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Special Session on “Satellite communications for 5G and beyond”39th Meeting of the Wireless World Research Forum, Castelldefels, Spain, 18-20 October 2017.

Softwarisation of the ground segment system

for combined terrestrial-satellite

communications networks

R. Ferrús, O.Sallent

Universitat Politècnica de Catalunya, Spain


• Introduction

• NFV/SDN applicability into satcoms: VITAL Project

• Case study of NFV applicability

• Case study of SDN applicability

• Conclusions

Outline

2


Introduction: Role of satellite communications in 5G

• The role that satellite communications can play in the forthcoming 5G

ecosystem is being revisited

• The satellite communications industry pushing for better satellite-terrestrial cooperation as part of mobile networks of 2020

• Remarkably, a requirement for next generation 3GPP systems to be able to provide services using satellite access included within the normative Stage 1 requirements and on-going study item to address the support of non-terrestrial networks in 5G New Radio (NR) specifications

• Wide area service coverage and high availability of SatComs are well suited to

serve future 5G networks:

• Foster the roll out of 5G in un-served areas (e.g. remote areas, on-board aircrafts/vessels) and underserved areas (e.g. rural areas)

• Reinforce 5G service reliability by providing service continuity and ensuring service availability anywhere (e.g. disaster relief, critical communications)

• Enable 5G network scalability by providing efficient multicast/broadcast resources for data delivery towards network edges

In combination with terrestrial network

technologies !

3


VITAL Project Scope

Introduction: Technical progress from many angles

• Advances in satellite payload technologies− E.g. More powerful GEO HTS satellites taking capacities from 100’s Gbps to over a

Terabit/s with hundreds of spotbeams, enriched board signal processing and reconfigurable payload features to meet changing traffic patterns and demands.

− E.g. Expectations of over 100 HTS systems in orbit By 2020-2025, delivering Tb/s of connectivity in Ku- and Ka- bands at reduced cost.

• Alternative constellation architectures, involving hybrid and new mega-

constellations− E.g. A large number of low-cost micro-satellites is expected to come to fruition in the

forthcoming years, anticipating a further capacity cost reduction and improved performance in terms of latency.

• Improved satellite and terrestrial integration − E.g. Higher degree of radio interface commonality and tighter operational integration with

5G system architecture and NR specifications

− E.g. Adoption of mainstream networking technologies within satellite networks such as SDN and NFV, in line with the advances in network softwarisation technologies being consolidated in the 5G landscape.

4


NFV/SDN applicability into satcoms: VITAL Project

5

• VIrtualized hybrid satellite-TerrestriAlsystems for resilient and fLexible future networks (VITAL)

• H2020 RIA (Research and Innovation Action) Project – ICT 2014-1

• Duration: Feb 1, 2015 – July 31, 2017 (30 months)

• Budget: 2,9 MEuros

• Resource: 341 PM effort

• Project Coordinator: Tinku Rasheed/Roberto Riggio, Create-Net

• Website: https://ict-vital.eu

• Twitter: VITAL Project @H2020_VITAL

“The central goal of VITAL is the research, implementation and demonstration ofimproved integration capabilities for the hybrid combination of terrestrial and satellitenetworking infrastructures through the introduction of NFV/SDN paradigms andtechnologies into the satellite domain”

https://ict-vital.eu


NFV Applicability: Virtualised Satellite Network Concept

6

VSN SDN controller

VSN NCC

VSNSDN switch(es)

VSN NMS/EMS

SBG PNF

Exposed VSN management interfaces

Exposed VSN control interfaces

Data plane interfaces

SBG-VNF

SBG-VNF

SBG PNF

SNF-VNFSNF-VNF

SNF-VNF

Deployed in common purpose HW

RF subsystem

A VSN is a satellite

network in which most

of their functions are

supplied as VNFs

running in a distributed

NFV Infrastructure

(NFVI) and in which

control and

management

capabilities are

supported and exposed

through SDN-based

interfaces.

