xRAN and C-RAN Integration in M-CORD

Dr. Sassan Ahmadi

Director of 5G Wireless Systems and Standards

Xilinx Inc.

November 8, 2017

Outline

Cloud RAN Integration in M-CORD

• 4G to 5G Technology Evolution

• 3GPP NG-RAN High-Level Architectures

• Flexible Functional Split in gNB

• New Base Station (gNB) Architectures

• E2E Network Slicing

• Overall View of the C-RAN Fronthaul/Backhaul

• Summary and Remarks

• Appendix

Xilinx NGFI Gateway and Functional Offload Solution for M-CORD

2

4G to 5G Technology Evolution

Page 3Source: NMC Consulting Group

3GPP NG-RAN High-Level Architectures (SA vs. NSA)

Page 4

5GC

eLTE eNB gNB

NG-UNG-C

5GC

eLTE eNB gNB

NG-UNG-UNG-C

5GC

gNB

NG-UNG-C

EPC

LTE eNB gNB

S1-C S1-U

EPC

LTE eNB gNB

S1-C S1-US1-U

Network Deployment Option 2 (Standalone New Radio and Next Generation Core)

Network Deployment Option 3/3a (Non-Standalone New Radio and LTE-Assisted)

Network Deployment Option 7/7a (Non-Standalone New Radio and LTE-Assisted)

Source: 3GPP TR 38.801

5G Core Network

LTE Core Network

NG Control Plane NG User Plane

LTE Control Plane LTE User Plane

LTE-NR Dual Connectivity

Page 5

MgNB

PDCP

RLC

SgNB

PDCP

RLC

Xn

RLC

MAC MAC

MCG Bearer

MCGSplit

Bearer

SDAP SDAP

NR supports Dual Connectivity (DC) operation whereby a UE in RRC-CONNECTED is configured to utilize radio resources provided by two distinct schedulers, located in two gNBs connected via a non-ideal backhaul.

A gNB may either act as an MgNB or as an SgNB. In DC, a UE is connected to one MgNB and one SgNB

SgNB

PDCP

RLC

MgNB

PDCP

RLC

Xn

RLC

MACMAC

SCGSplit Bearer

SCGBearer

SDAP SDAP

Source: 3GPP TR 38.801

SDAP: Service Data Adaptation ProtocolMgNB: Master gNB (terminates NG-C)

SgNB: Secondary gNB (terminates NG-U)

Flexible Functional Split in gNB

PDCP Low-RLC

High-MAC

Low-MAC

High-PHY Low-PHY

PDCP Low-RLC

High-MAC

Low-MAC

High-PHY Low-PHY

Option 5Option 4 Option 6 Option 7Option 2Option 1

RRC

RRC

RF

RF

Option 8

Data

Data

High-RLC

High-RLC

Option 3

Source: 3GPP TR 38.801

Centralized (Cloud)--------------------------------------------------------Distributed

Central Unit (CU) Distributed Unit (DU)To/From vEPC/5GC F1 Interface To/From RRH

Split Option 2 is a 3GPP Rel-15 WIDSplit Option 7 is a 3GPP Rel-15 SID

Prominent Cloud-RAN Architectures

Page 7

X86 or ARM-based BBU Server

Connectivity

Ethernet PDCP + RRCHigher Layers

X86 or ARM-based BBU Server

Connectivity + L1* Offload

CPRI or Ethernet (TSN) L2 and above

RAU

Connectivity + L1* Offload

CPRI

X86 or ARM-based BBU Server

Connectivity + L1 Offload

L2 and aboveEthernet (TSN)

Centralized PDCP/RRC Architecture

Centralized L2/L3 Architecture

Centralized L2/L3 Architecture with Aggregator Node

RRU/RRH

Connectivity + L1 Offload

DFE

AFE + RF

RLC/MAC Processor

Facilitating Dual-Connectivity and Relaxing Handover

Increasing CoMP Gain

Preserving Legacy RRUs

Various Use Cases of Xilinx Fronthaul Gateway and L1

Offload Subsystem in Different C-RAN Architectures

RRU/RRH

Connectivity + L1 Offload

DFE

AFE + RF

RRU/RRH

DFE

AFE + RF

New Base Station (gNB) Architectures

Page 8

Separation of User-plane and

Data-Plane

Separation of Central Unit and

Digital Unit

New Interfaces

E1

Source: 3GPP TS 38.401

NG-RAN Network Architecture

Page 9

gNB gNB

gNB

NG-RAN

5GC

AMF/UPF AMF/UPFAccess and Mobility Management Function (AMF)User Plane Function (UPF)

