1. SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE
Concept History:Originally conceived for service by search & rescue operations, compete with services like Argos but bi-directional.
Personal location
Buoys
Scientific data
Intermittent service
Early 1990’s refocused design to provide better coverage
Telematics
Emergency Notification
Low latency, very good coverage
Mid 1990’s advent of low-cost GPS modules brings new applications
Shipment Tracking
Trailer
Container
Marine
Boating
Fishing Fleets
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

2. SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE
ORBCOMM Satellite
30 Satellites in Service
Fully independent operation gives built-in redundancy
Frequencies
Uplink MHz
Downlink MHz
Payload
Gateway Transceiver 57,600 bps
Subscriber Transmitter 4,800/9,600 bps
Subscriber Receiver 2,400 bps
UHF Transmitter CW
Nadir-pointing antenna
Tracking solar arrays: 200 W peak
Weight < 100 lbs
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

3. SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE
Why VHF?
In early 1990’s downlink bands already approved for satellite bands, uplink frequencies had provisional approval from FCC for use in satellite operations.
In1995 VHF satellite equipment was an order on magnitude cheaper than L band. VHF equipment was smaller and already space-rated.
2400 baud uplink allows lower spacecraft power (cheaper/smaller). Uplink was required to operate between pre-existing terrestrial services bands.
DPQSK was a good choice at the time, good balance between bandwidth, signal strength, data rate, error correction. Now we might consider trading BW for power but keep same frequencies.
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

4. Launch Vehicle and Payload Design
Existing satellites were launched with the Orbital Sciences Pegasus
The Pegasus is flown to 50k ft. via a L1011 aircraft. The rocket is dropped and ignited.
Two stages lift the payload to 500 mile altitude.
Eight satellites were delivered in one launch. Each one ejected from the bundle at the proper orbital spacing.
The solar panels are dithered to cause braking. Each satellite also contains air jets.

5. ORBCOMM Satellite Overview
Sun-Nadir Steered Configuration
Vertical disk-shaped body with nadir oriented quad helix antennas
Single-axis, dual panel solar array deployed normal to body
VHF / UHF Communications Payload
Seven channel subscriber uplink receivers at 2400 bps
Dual rate / power subscriber transmitter at 4800 / 9600 bps
Full duplex gateway links at 57.6 Kbps
UHF Beacon
Bus Subsystem
Peak Power Tracking with GaAs Solar Array
Wheel - augmented gravity gradient / magnetic 3 - axis ACS
GPS state vector determination
Central flight computer for T&C, data / command storage
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

6. ORBCOMM Satellite Constellation
Primary Planes
Planes A, B C and D:
Six to Eight Satellites
Secondary Planes
Plane F: [Polar]
One Satellite
Plane G: [Polar]
One Satellites
Plane E: [Planned]
Eight Satellites
Show planes image
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

7. Current Constellation Coverage Pattern
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

8. Constellation Design Criteria
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

9. Ground Segment Components
Gateway Earth Stations
12 in service around the world
Connect satellites to ground network
Dual redundant antennas/radomes
Remote, unattended operation
Monitored & controlled from NCC
Gateway Control Center
4 in service: Brazil, Japan, South Korea, United States
Ground network operation
Fault-tolerant Message Switch controls message queuing and delivery
Connections to terrestrial networks
Internet SMTP , X.400 Mail, XML Gateway
Frame relay, ISDN, Internet VPN, Leased Line
Network Control Center
Manages U.S. GCC functions
Satellite monitoring and control functions
Gateway Earth Station
OPERATIONAL GROUND SEGMENT
7 GATEWAYS ON 3 CONTINENTS
4 UNITED STATES
2 GOLFBALL LIKE RAYDOME . . Containing antennas
REDUNDANCY
CONNECT TO TERRESTRIAL NETWORKS
PAGING,DATA, FAX INTERNET
EXTENDS REACH AND VALUE…
OTHER SYSTEMS OPERATIONAL
NETWORK CONTROL CENTRE OPERATING IN VIRGINIA
CUSTOMER SERVICE OPERATION
BILLING SYSTEM is working in US
ONE BILLING THE WORLD
ONE BILL CUSTOMER
BUILDING VALUABLE EXPERIENCE IN CRITICAL AREAS 0F THE BUSINESS
Network Control Center
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

10. Subscriber Downlink Channels
Downlink Frequency Range
Tunable Between Mhz to Mhz
Khz Channels
12 Allocated 25khz Downlink Channels
A Plane Channel 265 & 285
B Plane Channel 295 & 320
C Plane Channel 100 & 176
D Plane Channel 80 & 90
F Plane Channel 184
G Plane Channel 275
Two Test Channels
4.8 Kbps SDPSK
50 Segments per second
Max Power -125dbW/ m2 / 4Khz *
SUBSCRIBER
COMMUNICATOR
***
One Second
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

11. Types of Service: Two Way Data Messaging
Size: SC-O1 generally <0.5k, can do > 8k
Size: SC-T2 generally <0.5k, can do > 8k
Addressing explicit w/ multi
7 OR Indicator
Body Part Multiple Bilaterally defined
Delivery Assurance acknowledgement
ORBCOMM Message Switch
ORBCOMM Message Gateway
Message Transfer Agent
Firewall
Leased Line
Internet
VSAT
Gateway
Earth Station
(GES)
Subscriber
Communicator
(SC)
Gateway Control Center (GCC)
NOTES
1. Subscriber Communicator-Originated
2. Subscriber Communicator-Terminated
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

12. ORBCOMM Space and Ground Segments
Satellites
(30 in service in 6 Orbital Planes)
Subscriber Links
Uplink Downlink VHF VHF MHz MHz 2,400 bps 4,800/9,600 bps
Gateway Links
Uplink Downlink VHF VHF 149 MHz 137 MHz 56 Kbps 56 Kbps
Gateway Earth Stations
(12 in service, additional 10 to 14 expected)
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

13. SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE
Messaging
Report
6 bytes
Special position report includes
Messages
Up to 8kbyte, typically 100 bytes
SC protocol is the ORBCOMM Serial Specification via an RS-232 port
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

14. SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE
ORBCOMM US Latency
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

15. ORBCOMM’s Market Niche
ORBCOMM is the only operational Little LEO system and leads the other Global Mobile Satellite Service Providers in certain Important Data Capabilities and Services
There are many data communications service providers in the world, but few can be considered direct competitors
Terrestrial tower-based systems complement
Some satellite service providers offer competitive service but are only regional (not global)
Other GMSS providers either have inferior equipment or are struggling with early product/rollout issues
ORBCOMM is a good match for an OEM or VAR application with a majority of the following attributes:
fielded product in multiple regions of the world
high sensitivity to user equipment cost
infrequent transmissions of small messages
limited available power for the user equipment
communication in both rural and urban areas
field use may result in long-term blockage to geostationary orbiter
send as well as receive messages
ORBCOMM truly provides global service:
Inside the contours shown above, a subscriber can communicate messages at least part of the time directly through a satellite to a Gateway
In the remaining areas, communications takes place using store and forward GlobalGram services
As additional Gateway Earth Stations are deployed, the availability of real-time messaging communications will increase
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

16. Existing Automotive Antenna Products
VHF Applique Antenna
GPS Applique Antenna
Molded Ruggedized Antenna
Can be molded into custom shapes
Diversity switch
Allows multiple antennas to be used on the same vehicle
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

17. SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE
Antenna Developments
World’s first genetic antenna,
currently prototype
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE

18. SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE
THANK YOU
20/10/2017
SC/ UNIT- 5 CBS ORBCOMM / KARTHIKA A, AP/ECE