virtualizing the ran – a small cell forum update

Virtualizing the RAN – a Small Cell Forum UpdateMark GraysonSCF Release Steering Group & Cisco Distinguished Engineer

Base Station Densification

Broader set of use cases NFV and SDN

Mobile Networking Mega Trends

Indoor coverage, higher frequencies, shorter ranges

Not just Mobile Broadband, but agility to support verticals and IoT value chains

Twin focus on CAPEX/asset utilization as well as OPEX/automation

© Small Cell Forum Ltd 2015

SCF Virtualization Activities: Addressing the historical architectural tension

• Flattening the RAN architecture• Adding intelligence into the base

station• Facilitating Small Cell Ecosystem• Hot Spot Capacity and Indoor

Propositions• Non-ideal backhaul transport

• Data Centre evolution and centralization of workloads

• Simplifying the radio access network• Macro and Hot Spot Capacity

Propositions• Advanced RF Co-ordination• ETSI NFV Use Case #6• Ideal fronthaul transport

CentralizationDistribution

“43% of operators deploying small cells will be deploying virtualization in part of their RAN” Source: Maravedis-Rethink


1. Is there any divergence between how virtualization is viewed from a macro RAN perspective versus a small cell perspective?

2. What are the real business benefits of virtualization in the RAN? Do benefits apply equally to macro and small cell deployment use cases?

3. Are current small cell architectures well suited to virtualization/cloudification? 4. Are there unique attributes of small cell transport that impact fronthaul

considerations? 5. Can virtualization deliver a phased roadmap, e.g., aligned with longer-term 5G

directions? 6. How do we ensure virtualization supports innovation across a multi-vendor

ecosystem?

Key Questions from Forum’s Operator Group (May 2014)


Business Rationale for Virtualization (and associated centralization)

PHYRLC/MACSONOAMAPPS

RRCPDCP

UpperMAC

Lower MAC

Upper PHY

LowerPHY RF

Centralization BenefitsRF Benefits

DRAN PDCP Split MAC MAC/PHY Split PHY CPRI

Transport Costs Centralization Benefits Independent of Split

RF Gains improved with lower splits

Transport costs minimized with higher splits


Accommodating Transport Limitations

Physical Network Function

Virtual Network Function

Virtualization split

One-Way Latency DL Bandwidth UL Bandwidth

PDCP-RLC < 30ms 150Mbps 50MbpsSplit MAC < 2ms - 6ms 150Mbps 50Mbps

MAC-PHY < 2ms - 6ms 150Mbps 50MbpsSplit PHY < 250µs 1000Mbps 1000Mbps


VNF Centralized Functions PNF Remote SC Radio

Small Cell Forum: Accelerating Virtualization for non-ideal transport

Centralization benefits with no additional transport

requirements

Additional RF benefits with limited enhanced transport

requirements

Dark fiber not applicable to

venue

PHYRLC/MACSONOAMAPPS

RRCPDCP

UpperMAC

Lower MAC

Upper PHY

LowerPHY RF

nFAPIMobility, Enhanced SON, RF Co-ordination, Improved Security, Policy Enforcement…

Simplified management, Advanced RF Co-ordination


BS Site NFVI

BS Site

Leveraging Existing MEF Transport Architectures


SmallCell RAN BS

RAN BS

RAN NC CEN CEN

EVC(m) PT2 20ms EVC(sc) PT1 5ms

PHYRF

Physical Network Function


PDCP/RLC/MAC

Virtual Network FunctionCo-located with Macro RAN, on-

premise or in data center

NFVI PoP


PDCP/RLC/MAC


PDCP/RLC/MAC

On-prem NFVI

nFAPI

1. Evangelizing Small Cell Virtualization2. Defining a multi-vendor nFAPI interface to enable PNF/VNF decomposition based

on MAC/PHY split3. Accelerating demonstration of multi-vendor nFAPI interface4. Driving ETSI ISG NFV to enable data-plane acceleration support for air interface

crypto, RoHC and PTP/Sync5. ETSI NFV ISG PoC showcasing feasibility of Virtualized Centralized Small Cell

supporting nFAPI interface to remote PNFs (Scoping work and demonstration)6. Co-ordinating with BBF to define PNF Management Object and associated

counters7. NFV-MANO aspects related to transport integration to enable workload

placement/affinity rules to account for transport BW and Delay 8. Initial scoping to understand multi-operator aspects of virtualized small cells9. Driving learning's of SCF virtualization work into 5G evolution

