Download Broadband Roaming over DVB Networks

Asymmetric Broadband Roaming over DVB
Workshop on Broadband Wireless Ad-Hoc Networks and Services
12th - 13th September 2002
ETSI, Sophia Antipolis, France
UNCLASSIFIED
R. Segura, NATO C3 Agency, ACT/CISD
[email protected]
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
UNCLASSIFIED
The NATO C3 Agency Role
• Perform central planning, systems integration, design, systems
engineering, technical support and configuration control for NATO
C3 systems and installations
• Provide scientific and technical advice and support to the Strategic
Commands and other customers on matters pertaining to
–operations research,
–surveillance, air command and control including theatre missile
defence,
–electronic warfare and airborne early warning
–communications and information systems
• Provide technical support for exercises and for unforeseen
operations assigned to the NATO Military Authorities (NMA) by the
North Atlantic Council (NAC)/Defence Planning Committee (DPC)
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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The NATO C3 Agency Role (cont.)
• Perform technical policy and
standardization work in support
of the NATO C3 Board (NATO
Standardization Agreements,
a.k.a. STANAGs)
• Procurement and project
implementations
The NATO C3 Agency became Member
of Project MESA in April 2002
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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IP Roaming over DVB: Motivation
• Supporting the wideband communications requirements of multinational forces engaged in rapid coalition deployments, e.g.:
–Humanitarian relief
–Peacekeeping, Peace Enforcement, Collective defence
• Nomadic networks provided by participating nations are integrated
into mobile Virtual Network (VN) overlays, subtended by a fixed
backbone established by the nation leading the deployment
• VNs shall support broadband content delivery from fixed data
repositories to hosts in the Mobile Networks through symmetric or
asymmetric data transactions
• VNs shall support communications between mobile networks
• Satellite and Terrestrial DVB bearers, carrying IP over MPEG2 are
proposed to transport the forward traffic from fixed to mobile hosts
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Mobile Networks, Mobile Routers
• Mobile Network: a stub LAN connected to an access router that
supports IP mobility as per RFC 2002 (Mobile Router)
• A Mobile Router can have multiple roaming interfaces, which can
dock into the fixed IP network over different wireless media and
access points
• The Mobile Router’s counterpart in the fixed network is the Home
Agent Router
• The Home Agent has WAN access to a number of Foreign Agent routers,
which cover the area where Mobile Routers will be roaming during the
mission
• The Home Agent is the single gateway for all traffic addressed to the
Mobile Networks, effectively acting as a registration and routing broker
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Mobile Router Principle
• The Mobile IP model (RFC 2002) is extended from the classic Mobile
Host to the Mobile Router implementation (e.g. Cisco IOS 12.2)
• Mobile Routers listen to routing service advertisements from
Foreign Agents after entering their coverage area, and can register
with the Home Agent through the Foreign Agent of their choice
• Following registration, all traffic from fixed and mobile hosts
addressed to the Mobile Networks is routed to the Home Agent, and
then double-tunnelled (using IP-IP encapsulation):
– Outer Tunnel: from Home Agent to Foreign Agent
– Inner Tunnel: from Home Agent to Mobile Router
• All traffic from the Mobile Networks is by default sent to the Foreign
Agent, and passed to the destination host using standard routing
mechanisms (or mobile IP if the destination host is in a Mobile Network)
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Virtual Networks
• Objective is to build Virtual Networks in which all nodes are mobile
over a wire area of operations
• Mobile Routers are access routers in motion around a wide area
wireless access infrastructure
• Mobile Networks hooked to the Mobile Router need not be Mobile-IP
aware, and can maintain their home IP configuration
• All traffic is tunnelled through a virtual Home Agent down to the
Foreign Agent covering the area visited by the Mobile Network
–The Home Agent is virtual in the sense that it is not attached to the
actual (domestic) home network of any of the mobile networks
–The Home Agent advertises IP routes for all registered mobile networks
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Virtual Networks
MN #2.1
MN #4.1
MN #2.2
MN #1.1
MN #4.2
MR #2
192.182.3.2
MN #3.1
MR #1
192.182.3.1
MR #4
192.182.3.4
MR #3
roaming
interfaces
192.182.3.3
Docking Switch (192.182.3.0/24)
MN: Mobile Network (LAN)
MR: Mobile Router
…at the docking site
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Virtual Networks
MR #2
Foreign
Agent
Foreign
Agent
MR #1
Deployed
WAN
Home
Agent
Virtual Network
192.182.3.0/24
Foreign
Agent
Foreign
Agent
