Future of Wireless Networks: SDN/NFV, MEC and Network Slicing

Dr. Sassan AhmadiDirector of 5G Wireless Systems and Standards, Xilinx Inc.Lecturer at Stanford University

June 8, 2016

5G Network Architecture

Network Architecture Evolution

RAN Virtualization

Cloud-based Service Models

Cloud Server Models

SDN and NFV

– SDN Reference Architecture

– NFV Reference Architecture

– Virtualized Evolved Core Network (vEPC)

– SDN Deployment Models

– NFV and Coexistence with Legacy Networks

Virtualization and Network Slicing

Outline

Page 3

5G Network Architecture

…

Virtualized NW

Functions (vEPC)

Virtualized NW

Functions (vRAN)

E2E Control, Software Defined, Management and Orchestration

Server Farm and

Network Infrastructure

Cloud RANCloud Core

Fronthaul/Backhaul

Full Functional Base Station

MEC Server

(Edge Cloud)

NFVI

(Network Function Infrastructure)

Fronthaul

NGFI/CPRI Switch

A Virtualized, Programmable, Flexible Network with Edge Computing Capability based on Open and Standard Interfaces

CPRI

RRH

RRH

CPRI

RoE/CPRI

Various Baseband and Radio Functional Splits

Centralized

Distributed

Source: Xilinx

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Network Architecture Evolution

Source: NMC Consulting Group

Separation of Baseband and

Radio

Separation of Control Plane and

User Plane

Network Slicing and Virtualization

Wireless/Wired

Backhaul

Wireless/Wired

Fronthaul

Air-Interface

RAN Virtualization

Cloud RAN Use Cases (Flexible Functional Split)

RAN functions can be mapped

to VMs in different ways depending on the network

architecture and applications

Traditional BBU

L1

MAC

RLC

PDCP

Transport

S1

Fronthaul Connectivity

CPRI

RRC

L1-Low

MAC

RLC

PDCP

L1

L1 split

MAC

RLC

PDCP

S1

L1-High

vNIC

To RRH

VNF2

VNF1

VNF4 Transport

S1

RRC

VNF3

Transport RRC

Move to fronthaul switch or RRH

vNICVS

VS

L1

MAC

RLC

PDCP

Transport

S1

RRC

vNIC

To RRH

VS

VNF

L1

MAC

RLC

PDCP

S1

Transport RRC

vNICVS

To RRH

Apps

Hardware

Host OS

Hypervisor

Guest OS

Bin/Libs

Apps

VM

Bin/Libs

Apps

Container

Bin/Libs

Apps

Container

Hardware

Host OS

Bin/Libs

Apps

Bare Metal

Network and RAN Functions are Virtualized and Realized as Applications over Virtual Machines (VM)

GPP + Accelerator + Memory + Storage + Connectivity

RTOS

Next Generation BBU

Cloud-based Service Models

Source: Microsoft Azure

IaaS is a form of cloud computing that provides

virtualized computing resources over the Internet.

PaaS is a cloud computing model that delivers

applications over the Internet.

SaaS is a software distribution model in which applications are hosted by a

vendor or service provider and made available to customers over the

Internet.

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Cloud Server Models

Top of Rack

CPU

MEM Storage Acceleration

10/25/40G

CPU

MEM Storage Acceleration

10/25/40G

CPU

MEM Storage Acceleration

10/25/40G

Storage

10/25/40G

Storage

StorageStorage

…

Traditional Server Model

CPU

MEM Storage

CPU

MEM Storage 25/40/100G

CPU

MEM Storage

StorageStorage

StorageStorage

…

Acceleration

Acceleration

Acceleration

Acceleration

25/40/100G

25/40/100G

25/40/100G

25/40/100G

Disaggregated Server Model

PCIe or Ethernet

Top of Rack

PCIe or Ethernet

By separating critical components from one another, each resource can be upgraded or scaled independently. The disaggregation of hardware accelerators, enables sharing of accelerator resources across many computing or

networking blades, thus providing improved amortization of traditionally expensive components.

Server Connectivity Models

OVS with DPDK Running on

High Performance NFV NIC

Full VNF Portability Full Throughput

VNF VNF

Virtual Switchenables

VNF Portability

VNFFully

Portable

High Performance NFV NIC

Full Throughput Zero Packet Loss

OVS with DPDK Running on

Standard NIC

Full VNF Portability Limited Throughput

VNF VNF

Virtual Switchenables

VNF Portability

VNFFully

Portable

Standard NIC

Limited Throughput Packet Loss Issues

Direct Attach or SR-IOVRunning on

Standard NIC

No VNF PortabilityFull Throughput

VNF VNF VNF

Standard NIC

with SR-IOV

Virtual Switchbypassed

Not Portable

DPDK: Data Plane Development KitOVS: Open Virtual SwitchSR-IOV: Single Root Input Output VirtualizationVIM: Virtual Infrastructure Manager

Source: Napatech

SDN and NFV

Source: Cambridge Wireless Virtual Networks SIG

SDN decouples the software-based control plane from the hardware-based data plane of networking and switching

entities, moving control logic (and states) to logically centralized controllers.