AMF

Idle State Mobility Handling

NAS Security

UPF

Mobility Anchoring

PDU Handling

Source: 3GPP TS 38.300

E2E Network Slicing

10Source: NMC Consulting Group

MPLS: Multiprotocol Label SwitchingSW: SwitchDC G/W: Data Center Gateway

Overall View of the C-RAN Fronthaul/Backhaul

11

NGFI-I:Sub-class 1 [100 µs]

PDCPRRC

DataPHY MAC RLC

Native RoE/eCPRI

Native CPRI[CPRI]

[ETH]

RRH

Backhaul

Transport connection(server layer)

CUEPCNGC

FTNx1FTNxFTN1 FTNy BTNy1 BTNz

PHY’

[ETH] [ETH]

DU

NGFI-II:Sub-class 2 [1 ms]

BH:Sub-class 3 [10 ms]

NGFI-I NGFI-II

FTN1 FTNx FTNx1 FTNy BTNy1 BTNz

RRH DU CU

BS/eNB/gNB blocks

CPRI aggregation blocks

ETH aggregation blocks

Transport connection (Lx-server layer, x=0, 1, 2) [...] Radio protocol carried

Source: IEEE 1914 NGFI (xhaul)

Summary and Remarks

Cloud RAN Integration in M-CORD necessitates alignment with 5G requirements, which means

• M-CORD platform must support prominent functional splits

• M-CORD platform must support various fronthaul options

• M-CORD platform must support RAN virtualization and SDN control

• M-CORD platform must support RAN slicing

12

Appendix:Xilinx NGFI Gateway and Functional Offload Solution for M-CORD

13

Cloud-RAN Fronthaul Gateway

Page 14

vBBU (Emulated) vBBU Fronthaul Gateway RRH Gateway RRH (Emulated)

Xilinx FPGA-based Implementation of NGFI Gateway and L1 Offload SDN-based configurable fronthaul gateway to support fast connectivity Ethernet up to 100 Gbps Ethernet with TSN up to 25 Gbps for RoE Multiple CPRI links up to 25 Gbps (eCPRI support is planned) Support of flexible functional splits

Xilinx Cloud-RAN Fronthaul Gateway

Page 15

FEATURE AVAILABILITYTARGET BOARD VCU108STRUCTURE AGNOSTIC MAPPER YESSTRUCTURE AWARE MAPPER YESNATIVE ROE YESTOD SUPPORT BY ROE STRUCTURE AGNOSTIC MODE YESTOD SUPPORT BY ROE STRUCTURE AWARE MODE YESTOD SUPPORT BY NATIVE ROE MODE YESSUPPORT FOR SYNCE YESFREEDOM TO CHOOSE MASTER/SLAVE MODE AT ANY POINT MIXEDIEEE1588 BUILT-IN YESIEEE1588 PRECISION 2.5 NSNUMBER OF CPRI PORTS 10MAX. CPRI LINE RATE 25GCOMPRESSION OPTIONALL1 OFFLOAD 3GPP OPTION 7-X DOWNLINK 100 MHZL1 OFFLOAD 3GPP OPTION 7-X UPLINK 100 MHZDOWNLINK DATA GENERATION OPTION AT BBU YESUPLINK SIGNAL ANALYSIS OPTION AT BBU YES

RS-FEC OPTIONPCS 1-25G YESPCS 40G YESPCS 50G YESPCS 100G YESTSN MAC 10G YESTSN MAC 25G YESBACKGROUND TRAFFIC FEATURE AVAILABLE YES

RF TRANSCEIVER SUPPORTED ADRV9371JESD204B TRANSCEIVER INTERFACE SUPPORT YES

10G ETHERNET SUPPORT YES25G ETHERNET SUPPORT YES40G ETHERNET SUPPORT YES50G ETHERNET SUPPORT YES100G ETHERNET SUPPORT YES

CLI YESGUI YES

Xilinx Virtex UltraScale FPGA VCU108 Board