Using ORBCOMM for Global High-Altitude Communications Tim Maclay Celestial Insight, Inc. Bridging the Gap to Space Boulder, CO October 26-28, 2009 1
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 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 Marine & Homeland Security Transportation Heavy Equipment Fixed & Industrial Assets
Messaging Network Elements Types f Service Messaging Network Elements Packetized Fully-acknowledged Optimized for short msg Narrow band VHF 2.4 kbps u/l 148-150 MHz 56 kbps 4.8 kbps d/l 137-138 MHz Leased Line Internet VSAT Subscriber Communicator (SC) Gateway Earth Station (GES) Gateway Control Center (GCC)
Messaging Types Reports SC-Originated Messages SC-Terminated Messages 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 First launch in 1995, one to two per year since 1997. VHF frequencies, key aspect of system design to keep costs low Gateway for backhaul, dedicated subscriber Rx, Tx
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
Subscriber Communicators Subscriber Communicators (SC’s) are small, rugged, two-way devices built to industrial standards. They are available in many different configurations and form-factors General Specifications Transmit 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
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