1804 DL Carrier Aggregation 3CC 60 MHz (2/2)

3CC 60 MHz CA principles: • Enables aggregation of three CC • Contiguous and non-contiguous intra-band and inter-band CA supported

band 1

Intra-band, contiguous

CA capable UE

f band 1 CA noncapable UE

Intra-band, noncontiguous f band 1

band 2

Inter-band, non-contiguous f

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Supported band combinations Operating band

Note*

Operating band

Frequency band

Frequency band

2

5

30

0

1900

850

2300

2

12

30

0

1900

700

2300

2

29

30

0

1900

700

2300

3

3

7

0

1800

1800

2600

3

3

8

0

1800

1800

900

3

7

20

0

1800

2600

800

4

5

Band 4, NC, 0

1700

1700

850

1

3

5

0

2100

1800

850

1

3

8

0 and 2

2100

1800

900

1

5

7

1

2100

850

2600

1

18

28

0

2100

850

700

2

2

5

Band 2, NC, 0

1900

1900

850

1900

1900

700

4

LTE1803

Note*

2

2

12

Band 2, NC, 0

2

2

29

Band 2, C, 0

1900

1900

700

4

4

12

Band 4, NC, 0

1700

1700

700

2

4

4

Band 4, NC, 0

1900

1700

1700

4

5

30

0

1700

850

2300

4

12

30

0

1700

700

2300

4

29

30

0

1700

700

2300

2 2

4 4

5 12

0 0

1900 1900

1700 1700

850 700

* - numbers indicate the bandwidth combination set supported, C – contiguous, NC – non-contiguous

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Supported bandwidth and eNB antenna combinations Supported bandwidth combinations

38

5

5

5

10

10

10

5

5

10

10

10

15

5

5

15

10

10

20

5

5

20

10

15

15

5

10

10

10

15

20

5

10

15

10

20

20

5

10

20

15

15

15

5

15

15

15

15

20

5

15

20

15

20

20

5

20

20

20

20

20

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Antenna configuration 2TX/2R X

2TX/2R X

2TX/2R X

2TX/2R X

2TX/2R X

4TX/4R X

2TX/4R X

4TX/4R X

4TX/4R X

4TX/4R X

4TX/4R X

4TX/4R X

LTE1803

Bandwidth [MHz]

LTE1803

Bandwidth [MHz]

Supported eNB antenna combinations


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Development timeline of related features Related features: • LTE1089 – DL Carrier Aggregation • LTE1332 – DL Carrier Aggregation 40 MHz

• LTE1562 – Carrier Aggregation for multi-carrier eNBs • LTE1803 – Downlink Carrier Aggregation 3CC 40 MHz

LTE1089 RL50

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LTE1332 RL60

LTE1562 RL70

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LTE1803 RL70

LTE1804 FL15A

LTE1804 Downlink carrier aggregation 3CC 60 MHz

Extends LTE1803 functionalities

SCell (de)configuration and (de)activation procedures are reused


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With and without the LTE1804 DL Carrier Aggregation 3CC 60 MHz (1/2) • Maximum aggregated

• Maximum aggregated

• Maximum aggregated

bandwidth of 40 MHz

bandwidth of 40 MHz

bandwidth of 60 MHz

• Maximum throughput of



287.7 Mbps

283.0 Mbps

• Fragmented spectrum

431.1 Mbps

• Inter-band CA only

tailored

tailored

2CC CA

40

• Fragmented spectrum

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3CC CA in LTE1803

3CC CA in LTE1804


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With and without the LTE1804 DL Carrier Aggregation 3CC 60 MHz (2/2) • Only one (20+10+10) MHz bandwidth combination supported • Joint activation of SCells • CA limitations in case of fragmented spectrum owned • Limitation of CA UEs number

• Additional twenty bandwidth and eighteen band combinations supported • Stepwise (de)activation of SCells • Contiguous and non-contiguous intra-band and inter-band CA • Increased number of UEs with SCell(s) configured • Increased number of PRBs for PUCCH Format 3 • PUCCH Format 3 ACK/NACK and periodic CSI multiplexing

3CC CA in LTE1803

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3CC CA in LTE1804


39

Slide 42

LTE1836 TDD DL Carrier Aggregation 3CC 60 MHz and LTE1838 TDD DL Inter-band Carrier Aggregation 40 MHz features introduced in TD-LTE15A are very closely related to each other and share the same solutions (for example many functionalities implemented in LTE1838 are essential for proper LTE1836 operation) Due to that fact there cannot be initiated clear division between pure LTE1836 or pure LTE1838 functionalities In combination with legacy RL55TD LTE1830, they create complete solution for flexible TDD Carrier Aggregation configuration in intra-band and inter-band scenarios with support of up to three Component Carriers

40

Slide 43

LTE1836 DL Carrier Aggregation 3CC 60 MHz is a first feature introducing possibility of aggregating three component carriers by the UE in Nokia TDD product FDD counterpart features are RL70 LTE1803 DL CA 3CC 40MHz with extensions introduced in FDD-LTE15A LTE1804 DL CA 3CC 60 MHz Primary aim of the features is to boost mean and peak downlink user throughput via sending user data simultaneously over two or three component carriers Maximum achievable peak user throughput can be even three times higher in 3CC scenario (LTE1836) in contrast to non-CA case Maximum peak user throughput in 2CC scenario (LTE1838) remains unchanged comparing to legacy LTE1558/LTE1830

