5g-ppp project sesame. bringing virtualization, control ......•global data traffic is growing...

5G-PPP Project SESAME. Bringing Virtualization, Control and

Intelligence to the Network EdgeLeonardo Goratti

Email: [email protected]

Outline

• Introductory Facts

• Introduction to Mobile Networks

• SDN & NFV

• The SESAME Project

• Conclusions and Future Work

Chapter I:

Introductory Facts

A Few Facts – 1

• Global data traffic is growing relentlessly: Global Mobile traffic reached 3.7 exabytes/month at the end of 2015, with a growth of nearly 76% compared to the end of 2014

• Mobile data traffic has grown 4000-fold in the past 10 years and 400-million-fold in the past 15

• Globally, mobile devices and connections reached 7.3 billion

• Traffic offloading over Wi-Fi reached 51% in 2015

Source: http://www.cisco.com/c/en/us/solutions/collateral/service-provider/visual-networking-index-vni/mobile-white-paper-c11-520862.html

A Few Facts – 2

• Smart devices (≥3G) accounted for 89% of total mobile data traffic

• Predictions forecast that by 2020 traffic on smartphones will grow by 58%

• Globally IP traffic is expected a 22% annual growth until 2020

• With 5G the traffic and number of mobile subscriptions will grow more (D2D, IoT, etc)

• Conclusion:Current technologies are unable to keep up with this pace of growth

spectrum resource is insufficient, at least according to the way it is managed Source: http://www.cisco.com/c/en/us/solutions/collateral/service-provider/visual-networking-index-vni/mobile-white-paper-c11-520862.html

A Few Facts – 3

Source: “Ten key rules of 5G deployment Enabling 1 Tbit/s/km2 in 2030,” Nokia Networks white paper, available at: http://networks.nokia.com/it/file/39891/ten-key-rules-of-5g-deployment

The Role of 5G – 1

• The Fifth Generation (5G) of mobile technology is meant to fulfill the demands and business opportunities beyond 2020

• 5G aims to bring the new wave of innovations in many technological aspects and business sectors

• 5G favours the convergence between telecom and IT sectors

• While the mobile network is becoming a flat IP network, operator struggle to maintain profit margins

• If 5G would be conceived as previous generations of mobile technology CAPEX and OPEX would grow dramatically

• New radio interfaces will be developed for 5G and new architectural solutions

• A plethora of new services and applications will be fueled by 5G (IoT, video services, etc)

The Role of 5G – 2

A Clear Example

2005

2013

Standard Activities and Industry Fora

• 3GPP Working Groups– 3GPP SA1 Use Cases & Requirements – 5G– 3GPP SA2 System Architecture– 3GPP RAN Plenary– 3GPP SA5 Network Management

• ETSI Bodies– ETSI NFV– ETSI Mobile Edge Computing (MEC)

• Industry Fora– Next Generation Mobile Network (NGMN)– Small Cell Forum (SFC)– Broadband Forum

• IEEE SDN

• IEEE Next Generation Fronthaul Interface (NGFI)

• Heterogeneous System Architecture (HAS) Foundation

• Open Cloud Computing Interface (OCCI)

• Distributed Management Task Force (DMTF)

Mobile Edge Computing

A Plethora of Solutions

• Several solutions proposed to overcome resources shortage• C-RAN, higher frequency, advanced SON, CoMP, carrier aggregation, etc

• Emerging trend: network densification through small cell (SC) devices

• For the first time there is the possibility to merge network and cloud computing: XaaS (anything-as-a-service)

• SESAME is built upon ScaaS (SC-as-a-Service)

• Traditional roles such as infrastructure provider and (virtual) operators can be decoupled

• Anyway SCs possibly overlaying the macrocell require adequate control and management functions: Software-Defined Networking (SDN) and Network Functions Virtualisation (NFV)

5G Private Public Partnership (5G-PPP)

• The 5G-infrastructure-PPP is a 1.4 billion Euro program between the European industry and the European Commission to create the next generation of communication networks

• Currently 19 projects are running in the Phase I

• All projects have started the 1st of July 2015 and will end the 31st of December 2017

• Other 2 phases will be launched soon

• 5G-PPP has identified several important KPIs including extremely higher throughput (1000x), much lower latency, enabling 90% energy saving, promote very dense deployment, ubiquitous connectivity and virtualized network functions

5G-PPP Working Groups

• Pre-Standardisation WG

• Spectrum WG

• 5G Architecture WG

• SDN/ NFV WG

• Network Management, QoS and Security WG

• Vision and Societal Challenges WG

• Security WG

• SME WG

The Disruption of Cloud RAN…

• In 2011 China Mobile published the seminal whitepaper on Cloud RAN (C-RAN)