…on the move
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MR #4
MR #3
Workshop on Broadband Wireless Ad-Hoc Networks and Services
IP-IP tunnel
UNCLASSIFIED
Tunnel Overlays
• Mobile Routers are logically meshed over a star-shaped overlay of
IP-IP tunnels
• Hub & spoke topology: spokes are established on-demand,
between the Home Agent (hub) and the edge Foreign Agents
• IP encryption devices can be used for securing all mobile network
traffic, either
– as an IPSEC tunnel overlay, i.e. the crypto is placed between the Mobile
Router and the Mobile Network(s) => mobile IP protocol goes in the clear
- or – at the air interface edge (*), i.e. the crypto is placed as a bump-in-thewire between the Foreign Agent and the wireless/broadcast front-end
(and between the wireless front-end and the Mobile Router)
(*) this configuration requires the IP crypto to support broadcast/multicast
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Implementation Constraints
• Time, budget and technology constrained military deployment
scenarios
 establishing a cellular network of several access points with omni
directional antennas, full-duplex, wide area coverage and broadband
capabilities may not be feasible
• Yet traffic flows between fixed and mobile networks are expected to
be highly asymmetric in bandwidth, therefore…

broadband unidirectional bearers (e.g. DVB-S / T) could carry forward
traffic downstream into the mobile nodes
 narrowband channels of opportunity could carry return traffic
upstream (mobile IP registration and user traffic)
 …take advantage of users in mobile networks already carrying legacy
narrowband and personal communications systems, which can be used
to hook into the fixed network
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Cellular Broadcast Solution
• Combine asymmetric split-path network configurations with mobile
routing protocols
• Connect transmit-only Foreign Agent routers to a star network of
broadcast stations blanketing the mission’s target area
• Broadcasts from a Foreign Agent can go over a satellite spot beam
(DVB-S) or a terrestrial cell (DVB-T)
• Mobile Routers will receive the broadcast over one or more
wideband roaming interfaces (receive only)
• Mobile Router’s return traffic will be diverted over narrowband
transmit media, and reach the Foreign Agent over one or multiple
hops across the fixed network (first hop being wireless)
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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DVB-S Scenario
• Macro-cellular infrastructure: intent is to provide broadband roaming
services to very high-speed moving platforms, e.g. aircrafts, equipped
with steerable antennas (phased arrays or reflectors)
• Continuous coverage can be provided by multiple downlink spot beams
(e.g. at Ka-band), or by multiple satellites
• Each footprint is fed by a different Foreign Agent and uplink hub
• Mobile units are equipped with satellite tracking antennas, and DVB-S
Integrated-Receive-Decoders (IRD) with multiple tuners (one per beam)
• Changing beams involves re-registering with the Home Agent through a
different Foreign Agent
• Registration and return traffic goes over a different medium (e.g.
Inmarsat phone, VHF radio, etc.)
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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DVB-T Scenario
• Micro-cellular infrastructure: intent is to provide roaming services to
fast moving land platforms equipped with omni-directional antennas
• Target area covered by cells of a DVB-T Multi-Frequency Network (MFN)
• Each cell is fed by a different Foreign Agent and transmit front-end, and
operates at a different channel frequency
• Mobile units are equipped with light UHF omni-antennas (GSM-like), and
DVB-T IRD, fitted with multiple tuners (one per MFN channel)
• Handovers between cells involve re-registering with the Home Agent
through a different Foreign Agent
• Registration and return traffic goes over a different medium (e.g.
GSM/GPRS, TETRA, 802.11b, UMTS, etc.)
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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IP over DVB Bearers
• Multi-Protocol Encapsulation (MPE, ISO/IEC 13818) to carry unicast
and multicast IP packets encapsulated into MPEG2 transport streams
• IP/MPEG2 Encapsulator (IPE) placed between the Foreign Agent
Router and the DVB modulator (satellite or terrestrial), over Fast
Ethernet and MPEG-2 ASI interfaces
Broadcast Station
Home Agent
Router
Foreign Agent
Router
IP/MPEG2
Encapsulator
DVB
Modulator
Terrestrial
WAN
Mobile
Router
DVB IRD
DVB
Broadcast
Bearer
(Wideband)
Wireless
Return
(narrowband)
IP-encryption as IPSec VPN
Mobile Network
IP-encryption of broadcast channel
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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The DVB-T Advantage
• COFDM over Band IV/V UHF channels (470–872 MHz; 6, 7, and 8 MHz)
–NATO can use channels 61 to 69 (790 MHz – 862 MHz), which are part of the
military radio relay band (Chester Multinational Coordination Agreement, 25 July 1997)
