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How many Iridium satellites are there? 

Iridium has a constellation consisting of 66 low-earth orbiting (LEO) satellites (plus 9 in-orbit spares), cross-linked to operate as a fully meshed network. Several overlapping satellites ensure coverage over the entire globe. 

How do I make a call with my Iridium satellite phone? 

Extend the antenna into its full position and point it straight up at the sky. Press the power button on the phone. You should see the Iridium splash screen, followed by 'Searching' and finally 'Registered'. Once the phone is registered you are ready to dial. 

How do I call a landline or mobile number using an Iridium satellite phone? 

Press the 0 key until the + appears or dial “00”. Dial the country code, area code and phone number. 

•Example: + (country code) (area code/city code) (phone number) 

•Example: + 1 416 253 6008 

How do I call another Iridium satellite phone? 

From your, Iridium satphone, or dial “00” or press and hold the 0 key until the + appears followed by the 8816 Iridium phone number. 

•Example: + 8816 666 9253 

Do Iridium satellite phones support text messaging? 

Yes, it is easy to send a text message and incoming text messages are free. Visit our send a free SMS web page. 

How do I receive calls on my Iridium satellite phone? 

The Iridium phone antenna needs to be fully extended with an unobstructed view of the sky in order to receive a call.  

How do I send an e-mail to an Iridium satellite phone? 

Send your e-mail to iridium telephone (where 8816xxxxxxxxx is the Iridium mobile number) 

How do I check my balance? 

You can check the balance of your Iridium prepaid SIM card by simply dialling 2888, free of charge. 

If I have a pre-paid Iridium satellite contract, how can I top-up my balance? 

Easy! Just visit AST’s top-up portal and top-up as and when you need to. 

How can I test my Iridium satellite phone? 

Iridium post-paid and pre-paid customers can place a free call to 00-1-480-752-5105 to test their phone. An automated message will play stating that the call was successful. If an error message is played or if the call does not connect at all, please contact AST Global Customer Support. 


Truly global satellite radio is a critical communication tool for a variety of scenarios. While standard mobile phones require very little preparation and training, satellite-enabled devices may be unfamiliar to users at first. It is important to ensure your team is familiar with the recommendations of how to best use two-way satellite radio communications. 

Be Prepared Before Talking 

Before using your Iridium Push-to-Talk (PTT) enabled device, charge the battery and turn the phone on. 

Make sure the device is within the geographic area covered by your Iridium PTT talk-group. 

Two-way radios are a “one-at-a-time” system; when you press the Push-to-Talk button, no one else in your group can speak or be heard. In order to make the most of your talk session and avoid blocking other speakers, it is important to think about your message in advance. 

Identify Yourself and the Recipient of Your Message 

There may be a group of intended users all sharing the same PTT talk-group, so it is important to identify yourself and your target audience immediately when you initiate a transmission. Talker’s name will appear on the screen if provided in the Command Centre. 

Be Patient 

The other user(s) in your talk-group may not be able to respond immediately. Give them time to reply. 

Use Short, Clear and Concise Messages 

As two-way radios only allow one person to speak at a time, it is best to keep your transmissions clear and to the point. This gives other users an opportunity to acknowledge your message and/or request further clarification before continuing on with your next point. 

Know-How Much Time You Have To Talk 

You have a total of 40 seconds to say your message before your session expires. If your message is longer than the allowed talk time, simply press the push-to-talk button again and share the rest of your message. 

Pause Before Speaking 

When you first press the PTT button, there can be a short delay before your message transmits which could result in your first few words being truncated. Wait a second before speaking to be sure your listeners receive your whole message. 

Learn the Lingo 

Two-way radio communications are most effective when everyone understands and uses similar language and etiquette, especially when there are more than two people in the talk-group. 

• “Over” – I’ve finished speaking 

• “Say again” – Repeat your last message 

• “Stand-by” – I acknowledge your transmission, but can’t respond right now 

• “Go ahead” – I can respond, go ahead with your message 

• “Roger” – message received and understood 

• “Out” – Conversation is finished, the channel is clear for other users 

Quick Tips 

• Deploy Antenna for maximum signal strength and improved standby use. 

• Keep your device antenna extended and vertically oriented whenever you want/need to be accessible. 

• If the signal strength is weak, attempt repositioning your device. 

• Press the PTT button and wait for the beep before talking. 

• Hold the handset approximately 4 in. (10 cm.) from your mouth when talking. 

• Identify yourself and recipient of the message. 

• Be Patient! The recipient may be busy. 

• Turn the volume to an appropriate level for your environment. 

• Speak slowly and clearly. 

• Test your Iridium PTT-enabled device on a monthly basis. 

• Ask AST Global Customer Support for the latest Iridium PTT firmware. 


Please visit our Iridium Certus page to find out more about the network, coverage areas and products available.

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