• The key idea was to separate control and data plane leave on the field Remote Radio Heads (RRHs)

• Centralise processing and network functions in a Base Band Unit (BBU) pool of resources as virtualized functions

• C-RAN adopts centralized processing and joint scheduling of multiple cells

• Moving processing resources into a cloud, general purpose and DSP processors are hosted in a datacenter

• A crucial challenge has emerged: the need of a high capacity and low latency fronthaul (CPRI specs) connection between RRH and BBU

…From a Distributed RAN…

❏ All Functions centralized at the eNodeB

❏ Suitable for sparse deployments

❏ Large macro cells

RRC

PDCP

RLC

MAC

PHY

Distributed RAN (D-

RAN)

Architecture

…to a Centralized RAN

RRC

PDCP

RLC

MAC

PHY

Centralized RAN (C-

RAN)

Architecture

RRH

BBU

CPRI, Common Public Radio Interface, RRH-Remote Radio Head, BBU-Baseband Unit, RRH+BBU = eNodeB

❏ Decouples baseband processing from

radio elements

❏ I/Q signals A/D converted and

transmitted over the CPRI interface

❏ Originally intended for short-haul links

❏ BBU is upgradeable through firmware

update (software defined in a sense)

The Role of Small Cells

• A SC is base station with a smaller form factor ( lower weight, ~0.5 kg) compared to a standard eNB and significantly lower energy consumption (~ 20 dBm against 46 dBm)

• A SC is meant to cover a smaller area (~100 m) to enable high throughput connectivity to the users in radio range

• User Equipment in range can benefit of higher modulations than in 4G, better signal quality due to proximity and more flexibility in resource management

• Among the specific challenges of 5G, it is well understood da almost 80% of traffic is generated indoor

• Major drawback is caused by severe interference, with the problem even worse in indoors

Current Trends – 1

• Starting with GSM each cellular technology has implied a new air interface

• Each generation has offered higher data rate to the customers

• Widespread of smartphones, tablets and other electronic gadgets has led to traffic booming

• Mobile broadband Internet access is a must

• Starting from Rel. 10 3GPP has started developing LTE-A

• Several new features added

• Several new device category introduced


• Starting from 3GPP Rel. 12 device-to-device (finalization expected in Rel. 14)

• Cellular technology is currently deployed by national mobile network operators (MNOs)

• Operators might own the network or just rent it such as Virtual MNOs (VMNOs)

• Vendors, mobile operators and academia have realized that conventional way the cellular network is designed and deployed is unsuitable

• We need more bandwidth, lower delay, higher data rates and more elasticity in radio resource provisioning

• CAPEX and OPEX will easily skyrockets at this pace


Z. Lozinski, Context of software-based networking, IBM Systems Journal

Challenges in 5G networks

What 5G would look like?

7/4/2016 Network Softwarization Workshop 22

Network

Function

Layer

Orchestrator

Business

Function

Layer

Business

Service

Layer

Infrastructure

Layer

RAN and

wireless

backhaul

Core

Cloud

Optical Edge

Cloud

Optical

Core

Network

Optical

Metro

Network

Optical

Access

Network

Wireless

Edge Cloud

Network

Function

Repository

Vertical #1 Services

(e.g., Factory of the

Future)

Mobile broadband

Services Vertical #2 Services

(e.g,, Automotive)

Service

#1Service

#2

Service

#3

Service

#1Service

#2

Service

#3Service

#1Service

#2

Service

#3

Vertical #1

Function

Repository

Vertical #2

Function

Repository

Vertical #3

Function

Repositor

y

Network

Function

Repository

Northbound interface Northbound interfaceOperator A Operator B

7/4/2016RAN and wireless

backhaul

Core Cloud

Optical Edge

Cloud

Optical Core

NetworkOptical Metro

Network

Optical Access

Network

Wireless

Edge Cloud

Chapter II:

Introduction to Mobile Networks

Global System for Mobile Communciations(GSM)

• GSM is an ETSI Standard

• Typical carrier frequency: 900 MHz, 1800 MHz

• Max. practical distance: 35 Km

• TDMA based

• Up to 8 full rate channels and nearly 270 Kbit/s

• Max. transmit power up to 2W

Global System for Mobile Communciations(GSM)

G-MSC

HLR

BSC

MSC/VLR

BTS

BTS

Radio Interface

Data Plane

Control Plane

Radio Access Network Core NetworkHLR

PSTN

Voice only service - Circuit Switched - 200 KHz per user

BTS• BSS: Base Station Subsystem‒ BSC: Base Station Controller‒ BTS: Base Transceiver Station

• NSS: Network Switching Subsystem ‒ HLR: Home Location Register‒ VLR: Visitor Location register‒ MSC: Mobile Switching Center