41

Slide 44

To make the aggregation of carriers possible, regular cell is paired with two additional logical cells serving the same site sector Primary Cell and both Secondary Cells have to be collocated with each other

Only non-GBR data could be sent via Secondary Cells (SCells) All cells handling CA UEs serve simultaneously also regular, non-CA UEs There is no carrier aggregation in the uplink direction – all UL traffic is sent via Primary Cell (PCell) only

42

Slide 45

LTE1836 TDD DL Carrier Aggregation 3CC 60 MHz • Cells that will be aggregated have to be co-located and served by the same eNB • 20 MHz + 20 MHz + 10/15/20 MHz channel combinations are supported by LTE1836 - It gives possibility of using up to 60 MHz spectrum by the 3CC CA-capable UEs

• Only certain band combinations for 3CCs are supported by LTE1836: - Intra-band 2300 (3GPP band 40) - Intra-band 2500 (3GPP band 41) - Inter-band 2600, 2500 (3GPP bands 38 and 41)

- Inter-band 1900, 2500 (3GPP bands 39 and 41)

• All 2Tx/4Tx/8Tx site configurations are supported by LTE1836 • There is no restriction on which of the carriers could play a role of PCell

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Slide 46

LTE1838 TDD DL Inter-band Carrier Aggregation 40 MHz

• Cells that will be aggregated have to be co-located and served by the same eNB • 20 MHz + 10/20 MHz channel combinations are supported by LTE1838 - It gives possibility of using up to 40 MHz spectrum by the 2CC CA-capable UEs

• Only certain band combinations for 2CCs are supported by LTE1838: - Intra-band 2600 (3GPP band 38) - Intra-band 2500 (3GPP band 41) - Inter-band 2600, 2500 (3GPP bands 38 and 41)

- Inter-band 1900, 2500 (3GPP bands 39 and 41)

• 2Tx and 8Tx site configurations are supported by LTE1838 • There is no restriction on which of the carriers could play a role of PCell

46

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Slide 47

LTE1836 TDD DL Carrier Aggregation 3CC 60 MHz LTE1838 TDD DL Inter-band Carrier Aggregation 40 MHz

LTE1558 TDD DL Carrier Aggregation 40 MHz

47

LTE1830 TDD DL Carrier Aggregation enhancements

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LTE1562 Carrier Aggregation for multicarrier eNBs

LTE1803 DL Carrier Aggregation 3CC 40 MHz


In general LTE1836 TDD DL Carrier Aggregation 3CC 60 MHz and LTE1838 TDD DL Inter-band Carrier Aggregation 40 MHz are based on the legacy features: RL45TD LTE1558 TDD DL Carrier Aggregation RL55TD LTE1830 TDD DL Carrier Aggregation enhancements TD-LTE15A LTE1562 Carrier Aggregation for multi-carrier eNBs

LTE1836 TDD DL CA 3CC 60 MHz adapts also many solutions from FDD counterpart features LTE1803 DL Carrier Aggregation 3CC 40 MHz and LTE1804 DL Carrier Aggregation 3CC 60 MHz

45

Slide 48

LTE1836 TDD DL Carrier Aggregation 3CC 60 MHz LTE1838 TDD DL Inter-band Carrier Aggregation 40 MHz

48

Before

After

• Only two intra-band Component Carriers could be used at the same time by CAcapable UEs

• Up to three Component Carriers can be used at the same time by CA-capable UEs

• In case customers have two or three frequency layers, part of the spectrum couldn’t be used to improve throughput of CA-capable UEs

• Additionally inter-band scenarios with two Component Carriers are supported

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• More flexibility for CA configuration, especially in cases where customers have quite fragmented spectrum


46

Slide 49

LTE2305 Inter-eNB CA for two Macro eNBs works with all legacy 2CC and 3CC Carrier Aggregation features: LTE1089/LTE1332 DL Carrier Aggregation 40 MHz (2CC) LTE1562 Carrier Aggregation for multi-carrier eNBs (2CC) LTE1803/LTE1804 DL Carrier Aggregation 60 MHz (3CC) LTE2006 Flexible SCell selection (2CC/3CC) Feature is mainly focused on the inter-eNB cooperation in terms of connectivity and messages exchange (i.e. it does not modify any of the legacy CA features): list of supported band/bandwidth combinations remains unchanged comparing to legacy CA features (no new combinations are introduced nor none of them are removed) none of the RRM algorithms or procedures (SCell(s) configuration/activation, scheduling, data split among serving cells, HARQ feedback, etc.) implemented in legacy CA features are modified

47

Slide 50

LTE2305 Inter-eNB DL CA for two Macro eNBs • LTE2305 Inter-eNB CA for two Macro eNBs should not be confused with socalled Dual Connectivity solution introduced in 3GPP Release 12 that allows Carrier Aggregation between separate eNBs using the X2 connection, or by splitting the bearer path at the serving gateway. - Dual Connectivity in Nokia product will be introduced in the future releases. It will require new scheduling algorithms that are more tolerant for long latencies.

