What still works when the phone doesn't — a quiet comms plan
Mobile networks can fail exactly when you need them most. Three steps that mean your people still find each other when the bars disappear.
The fragility nobody plans for
Mobile networks fail in three ways: total outage (cell-tower power loss during a blackout), congestion (everyone calling at once after an incident — Brussels 2016, London 2005), and partial failure (data down, SMS works, or vice-versa). ENISA's annual telecom security incident reports show that serious network outages are reported across the EU every year.
The household that has thought about this for ten minutes is in a very different position from the one that hasn't.
Three steps
- Agree on a meeting point now. One indoor (a relative's flat, a café), one outdoor (a specific bench in a specific park). If you can't reach each other for >2 hours during a daytime incident, you both head to the indoor point. After dark, the outdoor one becomes a check-in only — not a destination. Decide who triggers which.
- Memorise three numbers. One household member, one local contact, one out-of-region contact (often easier to reach during a regional event because they're not in the congested area). Write them on paper in your wallet. Yes, on paper.
- Use SMS, not voice, first. In a congested network, a text message often gets through when a call does not, as the US FCC also advises. "I'm OK, going to [meeting point]" is six words. Send to all three numbers.
What this is not
This is not about ham radio, walkie-talkies, or hardened communications. Those are useful in specific scenarios but they don't help the typical case, which is a cell outage of a few hours in a city. That case is solved by three numbers and a meeting point.
One thing this week: agree on your two meeting points with one person. Tell them the rules.
— Systems Fail Lab