Satellite Airtime Explained: Choosing the Right Plan for Your Equipment

When you invest in a satellite phone, tracker, or communicator, the hardware is only part of the equation.

Without an active airtime plan, your device can’t connect to its satellite network. No calls. No messages. No tracking. No SOS capability.

Satellite airtime is what turns your equipment into a working communication tool.

At OSC, we provide airtime across the major global networks including Iridium, Inmarsat, Globalstar, and Garmin. Each one serves a different purpose depending on where you operate, how often you need connectivity, and what you actually want your device to do.

You can explore the full range here: https://osat.com/collections/airtime

This guide walks through how satellite airtime works, the difference between plan types, and which networks are best suited to different real-world scenarios.

What Is Satellite Airtime?

Satellite airtime is essentially your access to a satellite network.

Just like a mobile phone needs a plan to make calls or send messages, a satellite device needs airtime to transmit over its network. Without it, the device may power on, but it won’t communicate.

Your airtime plan determines:

• How many minutes or messages you can use

• Where your device will work (regional or global coverage)

• How long your credit remains valid

• Whether features like voice, messaging, tracking, or SOS are active

Choosing the wrong plan can mean paying for coverage you don’t need, running out of credit mid-trip, or worse, discovering your device isn’t active when you need it most.

Prepaid vs Monthly Airtime

Airtime typically falls into two categories.

Prepaid plans give you flexibility. You purchase credit and use it within a set validity period. This suits occasional users, seasonal trips, and expedition-style deployments.

Monthly plans provide ongoing access with predictable billing. They tend to offer better value for regular users, professional teams, and anyone who relies on satellite connectivity as part of their workflow.

If you already own compatible equipment, SIM-only options allow you to activate or switch service without replacing hardware.

Iridium Airtime

The Only Network With Truly Global Coverage

Iridium operates a low-earth orbit constellation that covers every corner of the planet, including both polar regions and open oceans.

If your work or travel takes you beyond traditional routes, Iridium is often the safest choice.

Because its satellites orbit closer to Earth than geostationary systems, connections are fast and consistent. It’s widely used by maritime professionals, emergency services, expedition teams, and remote operators who simply cannot afford coverage gaps.

Iridium airtime supports:

• Satellite phones

• Communicators

• Wi-Fi hotspots

• Tracking devices

For global travel, polar operations, or offshore work, Iridium remains the benchmark.

Inmarsat Airtime

Reliable, Cost-Effective Coverage for Most of the World

Inmarsat uses geostationary satellites positioned above the equator to cover roughly 85% of the Earth’s surface.

While it does not reach extreme polar regions, it performs exceptionally well across:

• Europe

• Africa

• The Middle East

• Asia

• Major shipping routes

It’s particularly well known in maritime environments and supports both voice and broadband connectivity through solutions like BGAN.

For users operating in populated regions or key remote corridors, Inmarsat offers a strong balance between coverage and cost.

Globalstar Airtime

Regional Connectivity With Strong Value

Globalstar’s low-earth orbit network focuses on delivering reliable connectivity across key regions such as:

• North America

• Europe

• Australia

• Parts of South America and Africa

It does not provide full global coverage and has limitations over open ocean and polar regions. However, within its supported zones, it offers dependable service at competitive pricing.

Globalstar is widely used for:

• Land-based operations

• Asset tracking

• Outdoor safety devices

Within its footprint, it’s often one of the most cost-effective options available.

Garmin inReach Plans

Messaging, Tracking, and SOS for Outdoor Use

Garmin inReach devices operate on the Iridium network but use subscription-based airtime tailored specifically for messaging and tracking rather than voice calls.

These plans are popular with:

• Hikers

• Hunters

• Climbers

• Sailors

• Remote travelers

They allow users to send two-way messages, share locations, and trigger monitored SOS alerts from anywhere on Earth.

Plan tiers range from basic safety-focused options through to expedition-level subscriptions designed for regular communication and tracking.

Flexible month-to-month options make Garmin airtime particularly attractive for seasonal users.

Choosing the Right Airtime

Selecting the right plan comes down to a few simple questions.

Where will you be operating?
If you’re heading offshore or into extreme latitudes, Iridium is the only fully global option.

How often will you use it?
Occasional trips are often best served by prepaid plans. Regular operations typically benefit from monthly subscriptions.

What do you need to do?
Voice calls, messaging, broadband data, tracking, and SOS are not available across all networks in the same way.

What equipment are you using?
Your device determines which network you can access.

Budget also plays a role. Satellite airtime is more accessible than many expect, especially when matched correctly to usage.