• G-MSC: Gateway MSC

General Packet Radio Service (GPRS)/EDGE

G-MSC

HLR

BTS

BTS

BTS

PSTN

Radio Access Network Core NetworkHLR

S-GSN G-GSN

BSC

Internet

Radio Interface

Data Plane

Control Plane

MSC/VLR

Packet data path similar to circuit switched voice - GTP Tunnelling

• BSS: Base Station Subsystem‒ BSC: Base Station Controller‒ BTS: Base Transceiver Station

• NSS: Network Switching Subsystem ‒ HLR: Home Location Register‒ MSC: Mobile Switching Center

• G-MSC: Gateway MSC• GSN: GPRS Support Node

‒ S-GSN: Serving GSN‒ G-GSN: Gateway GSN

Universal Mobile Telecommunication System (UMTS)• UMTS – ITU IMT2000

• Carrier frequency: 1885-2025 MHz (uplink), 2110-2200 MHz (Downlink)

• CDMA based

• Data rate up to 384 Kbit/s

• HSDPA: 7.2 Mbit/s

• HSDPA+: 42 Mbit/s

• Higher power consumption than GSM

Universal Mobile Telecommunication System (UMTS)

G-MSC

HLR

NodeB

NodeB

NodeB

UTRAN Core NetworkHLR

S-GSN G-GSN

RNC

Radio Interface

Data Plane

Control Plane

PSTN

Internet

MSC/VLR

Architecture still based on GSM/GPRS/EDGE

Iur

Iur

Soft/softer handover (make-before-break), MUD (interference cancellation), higher bitrates

• UTRAN‒ RNC: Radio Network Controller‒ NodeB: Base Station

• NSS: Network Switching Subsystem ‒ HLR: Home Location Register‒ VLR: Visitor Location register‒ MSC: Mobile Switching Center

• G-MSC: Gateway MSC• GSN: GPRS Support Node

‒ S-GSN: Serving GSN‒ G-GSN: Gateway GSN

4G Long Term Evolution (LTE)

• LTE and LTE-A – ITU IMT Advanced

• Carrier frequency: depending on the region

• MIMO, FDD / TDD

• OFDMA (downlink), SC-FDMA (uplink)

• LTE downlink rate up to 300 Mbit/s (LTE-A 3Gbit/s), uplink rate 75 Mbit/s (1.5 Gbit/s)

• Supported speed 350 Km/h

• Latency up to 5ms

4G Long Term Evolution (LTE)eUTRAN Core Network

S-GW P-GW

MME HSS PCRF

Radio Interface

Data Plane

Control Plane

Internet

eNodeB

eNodeB

X2

X2

Only one node type in the RAN - Flat IP Core Network (Partial) control and data plane separation

X2-based handover

eNodeB

Control plane easy upgradeable, Data plane function relatively simple

• eUTRAN‒ 3NodeB: Base Station

• MME: Mobility Management Entity• HSS: Home Subscriber Server• PCRF: Policy and Charging Rule

Functions• S-GW: Serving Gateway• P-GW: Packet gateway• How about Voice: VoLTE

Control and Data Plane in 4G LTE

How an IP Flow is setup in LTE

Cloud-RAN

RRH

RRH

RRH

RRH

RRH

RRH

RRH

BBURRH

RRH

CPRI

RRH

RRH

RRH

Core Network

BBU

BBU

BBU

CPRI

S1 S1

S1S1

CPRICPRI

• Common Public radio Interface (CPRI) is an industry effort

• specs provide the requirements and specifications for connecting Radio Equipment to the Radio Equipment Control

• Specs cover Layer-1 and Layer-2 of the OSI protocol stack

• Specs comply with 3GPP UTRA Rel. 5

• Data in the form of IQ samples

• Layer-1 rate up to 12 Gbps• Layer-2 follows the IEEE

802.3 2005 specifications• Time Division Multiplexing of

Multiple data flows

Cloud-RAN

Core Network

BBU Pool

RRH

RRH

RRH

RRH

RRH

RRH

RRH

RRH

RRH

RRH

RRH

RRH

CPRI CPRI

CPRICPRI

• Can we move everything centralized in a datacenter?

• Possible but need to pay attention to high capacity and low latency between RRH and BBU pool

• Physical distance cannot exceed some km to fulfill network constraints

• Expensive, since optical fiber is needed to support CPRI

Chapter III:

SDN & NFV

What’s New Out There

• Recently, academia and vendors and operators have recognized the limitations of current approaches in deploying networks

• Solutions based on dedicated specialized hardware are inflexible to scale, difficult to upgrade and above all very expensive

• All this causes to slow down the pace of innovation due to complex design challenges and need to amortize costs

• In 2011 the first OpenFlow specs but for wired networks

• OpenFlow is a building block and the most notable example of SDN

• The first trace of OpenFlow and SDN revolution dates back to the original Thesis work of Martin Casado in 2005, student at Standford University, the USA

• Anyway, similar concepts were used in optical communications even before

• The new challenge is to apply the concept to wireless

What SDN is?

