Iridium logo

Iridium Communications Network

The Only Satellite Network That Provides Voice and Data Coverage Everywhere.

Iridium Network Overview

The Iridium network is largest commercial satellite network in the world and the only network that offers true global communications coverage over 100% of the planet. Uniquely, Iridium satellite coverage map spans Earth’s polar regions and every inch of land, sea or sky in between.

Reliable, seamless voice and data coverage everywhere is a compelling advantage of the Iridium communications network, but there’s more. Iridium’s low-earth orbiting (LEO) network advantage also enables the use of smaller omni-directional antennas, resulting in devices with a compact, lightweight and streamlined form factor and shorter network registration times. In a nutshell, Iridium is a great choice for anyone that wants to have access to satellite voice and data anywhere on earth, or wants to be able to use their satellite phone while moving around.

The Iridium constellation consists of 75 satellites (66 operational and 9 in-orbit spares) that are cross-linked in space just 780 kilometers above Earth. Because Iridium is the largest constellation, and orbits closer to earth than other networks, Iridium users enjoy worldwide access to phone, text, or data services with shorter network registration times and low communications latency. The large number of cross-linked Iridium satellites also makes it easier to maintain a connection while walking-and-talking on your satellite phone, while a variety of external antenna and docking stations can be used to extend the utility of Iridium devices for use in a building, vehicle, small plane or on a vessel.

Iridium network coverage map

Does the Iridium Network Cover the Entire Planet?

With a constellation consisting of 66 low-earth orbiting (LEO) satellites, cross-linked to operate as a fully meshed network, several overlapping satellites ensure coverage over the entire globe.

With Iridium there are no coverage gaps and an independent study found that Iridium satellite phone call quality and call completion rates are superior to its competition. This is one of the reasons that the US Military uses Iridium communications network.

Iridium NEXT

In January 2019 Iridium completed its Iridium NEXT campaign, a complete technological upgrade of its constellation. Iridium is now arguably the world's highest performance and most sophisticated constellation.

Iridium NEXT Infographic

Iridium Satellite Constellation

Operating the largest constellation of any satellite network, the Iridium constellation consists of a fully meshed network of 66 low-earth orbiting (LEO) cross-linked satellites, and 9 in-orbit spares, that ensure coverage over the entire globe in a constellation of six polar planes. Each plane has 11 mission satellites performing as nodes in the telephony network. The 9 additional satellites orbit as spares ready to replace any unserviceable satellite. This constellation ensures that every region on the globe is covered by at least one satellite at-all-times. The satellites are in a near-polar orbit at an altitude of 485 miles (780 km). They circle the earth once every 100 minutes travelling at a rate of 16,832 miles per hour. Each satellite is cross-linked to four other satellites; two satellites in the same orbital plane and two in an adjacent plane. These links create a dynamic network in space - calls are routed among Iridium satellites without touching the ground, creating a highly secure and reliable connection. Cross-links make the Iridium network particularly impervious to natural disasters - such as hurricanes, tsunamis and earthquakes - that can damage ground-based wireless towers.

Iridium Ground Network

The ground network is comprised of the System Control Segment and gateways to the terrestrial networks. The System Control Segment is what commands and controls the satellites for the Iridium system. It provides global operational support and control services for the satellite constellation. It also delivers satellite tracking data to the gateways. It consists of three main components: four Telemetry Tracking and Control sites, the Operational Support Network, and the Satellite Network Operation Center. The primary linkage between the System Control Segment, the satellites and the gateways is through a satellite to satellite communications system called K-Band feeder links and cross-links throughout the satellite constellation.

Iridium Satellite Phones & Devices

How to Connect to the Iridium Network

Demo: Using the Iridium Extreme Satellite Phone

Why Choose the Iridium Network?

  1. 100% global coverage including the Poles
  2. Good quality of service
  3. Truly mobile (walk and talk)
  4. Short network registration times
  5. Largest constellation with the most satellites and spares

The downside? These advantages come at a slightly higher cost.


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 call a landline or cellular number using an Iridium sat 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 sat phone, or dial “00” or press and hold the 0 key until the + appears followed by the 8816 Iridium phone number.

  • Example: + 8816 325 12345

Do Iridium sat phones support text messaging?

Yes, it is easy to send a text message and incoming text messages are free. Visit our Knowledge Base for step-by-step instructions.

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. TIP: Roadpost’s Iridium monthly plans and Iridium prepaid cards include voicemail service in case you miss a call.

What is the dialing sequence for my contacts to dial my Iridium satellite phone number?

There are three ways that someone can contact you on your Iridium satellite phone.

  1. Dial your Iridium phone number directly. This can be expensive depending on the network they are calling from.
  2. Use the 2-Stage Dialing service. This enables someone to reach you by dialing +1-480-768-2500 (an Arizona-based number). When prompted, they enter your Iridium phone number and the call will automatically be routed to your phone. There is no monthly fee for this service, however you pay a low per-minute rate to receive the call. The caller pays the rate associated with a call to Arizona if applicable.
  3. Dial the US phone number that you receive if subscribe to the Dedicated US Phone number option. This Dedicated US Phone Number is an option you can add to your monthly service plan. With this you will be assigned your own Arizona-based phone number, in addition to your Iridium phone number. Callers can reach you directly using either phone number. You pay a low monthly fee for this dedicated US number, and a low per-minute rate to receive calls made to your US phone number.

What does it cost to call an Iridium satellite phone?

Cellular and landline network operators can charge quite a lot for calls to a satellite phone number. To reduce this cost for your contacts, consider using the 2-Stage Dialing service, or add an optional Dedicated US Phone Number to your monthly plan. Both are less costly than dialing your Iridium number directly and enable callers to dial a US-based number which connects to your Iridium phone number.