LTE2305 Inter-eNB CA

Dual Connectivity

SRIO link

X2 connection …

eNB 1

50

eNB 2

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eNB 1

eNB 2


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Slide 51

LTE2305 Inter-eNB DL CA for two Macro eNBs

Before

After

• Only intra-eNB Carrier Aggregation was possible (all cells involved in CA had to be hosted by the same eNB)

• Inter-eNB Carrier Aggregation between two co-located Macro eNBs is possible

• More complex CA configurations (such like 2 carriers of 3 x 20 MHz cells with UL CoMP) could not be used due to the HW limitations (deployment on separate eNBs required)

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• More advanced configurations that have to be deployed on separate eNBs, can now be used for DL Carrier Aggregation allowing for more flexibility in CA configuration


49

Slide 52

MIMO Extension Key aspects in 3GPP Rel.10

Carrier Aggregation


8x

MIMO

Carrier n

4x


Relaying


52

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• Uplink MIMO for up to 4 UE antennas Increase peak data rate, and average and the cell edge throughput Fall back to TX diversity available for data and control (use the power amplifiers of all antennas even if multi-stream doesn’t work) Advancements in reference signal structure, channel sounding and feedback • DL MIMO for 8 TX antennas Increase peak data rate, and average and the cell edge throughput Release 8 LTE UEs support up to 4 TX antennas (which are actually combinations of the 8 physical antennas) Improved reference signal design, scheduling and feedback schemes

50

Slide 53

LTE568 : DL adaptive closed loop MIMO (4x2) TX diversity for 4 antennas For 4 Tx ant, TX diversity uses combination of SFBC and FSTD

To balance for channel estimation accuracy • {s1, s2} are transmitted by antenna ports 0 and 2 • {s3, s4} are transmitted by antenna ports 1 and 3

s1 s2* 0 0 Antenna Port 0

0 0 s3 s4* Antenna Port 1

… s4, s3, s2, s1

Alamouti encoder

s2  s1* 0 0 Antenna Port 2

Weaker channel estimation for antenna ports 2 and 3 (only 2 symbols for RS per PRB per slot)

0 0 s4  s3* Antenna Port 3

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• DL adaptive closed loop MIMO (4x2) supports Transmit Diversity for 4 antenna ports in Transmission Mode 4 (TM4) and in Transmission Mode 2 (TM2). • 3GPP has specified open loop Transmit Diversity using one codeword: Precoding Feedback and Rank Information is not required! • Transmit Diversity using 4 antenna ports is used whenever there is no valid, complete and consistent Channel State Information available as detected by eNodeB. • During Initialization when RRC setup is performed • No update of valid CSI reports for single layer (RI=1) and dual layer (RI=2) transmissions since a characteristic update time. • UE does not send valid reports (e.g. Category 1 UEs). Transmit Diversity for 4 antenna ports is implemented as a combination of SFBC (Space Frequency Block Coding) with FSTD (Frequency Switched Time Diversity).

51

Slide 54

LTE568 : DL adaptive closed loop MIMO (4x2) Fast adaptive MIMO switching • Closed Loop MIMO (4x2) uses ‚Fast Adaptive MIMO Switching

• eNB supports fast switching between Dual Layer and Single Layer SpMux depending on the Rank only • eNB will not override UE requests regarding the used number of codewords and PMI • avoids cyclic PMI switching which was used with “Dynamic Adaptive MIMO Switching” when transmission rank was overridden by the eNB. • If no valid CSI report - fallback to 4 way Tx diversity

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“Fast Adaptive MIMO Switching” MIMO Mode Control algorithm is introduced with LTE568, but can be used also with LTE703 since RL50/RL35 After elapsing a certain time from the latest valid PMI report, eNB will switch the transmission mode to 4-way Transmit Diversity to the user in question. Single/dual codeword transmission will resume immediately after valid report is received. For Fast MIMO Switching, following parameters must be configured: LNCEL-actFastMimoSwitch = true LNCEL-riPerM must be set to '1‘ LNCEL-riPerOffset must be configured to '-1' Above parameters ensures that RI are immediate and current

52

Slide 55

LTE568 : DL adaptive closed loop MIMO (4x2)

• Code book based 16 index values as per 3GPP 36.211 R9, precoding matrix W: • UE feedback: precoding matrix indicator (PMI)

• No mapping 1 CW to 2 layer, only 1 CW to 1 layer TxDiv 2 layer

Codeword 0

Layer Mapper

4x2 CL MIMO is comparable to 2 x

Layer 0 Precoding

Layer 1 Layer 2

Codeword 1

Layer 3

Feedback: CQI RI PMI 55

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2 codewords are the 3GPP max – Ack/Nck and CQI are per codeword – 2 CW gives an optimum overhead. Even with high order layers (say 8x8) still only 2 CW but we are sending the codewords much faster!

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Slide 56

LTE569 Downlink adaptive closed loop SU MIMO 4x4 - TM 4 Brief description

• This feature extended MIMO functionality to support MIMO 4x4 TM4 with transmission up to 4 layers in downlink. • Feature operates with: - UEs cat.5 and cat.8 - bandwidth 10MHz and 20 MHz • LTE569 uses closed loop and adaptive fast switching between number of layer (1, 2, 3 or 4 layers). The selection between transmission mode is based on the RI and PMI provided by the UE (RI=1 indicate for 1 layer, RI=2 indicates 2 layers, etc.) PMI Є<0,1,2,…,15>. Uplink Control Information (Desirable RI & PMI)

eNodeB UE

layer1

layer2

layer3

layer4

Downlink Control Information

56

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Slide 57

LTE1543: 8x2 SU MIMO with TM9 • First Transmission Mode 9 (TM9) feature in Nokia • 8x2 MIMO over 8 TX pipes and 2RX UE antennas with closed-loop CSI feedback • effects in beamforming of UE dedicated PDSCH