• SDN originally separates control (i.e. control plane) and forwarding behavior (i.e. data plane) of switches in packet networks (virtual switch)

• A virtual switch has the benefit of a centralized intelligence for programming the forwarding behavior (i.e. flow tables)

• Switches merely implement the centralized logic

• Could this be extended also to mobile coms?

• Software-Defined Radio a very preliminary attempt

What is SDN?

• With OpenFlow it can be specified:• Flow Table

• Flow entry: An element of a flow entry to forward packets

• Flow match: Rule used to match packets, including packet header, ingress / egress ports and metadata values

• Flow action: way to forward packets (i.e. traffic type dependent)

• SDN relies on abstracted views of the network: • Way to characterize the network through the collection of statistics (e.g. RSSI

in wireless networks)

• Abstractions allow to obtain a network model view on which decisions can be taken

An Example with OpenFLow

Underpinning SDN – 1

Network Element

Network Element

Network Element

Network Element

Network Element

SDN network controller

Southbound API

Northbound API

Network Application

Network Application

Network Application

Network Application

Hardware

Operating System

Drivers

API

Application

Network Operating

System (NOS)

Goal: Simplify networking and enable new applications


Network Element

SDN Controller

NetApp

Forw

ard

, blo

ck, e

tc.

• In computer programming:• Software represents system intelligence• It performs tasks on top of the hardware• Software functionalities can be customized

based on user’s needs

• In SDN networks:• Applications represent the intelligence of

the network substrate• Network device is programmed by

software applications• Network functionalities can be customized

based on administrator’s needs• Uniform policy enforcement and fewer

configuration errors


Network Element

SDN Controller

NetApp

• In computer programming:Use OS and Compilers to avoid applications to be developed in hardware language

• In SDN networks:Use standard APIs to control the network device, ignoring their specific commands of the firmware

• In computer programming:Share and allocate the same hardware resources between different OS

• In SDN networks:Share and allocate the same network substrate (device, topology, resources) between different users

Network Element

SDN Controller

NetApp

1

NetApp

2

Relevant SDN Activities

http://www.onosproject.org http://www.opendaylight.org

Examples of Network Apps

An Introduction to NFV – 1

• Network Functions Virtualization (NFV) is a stand alone concept compared to SDN

• NFV and SDN can work together to reach common objectives

• NFV allows to move away from costly hardware-specific solutions by replacing with COTS hardware and software-based solutions

• NFV allows to create network services in a flexible unprecedented manner in software

• Easy to upgrade NFV; very difficult with hardware solutions (so called middle boxes)


• What a VNF is?• It is a software function

• An image (.iso) of the function is loaded into a virtual machine (VM)

• Hypervisor (e.g. Xen) is a software that can be created on top of the bare metal hardware

• A hypervisor is the virtualization layer which creates the virtualized infrastructure

• VMs are created on top of the hypervisor


• The four pillars of VNF:

• Virtualized network functions• Functions are implemented in software

• General purpose infrastructure• Reuse hardware across tenants

• Software reuse• Combine/chain/reuse virtual functions

• Dynamic scaling of network services• Elastic provisioning and consolidation


Examples of VNF:• Switching elements: Switches, Gateways, CG-NAT, Routers

• Mobile network nodes: HLR/HSS, MME,PDN-GW,NodeB, eNodeB, PCRF…

• Residential nodes: home router and set-top box functions

• Tunnelling gateway elements: IPSec/SSL VPN gateways

• Traffic analysis: DPI, QoE measurement

• QoS: service assurance, SLA monitoring, test and diagnostics

• Converged and network-wide functions: AAA, charging

• Application-level optimization: CDN, cache server, load balancer

• Security functions: firewall, virus scanner, IDS/IPS, spam protection


• A virtual network service (NS) can be a single VNF or given by the composition of several VNFs

• By the ONF a NS is called ‘Service Chain’

• By ETSI a NS is called VNFFG

• New novel concepts such as Infrastructure-as-a-Service (IaaS) can be developed

• Possible to decouple traditional roles such as service provider, infrastructure provider and network management


• SDN is used to chain together VNFs, or in other words to create Forwarding Graph (FG)

• Connectivity between VNFs is based on Layer 2 and Layer 3 rules

VNF1: DPI

VNF2: Load Balancer

VNF3: Firewall

“OpenFlow-enabled SDN and Network Functions Virtualization,” ONF, Feb. 2014.

