This is an excerpt from my book Emergency Preparedness and Off-Grid Communication.
One option for communication when internet and cellular services are not available is a device that connects to a satellite network. A personal locator beacon (PLB) is a satellite-linked device that, when activated, sends a distress signal to nearby search and rescue units. Typically used for mountaineering, they can be used in other emergencies, but caution should be exercised. PLBs should only be activated in an actual emergency.
For years, two-way satellite communication required buying a phone and paying for a monthly data plan. Satellite phones and data plans can be cost-prohibitive. In 2022, top-tier Apple iPhones offered satellite communication for emergencies. The service is not available for messaging friends and family. It only works if your phone does not have wireless or cellular service. It allows you to send and receive text messages with emergency services near you. When used with an app, it can send your location to people in your emergency contact list.
In 2023, Qualcomm announced that it would partner with Iridium to offer Android phones that connect to a satellite network to provide similar services. Samsung announced it will soon offer phones with satellite connectivity. So far, phone manufacturers are only aiming to provide connection to emergency services. Off-grid communication with friends and family is not an option.
Satellite communication with friends and family via smartphone is available with a device that connects to a satellite network. These devices are sold by Zoleo, Bivy Stick, Garmin, and other manufacturers. They connect to a smartphone or tablet by Bluetooth and a mobile app. The communicator sends text or email messages composed on the app over a satellite network.
The Zoleo communicator allows text or email messages to be sent to any email address or phone number that has service, even if the receiving party is not on the Zoleo network. When a message is sent, the device will first try to send it over a cellular or wireless network. If one is not available, it will be sent over the satellite network. Since charges are incurred for each message sent, this reduces monthly costs. Zoleo’s monthly plans start at $20 per month. Once a user has had a paid monthly plan for three months, the plan can be paused indefinitely for $4 per month and restarted at any time.
It may sound like a bomb-proof solution, but there may be a fly in the ointment. Satellite communicators receive messages from a user who may not have internet or cellular access. The communicator sends a signal directly to a satellite. So far, so good. If the entire message chain were space-based, there would be no problem during a terrestrial internet disruption. But if, at any point, the message must go through a ground-based internet gateway, an internet outage that affects that gateway would render this option unusable. I spoke with a Zoleo technical support assistant who confirmed their system does use ground-based servers to handle messaging traffic. The assistant could not state confidently that their service would be available during a widespread internet outage. The availability of satellite service would seem to depend on how widespread the internet outage is. If traffic from an affected area could be rerouted to an unaffected area, messages may go through. When cellular carriers are not able to provide service, satellite communicators are a good alternative, but it is unclear just how reliable they would be during a widespread internet outage.
Satellite Internet
Many people have switched to satellite internet service providers like Starlink. Some believe that satellite internet service will be available when other internet providers don’t have service. As popular as this idea is, it has a major flaw. Although the end user receives their internet data via satellite, that data passes through the same ground-based servers used by all internet providers. Until satellite internet providers host their own servers in space, their services will be susceptible to the same disruptions as other providers.
One issue with satellite, cellular, and internet services is that the end user doesn’t control the network. While it’s convenient to use a communication network someone else maintains, the availability of service is completely dependent on others. In a crisis where communication networks are not available, it's preferable to have equipment that you control. That is where our discussion turns to the use of radios. With two-way radio, the end user controls the network.