• 3GPP Rel. 10 compliant • Dual stream transmission with TM9 for Rel. 10 TM-9 enabled UEs • Non-TM9 UEs can still be served using TM8, TM7 or TM2, depending on UE capabilities • Although TM9/TM3 switch is not in scope of LTE1543, non-TM9 UEs may still benefit from TM7/TM3 or TM8/TM3 switching (LTE1013-a, LTE1013-b)

• Compared to LTE541 (TM8-based Dual Stream Beamforming), LTE1543 allows for higher average and cell edge DL throughput

• Peak throughput is not changed w.r.t. LTE541

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Slide 58

LTE1543: 8x2 SU MIMO with TM9

After LTE1543 : Increase in cell DL throughput and coverage made possible by better DL channel feedback

Before LTE1543: Cell uses LTE541 Dual Stream Beamforming

Improved PDSCH beam enhances DL SINR allowing for higher DL throughput

Resulting PDSCH beam is inferior due to limited channel state information

SRS is used for DL channel estimation

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Rel. 10 CSI-RS are sent in DL to help with channel estimation

Preferred beam information is signaled to eNB in an improved PMI report


56

Slide 59

LTE1543: 8x2 SU MIMO with TM9 • Supported 3GPP Transmission Modes: • TM9 •

PDSCH PDCCH CRS DM-RS CSI-RS

This feature (LTE1543)

DL feedback

CQI PMI Rank

• PDSCH channel estimation based on demodulation reference signals (DM-RS) – ports 7..14 (up to 8 layers) • CQI report based on Channel State Information Reference Signals (CSI-RS) – ports 15..22 • Closed loop precoding based on CSI-RS, reported by PMI • CSI-RS is configured to each Rel10 UE via RRC reconfiguration

CSI-RS

DM-RS

CRS

0 1 2 3 4 5 6 0 1 2 3 4 5 6

MCS Rank UL feedback

59

Note: This example shows CRS and DM-RS for 2 TX antenna ports. 3GPP specifies CRS for up to 4 TX antenna ports and DM-RS for up to 8 antenna ports. See 3GPP 36.211 6.10.1, 6.10.3.2 for details

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Slide 60

LTE1545 UL MU-MIMO 8RX

Single User MIMO

Multiuser MIMO (or Virtual MIMO, V-MIMO) allows pairs of UEs with appropriate radio conditions to be scheduled on the same time and frequency radio resources Contrary to DL, 3GPP Rel. 8 and 9 does not standardize single user MIMO in UL – UE is able to transmit only one stream of data. Scheduling UEs on the same resources (MU-MIMO) is still possible given the standard definition

SIMO MU-MIMO

MU-MIMO scheme enables MIMO capacity gain on low-cost terminals with single TX antenna

60

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First UL MU-MIMO feature in Nokia LTE at RL55

UL MU-MIMO already proven technology in Nokia product e.g. in GSM DL MU-MIMO based on TM8 already available in RL35 (LTE1169 TM8 Based Dual User Single Layer MU-MIMO)

58

Slide 61

LTE1545 UL MU-MIMO 8RX Paired UEs are received by MU-MIMO receiver

LTE1545 is implemented for 8RX UL eNBs Advanced UL receiver is able to separate data streams from MU-MIMO UEs

MU-MIMO receiver implementation bases on MRC (Maximum Ratio Combining) algorithm RRM algorithm will ensure that only the UEs that will benefit from MU-MIMO will be paired

For single mode UE any suitable receiver algorithm can be configured for the eNB (MRC or IRC) by ulCombinationMode parameter

Unpaired UEs are received by legacy MRC or IRC

eNB

61

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Pairing algorithm overview

MU-MIMO UE pairs are selected in the scheduling algorithm Pairing candidates are chosen from among the UEs that are to be scheduled in the same TTI Pairing criterions are based on radio conditions of individual UEs and potential pairs. Final pairing decision is made based on the joint throughput –to-average metric (Max-PF metric) MU-MIMO UE pairs are assigned the same number of PRBs and same position in the frequency domain

Pairing decisions are done in every TTI

59

Slide 62

LTE1545 UL MU-MIMO 8RX Before & after

62

Before

After

• All UEs transmit on the dedicated time and frequency resources, neglecting spatial dimension of the channel

• UEs with good enough UL SINR and low channel orthogonality are scheduled on the same time and frequency resources

• Standard uplink capacity

• Average UL capacity is increased

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f

f

f

f

f

f


Gains from the feature: Feature could double UL peak cell throughput No increase in UE peak throughput In real radio conditions, over 20% average capacity increase can be expected Cell edge UEs will benefit indirectly as they would get more scheduling opportunities

60

Slide 63

Coordinated Multipoint Transmission (CoMP) Key aspects in 3GPP Rel.10

Carrier Aggregation


8x

MIMO


Carrier n

4x

 Cooperation of antennas of

multiple sectors / sites  Interference free Relaying

by coordinated transmission / reception  Highest


performance potential Service Area

63

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• Joint Processing (JP): data is available at each cell in the CoMP set As if all sites formed a single multi antenna base station • Coordinated Scheduling/Beamforming (CS/CB): data only at the serving cell scheduling coordinated among cells • Standardization will be done in Rel. 11 Utilizing enhanced reference schemes introduced for MIMO enhancements, which were already done forward looking to CoMP applications

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Slide 64

LTE1691:uplink intra-eNB CoMP 4Rx

•

In general, LTE has frequency reuse of 1. That means a lot of interference on cell edges. In effect, on cell edge UEs are received with similar power by serving and neighbor cell…

•

…but not always as a useful signal. To the neighbor cell, this is interference.