NFV is the virtualization of network functions and services that could run on

general purpose hardware, allowing dynamically placing and moving these

functions in various locations of the network and service infrastructures.

Network Function Virtualization (NFV)

Concept

Software-Defined Network (SDN)

Concept

SDN and NFV are different concepts

Combination of SDN and NFV concepts

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SDN Reference Architecture SDN Applications are programs that communicate behaviors and needed resources with the SDN Controller via APIs. In addition, the applications can build an abstracted view of the network by collecting information from the controller for decision-making purposes. These applications could include networking management, analytics, or business applications used to run large data centers.

The SDN networking devices control the forwarding and data processing capabilities for the network. This includes forwarding and processing of the data path.

The SDN Controller is a logical entity that receives instructions or requirements from the SDN Application layer and relays them to the networking components. The controller also extracts information about the network from the hardware devices and communicates back to the SDN Applications with an abstract view of the network, including statistics and events about what is happening.

Source: ONF

NFV Reference Architecture

NFV End-to-End Reference Architecture

Operational/Business Support System

Source: ETSI

VNF is the software implementation of a network function which is capable of

running over the NFVI. It can be accompanied by an Element Management System (EMS).

The NFV Management and Orchestration, which covers the orchestration and lifecycle

management of physical and/or software resources that support the infrastructure

virtualization, and the lifecycle management of VNFs.

NFVI provides the virtual resources required to support the execution of

the VNFs. It includes commercial hardware, accelerator components

where necessary, and a software layer which virtualizes and abstracts the

underlying hardware

The entire NFV system is driven by a set of metadata describing service, VNFs and Infrastructure requirements, so

that the NFV Management & Orchestration systems can act

accordingly.

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Virtualized Evolved Core Network (vEPC)

Source: SDx Central

SDN Deployment Models

In the centralized model, a centralized manager with a single controller talks to distributed data planes. The route and data flow definitions are all done within that centralized manager. As networks scale and become more distributed, centralized control requires bigger, more costly systems with more powerful CPUs, larger storage and

a more resilient infrastructure with less failure tolerance, which makes it cumbersome and expensive.

In the distributed model, a centralized manager talks to combined distributed controller and data planes. The distributed SDN networks are evolutionary and easy to scale, as networks expand rather than the traditional

centralized model of rip and replace. It is also easier to apply policies to individual sections for specific applications with this approach.

Source: Open Networking Foundation

Migration path from the existing networks to full SDN implementation

NFV and Coexistence with Legacy Networks

Functional Block Architecture

Virtualization of Network Function

The VNF cannot exist in stand-alone form and relies on the host function for its existence and if the host function is interrupted, or disappears, then the VNF will be interrupted or disappear.

The container interface reflects this existence dependency between a VNF and its host function.

Source: ETSI

In a telecomm operator's environment, network functions are capable of remote configuration and management. In order to achieve this, the network functions have an interface, referred to as a north-bound interface, to a management and orchestration function. This management and orchestration function is often highly complex and composed of many distributed component parts.

The objective of NFV is to separate the virtualized network functions from the infrastructure, and this includes their management. The management and orchestration functions are divided between the management and orchestration of the network functions virtualization infrastructure (NFVI) and the management and orchestration of the VNFs.

NFV and Coexistence with Legacy Networks

Management and orchestration of virtualized network functions

Management and orchestration of network functions

Source: ETSI

Virtualization and Network SlicingNetwork operators like KT, SK Telecom, China Mobile, DT, KDDI and NTT DoCoMo, and also vendors like Ericsson, Nokia and Huawei are all recognizing Network Slicing as an ideal network architecture for 5G

It allows operators to slice one physical network into multiple, virtual, E2E networks, each logically isolated including device, access, transport and core network and dedicated for different types of

services with different characteristics and requirements. For each network slice, dedicated resources (like resources within virtualized servers, network BW, QoS, etc.) are guaranteed.

Mobile Broadband,

Massive MTC, and Ultra-

Reliable Low Latency

Communications require different type of features and networks in

terms of mobility, charging,

security, policy control, latency, reliability, etc.

Source: NMC Consulting Group

How Do We Implement E2E Network Slices?

Dedicated slices are created for services with different requirements and virtualized network functions are placed in different locations in each slice (i.e., Edge or Core cloud) depending on

services.

Edge Cloud (vMEC)

Core Cloud (vEPC)

DU UPCache Server

MVO Server

Internet

Access Management

Session Management

Mobility Management

Charging

Access Management

Session Management

DU UP V2X Server

Ultra-High-Density Services Slice

Telephony Services Slice

Massive MTC Services Slice

Ultra-Reliable MTC Services Slice

V2X Server

DU

CP/UPDU

IoT Server

SDN

Hypervisor Hypervisor

GPP + Accelerator GPP + Accelerator

Connectivity among VMs located in the edge and core clouds is provisioned by SDN

CP

TCP IMS

CP/UP

VM/VNF

UP: User PlaneCP: Control PlaneDU: Digital Unit (BBU)RU: Radio Unit (RRH)