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IMT-Advanced Relay

Institute for Information Industry ()Research Fellow

Kanchei (Ken) Loa ()loa@iii.org.tw

06/04/2010

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IIIs Contributions in 4G Standards

IEEE 802.16j (16j Relay) 253 major contributions had been submitted 116 contributions had been approved as standard baselines 37.54% of total approved contributions in 16j Ranked #2 (Nortel ranked #1)

IEEE 802.16m (Relay & Femtocell) 05/2010 274 major contributions have been submitted 141 contributions have been approved as standard baselines

3GPP LTE-A (LTE-A Relay) 05/2010 57 major contributions have been submitted 28 contributions have been treated with 13 approved/agreed

III has been focus on building relay & femtocell essential patents in IEEE 802.16 and 3GPP LTE-A

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Introduction of Relay

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Relay Applications

Problems:1. Shadow of buildings2. Valley between buildings3. Coverage extension at cell edge

Advantages of Relay Expands Coverage/Penetration Improves Capacity and QoS Lower CAPEX & OPEX approach

to expand WiMAX infrastructure Decreases MS power consumption

and Increases battery life Load sharing and multi-path

redundancy: reduces costs Spectrally efficient architectures:

reduces costly antenna structures

Advantages of Relay Expands Coverage/Penetration Improves Capacity and QoS Lower CAPEX & OPEX approach

to expand WiMAX infrastructure Decreases MS power consumption

and Increases battery life Load sharing and multi-path

redundancy: reduces costs Spectrally efficient architectures:

reduces costly antenna structures

Source: IEEE 802.16j TG,80216j-06_015

Fixed Infrastructure

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Source: 16j TG, 80216j-06_015

Emergency/Temporary Coverage

In-building Coverage

Relay Applications (cont.)

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Source: 16j TG, 80216j-06_015

Coverage on Mobile Vehicles

Relay Applications (cont.)

RS

MSMS

BS

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Relay Standards

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Relay Standards Completed standards

1. IEEE 802.16-2009 published in 2009, which incorporated IEEE 802.16j

Work-in-progress standards1. IEEE 802.16m Relay

P802.16m/D6

2. 3GPP LTE-Advanced Relay 36.912 36.814 36.806 (RAN2/RAN3 internal TR) 36.300 (R2-102659 CR to 36.300 on relaying)

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IEEE 802.16j Relay

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802.16j Protocol Stacks

MR data protocol stack for RS in centralized security mode

MR data protocol stack for RS in distributed security mode

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TDD versus FDD In terms of duplex scheme TDD (Time Division Duplex)

Transmit and Receive are time-division on single frequency FDD (Frequency Division Duplex)

Transmit and Receive are performed on a pair of frequencies A 802.16 frame structure is divided into a DL subframe and a UL subframe

In TDD, the UL subframe is followed by the DL subframe In FDD, the DL subframe and the UL subframe are transmitted on different frequencies

time

frequency

f1 DL UL

time

frequency

DLf1

f2 UL

TDD FDD

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STR versus TTR In terms of RSs capability of handling dual RF modules STR (Simultaneous Transmit and Receive) relaying

Definition in 802.16j /D9 3.121 a relay mechanism where transmission to subordinate station(s) and reception from the superordinate

station, or transmission to the superordinate station and reception from subordinate station(s) are performed simultaneously.

RSs RF module handles TX and RX on distinct RF modules simultaneously, Able to retain the same frame structure as 802.16e

TTR (Time-division Transmit and Receive) relaying Definition in 802.16j /D9 3.123

a relay mechanism where transmission to subordinate station(s) and reception from the superordinatestation, or transmission to the superordinate station and reception from subordinate station(s) is separated in time.

RSs RF module handles TX and RX on distinct RF modules at different time Frame structure may differ from 802.16e

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Relay/Duplex Modes TDD/FDD is distinguished by duplex scheme TTR/STR is distinguished by RSs relaying capability of

handling dual RF modules

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Types of 802.16j RS

Non-transparent RS A non-transparent RS transmits preamble, FCH

and DL-/UL-MAP MS recognizes the non-transparent RS as a BS Centralized scheduling or distributed scheduling Capacity enhancement & range extension

Transparent RS A transparent RS does not transmit preamble,

FCH and DL-/UL-MAP MS never recognizes the transparent RS as a BS Centralized scheduling at MR-BS Capacity enhancement only UL only RS or UL/DL RS

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Frame Structure Breakdown

UL(MS->RS)

DL(RS->MS)

DL(BS->RS)

UL(RS->BS)

Frequency 1

(R-link)

Frequency 2

(Access link)

TTG

N subchannel

N subchannel

DL(RS->MS)

UL(MS->RS)Frequency 1

TTG

N subchannelDL

(BS->RS)R-TTI

UL(RS->BS)

R-TTI

TTR

STR

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802.16j Relay Features 802.16j Relay Station (RS)

