Think through when designing a C-RAN solution

Dr. Xinjie Yang

Global RAN Strategies

NEC Europe Ltd

24th September 2015

2 © NEC Corporation 2015 NEC Group Internal Use Only

Network evolution through small cell Cloud-RAN

▌ NEC believe small cells (densification) is the most effectively way to meet the future network capacity demand

Traffic creation is becoming localized and on-demand

Network node coordination required for more efficient capacity delivery

▌ NEC believe Cloud-RAN architecture with flexible frounthual plays an important part of future network

Offer high capacity with low costs

MEC platform to deliver rich contents and other VAS at network edge

▌ CPRI C-RAN provide best performance however relying on fibre and low latency

3 © NEC Corporation 2015 NEC Group Internal Use Only

C-RAN: splitting in the right place

Layer 2 Structure for DL with CA configuredLayer 2 Structure for

UL with CA configured

HARQ HARQ

DL-SCH

on CC1

...

Segm.

ARQ etc

Multiplexing UE1 Multiplexing UEn

BCCH PCCH

Unicast Scheduling / Priority Handling

Logical Channels

MAC

Radio Bearers

Security Security...

CCCH

MCCH

Multiplexing

MTCH

MBMS Scheduling

PCHBCH MCH

RLC

PDCP

ROHC ROHC...

Segm.

ARQ etc...

Transport Channels

Segm.

ARQ etc

Security Security...

ROHC ROHC...

Segm.

ARQ etc...

Segm. Segm.

...

...

...

DL-SCH

on CCx

HARQ HARQ

DL-SCH

on CC1

...

DL-SCH

on CCy

Multiplexing

...

Scheduling / Priority Handling

Transport Channels

MAC

RLC

PDCP

Segm.

ARQ etc

Segm.

ARQ etc

Logical Channels

ROHC ROHC

Radio Bearers

Security Security

CCCH

HARQ HARQ

UL-SCH

on CC1

...

UL-SCH

on CCz

L2(FAPI-like)

L1(CPRI)

L3(&PDCP)

L1 L1 L1 L1 L1

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Be aware when splitting

AIO

L1 C-RAN

C-RAN with 4 radio units

5 © NEC Corporation 2015 NEC Group Internal Use Only

Be aware when splitting

C-RAN with 4 radio units

AIO

L1 C-RAN

▌ The performance of C-RAN over standalone AIO small cell is clear

▌ Considering the reduced costs of C-RAN solution, a L2 C-RAN FH delay can be relaxed to ~7ms, to still compete with AIO

6 © NEC Corporation 2015 NEC Group Internal Use Only

Be aware when splitting

C-RAN with 4 radio units

AIO

L1 C-RAN

▌ L2 C-RAN performance very sensitive to FH delay

▌ L3 C-RAN performance is relatively stable against delay

7 © NEC Corporation 2015 NEC Group Internal Use Only

Be aware when splitting

C-RAN with 4 radio units

AIO

L1 C-RAN

▌ When FH is larger than 2ms, L2 split does not show better performance than L3

▌ Meaning the full CoMPscheduler is less effective than dedicated scheduler in RU

