ip over satellite - esa's artes programmes · pdf fileip over satellite gorry fairhurst...

IP over Satellite

Gorry Fairhurst

http://www.erg.abdn.ac.ukElectronics Research GroupUniversity of Aberdeen, UK

(c) University of Aberdeen, 2004

IP over Digital Video BroadcastAdaptation LayerDVB-SDVB-S2DVB-RCSExampleConclusions

Tutorial provided by the

EC SATNEx NOE

The Satellite Network of ExcellenceExaples

1

IP over Digital Video Broadcast

Adaptation Layer

DVB-S

DVB-S2

DVB-RCS

2

Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk

LAN /Internet

Server

Client

Why choose DVB?

Common (mass-produced) componentsSupport for narrowcast and broadband

Clients cheap & standards-based

Receiver

Gateway

3


Link

TCP

IP

Phy

Middleware

Client

Enet

UTP

FR

X.21

PoS

Fibre

PPP

V.fast

IP

TCP

Middleware

Client

IP

IP over foo

4


IP IPNetwork Flow

Gateway Receiver

IP over DVB

AL AL

Server Client

TCP TCPTransport Connection

Coding& QPSK

Coding& QPSK

MPEG-TS MPEG-TS

5


MPEG-2Transport

MUXMPEG-2

Compressors

Other Transport Streams

Video

Audio

DVB: MPEG-2 IP Streams

IP Encapsulation

GatewayIP Packets

1-60 Mbps

Receivers

MPEG-2Transport Stream (TS)

[ISO 13818-1; EN300468]

6


Adaptation Layer

DVB-S

DVB-S2

DVB-RCS

7


MPEG-2 TS Packet payload 184 B

StartPointer

IP packets typically 40 B – 1500 B

IP Header, IP Payload16B MPE Overhead

IP packets (upto 4 KB) encapsulated using MPE

Multi-Protocol Encapsulation (MPE)

8


[ETSI EN 301192]

DVB Section

IP Packet

MPEG-2transportstream

payload_unit_start_indicator=1

6-byte dst MAC address

1-byte MPEG-2Start pointer

3E

Len3-byteSection header

4-byte trailerCRC-32 or Checksum

Section No.& Last section No.

Flags field

Optional section padding

Optional 8-byte LLC SNAP header

Multi-Protocol Encapsulation

9


MPE IPv4 Packet CRC-32

IPv6 packet

LLC/SNAP 8, 24, or 28B

IPv4 / IPv6 PacketMPE LLC CRC-32

IPv4 packet

MPE has no type fieldWhat if you want to carry something other than IPv4?Need to add LLC/SNAP overhead

IPv6 and other L2/ L3

10


Ultra-Lightweight Encapsulation (ULE)

From IETF ipdvb WG

[currently draft-ietf-ipdvb-ule-01.txt]

ULE Packet / Frame

Native Support for: IPv4/IPv6/MPLS/Ethernet

Payload up to 32 KB

Extension headers supported (similar to IPv6)

4-10 B

CRC-32

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0000: 00 3f 86 dd 01 02 03 04 05 06 60 00 00 00 00 0d

0010: 3a 40 20 01 06 60 30 08 17 89 00 00 00 00 00 00

0020: 00 05 20 01 06 60 30 08 17 89 00 00 00 00 00 00

0030: 00 06 80 00 9d 8c 06 38 00 04 00 00 00 00 00 78

0040: 46 79 a5

ULE SNDU Length : 0x3f (63 decimal)

D-bit value : 0 (NPA Present)

ULE Protocol Type : 0x86dd (IPv6)

Destination ULE NPA Address: 01:02:03:04:05:06

ULE CRC32 : 0x784679a5

Source IPv6: 2001:660:3008:1789::5

Destination IPv6: 2001:660:3008:1789::6

IPv6 Payload: 0xd (13 decimal) bytes

Ultra-Lightweight Encapsulation

[currently draft-ietf-ipdvb-ule-01.txt]12


Adaptation Layer

DVB-S

DVB-S2

DVB-RCS

13


Server

Client

FromServer

Packet Routing (from Server)

DVB Modemtypically 1 - 60 MBps

Scrambling, Modulation, Coding

Multiplexing

Encryption

EN 200 421

Gateway

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DVB Transport Stream Coding

Convolutional Coding

Level of convolutional coding selected by satellite service provider(e.g. 1/2, 2/3, 3/4, 5/6, 7/8)