(Control plane)

(Management plane)

(Satellite network

functions e.g. optimization, security, etc)

(Satellite BB

Gateway with Link Layer Functions)

(Satellite BB Gateway with Physical LayerFunctions)

RF subsystem

Deployed in purpose-specific HW

Satellite

Gateway

Functions

Special Session on “Satellite communications for 5G and beyond”39th Meeting of the Wireless World Research Forum, Castelldefels, Spain, 18-20 October 2017. 7

NFV Applicability: Management and Orchestration Architecture

Management and orchestration architecture for the composition and lifecycle management of VSN

Key features:• Multi-tenancy

(network slicing)• Dynamic

customisation(VSN as a Service)

VSN#m

VSN#k

Te

rmin

al s

ide

(e

.g. L

AN

ne

two

rk)

Ne

two

rk s

ide

(e.g

. WA

N li

nks

)

…

SBG-PNF Controller

(SBGC)

SBGC-VSNSBGC-SBG

NFV Manager

Or-Vi, Vi-Vnfm

Ve-Vnfm-em, Ve-Vnfm-vnf

SO-NVFM

SO-SBGC

SO-VSN

Service Orchestrator(SO)

Federated Network Resource Manager

(FNRM)

SNO’s OSS/BSSDashboard/Customer portal

xD-F

M-F

A /

xD-F

A-S

O

xD-FA-SO/ internal

NFVI

CentralisedNFVI-PoPs

Transport network

SBGPNF

…

Physical network infrastructure with virtualization support

NFVISBGPNF

RF gateway

Lightweight NFVI-PoP

ST

VIM

VIM

WIM RF gateway NFVI

VIM

NFVIVIM

Edge NFVI-PoPs

xD-C

&M

-itf

VSN#n


NFV Applicability: Implemented components

vWOC

A satellite PEP VNF that optimizes the traffic to reduce the perceived satellite

delay, via TCP optimization, data compression or Data Redundancy

Elimination (DRE).

SW

vHYAA multi-link traffic distribution VNF with flexible rules to balance user traffic

across terrestrial and satellite links.SW

vVPNAn IPSec VNF preventing eavesdropping via sessions tunnelling and

encryption. SW

3 VNFs implemented

Data Models and Descriptors

Code implementation of the NFV

Manager and FNRM

GUIs


NFV Applicability: Experimental testbeds

External network

(TCP clients)

NFVI-PoP at central location

Lightweight NFVI-PoP for user location

External network

(File server)

vVPN

vHYA

vWOC

vVPN

vHYA

vWOCTerrestrial Link

Satellite Link

(Real Connection @CNES premises and emulated connection with OpenSAND

Title/ID Description Observed KPI

Test 1: Satellite

only, using the

satellite link

alone

Stops the terrestrial link,

starts the satellite link on the

edge vHYA VNF .and

launches the SSH test

The elapsed and

expected SSH

durations for the

3 SSH scenarios

Test 2:

Terrestrial only,

using the

terrestrial link

alone

Starts the terrestrial link,

stops the satellite link on the

edge vHYA VNF, and


The elapsed and

expected SSH

durations for the

3 SSH scenarios

Test 3:

Terrestrial +

satellite

Starts the terrestrial and

satellite links, on the edge

vHYA VNF. Enables

MPTCP with

PSBOL+Offload path

selection on both the core

and edge vHYA VNFs, and


The elapsed and

expected

download

durations

Lightweight NFVI-PoP at terminal side

(OA Whitebox Platfotm)


• Mobile backhauling is a compelling scenario for the exploitation of SDN-based satellite

networks

• Satellite capacity can be used to complement the terrestrial infrastructure for reaching remote/rural areas, more

efficient multicast traffic delivery, increased resiliency and better support for temporary cell deployments and

moving cells

• The exposition of SDN-based interface for satellite connectivity management would allow

a MNO to easily integrate and operate the satellite component within its backhauling

infrastructure progressively relying on SDN technologies for the terrestrial capacity

counterpart.

10

SDN Applicability: E2E SDN-based TE in satellite-terrestrial

backhaul networks

Internet

NE#B NE#C

NE#A

TEApplications

(PCE) …

SDN controller(s)

Mobile Core Network Applications (e.g., MME, S/P-GW)

VSN

Mobile terminal RAN node(e.g. BS)

xD-C&M-itf


SDN Applicability: SDN-based satellite network architectures

• A SDN architecture of a VSN has been detailed, assessing the pros and cons of candidate SDN data models, protocols and Application Program Interfaces (APIs)

NCC App

ST

ST

ST

…

Satellite payload

…

NMC App

G

G

T

U/UST

U/UGW

NM

T

T

T

T

L3 and/or L2 packets

BSM Bearer Service (QID, QoS profile)