NFV Use Cases

• Cloud:• NFV infrastructure as a service (NFVIaaS) like IaaS

• Virtual Network Functions (VNFs) as a service (VNFaaS) like SaaS

• Virtual Network Platform as a Service (VNPaaS) like PaaS

• Mobile:• Virtualization of the Mobile Core Network and IMS

• Virtualization of Mobile Base Stations

• Access/Residential:• Virtualization of the Home environment

• Virtual CPE

ETSI ISG NFV – 1

“Network Functions Virtualisation (NFV); Management and

orchestration,” ETSI GS NFV-MAN 001 V1.1.1, Dec. 2014

NFVI

Hardware Resources

Computing

Hardware

Storage

Hardware

Network

Hardware

Virtualization Layer

Virtual Resources

Virtual

Computing

Virtual

Storage

Virtual

Storage

EM 1 EM 2 EM 3

VNF 1 VNF 2 VNF 3

OSS/BSS

Virtual

Infrastructure

Manager(s)

VNF Manager(s)

NFV

Orchestrator

• Virtual Network Function:‒ VNF the virtualized version of a

physical Network Function‒ Functional aspects of a Network

Function are independent from the function being physical or virtual

• Element Manager:‒ Standard Element Management

System‒ Can manage one or more VNFs‒ The operational interface of PNFs

and VNFs are in principle the same

ETSI ISG NFV – 2

NFV Infrastructure:‒ The environment where

VNFs are deployed (Hardware & Software)

‒ Hardware components:• Computing, Storage, and

Network• Wired and wireless links,

switches, routers, access points, etc.

‒ Virtualization layer:• Provides the virtual

resource for executing the VNFs

• Abstracts, and partitions the hardware resources

• Hypervisors are one way of doing it

NFVI

Hardware Resources

Computing

Hardware

Storage

Hardware

Network

Hardware


Virtual Resources

Virtual

Computing

Virtual

Storage

Virtual

Storage

EM 1 EM 2 EM 3

VNF 1 VNF 2 VNF 3

OSS/BSS

Virtual

Infrastructure

Manager(s)

VNF Manager(s)

NFV

Orchestrator

“Network Functions Virtualisation (NFV); Management and

orchestration,” ETSI GS NFV-MAN 001 V1.1.1, Dec. 2014

Possible ways to Implement the Architecture

NFVI

Hardware Resources

Computing

Hardware

Storage

Hardware

Network

Hardware


Virtual Resources

Virtual

Computing

Virtual

Storage

Virtual

Storage

EM 1 EM 2 EM 3

VNF 1 VNF 2 VNF 3

OSS/BSS

Virtual

Infrastructure

Manager(s)

VNF

Manager(s)

NFV

Orchestrator

vRoute

r

vPCE

F

vEN

B

vSB

CvDPI vFW

ETSI ISG NFV – 3

• Network Function (NF): Functional building block with a well defined interfaces and well defined functional behavior

• Virtualized Network Function (VNF): Software implementation of NF that can be deployed in a virtualized infrastructure

• VNF Forwarding Graph: Service chain when network connectivity order is important, e.g., firewall, NAT, load balancer

• NFV Infrastructure (NFVI): Hardware and software required to deploy, manage and execute VNFs including computation, networking, and storage

• NFV Management and Orchestration: The orchestration of physical/software resources that support the infrastructure virtualization, and the management of the VNFs

ETSI ISG NFV – 4

• A forwarding graph of network functions

• Can be implemented over one or multiple infrastructure networks

• The end points could be end-users devices, applications, and/or servers

• Links in the forwarding Graph are logical

• E.g. a mobile video delivery platform: ‒ Mobile phones‒ Mobile network‒ Load balancer‒ Content delivery network

Infrastructure

Network

Infrastructure

Network

Infrastructure

Network

End

Point

A

End

Point

B

NF NF NF

Network Function (NF) Forwarding Graph

End-to-end network service

ETSI ISG NFV – 5

• Hardware/software decoupling provided by a virtualization layer

• The NFVI-PoP embeds the physical network resources‒ Computational‒ Storage‒ Network

• Virtualized network functions run on top of the virtualization layer

• VNFs replace the NFs ‒ VNFs can also be nested

• VNF-FG replaces the NF-FG

End

Point

End

Point

VNF-

1VNF-

3

VNF-

2A

VNF-

2B

VNF-

2C

VNF-FG-2


NFVI-PoP

NFVI-PoP


Virtualization

ETSI ISG NFV – 6

• End-to-end network services can use resources without knowing where they are physically located

• Specific constraints may apply‒ CDN nodes placed near end users ‒ Redundant VNFs placement

• VNF instance can be dynamically orchestrated (scaled, migrated, terminated) according to load

