Download here - Online Journal of Space Communication

Satellite Communications Systems and
Emergency Communications
Dr. Joseph S. Bravman
Omnisat, LLC
December 12, 2005
Why Satellites
• Advantages
–
–
–
–
Highly portable & ubiquitous connectivity
Independent of damaged or unreliable infrastructure
Assured access
Work well to interconnect hybrid network links
• Issues
–
–
–
–
Beyond Line of Sight limitations
Can be expensive or unfamiliar
Often not what is in use at local level
GEO Delays cause unexpected IT problems
Commercial Satellite Markets
• Communications
– Backhaul Capacity
– VSATs & Private Networks
– Broadcast (DTH & SDARS)
– Internet & IP based
– Satellite Telephony
– Misc.
• Navigation
• Remote Sensing
Shares Solutions with Urban Warfare
• Similarities
– Need for collaboration
– Similar operating environment
– Complex interoperability and multilevel security
• Differences
– Dual use and commercial technologies are more easily
embraced
– No export issues with coalitions
– AJ/LPI/LPD not a major factor
– Less issue with sharing with civilian population
Elements of Emergency Communications
• Phases of a disaster or event
–
–
–
–
–
Monitoring & preparation
Warning
Crisis
Mitigation & management
Restitution
• System elements expand and contract through these phases
• Communication system functions
–
–
–
–
–
–
Sensor communications
Broadcast communications
Command & control
Collaboration
Tactical communications
Communications restitution
The Problem & the Solution
• Fragmented nature of responders - Stovepipes &
Interoperability issues
• “Bring your own” – small, low cost and flexible equipment
• Leverage off high impact commercial technology
• Mix of push and collaborative pull on data sets
• Caching with automated updating
• Multi-node
• Optimal use of spectrum for bandwidth and coverage
• Hybrid networks solve non-LOS and create local resiliency
• Satellites independent of infrastructure
• Secure interaction with flexible authorization required
• User attributes are used to tailor data transfer
• Must be scalable at all levels
Platform Features
• Multilevel security - encrypted data transfer with distributed
administration
• Assures access due to multi-tier priority scheme and automatic
queue management
• Packetization and data scheduling provides flexibility and efficiency
in intermixing and transferring all types of files (data, software,
commands, media)
• Version control allows simultaneous operation of multiple versions
• Conditional access defines >10 million users or user groups
• Files are assigned address to create bundles of information ( >10
million addresses are initially provided)
• Conditional access insures that the right information gets to the
correct user using address fields & can be changed at any time
• Geocoding can be added to provide convenient additional filter
• System time is distributed and controls timed features
Hybrid Network
Various Satellite Systems
.
Various
Satcom
Uplinks
Multiple terminals
link to mesh for
redundancy
Data
Data is cached &
locally archived
Local
Cache
.
Internet
Mesh
Mobile
Terminal
Additional Fixed
Sites connected
by conventional
means or Satcom
terminals
Mesh
PDA with
Wireless
Mobile &
Portable assets
Laptop with
Wireless
Packet Radio
Mesh Network
Mesh
`
Fixed &
transportable assets
Mesh
Uses of terminals
• Packet Radio nodes create resilient mesh
• Ad hoc users gain local and long range connectivity beyond
LOS
• Command and control features may be remoted to field
• Push/broadcast fills local cache with information that is likely
to be required
• Collaborative software allows multimedia interactivity
• Terminal characteristics are transmitted to control resolution,
etc. to minimize overwhelming links and processors
Communications Elements
50 Mb/s
5 Mb/s
500 Kb/s
50 Kb/s
5Kb/s
P
A
C
K
E
T
R
A
D
I
O
Local
Ku/Ka-Band Satellite
L/S-Band Satellite
UHF/VHF Satellites
Regional
Continental
Satellite Solution Advantages
• Satellites provide instantaneous dissemination of information
and a common operating picture – Gets it to the user faster
and at low cost.
• Satellite systems not susceptible to terrestrial boundaries and
costs. Easily becomes part of hybrid solution.
• System solution benefits from off-the shelf components
leading to overall affordability and quick implementation – But
must be efficiently integrated with open standards
• System must be valuable beyond crisis usage – critical to
business case
• Demonstrations and rapid prototyping propels fieldable
solutions