•

CoMP aims to take this interference and turn it to the useful signal. Neighbor cell can do it to.

•

But the main obstacle is to get the data from one cell to the other: • There is a lot of data to be exchanged between cells • Delay is crucial

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Slide 65

LTE1691:uplink intra-eNB CoMP 4Rx •

Receive UEs uplink signal by more than one cell • Intra eNB CoMP: cells involved in reception of the UE belong to the same eNB (cells are colocated) • LTE1691: UL inter-cell intra eNB reception + Interference Rejection Combining (IRC)

•

UL SINR enhancement allows for increased UL throughput on average and cell edge. Gains depend on load and interference conditions in the network

• • • • •

LTE1691 is an extension of LTE1402 “UL intra-eNB CoMP for 2RX” feature In LTE1691 up to 2 cells can be selected for UL reception from so called CoMP sets containing up to 3 cells Cell selection is performed per TTI based on instantaneous SINR measurements CoMP reception can only be done for PUSCH. Other UL physical channels are received by serving cell antennas. Cells involved in LTE1691 CoMP sets can only have 4 RX antennas

•

In LTE1691 Interference Rejection Combining (IRC) algorithm is used for UL reception • FDD: using 1 cell: LTE980 “IRC for 4 RX paths”; using 2 cells: Enhanced IRC with Shrinkage • TDD: LTE936 “UL IRC Receiver”; using 2 cells: Enhanced IRC with Shrinkage

•

LTE1691 is transparent to UEs. All 3GPP Rel. 8 compliant UEs will benefit from this feature.

65

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Slide 66

LTE1691:uplink intra-eNB CoMP 4Rx •

Benefits of increasing the aperture in intra eNB UL CoMP

•

Combining gain on intra cell edge due to more antennas (up to 3dB) Effect of diversity gain in fading channel. 90

40

120

60

0

30 20

150

-10

30

4 Rx antennas 10

3dB combining gain

-20

180

0

0.5

1

1.5

2

2.5

3

0

0.5

1

1.5

2

2.5

3

0

0.5

1

1.5

2 2.5 Time [sec]

3

3.5

4

0

UL CoMP area 210

0

330

-10 2 Rx antennas

240

-20

300

•

66

Additional diversity gain in fading channels – usually antennas from two cells will have high enough separation to allow for close to perfect decorrelation

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Channel Gain [dB]

270

3.5

4

0 -10 1 Rx antenna -20

3.5

4


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Slide 67

LTE1691:uplink intra-eNB CoMP 4Rx Combining using neighbor cell antennas – inter eNB interference •

More inter cell interference will be picked up by the eNB when combining with neighbor cell antennas The interference may come from various cells, they might be multiple interferers to the subcarrier

•

Conclusion: •

•

f

Using intra eNB cell antennas for UL combining will expose the UL receiver to higher interference levels.

f

f

This is the reason why Interference Rejection Combining (IRC) algorithm must be used for UL reception

f

UL co-channel interference from neighbor cell

67

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Slide 68

LTE1691:uplink intra-eNB CoMP 4Rx Quick recap on Interference Rejection combining (IRC) •

IRC will maximize SINR of the wanted user by applying complex weights to the antenna elements

•

IRC cannot cancel white noise, just (spatially correlated) interferers

•

Rule of thumb: IRC can cancel up to N-1 interferers where N is number of antenna elements

•

IRC is performed per subcarrier

•

IRC is applicable to PUSCH only. Control channels are received using MRC or incoherent combining

90

30

120

60

MRC pattern

20 150

30 10

4RX IRC vs. 4RX MRC

DMRS

180

0.0 no interf.

SDI

3 IF

1PRB

IRC per subcarrier processing

SINR [dB]

-5.0

4 IF

5 IF

0

SINR required to reach 10% BLER on PUSCH 210

-10.0

MRC IRC (switching) high interf.

330

240

300 270

IRC pattern

IRC (switching) medium interf.

-15.0

IRC (switching) low interf.

Wanted UE -20.0

interferers

Number of interferers

1 slot (0.5 ms)

-25.0

UL slot structure

68

Interference scenario

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Slide 69

LTE2128 Uplink Intra eNodeB CoMP 8 RX with Softbit Combination IQ combining

Softbit Combining •

With 8RX antennas and 2 cell combining receiver needs to combine 16 RX paths

•

Our system module does not have the capacity to handle this amount of processing load

•

An alternative approach to IQ signal combining is softbit combining. It requires less processing power on the baseband level

•

The soft bit combining simply adds the Log-Likelihood Ratio (LLR) soft bits from both receivers to obtain the improved soft bits. Therefore, if we denote the LLR (soft bit) for the mth bit of ith received symbol in the serving and neighbor cells as i and