• End-to-end service level agreement and other constraints shall be maintained

• VNFs and NFVI must be visible for Management

End

Point

End

Point

VNF-

1VNF-

3

VNF-

2A

VNF-

2B

VNF-

2C

VNF-FG-2


NFVI-PoP

NFVI-PoP

Physical

Link

Virtualization


3GPP View

NFV Orchestrator

(NFVO)

VNF Manager(VNFM)

Virtualized Infrastructure

Manager(VIM)

EM

VNF

NFV-MANO

Vn-NfNE

(PNF)

VNF

Vn-Nf

NFVI

Os-Ma-nfvo

Ve-Vnfm-em

Ve-Vnfm-vnf

Nf-Vi

Or-Vnfm

Vi-Vnfm

Or-Vi

Itf-N

EM

NE(PNF)

EM

DM

NM

OSS/BSS

Itf-NItf-N“Technical Specification Group

Services and System Aspects; Telecommunication Management; Study on Network management of Virtualized Networks (Release 13), ” 3GPP TR 32.842 v13.1.0, Dec. 2015

Chapter VI:

The SESAME project

Introduction to SESAME – 1

• Innovation and Research Action (RIA) of H2020 ICT-14, Grant Agreement No. 671596

• Project Duration: 1st of July 2015, 31st of December 2017

• Project Coordinator: OTE (Hellenic Telecommunications Organization S.A.)

• Technical Coordination: NCSRD (National Centre for Scientific research, Demokritos)

• Link to SESAME: http://www.sesame-h2020-5g-ppp.eu

http://www.sesame-h2020-5g-ppp.eu/

Introduction to SESAME – 2

• SESAME promotes the adoption of Mobile Edge Computing (MEC)

• SESAME closely follows activities of 5G-PPP, ETSI NFV MANO, Small Cell Forum (SCF), 3GPP

• Small Cells virtualization is a key concept

• Virtualized functions are moved into an edge cloud environment based on an ARM processors environment

• SESAME develops functional split solutions for SCs

SESAME Enabling Technologies

• Small Cells: base stations with small form factor to provision improved coverage, much higher capacity and radiating lower transmit power. In SESAME SCs are designed for multi-tenancy since day-one => CAPEX and OPEX reduction

• Mobile Edge Computing (MEC): SESAME leverages on the edge-cloud computing idea bringing services closer to the end-users. Several benefits are possible such as lower content access delay and relieved traffic on the backhaul connection / network

• Virtualisation: Pivotal in SESAME to decouple physical functions from those virtualized. Virtualised functions can be executed where more convenient provided that capacity and latency constraints are fulfilled. The ETSI ISG NFV is used as main reference in SESAME

SESAME Goals

• To address the requirements and building upon the pillars of network virtualization, mobile-edge computing and cognitive management, SESAME’s main goal is: • The development and demonstration of an innovative architecture, capable of providing

Small Cell coverage to multiple operators, “as a Service”.

• Enabling Features:• SESAME envisages the logical partitioning of the localized Small Cell network to multiple

isolated slices, as well as their provision to several tenants.

• In addition to virtualizing and partitioning Small Cell capacity, SESAME supports enhanced multi-tenant edge cloud services by enriching Small Cells with micro servers.

• Apart from benefits offered to existing market players, the SESAME approach allows new stakeholders to dynamically enter the network value chain

SESAME Main Innovations

SESAME will bring services which are nowadays exclusively consumed via the Internet nearer to the users, provisioning radio connectivity and IT resources as-a-service (extremely-high throughput).

SESAME will bring storage and computational power at the mobile network edge (ultra-low latency).

SESAME will fully rely on the cloud approach managing and controlling virtual and physical resources assigned to tenant operators (unprecedented manageability and scalability).

SP-1

SP-2

EPCData

Centre

End User-1

From…

End User-2

EPC Data Centre

Internet

SP-2

SP-1End User-1

End User-2

CESC

To…

EPCData

Centre

EPC Data Centre

InternetSmall Cell Light DC

SESAME in 5G• SESAME aims to become the glue layer

between SPs and end-users

• Any type of service can be triggered

• SESAME relies on SCs combined with edge-cloud infrastructure called the Light Data Center (Light DC)

• The Light DC is composed of the interconnection of the ensemble of reduced computational power, cheap micro-servers

• One micro-server connected to fronthaultechnology to the SC is called the CESC

• The collection of several CESCs is called the CESC Cluster: the smallest, complex entity in SESAME

SESAME Pillars

• Cloud-Enabled Small Cell (CESC): It is the minimal entity grouping radio and computing resources to be developed within SESAME, conceived to support multi-tenancy and that relying on “Self-x” (self-organizing, self-optimizing and self-healing) features can provide automated operations. Clusters of CESCs are also to be developed by the project.