Transparent or non-transparent Time-division Transmit & Receive (TTR) or

Simultaneously Transmit & Receive (STR) Fixed RS or mobile RS Two-hop or multi-hop Centralized or distributed scheduling Centralized or distributed security Centralized control RS group

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IEEE 802.16j RS Tree

16j Relay

TransparentRelay

Non-transparent (NT)Relay

TDD transparentRelay

FDD transparent Relay

STRRelay

TTRRelay

TDD STRRelay

FDD STRRelay

TDD TTRRelay

FDD TTRRelay

: 16e frame structure

: 16j TTR frame structure

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IEEE 802.16m Relay

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802.16m Relay Features 802.16m Advanced Relay Station (ARS)

Fixed Two-hop TTR Non-transparent Distributed scheduling Distributed security Distributed control

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IEEE 802.16m ARS Tree

16m Relay

Non-transparent (NT)Relay

STRRelay

TTRRelay

TDD STRRelay

FDD STRRelay

TDD TTRRelay

FDD TTRRelay

: 16m frame structure

: 16m TTR frame structure

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802.16m TDD TTR Relay Frame Structure

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802.16m FDD TTR Relay Frame Structure

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IEEE 802.16m R6-over-R1 Model

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R6 termination on the RS R6 logical termination is on the RS

R6 is expected to be enhanced for 16m by NWG R6 messages can be carried over AAI_L2-XFER MAC management

message between the RS and BS. Downlink: BS performs classification, and sends it using AAI_L2-XFER,

addressed to the STID of the RS and with FID=1 Uplink: RS sends the message using AAI_L2-XFER to the BS with FID=1.

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User-plane Delivery Steps

ASN-GWABSARS

Data is encapsulated in GRE packetData message is

forwarded in ARSstransport flow

ABS interpreates data message and forwards the data in ARSs transport flow

AMS

Data message is forwarded in AMSstransport flow

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U-plane protocol stack: option 1

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U-plane protocol stack: option 2

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C-plane protocol stack: option 1

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C-plane protocol stack: option 2

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Summary ARS is an ABS with a wireless backhaul

connection Easy to implement due to reuse the ABS

functionality NWG needs to work out R6-over-R1 details to

finalize the 16m relay standard No STR relay in 802.16m/D6

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3GPP LTE-A Relay

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LTE-A Relay LTE-A Relay Node (RN)

1. Type I RN Range extension Architecture Studied at RAN1, RAN2 and RAN3

2. Type II RN Throughput enhancement within an eNB cell Being discussed in RAN1 Similar to Transparent RS of 802.16j

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LTE-A Relay RN Tree

LTE-A Relay

Type-I Relay

OutbandRelay

InbandRelay

TDD OutbandRelay

FDD OutbandRelay

TDD InbandRelay

FDD InbandRelay

: Rel-8 frame structure

: Rel-10 frame structure

Type-IIRelay

TDD Type-IIRelay

FDD Type-II Relay

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LTE-A Type-I Relay Features LTE-A Type-I Relay Node (RN)

Fixed Two-hop RN Inband and Outband (TTR & STR) eNB-like

Non-transparent Distributed scheduling Distributed security Distributed control

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LTE-A Type I RN Type I RN has its own cell ID Appears as Rel-8 eNB to Rel-8 UEs TDM Tx/Rx at RN

Utilize MBFSN subframe for eNB-RN DL transmission Maintain backward-compatibility to Rel-8 UE New Un interface for the link between RN & DeNB

DeNBUE RN

Uu Un

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E-UTRAN Architecture supporting RNs

eNB

MME / S-GW MME / S-GW

DeNB

RNS1

S1X2

X2E-UTRAN

S1

S11

Un

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S1/X2 User Plane Protocol Stack

IP

UDP

GTP

PDCPRLCMACPHY

IP

UDP

RN DeNB S-GWS1-U

GTP

S1-U

UDP

GTP

UDP

GTP

PDCPRLCMACPHY

IP

L1

L2

L1

L2

IP

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S1 Control Plane Protocol Stack

IP

SCTP

S1-AP

PDCPRLCMACPHY

IP

SCTP

RN DeNB MMES1-MME

S1-AP

S1-MME

SCTP

S1-AP

SCTP

S1-AP

PDCPRLCMACPHY

IP

L1

L2

L1

L2

IP

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X2 Control Plane Protocol Stack

IP

SCTP

X2-AP

PDCPRLCMACPHY

IP

SCTP

RN DeNB eNB (other)X2-CP

X2-AP

X2-CP

SCTP

X2-AP

SCTP

X2-AP

PDCPRLCMACPHY

IP

L1

L2

L1

L2

IP

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Summary1. RN is an eNB with a wireless backhaul

connection 2. Easy to implement due to reuse the eNB

functionality3. Inband and out-band Type-1 relays are in Rel-10

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Thank You!