How It Works

The sections below discuss how GDB works and how users interact with the service.


The Global Data Broadcast system covers the entire planet – pole to pole. This includes oceans, mountains, deserts, jungles, and urban areas across the globe. It also covers the air and space above these regions.

Service delivery areas for your data can be as large as the entire planet or as small as a single U.S. state. The smallest delivery area is about 1000 km (600 miles) in diameter.

The message sender specifies the delivery area for the content. The areas can be customized to cover any area of the world to which you want to broadcast data. Delivery areas can even be disjoint – for example your data can be delivered solely to the major metropolitan areas of the world, or just the regions where you operate.


Sending Data

Entities that send data are called Data Providers. Data Providers can be commercial content providers, closed user groups, national or multi-national corporations, Non-Governmental Organizations, National, Regional or Local Governments or anyone that needs to send data to their group of users.

A single GDB message can be up to 10 Megabytes in size. The typical user will send messages that are only a few bytes to a few Kilobytes.

Data delivery rates vary with system load and capacity and range from a few kilobytes an hour to about a megabyte per hour.

Data Providers send data into the Global Data Broadcast service via a standards-based, authenticated interface. This interface enables the data providers to manage where and when their data is delivered, which groups it is delivered to and other options associated with the delivery of the data. Positive feedback in the form of status messages are sent back to the Data Provider to inform them of the delivery status of the messages they have sent. The Data Providers have the option of canceling or resending messages. They can also schedule messages for future delivery dates in advance.


Receiving Data

Data broadcasts are received by Global Data Broadcast terminals (see the Terminal Devices section below for more information about the terminals).

In order to receive data, ALL of the following must happen:

The terminal must be powered on.

The terminal must be in a position to receive the signal from the satellite.

The terminal must be authorized to receive the group to which the broadcast is sent. This authorization is done by the party that controls the group (generally the Data Provider). Additional groups can be added to a terminal already deployed in the field via an over the air operation.

The terminal must be in the geographic area covered by the message broadcast.

When a message is sent by a Data Provider, it is transmitted by the satellite constellation over the area requested by the Data Provider. Terminals in this area that are provisioned for the message group that the message was sent to are able to receive the data. This data is then presented by the terminal to the application attached to the terminal. The application can be a computer, smart phone, or a purpose built device capable of interacting with the GDB terminal.


Powerful Signal

The GDB Signal is transmitted with a very high power level for a satellite signal. GDB’s available signal strength is many times the power of typical satellite broadcasts and phones and provides a number of key advantages over other Satellite and Terrestrial broadcast systems. Line of sight can be managed to improve reception and Data Providers can schedule broadcasts that take advantage of the moving satellite position to increase the probability that your users will receive the broadcast.


Groups and More Groups

Each terminal is capable of being part of, and receiving, over 100 different message groups at the same time. The terminal also has its own unique group that allows a data provider to send information to a single terminal if it is needed.



Messages are sent using commercial grade security measures. This includes transport of the message from the Data Provider to the constellation and from the constellation to the ground. These measures help ensure that your users are getting your data and others are not. Additional security measures can also be implemented and controlled by the Data Providers in an end-to-end manner between the data origination point and the application attached to the terminal.


Receive Only

Global Data Broadcast is a one-way service. The terminals are receive only and do not transmit. Confirmation is sent to the data provider that the satellites transmitted the requested message. Reception at the terminal is not acknowledged.


Low Power Friendly

GDB terminals are small and do not consume much power. The terminals can be powered on and off locally. Data Providers can control when messages are sent. Combining these attributes, battery powered application of GDB is very possible.


Terminal Devices

GDB utilizes small terminal devices provided by Celestech. The Terminal is small, light, and power thrifty. Below are the specifications for the terminal.

Terminal Technical Specifications

Size:             1.6 x 1.8 x 0.5 inches (4.1 x 4.5 x 1.3 cm) {LxWxH}

Weight:                                                      1.06 oz (30 grams)

Power:     45 mA @ 5V DC (idle average) 195 mA @ 5V DC (peak)

Operating Temperature:           -40°F to 185°F (-40°C to +85°C)

Operating Humidity:                             ≤ 75% Relative Humidity


Terminals meet industry specifications for thermal shock, humidity, vibration and shock. Details are available on request.