• Light Data Centre (Light DC): It is the interconnection of micro-server facilities that rely on non-x86 ARM v8 architecture which uses HW accelerators to support computation intensive, low latency applications where hardware located modules are delivered as VNF.

• Fronthaul/Backhaul: Fronthaul is used to connect the small cells to the micro-servers, whereas Backhaul to connect to an operator’s core network

• CESC Manager (CESCM): It includes the necessary layers for NFV management (NFV lifecycle) and orchestration, it provides monitoring of the physical and virtual networks and it configure radio access parameters.

SESAME Architecture• Principle 1: The SESAME

system is sustainable and reconfigurable

• Principle 2: SESAME offers an infrastructure shared between operators, transparent and neutral

• Principle 3: SESAME accelerates the creation of innovative services with superior quality of experience through mobile edge computing

• Principle 4: SESAME develops a system which is capable of optimising the usage of radio, storage and computing resources

SESAME components – 1

CESC Manager (CESCM)• This is the entity responsible for managing the CESC cluster• The CESM implements orchestration, NFV management, virtualisation of

management views per tenant, self-x features and radio access management techniques

• The CESM Portal is used by externals (Virtual SC Network Operators –VSCNO ) to request for resources or apply (re)configuration of network parameters

• The SLA module provides inputs to both VSCNOs and infrastructure provider about correct execution of the environment, and it enables the orchestration subsystem to react accordingly to changes in the network when this required (i.e. SLA violation)

SESAME Components – 2

• SESAME relies on the ETSI Management and Orchestration (MANO) architecture

• The NBI provides access to the CESCM internal components• NFV Orchestrator (NFVO) is the entity responsible for instantiating

Virtualised Network Functions (VNF) and Network Services (NS) within the NFVI (i.e. Light DC)

• The NFVO interacts with the VIM and NFVM through specific interfaces to create VNF and NS (NFV Forwarding Graph – NFVFG)

• The VNFM is responsible to manage the lifecycle of VNF (creation, termination scale up/down)

• The VIM deploys VNF and NS in the NFVI according to the requirements available in appropriate descriptor files

SESAME Components – 3

• SESAME aims to virtualize both radio functions and services (e.g. virtualised VTU) hosted within the Light DC, with latter referred to as “service VNFs”

• Virtualised SC functions are called simply VNF, and physical SC is called Physical Network Function (PNF)

• For virtualized SC functions SESAME is evaluating different functional split

• Separate EMS entities are responsible for Fault, Configuration, Accounting, Performance and Security of both VNF and PNF• For example the EMS can host centralized self-x features

• The NMS is responsible to communicate with different EMS entities • NMS falls within the domain of the Physical SC Network Operators (PSCNOs)

• Core Network (i.e. EPC) falls within the domain of different SC Network Operators (i.e. VSCNO)

Many Possible Functional Split – 1

RRC

PDCP

RLC

MAC

PHY

RRC

PDCP

RLC

MAC

PHY

RRC

PDCP

RLC

MAC

PHY

RRC

PDCP

RLC

MAC

PHY

RRC

PDCP

RLC

MAC

PHY

Distributed PDCP Split RLC Split MAC Split Centralized


Hypervisor

EMS EMS

NMS

OVS

S1Virtual Network Connecting micro-servers

SC VNFsVM

(PDCP)VM

SC-C VNF

EMS

VM(SC VNS)

PNF

Micro-server

PHY

MAC

RLC


• Split RRC-PDCP: The RRC protocol is virtualized while the rest of protocols (PDCP and below) stay in the physical cell as PNFs. This functional split allows the virtualization of certain functions that are supported by RRC, such as centralized connection mobility control, measurement reporting and handover trigger control, performance measurement management and inter-cell Radio Resource Management (RRM). Estimated fronthaul data and control bandwidths for this functional split are 187.5 Mbit/s for DL and 62.5 Mbit/s for UL. This functional split is considered to be feasible with all fronthaullatencies considered in the analysis (i.e. from 250 s up to 30ms).

• Split PDCP-RLC: This case assumes that the virtualization split is done between PDCP and RLC. The estimated fronthaul bandwidth requirements are similar to the split RRC-PDCP case, and this functional split is also feasible with all the considered fronthaul latencies.

• Split RLC-MAC: In this case, the RLC layer functions are virtualized while the MAC and Physical layer functions reside in the physical small cell. This provides some storage and processor utilization benefits, but it introduces complexity into the small cell implementation, because the downlink RLC is tightly coupled to the MAC and scheduler which remain at the physical side. The fronthaul bandwidth requirements are similar to those of the previous cases, and it requires backhaul latencies of maximum 6ms.