Small Cell Virtualization: The Role of the Forum


Board agreed work item to develop definition of nFAPI central/remote MAC/PHY spilt

Conventional Small Cell

PHY / RF

Layer 2

RRC

S1 / X2 Client

IPsec

GPS / Location

Timing/Sync

SC Management

TLS / IPSec

Small Cell EMS

VNF Centralized Functions

Layer 2

RRC

S1 / X2 Client

IPsec

Timing/Sync

Management

TLS / IPSec

VNF EMS

PNF Remote SC Radio

PNF EMS

Timing/Sync

PNF Management

GPS / Location

PHY / RF

Service Discovery

Service Discovery


VNF Centralized Functions

Layer 2

RRC

S1 / X2 Client

IPsec

Timing/Sync

Management

TLS / IPSec

VNF EMS

PNF Remote SC Radio

PNF EMS

Timing/Sync

PNF Management

GPS / Location

PHY / RF

Service Discovery

P9

P2

P10

P3

nFAPI Decomposition

P2 – Service DiscoveryP3 – PositioningP4 – NMMP5 – RF and PHY ControlP7 – MAC-PHY main SAPP8 – PHY DiagnosticsP9 – OAMP10 – Synchronization – Frequency, Phase and Time P5, P7, P8

P4

Board agreed work item to develop definition of nFAPI central/remote MAC/PHY spilt


Acceleration of Multi-Vendor Virtualized RAN and Management/Automation

Centralized Small Cell VNF

NFVI

Hypervisor

Hardware Resources

(COTS)

Multi-VendorRemoteSmall Cell

(PNF)

DMVNF EMS

(OSS/BSS)NM: PNF/VNF Co-ordination

VNF Manager (VNFM)

Virtualized Infrastructure

Manager (VIM)

NFV Orchestrator

(NFVO)

NFV-MANO

DM

VNF Manager (VNFM)

Virtualized Infrastructure

Manager (VIM)

NFV Orchestrator

(NFVO)

Hypervisor

Hardware Resources

(COTS)

• Small Cell Workload Placement

Transport Network Management Integration

• Hardware Acceleration of VNF Small Cell Functions

IPSecAir interface CryptoRoHCPTP/Sync

• Real Time Processing Aspects

PCI/PCIe Pass-through, DPDK, CP/DP separation

nFAPI

TR-069/PNF MO

PNF EMS


Conventional DAS

Virtualized Small Cell: Addressing scalability of current multi-operator solutions

Multi-Operator DAS

SP#1ENB

SP#2ENB

WAN

Challenging to scale down due to need to bring on premise base stations from each operator

RF RF

Virtualized Small Cell

SP#1VNF

SP#2VNF

nFAPI nFAPI

WAN

Multi-Operator PNF

Multi-vendor nFAPI interface avoids i) RF interfacing and ii) on-premise base station requirement


DASOAM

PNFOAM

Driving the virtualization narrative into 5G


(Non-CPRI) virtualized RAN architecture is set to be a

foundational capability in 5G

Topic FindingsWhat are the real business benefits of virtualization in the RAN?

Identified centralization benefits, transport costs & MANO/Automation elastic scaling capabilities

Small Cell VirtualizationKey Takeaways




Are current small cell architectures well suited to virtualization?

Yes - FAPI MAC/PHY decomposition well suited to provide virtualization baseline







How do we ensure virtualization supports innovation across a multi-vendor ecosystem?

SCF’s nFAPI work stream set to accelerate multi-vendor PNF/VNF interoperability







How do we ensure virtualization supports innovation across a multi-vendor ecosystem?

SCF’s nFAPI work stream set to accelerate multi-vendor PNF/VNF interoperability

Can virtualization deliver a phased roadmap, e.g., aligned with longer-term 5G directions?

Yes - Flexible virtualization over non-ideal transport now emerging as core 5G requirements



virtualizing the ran – a small cell forum update

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