Product Info

GLOBALSTAR PROPRIETARY AND CONFIDENTIAL INFORMATION

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document.

06/18/20 Subject to Change without Notice P a g e | 10

Figure 2 LEO Constellation

Since the satellite position is constantly changing, simplex devices on the ground will transmit (with no knowledge of

any of the satellites locations) and the transmission may be received by one or more satellites. These satellites will then

relay the message to the nearest satellite gateway as shown below. Once received by the satellite gateway, the simplex

message will be delivered to the simplex gateway where redundant messages are discarded and the data from the

message is sent to the OEM via the Internet.

Figure 3 Simplex Messaging

Messages are composed of 1 or more 9-byte payloads. The user application may send a message via the Bluetooth Low

Energy interface to the ST100 board from 1 to 144 bytes in length. The ST100 board will break the message into 9 byte

packets. A 144 byte message would be broken into 16 packets.

INTERNET

Satellite Gateways

VAR, VAM

Simplex Transmitter

Simplex Gateway