Lim

Lm

,

s

n

respectively, the combined soft bit is

Lim  Lim  Lim C

s

n

Soft bit combining

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Slide 70

Softbit Combining LL performance 0

CellEdge, 2-Cell CoMP, 8Rx, 10RB, Mcs 0:5:25, UMiNLoS, IRC

10

RxTimeDomain Demodulator Off -1

BLER

10

-2

10

-3

10

-4

10 -30

70

-20

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0 10 SNR [dB]

20

30

40


Since softbit combining is sub-optimal , there is a slight performance loss on link level soft combining scheme vs. joint reception (IQ combining)

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Slide 71

Softbit Combining vs. Uplink Measurements LTE2128

71

• •

•

•

LTE1402, LTE1691

Measurement

Serving Cell Only

Timing advance estimation

x

Frequency offset estimation

x

UL CSI measurements per PRB

x

Received interference power measurement per PRB

x

RSSI (M1)

x

x

I+N (K1)

x

x

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Serving + Neighb cell

x


In LTE2128 only combining of soft bits demodulated from the UL Shared CHannel (UL-SCH ) in the Physical UL Shared CHannel (PUSCH) is performed All other physical UL signals and channels like the PRACH, SRS and PUCCH, will be just received based on the serving cell antennas, and their signals on the neighboring cells are not taken into account at all Also the UL control information (UCI) which is multiplexed into the PUSCH in time and frequency domain is not exchanged between cells and does not benefit from the soft bit combining. Therefore, CQI, Ack/Nack, PMI and rank indicator (RI) coming along on the PUSCH will have the same performance if this feature is enabled or not Additionally, the UL measurements: RSSI, interference power and SINR, TA and FO are based on the serving cell's measurements.

69

Slide 72

LTE1724/LTE1900 (Centralized RAN) LTE1724/LTE1900 (Centralized RAN) and LTE1402 (Uplink Intra eNodeB CoMP ) are off • No cooperation between cells and eNBs at all • Only signal received by serving cell is used in decoding process

Cell1

Cell2

Cell 3

Cell 4

Cell 6

X

X

X

Cell3

UE

X

X 72

Cell4

Cell5

Cell6

Cell 1

X

Cell 2 (serving) Interference

Cell 5

Useful signal

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Slide 73

LTE1724/LTE1900 (Centralized RAN) LTE1724/LTE1900 (Centralized RAN) is off but LTE1402 (Uplink Intra eNodeB CoMP ) is on • Signal from serving cell can be combined with one cell (the strongest one) that belongs to UL CoMP set, provided that:

1) Serving cell is in UL CoMP set 2) UE`s measured SINR at neighbor cell is less than ULCOMP:ulCoMpSinrThreshold below SINR of serving cell 3) UE`s measured SINR at neighbor cell > -10dB • UL CoMP set characteristics - Up to 3 cells of the same eNB only

Cell1

Cell2

Cell3

- One cell can belong to one UL CoMP set only

Cell 3

4 Cell 4Cell (serving)

Cell 6

X

X

X

UE

X

X Interference

Cell4

Cell5

X

CellCell 2 (serving) 2 Cell 1

Cell 5

Cell6

Useful signal

Note: UL CoMP set consists of Cells: 1,3,4 4,5,6

73

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Slide 74

LTE1724/LTE1900 (Centralized RAN)

LTE1724/LTE1900 (Centralized RAN) is on • Signals from serving cell and up to 3 cells that belong to CRAN CoMP set and with the highest measured SINR are combined [up to 8RX UL combining] • 6 cells create CRAN CoMP set Cells from the same as well as from different eNB

• CRAN CoMP set can change with change of serving cell

Note: CRAN CoMP set consists of Cells: 1,2,3,4,5,6 1,2,3,4,7,8

Cell1

Cell2

Cell3

Cell 8

Cell 2

Cell 4

Cell 6

X

X

X

X

UE

UE

Cell4

CRAN CoMP sets overlaps each other

X Interference

74

Cell5

Cell6

Cell7

Cell8

Cell 7

X

-

More than one CoMP set are defined per eNB

X

-

Cell 1 (serving)Cell 3 (serving) Cell 3 Cell 1

X

-

Cell 5

Useful signal

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Slide 75

Relaying Key aspects in 3GPP Rel.10

Carrier Aggregation


8x

MIMO

Carrier n

4x

 Fast deployment  Coverage with low


infrastructure costs

Relaying


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Not Part of RL60

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Slide 76

Heterogeneous Network

Key aspects inCarrier Aggregation 3GPP Rel.10 ….. Carrier1 Carrier2

8x

MIMO

Carrier n

4x


Heterogeneous Networks – The Combined Benefit of Wide & Local Area Wide Area sites

Relaying

Medium area sites


Local area

Local area

WLAN

WLAN

Local area

WLAN

Medium area sites

Local area

Local area

WLAN

WLAN

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The term “Heterogeneous Networks” does not necessarily refer to a specific technology or feature as such, but is instead used to describe networks that have both wide area and local area (small cell) deployments. In many expected deployment scenarios, heterogeneous networks spread across multiple radio access technologies. Autonomous or automated interference coordination and handover optimization in such hierarchical network architectures are key aspects of heterogeneous networks. Other coordination technologies like selfconfiguration and self-optimization have been covered under Self Organized/Optimized Networks (SON) and Minimized Drive Testing (MDT) related study and work items since Release 8.