–Can also use VHF (46-250 MHz) or L-band
• COFDM provides
–unprecedented performance against fast and selective multipath fading
–resilience against narrowband interferers
–support of fast moving platforms at data rates up to 10-15 Mbps
• DVB-T IRDs are small, compact and inexpensive (e.g. PCMCIA)
• DVB-T cells can be very large in open field propagation environments
• Use of civilian broadcast infrastructure can significantly shorten the
deployment times (i.e. ‘transmitters and bandwidth of opportunity’ )
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Mobile IP - Asymmetric Link support
• Asymmetric link support is provided by the latest implementation of
RFC 2002 in Cisco IOS (12.2) (*)
• Foreign Agent interface can now be a transmit-only Fast Ethernet port
• Mobile Router roaming interface is receive-only, return traffic is
redirected to a different interface (e.g. a dial-up GSM/GPRS)
• One single IP/DVB broadcast bearer can serve multiple Mobile
Routers in the cell, each attached to multiple Mobile Networks (stub
LANs)
–Each Mobile Router roaming interface address is assigned an MPEG2
Program ID (PID). Multicast advertisements’ PID is defined in all receivers
• One single Home Agent can manage multiple VN in the area, each with
a variable number of “hosts” (Mobile Routers)
(*) NC3A tested experimental version in March 2002
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Mobile
Router
2
Mobile Router sends
registration request
(over the return
channel)
1
Foreign
Agent
(Deployed)
Ho
t to
t
Ho
me
Ag
en
t
4
3
Fixed Network
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2
WAN
WAN
Home
Agent
(Strategic
or
Deployed)
Mobile Router
split-path registration
over a DVB-T
broadcast bearer
IP-IP tunnel between HA and FA
IP-IP tunnel between HA and MR
Workshop on Broadband Wireless Ad-Hoc Networks and Services
UNCLASSIFIED
Mobile Node: a sample PC-104 stack
PC-104
ruggedized
enclosure
PCMCIA
DVB-T IRD
Western Datacom
Type-2 IP Crypto
(PC-104 form-factor)
to LAN
DVB-T
IRD
PC-104
embedded PC
w. PCMCIA slot
IP
CRYPTO
PCMCIA
PC-104
BUS
Ethernet
10BT
PC
Ethernet
10BT
MOBILE
ROUTER
802.11b
UMTS
GSM
GPRS
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Cisco’s Mobile Router prototype,
now Cisco 3200 (PC-104 form factor)
Workshop on Broadband Wireless Ad-Hoc Networks and Services
UNCLASSIFIED
Satellite-Terrestrial Augmentation
• Motivation: need to receive broadband content from strategic data
repositories, as well as from theatre-deployed sources (sensors)
–The former is of global interest, and can be transmitted as multicast to all
theatres over satellite DVB
–The latter is of local interest, and can be transmitted as roaming unicast to
a limited area (cell) over terrestrial DVB
• Target: mobile units receiving both global and local products
aggregated over the same DVB-T broadcast carrier, eliminating the
need for a motion-stabilized satellite dish
• Means: satellite-terrestrial MPEG2 relay stations, IP/MPEG2 inserters
(using opportunistic bandwidth on the received MPEG2 transport stream)
–Mobile IP tunnels are combined at MPEG2 level with IP multicast flows
received over the satellite channel
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Satellite-Terrestrial Relays
IP/MPEG2
Encapsulator
Strategic
WAN
DVB-S
Modulator
Satellite Broadcast Station
DVB-S
IRD
Fixed
Sources
MPEG2
Deployed
WAN
Theatre
Sources
IP/MPEG2
Inserter
IP
MPEG2
DVB-T Modulator
FOREIGN AGENT
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Satellite-Terrestrial
Relay Station
Workshop on Broadband Wireless Ad-Hoc Networks and Services
UNCLASSIFIED
… with Mobile Routers
Wheater
Satellite
Imagery
Video
Feeds
-S
DVB
S
BDV
Fixed HQ
Content Sources
Mobile
Router
DVB-T
Foreign Agent
WAN
Other Sensors
Data
Intel
Home
Agent
Deployed
WAN
Deployed
CJTF HQ
SIGINT
DVB-S
IRD
UAV raw
video
DVB
Foreign
Agent
MPEG
-T
IPinserter
MPEG
Deployed
WAN
IP
Foreign Agent
Router
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Mobile
Router
Foreign Agent
DVB-T
Modulator
Mobile
Router
Mobile
Network
Return channel
(registrations, return traffic)
Workshop on Broadband Wireless Ad-Hoc Networks and Services
UNCLASSIFIED
Conclusions
• Combining DVB broadcast with mobile routing under very
asymmetric networking configurations can speed up deployments
involving mobile networks from multiple coalition partners
• Virtual-network topology enables communications among mobile
networks through a virtual Home Agent acting as a hub
• Proposed architecture is fully based on open standards (ETSI,
ISO/IEC, IETF); mainstream, multi-vendor components
• COTS technology is combined with MOTS/GOTS Type-1 IP
encryption devices to meet military COMSEC requirements
• Tradeoff space: symmetric vs. asymmetric broadband access
alternatives, in terms of deployment costs, channel capacity,
mobility support and coverage range
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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Questions?
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Workshop on Broadband Wireless Ad-Hoc Networks and Services
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