8 © NEC Corporation 2015 NEC Group Internal Use Only

Be aware when splitting

AIO

L1 C-RAN

C-RAN with 4 radio units

▌ Studies on UL show similar conclusions

▌ Further studies show a bigger C-RAN cluster achieves more effective CoMP

9 © NEC Corporation 2015 NEC Group Internal Use Only

Utilising concept of network slicing

Virtual Machine

For L3

VM for

Higher L2

HOST OS: Commercial Linux

Digital Unit

VM for

Lower L2

PDCP

Intel Architecture CPU

10GbE NIC (SRIOV) L2/L3 Acceleration HW

Hypervisor: Real Time KVM

Open vSwitch

MAC

RLC GTP-U

L3 RRM

SON OAM

Software

Hardware

L3 (&PDCP) C-RAN

DU consists of

• VM for L3

• VM for Higher L2

L2 (FAPI-like) C-RAN

DU consists of

• VM for L3

• VM for Higher L2

• VM for Lower L2

DPDK

Core 0 Core 1 Core 2 ・・・ Core n

10 © NEC Corporation 2015 NEC Group Internal Use Only

Support flexible L2/L3 architecture

C-RAN DU

RF

L1

RF

L1

Ethernet

Hypervisor /

Accelerator

Virtual Machine

L2/L3 OAM

L2 RUs

RF

L1

RF

L1

L2

L3-CRAN L2-CRAN

RUs

11 © NEC Corporation 2015 NEC Group Internal Use Only

CPRI C-RAN remains as an option

C-RAN DU

RF

L1

RF

L1

RF

Layer1 AcceleratorsEthernet

CPRI

Hypervisor /

Accelerator

Virtual Machine

L2/L3 OAM

L2

RF

RUs

RF

L1

RF

L1

L2

L3-CRAN L2-CRAN

L1-CRAN

RUs

RUs

12 © NEC Corporation 2015 NEC Group Internal Use Only

Unified management

NFV-EMS

Hardware Resources

Computing Hardware Storage Hardware Network Hardware

Virtualization Layer

Virtual Computing Virtual Storage Virtual Network

vCPEvEPCDU

EMS-vENB EMS-vEPC EMS-vCPE

NMS

OSS/BSS Orchestrator

VNF

Managers

Virtualized

Infrastructure

Manager

Service, VNF and Infrastructure Description

RU RU RU

FM PM CM

13 © NEC Corporation 2015 NEC Group Internal Use Only

Flexible fronthaul support

Product

Name

Frequency Capacity

(Maximum)

ipasolink SX 60GHz 320Mbps

ipasolink VR

and iX

6-42GHz 1Gbps

ipasolink EX 70–80GHz 3.2Gbps

Ethernet cable*

Optical fibre

LOS/NLOS MW and mmWaveRUDU

NVF C-RAN runs

over various medium

NEC a leader in small sized,

world class microwave

14 © NEC Corporation 2015 NEC Group Internal Use Only

Protecting existing investments

F3

F2

F1

EPC

X2S1L2

L3

F1F1

Dual Connectivity

L2/3 C-RANDU

RU

Macro

Upgrade already deployed

NEC All-In-One ePico as RU

15 © NEC Corporation 2015 NEC Group Internal Use Only

Not limiting to small cells

DU (L2/L3 processing)

EPC

L1

L1

L1

L1L1

L1

L1

Low power RU (<5W) High power RU (>20W)

▌ High powered RU can be planned where needed and share the same DU

▌ Support of ORI (Open Radio Equipment Interface)

Third party RRH can be supported

16 © NEC Corporation 2015 NEC Group Internal Use Only

5G proof platform

F3F3F3

F2

RF

L1

HARQ

EPC

X2S1

L2

L3

F1F1 F1

L1 Accelerator

L1

HARQ

RF

CPRI

RURU

AAS

C-RAN

DU

Macro

17 © NEC Corporation 2015 NEC Group Internal Use Only

Local Mobile Edge Computing platform

Application

Cloud

Core

Network

Edge

Cloud

Traditional RANTraditional RAN

Cloud Computing

(Virtualized

Platform)

VMeNB

CP

VMService

Server

MEC

NFV C-RAN

With MEC

▌ Mobile-edge Computing ideal for new services requiring real-

time processing or analysis of massive data more effectively

▌ NEC NFV C-RAN provides the platform for MEC by

virtualization of the DU server resources

MECLatency Reduction

18 © NEC Corporation 2015 NEC Group Internal Use Only

Moving beyond general C-RAN

Low High

General

C-RAN

solution

TCO Reduction (Agility, Flexibility)

High

Low

Incre

ase

th

e r

eve

nu

e

(Ab

ility

of n

ew

se

rvic

e C

rea

tio

n) NEC’s advanced IT technologies

help to introduce new services.

NEC’s advanced SDN/NFV

technologies help to provide

agile, flexible and scalable

NW solution.

NEC’s

C-RAN

Solution