74

Slide 77

Heterogeneous Networks – The Combined Benefit of Wide & Local Area Majority of cell sites today • > 300 m • > 5 W output power

Wide Area sites

Medium area sites

Local area

Local area

Medium area sites

Local area

Local area

Macro

Share of sites growing • 100 – 300 m • 1–5W

Local area

Micro

Share will grow in future • 10 – 100 m, • < 500 mW Pico, Femto

WLAN

License exempt growing & Secondary services emerging • 10-100 m • < 100 mW

WLAN

WLAN

Access Points

WLAN

WLAN

Benefits of Multi-Layer Deployment • Coverage improvement from local area cells in edge or shadowed regions • Capacity increase from more transmission points in a given area

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Tradeoffs involved with Multi-Layer • Co-channel deployment needs no additional spectrum but creates interference between the layers and within the same layer >> this interference needs to be controlled for QoS


75

Slide 78

Heterogeneous Networks Heterogeneous Networks

78

•

LTE1821: Neighbor Detection Optimization for HetNet

•

LTE1822: PCI Assignment Optimization for HetNet

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LTE1823: Neighbor Prioritization Optimization for HetNet

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LTE2020: PRACH Management Optimization for HetNet

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HetNet Deployment SON Optimization Optimized SON support for multi-layer HetNet deployments Micro

Macro

DAS

HetNet deployments include cells of various types and sizes

WiFi

Femto Pico WiFi

Greater cell density with deployment of small cells

 Avoid the addition of unnecessary neighbor relationships

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• SON Central Management works well with mixed Macro and Small Cell Setup • Optimize PCI assignment for LTE multi-layer HetNet environments • Dedicated consideration of Macro and Small Cells for • PCI Assignment, • Neighbor Relation Establishment and • Neighbor Prioritization • By identifying and utilizing site specific neighbor distances relative to both the source and all potential target cells.

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LTE1821 Neighbor Detection Optimization for HetNet Functional overview Multi-layer heterogeneous networks (HetNet) consists of many types of cells, for example: macro, small, micro, and pico. In the HetNet, neighbor relationships are determined based on overlapping cell ranges, and based on the distance between the source cell and other cells in the network. R2 = ll ll Ce Sma s Radiu

Purpose Existing SON functionality (RL60 and backwards) treat all cells the same and thus does not account for variances such as differing cell coverage areas or multi-layer networks. However, a 5W Flexi Zone Micro BTS cannot be treated the same as a 40W macro eNB cell for finding appropriate neighbors.

D1

LTE1821 provides more precise detection of neighbor cells in a HetNet environment by calculating and using estimated cell specific ranges for both the source and target cells.

Macr

R1 = adius ll R o Ce

Cell under configuration

A target cell is considered a neighbor candidate if the sum of the target cell range and source cell range is smaller than distance between the cells. D2

• Cells which are not neighbors are excluded from neighbor list • Less neighbors means less X2 links to manage

R2 Sma = ll C Radiu ell s

Benefits:

Macro eNB which belongs to the cell under configuration with Cell Radius = R1 Small Cell with Radius R2. R1 +R2 >= D2, so Cell is considered a neighbor candidate. Small Cell with Radius R2. R1+R2 < D1, so cell is not a neighbor candidate.

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Cell range Cell range is a potential coverage range of the cell. The operator can determine the cell range in several ways by: configuring a cell range per cell - importing cell ranges from an external planning tool is available defining a static cell range based on existing PDDB parameters allowing the iSON Manager to calculate cell-specific ranges based on configured parameters for each cell. This option uses path loss models. For the cell range via path loss model option, the operator can choose editable range extension factor (REF) to calculate the cell range (particularly for small cells). The REF allows the operator additional control over the cell ranges that might be automatically calculated by the iSON Manager using path loss models

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LTE1821 Neighbor Detection Optimization for HetNet Distance calculation The distance is calculated based on the geo-coordinates between the source cell and each of the other cells in the network, or current scope. It is already implemented in the common distance service in the iSON Manager. The distance calculation is done for each cell in the network. Neighbor relationship The neighbor relationship between two cells are determined as follows: • If (R1*REF1) + (R2*REF2) >= D, then Cell 1 and Cell 2 are potential neighbors due to possible coverage overlap

Cells considered as neighbor cells

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LTE1821 Neighbor Detection Optimization for HetNet If (R1*REF1) + (R2*REF2) < D, then Cell 1 and Cell 2 are not considered as neighbors; Cell 2 is dropped from neighbor prioritization

Cell not considered as neighbor cells where: Rx - the range of Cell x D - the distance between the source cell (Cell 1) and the potential neighbor cell (Cell 2) To reduce the neighbor search space: • The range calculation and the coverage overlap check are performed only for the cells that lie within the search distance from the cell being configured. • The LTE1821: Neighbor Detection Optimization for HetNet feature utilizes the estimated cell-specific range of the source and potential target cells in addition to the distance between the two cells

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LTE1822 PCI Assignment Enhancements for HetNet Purpose Operators today are deploying multi-layer heterogeneous networks (HetNet). The following are some examples: • Macro layer with underlying small cell layer at same frequency • Mix of macro cells and underlying 5W micro & 1W pico cells

