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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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
IP IPNetwork Flow
Gateway Receiver
IP over DVB
AL AL
Server Client
TCP TCPTransport Connection
Coding& QPSK
Coding& QPSK
MPEG-TS MPEG-TS
5
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
IP over Digital Video Broadcast
Adaptation Layer
DVB-S
DVB-S2
DVB-RCS
7
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
[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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
11
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
IP over Digital Video Broadcast
Adaptation Layer
DVB-S
DVB-S2
DVB-RCS
13
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
Server
Client
FromServer
Packet Routing (from Server)
DVB Modemtypically 1 - 60 MBps
Scrambling, Modulation, Coding
Multiplexing
Encryption
EN 200 421
Gateway
14
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
DVB LNB
DVB Data Receiver Adaptor
PCI Modem
DVB Client Components
16
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
Router
Hub LAN
Hub Server
From
ServerTo
Server
Packets (e.g. TCP ACKs)for server received here
Packet Routing with Dial-Up Return Link
18
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
To
Server
[RFC 3077]
Uni-Directional Link Routing (UDLR)
19
IP over Digital Video Broadcast
Adaptation Layer
DVB-S
DVB-S2
DVB-RCS
20
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
IP over Digital Video Broadcast
Adaptation Layer
DVB-S
DVB-S2
DVB-RCS
22
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
Client
Internet Server
Router
To
Server
All client packetsoriginate here
DVB-RCS Routing
Router
25
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
2 Mbps Terminal
TDMA Burst Size
Frequency
Time
Power
f
t
512 kbps Terminal
P
f t
P
128 kbps Terminal
28
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
TDMA Burst Time Plan
Frequency
TimeControl slots
26.5 milliseconds
29
Examples
30
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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
Gorry Fairhurst (c) 2004, University of Aberdeen, http://www.erg.abdn.ac.uk
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?
34
Questions
&
Answers
35