Interleaver & Sync

Sync byte of every 8th TS packet inverted

RS Code

188 B 16B

MPEG Transport Packet

8.5% overhead

Header Payload

184 B4 B PID in TS header

QPSK, 8PSK, 16QAM modulation

Modulation

Baseband shaping

15


DVB LNB

DVB Data Receiver Adaptor

PCI Modem

DVB Client Components

16


Uplink Station

QPSKMod& FEC

MPEG-2Mux

MPEG-2Packet DataProcessor

LANSwitch

Server

Client with DVB Card

TerrestrialInternet / ISDN

Overview of DVB-S with Dial-Up Return Link

17


Router

Hub LAN

Hub Server

From

ServerTo

Server

Packets (e.g. TCP ACKs)for server received here

Packet Routing with Dial-Up Return Link

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To

Server

[RFC 3077]

Uni-Directional Link Routing (UDLR)

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Adaptation Layer

DVB-S

DVB-S2

DVB-RCS

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DVB-S2 Forward Protocol Stack

Forward Path

AL AL

Server

DVB PacketEncap

Client

TCP TCPTransport Connection

IP IPNetwork Connection

MPEG-TS MPEG-TS

Coding& Mod

Coding& ModControl

TrafficClass

Adaptive Coding & Modulation (ACM)TS Packets assembled into coding blocks

Generic Stream (GS) also supported

Null packets may be deletedCoding & Modulation per traffic class

21


Adaptation Layer

DVB-S

DVB-S2

DVB-RCS

22


Return Channel via Satellite

DVB-RCS

1990's ESA Projects for 2-way DVB Satellite

1999 Standardisation in DVB

2000 Official release

Normative Doc ETSI EN 301 790

Guidelines ETSI TR 101 790

2001 Field Trials

2002 Second release

2002 First commercial networks

2003 SATLABS forum started

23


ODU interfaces

Two Rx RF: ~ 40 Mbps

Tx RF: 144 -2048 kbps

RF Tx power 2 W, antenna dia. 96 - 120 cm

Network Interfaces

10/100 Mbps Ethernet interface

DVB-RCS Satellite Terminal

24


Client

Internet Server

Router

To

Server

All client packetsoriginate here

DVB-RCS Routing

Router

25


Server Client

Router

at Hub Site

Return Protocol Stack (Type-A ATM Satellite Return)

QPSK

MF-TDMA

QPSK

MF-TDMA PhysicalLayer

Return Link Satellite System (RLSS)

Operated by Satellite Service Provider

Bandwidth on Demand (BoD)

TCP TCP

Transport Connection

ATM

AAL5

ATM

AAL5 ATMLayer

IPIP

Network Connection

IP

NetworkLayer

26


Server Client

Router

at Hub Site

Return Protocol Stack (Type-B MPEG Satellite Return)

QPSK

MF-TDMA

QPSK

MF-TDMA PhysicalLayer

MPEG Return Link Satellite System (RLSS)

Compatible with MPEG-based regenerative OBP

MPEG-TS

MPE

MPEG-TS

MPE PhysicalLayer

TCP TCP

Transport Connection

IPIP

Network Connection

IP

NetworkLayer

27


2 Mbps Terminal

TDMA Burst Size

Frequency

Time

Power

f

t

512 kbps Terminal

P

f t

P

128 kbps Terminal

28


TDMA Burst Time Plan

Frequency

TimeControl slots

26.5 milliseconds

29

Examples

30


Antenna / LNB

Broadband

- Standard TV Antenna

Universal digital LNBSwitchable freq / polarisation (microwave resonator)High rate multiplex

Narrowcast

- Professional TV Antenna

Larger AntennaProfessional digital LNBUsually single polarisationLower phase noiseTracks small signal close to carrier

31


SUNRISE Project

Content from LSO1.5- 4 Mbps IP data

!London

90cm Antenna / Professional LNB

!

ESA ARTES 3 Programme

32

Conclusions

DVB: A Low-cost Receive System / Pt-2-Pt Standard low cost components

DVB-SDVB-S2 Better Efficiency (~ 35%)

Selectable modulation/coding, adaptive

Internet Service (Hub/Star)Adaption layer: MPE or ULEReturn link via dial-up modemRouting to Internet needs tunnels (e.g. UDLR)

Next GenerationNext generation OBP satellite payloadHigher frequency bands (Ka, V)

33

Client

Application performance impacted by delay ... generally not chosen by operator

Middleware

Middleware mostly ignorant of Internet ... long-standing problem :-(

TCP

TCP performance impacted by delay... signs of change in OSX/LINUX/Longhorn?

IPIP QoS an issue... policy; mobility; security

LinkLink Characteristics... how should TCP/IP interact with the link?Phy

Phy becoming more sophisticated... fading, adaptation, etc

Better integration with IP features Research issues being examined by SATNEx(see also IETF ipdvb WG, and ETSI/BSM WG )

Research Directions?

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Questions

&

Answers

35

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