Existing SON functionality (RL60 and backwards) treats all cells the same and thus does not account for variances such as differing cell coverage areas or multi-layer networks. However, a 5W Flexi Zone Micro BTS cannot be treated the same as a 40W macro eNB cell for finding appropriate neighbors and assigning other cell specific parameters, such as PCI. The PCI management algorithm will, for the most part, remain unchanged. The main difference is that, rather than use a PCI re-use distance to select the neighbor PCIs that should be blocked by the PCI Management algorithm, the PCI management algorithm will now use the prioritized neighbor list that is the result of LTE1821 and LTE1823 to create a cell specific forbidden PCI list for the cell being configured

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LTE1823: Neighbor Prioritization Optimization for HetNet 1. The iSON manager classifies the cells, selected as neighbors by the LTE1821: Neighbor Detection Optimization for HetNet feature, in three bins: a) Bin 1 - the neighbor candidate cells that overlay the source cell, Neighbor cell bin 1. b) Bin 2 - the neighbor candidate cells, whose antennas physically lie outside the coverage of the source cell, but the coverage of the neighbor cells at least partially overlaps with the coverage of the source cell, Neighbor cell bin 2. c) Bin 3 - the neighbor candidate cells that do not overlay the source cell, Neighbor cell bin 3.

All bin 1 cells have higher priority than any bin 2 cell, and all bin 2 cells have higher priority than any bin 3 cell.

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2. The cells, selected as neighbors, are prioritized in each bin. Cells in bin 1 and bin 3 are prioritized based on the ratio of transmit power to distance from the source cell. Cells in bin 2 are prioritized in a similar manner that in the LTE539: Central ANR feature, based on the distance from the source cell and bearing from the source to the neighbor. Additionally, transmit power factor is applied to calculate the relative size of the neighbor cell. 3. The neighbor cell list is cut, if needed. The prioritized neighbor list is used in PCI Management algorithms if the PCI management algorithms cannot assign PCIs using all the potential neighbors of the cell. It might happen that the number of found neighbors exceeds the maximum number of neighbors (N), which is defined by the operator for the cell being configured. Then, the prioritized cells from bin 1 followed by the prioritized cells from bin 2 are selected, until the N is reached. Cells in bin 3 can be used if the N is not reached by the cells in bin 1 and bin 2.

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LTE2020: PRACH Management Optimization for HetNet Introduction to the feature LTE2020: PRACH Management Optimization for HetNet enhances PRACH (Physical Random Access Channel) management in a multi-layer HetNet (Heterogeneous Network) environment. With this feature the PRACH Management algorithms optimize HetNet configurations. Functional overview This feature addresses three areas related to PRACH. ECR (Expected Cell Range) ECR is a key input into the PRACH algorithm used in the preamble and PRACH selection. This value currently needs to be configured manually by the operator for each LTE cell. This feature would automatically calculate the ECR for each cell based on the propagation model introduced in Central ANR with LTE1821: Neighbor Detection Optimization for HetNet and LTE1823: Neighbor Prioritization Optimization for HetNet for use in deriving PRACH and RACH parameters. Neighbor Identification The process of identifying neighboring cells to perform the PRACH analysis against will be enhanced to leverage that HeNet neighbor identification functionality introduced with LTE1821: Neighbor Detection Optimization for HetNet and LTE1823: Neighbor Prioritization Optimization for HetNet. The feature evaluates each cell-to-cell relationship individually based on cell specific characteristics and configuration. The underlying PRACH parameter selection algorithms are not being modified by this feature. Only the algorithms that determine the set of neighboring cells to be used for PRACH analysis will be modified High Speed UE Flag As the high speed UE flag impacts the root sequence selection for a cell, all small cells of size less than or equal to 5 W transmit power have the High Speed UE Flag disabled as it is assumed that small cells will be used for more pedestrian, low speed traffic. This can be overwritten and changed by the operator. .

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LTE2020: PRACH Management Optimization for HetNet LTE2020: PRACH Management Optimization for HetNet uses the algorithms for the calculation of neighbor relationships and cells ranges as defined in LTE1821: Neighbor Detection Optimization for HetNet. The iSON manager allows the operator several options to determine cells ranges: • The operator configures a cell range per cell. This allows the option to import cell ranges from an external planning tool. • The operator defines a cell range based on existing PDDB parameters such as cell type or Tx Power. • The operator allows the iSON Manager to calculate cell-specific ranges based on configured parameters for each cell.

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The algorithms defined in LTE1821: Neighbor Detection Optimization for HetNet and to be used by LTE2020: PRACH Management Optimization for HetNet are applicable to Intra-Frequency as well as Inter-Frequency neighbors and the neighbors can have the same or differing channel bandwidths

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LTE-A Improving the Radio Performance

Peak rate

Average rate (capacity)

Cell edge rate (interference)

Coverage (noise limited)

Carrier aggregation

++

+

++

+

MIMO enhancements

++ (o)

++ (+)

++ (+)

o

CoMP

o

+

+

++


o

++

++

+

Relays

o

o

+

++

= clear gain

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= moderate gain


LTE-A enables a smooth and backward compatible evolution of LTE towards true 4G performance • LTE-A comprises of various tools to enhance mobile broadband user experience and network efficiency • There are serious interdependencies between network implementation and the various tools of LTE-A, which require an experienced partner when planning and implementing LTEA • Nokia Solutions and Networks has always been at the forefront of LTE-A research and development, with a strong focus on real operator opportunities in terms of efficiency and user experience

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02_RA41202EN15GLA1_LTE_EPS_Overview.pdf

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