LTE-Advanced Relay. Oct 18, 2011

Transcription

1 LTE-Advanced Relay Oct 18, 2011

2 LTE/LTE-A Overview 3GPP Rel-10 Relay LTE-A Relay 3GPP Rel-11 Relay 2

3 LTE/LTE-A Overview 3GPP Rel-10 Relay LTE-A Relay 3GPP Rel-11 Relay 3

4 Cellular Roadmap

5 Spectrum Efficiency

6 LTE-A v.s j Comparison 3GPP LTE-A: Type 1 Relay IEEE j: non-transparency RS IEEE j 3GPP LTE-A Scheduling mode Distributed Distributed PHY mode Channel decoding Channel decoding Backward compatibility Yes Yes Coverage enhancement Yes Yes Throughput enhancement Yes Yes Number of hops Two or more two Transmission latency introduced by relays Largest Larger 6

7 Deployment Scenario 7

8 LTE/LTE-A Overview 3GPP Rel-10 Relay LTE-A Relay 3GPP Rel-11 Relay 8

9 Rel-10 feature Fix Two-hop No TTI bundling Relay Feature No flow control No MBMS Q1. Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q Q2 Relay study item starts Study Item (15 months) Relay study item stops Relay work item starts Work Item (15 months) Relay work item stops Subframe configuration Type 1 Type 1a Type 1b required N/A N/A SPS handling N/A Yes Yes RACH handling If contention based RACH is performed, Un configuration is suspended. normal normal 9

10 Relay Architecture (1) E-UTRAN Architecture supporting Relay MME / S-GW MME / S-GW S1 S1 S1 S11 S11 S1 enb X2 DeNB E-UTRAN S1 X2 Un RN 10

11 S11 (Relay) L3 Relay: Self backhauling Relay Architecture (2) Relay-UE s MME Relay Network Elements UE Network Elements UE S1 path S1-MME (Relay) E-UTRA- Uu (UE) enb Relay UE E-UTRA- Un (Relay) Donor-eNB function S1-U (Relay) Relay-UE s SGW/PGW Relay GW S1-U (UE) User-UE s SGW/PGW User-UE S1-MME (UE) S11 (UE) User-UE s MME 11

12 Relay Architecture (3) RN terminates the S1, X2 and Un interfaces. DeNB provides S1 and X2 proxy functionality appears as an MME (for S1-C) appears as an S-GW (for S1-U) appears as an enb (for X2-C and X2-U) DeNB provides the S-GW-like functions create a session for the RN manage EPS bearers DeNB provides the P-GW-like functions allocate an address for the RN

13 S1 interface: C-plane and U-plane Un link: S1 interface S1-AP S1-AP S1-AP S1-AP SCTP SCTP SCTP SCTP PDCP RLC MAC PHY PDCP RLC MAC PHY L2 L1 L2 L1 S1-MME S1-MME RN DeNB MME GTP GTP GTP GTP UDP UDP UDP UDP PDCP RLC MAC PHY PDCP RLC MAC PHY L2 L1 L2 L1 S1-U S1-U RN DeNB S-GW 13

14 X2 interface: C-plane and U-plane Un link: X2 interface X2-AP X2-AP X2-AP X2-AP SCTP SCTP SCTP SCTP PDCP RLC MAC PHY PDCP RLC MAC PHY L2 L1 L2 L1 X2-CP X2-CP RN DeNB enb (other) GTP GTP GTP GTP UDP UDP UDP UDP PDCP RLC MAC PHY PDCP RLC MAC PHY L2 L1 L2 L1 X2-U X2-U RN DeNB enb (other) 14

15 Un link: Radio interface Radio interface: C-plane and U-plane RN DeNB MME NAS NAS RRC PDCP RLC MAC PHY RRC PDCP RLC MAC PHY Un RN DeNB PDCP RLC MAC PHY PDCP RLC MAC PHY Un 15

16 RN Startup Procedure (1) Phase I: Attach for RN pre-configuration. The RN attaches as a UE The RN connects to the regular enb The RN retrieves initial configuration parameters from OAM.

17 RN Startup Procedure (2) Phase II: Attach for RN operation. The RN attaches as a RN The RN connects to the DeNB (based on the configuration)

18 PDCP No enhancement for the header compression in the Un link RN utilizes DRBs to carry S1-AP and X2-AP messages Integrity verification applies to this RN DRBs Applied to DRBs mapped on RLC AM and UM D/C R R R PDCP SN Oct 1 PDCP SN (cont.) Oct 2 Data Oct 3... MAC-I MAC-I (cont.) MAC-I (cont.) MAC-I (cont.) Oct N-3 Oct N-2 Oct N-1 Oct N (PDCP Data PDU format for RN DRBs using integrity protection)

19 Resource Partitioning for Relays (1) Relay transmission can be created by configuring MBSFN subframes Downlink subframes configured for enb-to-rn transmission shall be configured as MBSFN subframes by the relay node. Relay-to-DeNodeB transmissions can be facilitated by not allowing any terminal-to-relay transmissions in some subframes Relay-to-UE communication using normal subframes (left) DeNB-to-relay communication using MBSFN subframes (right) Subframes during which enb-rn transmission may take place are configured by higher layers. One subframe DeNB-to-relay transmission Ctrl Data Ctrl transmission gap ( MBSFN subframe ) No relay-to-ue transmission

20 Resource Partitioning for Relays (2) For RNs, RN-specific radio configuration control for the radio interface between RN and E-UTRAN; The RRC layer of the Un interface has functionality to configure and reconfigure an RN subframe configuration for transmissions between an RN and a DeNB. DeNB may initiate an RN reconfiguration procedure via RRC signalling for RNspecific parameters. SubframeConfigurationFDD Offset value element of BSC {xxxxxxx1} 7 {xxxxxx1x} 6 {xxxxx1xx} 5 {xxxx1xxx} 4 {xxx1xxxx} 3 {xx1xxxxx} 2 {x1xxxxxx} 1 {1xxxxxxx} 0 (Un subframe configuration: FDD)

21 Resource Partitioning for Relays (3) SubframeConfigurationTDD enb-rn uplink-downlink configuration Subframe number n D U 1 U D 2 D U D 3 U D D 4 U D U D 5 2 U D 6 D U 7 U D D 8 D U D 9 U D D D 10 D U D D 11 3 U D D 12 U D D D 13 4 U D 14 U D D 15 U D D 16 U D D D 17 U D D D D 18 6 U D (Un subframe configuration: TDD)

22 LTE/LTE-A Overview 3GPP Rel-10 Relay LTE-A Relay 3GPP Rel-11 Relay 22

23 Rel-11 features Mobile Relay Mainly for high speed vehicles. Provide continuous services for mobile users on high speed trains Q1. Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q Q2 Work Item Mobile Relay work item starts

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