SDN Controller

SBI for theM&C of Interworking and Adaptationfunctions

Satellite Network Connection/Flow (Traffic Flow Template, QoS profile)

NBI for theM&C of Connection/FlowService

Gateway ST

ST U-plane

SD Lower Layers

Interworking& AdaptationST

M-p

lan

e

ST C

-pla

ne

SI-SAP

SI-SAP

SI-SAP

Gateway ST

ST U-plane

SD Lower Layers

Interworking& AdaptationST

M-p

lan

e

ST C

-pla

ne

SI-SAP

SI-SAP

SI-SAP

…

User ST

ST U-plane

SD Lower Layers

Interworking& Adaptation S

T M

-pla

ne

ST

C-p

lan

e

SI-SAP

SI-SAP

SI-SAP

User ST

ST U-plane

SD Lower Layers

Interworking& Adaptation S

T M

-pla

ne

ST

C-p

lan

e

SI-SAP

SI-SAP

SI-SAP

U/UGW

U/UST

U/UST

U/UST

Models/Protocols/APIs assessed:• ETSI BSM SI-SAP• ONF OpenFlow• ONF Microwave Information

Model• ONF Transport API• IETF YANG models for traffic

engineered networks


SDN Applicability: Integration approach for E2E TE

“Satellite Network Switch”

…

NE#B

Satellite Network Connection/Flow (Traffic Flow Template, QoS profile)

NE#A

MNO’s SDN controller

NE#C Gi

CSR

eNB

RAN node #B

Switching/Routing

functions

Switching/Routing

functions

eNB

RAN node #C

eNB

RAN node #A

GW

SatelliteL1/L2

GWSwitching/Routingfunctions

Switching/Routing

functions

Switching/Routingfunctions

TEApplications

(PCE)

Mobile Core Network

Applications

Mobile network control protocols(e.g., S1-MME for LTE eNB)

Controller API

Internet

SDN Controller

ST

ST

ST

NCC

NMC

NBI for theM&C of Connection/FlowService

Integration approach: • VSN connectivity abstracted as an

OpenFlow switch• The operation of the MCN is supported

through SDN-based TE applications with a central Path Computation Engine (PCE).


SDN Applicability: Flow activation workflow

Internet

TEApplications

(PCE)

MNO’s SDN controller

Mobile Core Network

ApplicationsNE#A NE#B NE#C

2. Decision to establish a

dedicated EPS bearer

3. Path establishment request

“Satellite NetworkSwitch”

RAN node#B

4. Selection of best path

6. Path establishment response7. RAB activation (e.g. S1-MME protocol)

1. Network monitoring

5. OpenFlowcommands

8. Established data path for the dedicated EPS bearer

UE

Activation of a service with optimal path computation


SDN Applicability: Formulation and Assessment of a SDN-

based TE application

• The SDN-based TE application exploits a combination of control features and criteria:

• end-to-end path computation;

• satellite capacity resource reservations;

• allocation criteria depending on the traffic nature;

• admission control and rate control features; and

• network utility maximization criteria.

• Performance assessment under diverse scenarios, including homogeneous and non-homogeneous load situations, terrestrial link failures in some of the BSs and deployment of a number of transportable BSs that exclusively rely on the satellite capacity for backhauling.

• Compared to more traditional overflow strategies, the SDN-based TE application is able to provide a higher network utility in most of the analyzed cases, greatly improving the admission rejection ratio for GBR services and achieving higher fairness in the distribution of Non-GBR data rates


Conclusions

• VITAL results clearly advocate for the need to transition satellite network

equipment to NFV deployable software components and outfit them with a set

of control and management functions and interfaces (API and/or network

protocols) compatible with the mainstream SDN architectures and

technologies being adopted in 5G in order to realize a full E2E networking

concept.

• While VITAL work has established good basis for formulation and

assessment of potential benefits of a number of diverse SDN/NFV resource

management features, further work is still needed towards a full realization of

these concepts by developing and testing pre-operational SDN/NFV-enabled

satellite network systems that can seamlessly become a constituent part of

5G software network infrastructures.

15


Thank you for your attention

Ramon Ferrús

[email protected]

16

Acknowledgements

This document has been produced in the context of the H2020 VITAL project. The VITAL project consortium would like to acknowledge that the research leading to these results has received funding from the European Union’s H2020 Research and Innovation Programme (H2020-ICT-2014-1) under the Grant

Agreement H2020-ICT-644843.

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