Using ORBCOMM for Global
High-Altitude Communications
Tim Maclay
Celestial Insight, Inc.
Bridging the Gap to Space
Boulder, CO
October 26-28, 2009
Overview
• ORBCOMM service and applications• Network architecture• Messaging types• Constellation coverage• Subscriber communicators• Applications and service distribution• Other possibilities for cooperation
Global M2M Messaging via Satellite
Marine &HomelandSecurity
TransportationHeavy
EquipmentFixed &
IndustrialAssets
• Low Earth orbit (LEO) satellite constellation• Low-cost, two-way short messaging service• Remote monitoring and control of fixed and mobile assets• Coordinated fleet operations
Messaging Types
• Reports– 6 bytes of user data
– Often used for position reporting for tracking applications
• SC-Originated Messages– Typical size is under 300 bytes, but up to several kB possible
– Transmitted in segments of 135 bytes (first segment carries 107 user bytes, 111 bytes thereafter)
• SC-Terminated Messages– Typical sizes similar to SC-O messaging
– Often used for code uploads or remote device actuation
• Global Grams– 229 bytes in-bound (from SC), and 182 out-bound (to SC)
– Takes advantage of store-and-forward mode when satellite is not in view of a tracking station
Constellation Architecture
• First generation constellation– 4 principal planes of up to 8 satellites each
• 800 km altitude, 45-deg inclination• Optimized for CONUS coverage
– 2 high-inclination planes provide polar coverage
– Low latitude coverage can be augmented with Equatorial plane
– Original constellation deployed 35 satellites into 6 orbital planes from 1995 to 1999
• 6 replenishment satellites launched in 2008
• Second generation (OG2) constellation is in production
– Firm order for 18 satellites with options for more
– Launch of first set of 3-4 satellites anticipated for Q1 2011
OG1 Satellites
• Built and launched by Orbital Sciences
• Whole plane of 8 satellites launched on single LV
• Fully independent operation gives built-in redundancy
• Nadir-pointing antenna
• Tracking solar arrays: 200 W peak
• Weight < 100 lbs
• 27 OG1 satellites still operating today
Satellite Coverage at Ground Level
Depicted are four planes of six satellites each
Satellite Coverage at 80,000 ft
Depicted are four planes of six satellites each
Current Earth Station Coverage
General SpecificationsTransmit Frequency 148-150.05 MHz
Receive Frequency 137-138 MHz
Transmit Power 5 Watts (37 dBm)
Power Draw Rx 40-70 mA; Tx 1.8A
Dynamic Range 40 dB
Sensitivity -118 dBm (typical)
Uplink Data Rate 2400 BPS
Downlink Data Rate 4800 BPS
Operating Temp -40°C to +85°C
Subscriber Communicators (SC’s) are small, rugged, two-way devices built to industrial standards. They are available in many different configurations and form-factors
Subscriber Communicators
User Equipment
• Subscriber Communicator (potential feature suite)– ORBCOMM communications modem– Application space– GPS– I/O ports for logging, code loads, and sensors– Power conditioning– GSM card for dual-mode operation– Typically < $200
• Additional equipment– Power via battery, solar arrays, or direct electrical feed– Antenna(s)
Show and Tell
• Sierra Wireless Q52– ORBCOMM modem– GSM modem– GPS receiver– Application space– WaveComm microprocessor– Two RS 232 serial ports– 14-pin I/O connector for sensor integration +– Charging circuit for external Li Ion battery– Power conditioning/protection
Applications and Service
• ORBCOMM distributes service through VARs– SC application development support– Back office application development and operation– Service subscriptions
• SC manufacturers provide API environment– Development libraries– Visual DSP from Analog Devices, CygWin open source, etc.
• ORBCOMM also provides some standard application routines and development support
Other Commercial Opportunities
• ORBCOMM is interested in economical ways of augmenting capacity in targeted regions– CONUS has higher demand than international territories– Flying ORBCOMM payload on balloons concentrates
capacity where it is needed– Cost of equipment and operation may be cost-effective
Other Commercial Opportunities, cont’d
• ORBCOMM is interested in hosting scientific payloads on its OG2 satellites– 2 slots available in chasis, compact PCI form factor– <10 kg mass– 9 x 3 x 4 inch volume– 50 W power– 1 kbps data nominally, 800 kbps possible
• Cost likely in single-digit $millions NRE, lower per copy• Capability is powerful
– Faster and cheaper than dedicated satellite mission– Deploying constellation-wide provides continuous and
simultaneous global measurements