• Split MAC-PHY: In this case all the MAC layer functionalities are virtualized, while the physical small cell only carries out physical layer functions. The virtualization of the HARQ results in tighter latency constraints on the fronthaul, requiring one-way latencies below 250 s, which can be increased up to 2ms in case that HARQ interleaving technique is used. Bandwidth requirements are similar to those of previous splits.

• Split PHY: This involves the virtualization of some physical functions: Split between the upper part of the PHY layer and the lower part. There are different options for doing this split, depending on the amount of baseband functions that are virtualized. This use case provides added benefits of resource sharing and load balancing for the DSPs, FPGAs, and hardware accelerators, but it involves increased requirements for the fronthaul. For example, fronthaul bandwidth requirements reach up to 2.45 Gbit/s for the case in which all the processing is virtualized, and fronthaul latency should be below 250 s.

Data from the Small Cell Forum

Use Case One-way Latency DL Bandwidth UL bandwidth

PDCP-RLC Non ideal 30 ms 151 Mbps 48 Mbps

Split MAC Sub Ideal 6 ms 151 Mbps 49 Mbps

MAC-PJY Near Ideal 2ms 152 Mbps 49 Mbps

PHY Split Ideal 250 μsNear idea 2 ms

1075 Mbps 922 Mbps

*SCF 159.06.02 “Small Cell Virtualization: Functional Splits and Use Cases”, January, 2016.

Example Use Case 1

“This use case intends to highlight theSESAME functionalities to achieve: (i) anadvanced planning of the required radiocapacity to be proactively provisioned byCESCs at any time and at any place, (ii) anoptimized operation of the CESCs relyingon the use of self-x functionalities toconfigure the radio parameters. “

Example Use Case 2

“An Small Cell Network Operator (SCNO) is supporting two distinct Virtual SCNOs (VSCNOs) within its infrastructure (VSCNO1 and VSCNO2). Users of both VSCNO1 and VSCNO2 access the same content (e.g., video stream) repeatedly (e.g., at a sport event, recordings of previous records of an athlete). In SESAME a distributed storage cache is implemented at the level of the CESC (cluster) and can be accessed by both VSCNOs to look for content (so the storage cache is inter-operator). The Shared distributed cache can be accessed by the users of two different operators.”

Interference within the CESC Cluster

Victim Receiver

(Example)

Downlink Interference

RRM and SON in a Virtualised Environment

Light DC

EMSEMS

(SON Entity)

RRM SON

AC, Dynamic power control, Overload Control, QoS Control,Overload Control, Carrier Aggregation, COMP,Scheduling

Self-organizing: ANR, MRO, ICIC, Blanking patterns Self-optimizing: MLB, PCI collision handling

The functions that can bereally implemented inSESAME also depend on thefunctional split

Modeling Interference – 1

• For this purpose we rely on stochastic geometry and in particular on stochastic cluster point processes

• We denote with I the aggregate interference

• Example of downlink: I = Isc + Imc

Isc = aggregate interference due to surrounding small cells; Imc=aggregate interference due to surrounding macro-cells

||||),( yxyxl


• To model aggregate interference we use the Laplace transform approach

• With the Laplace transform we notice that interference modeling leads to the product of different Laplace transformations

t

tstdss

P

rs

d

sPEgsPCP

0

2/2

/

/2sin

2)(exp1exp

This way of modeling

interference is based on Poisson distribution of nodes under Rayleigh fading assumption


• Modeling of residual interference from macro-cell from a distance r≥ρ

• Path-loss and fading compensation

t

ttgtsms

sP

sPgsPgEsPP

1,1exp

2

,

tP

rs

0 11exp 2)( d

d

plfc

s ErsCP

Interference Management

• Network slicing: Assignment of resource slices per tenant + power control to reduce leakageResource slicing includes assigning different PRBs to different tenants (i.e. assign different

carriers even over non-contiguous bands)

• More conventional approachPower control in pure frequency reuse oneFractional frequency reuseExploitation of blanking patterns

• We shall use the link probability of success to develop algorithms

• We model the interference adapting to the specific context of SESAME

• Still work needs to be done for cluster networks in modelling interference

• We shall further take into account different levels of virtualization inside the CESC

Conclusions and Future Work

• The mobile network is facing a dramatic paradigm shift compared to the past

• The main motivation is to enable the end users with new services, which can be consumed reliably and ubiquitously

• 5G technology will fill the gaps between users, service providers and traditional operators

• The mobile network will be nothing than all other IP networks

• To manage denser and heterogeneous mobile networks, RAN functions will be virtualized

• Industry, academia and the European Commission are cooperating to achieve 5G by 2020

Thank you Very Much for your Attention and Best Luck in your

Future Career!

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