Emergency Communication Plan: Before, During, After

OSHI is a free, open-source, end-to-end encrypted messenger for iOS and Android that uses Bluetooth and Wi-Fi mesh networking to send messages without Internet or cellular service. This page is a practical plan for a family, a hiking party or a small crew: what to set up before the network fails, what actually works while it is down, and how to regroup afterwards. It uses OSHI as the tool, but most of it is useful with any offline messenger or none.

Why you need a plan, not just an app

Every emergency has the same first hour: cell towers are saturated or dark, the Internet is throttled or cut, and everyone reaches for the same apps that need it. A plan replaces guessing with a few agreed facts — where to meet, who checks in with whom, which app to open — that still hold when nobody can call anybody. The single most important fact, from the internet shutdown survival guide: you cannot download tools once the shutdown begins. Everything below the first heading must be done while the network still works.

Before: 45 minutes, once

1. Install the app on every phone. OSHI is free on iOS 17.5+ and macOS, and an APK on Android. Do it on the same evening, in the same room, so step 2 is easy.
2. Add each other by QR code. OSHI has no phone numbers; identities are keys. Scan each family member's QR code face to face. A contact added now is findable over Bluetooth later with no server involved.
3. Create the group. One group for the household or crew. Name it plainly.
4. Download the map. OSHI bundles offline OpenStreetMap regions with search and turn-by-turn routing. Download your region and the region you would evacuate to.
5. Agree two meeting points. One near home (a specific corner, not "the park"), one outside the neighbourhood in case the first is unreachable. Post them as the first message in the group so they are on every phone.
6. Agree a check-in rhythm. For example: everyone posts one line in the group at 08:00 and 20:00 while the network is down, and immediately on arriving anywhere. Short, predictable messages are what a mesh carries best.
7. Choose the relay. One person's phone stays with OSHI open and screen on at a known place (a window, a rooftop) so others can hop through it. Both phones must have OSHI open to find each other — this is the rule people forget.
8. Do one airplane-mode test. Switch Wi-Fi and mobile data off on two phones, send a message, walk to the far end of the flat, send another. Now you know your real indoor range (typically 10–30 m through walls, about 100 m in the open).
9. Optional: a LoRa node if your plan involves distance — base camp to trail, farm to village. OSHI pairs with a Heltec WiFi LoRa 32 V3 (see supported nodes). Set the region on first pairing; a new node ships with region unset and will not transmit. Note that the LoRa link is not encrypted by OSHI, and check /lora/ for the current status of LoRa delivery in the app.
10. Paper backup. Meeting points, the check-in times, an out-of-area contact's phone number, and the ICE numbers on a card in each wallet. Phones die; cards do not.
11. Power. One charged power bank per two people, a car charger, cables. Battery is the real limit of any phone mesh.

During: what works with no network

If any cellular signal exists, call your emergency number first. OSHI is for reaching the people around you when the network is gone, not a replacement for emergency services.

Battery habits while the network is down

• Turn the screen brightness down and switch off everything that is not needed — but keep Bluetooth and Wi-Fi on; the mesh runs on them.
• Send text. Photos and voice notes travel over Wi-Fi Direct and cost more power and range.
• Rotate the relay role every few hours so one phone does not burn its whole battery holding the mesh together.
• Keep phones warm in cold weather; a cold battery reports empty long before it is.
• Stick to the check-in times. A phone that scans for peers all day in a sparse area finds nobody and drains itself.

Moving as a group

Share live location inside the mesh so the group can see who is where without messages. Use the offline map's routing to reach the meeting point; do not rely on memory in an unfamiliar neighbourhood. If the group splits, the rule is simple: the last message that named a meeting point stands until someone reaches it and posts.

After: regroup and reset

1. Post one "all safe" line in the group as soon as any path exists. Queued messages will leave the moment one phone gets Wi-Fi or data; you do not need to resend.
2. Call the out-of-area contact on the paper card, who tells everyone else. One call instead of ten.
3. Charge everything before you do anything else, in case it happens again tonight.
4. Note what failed. Which meeting point was wrong, who could not be found, where the range ran out. Fix the plan the same week, while it is fresh.
5. Re-scan anyone who got a new phone. OSHI identities live on the device; a replaced phone is a new key.

The same plan without OSHI

Most of this plan is app-independent: meeting points, check-in times, paper cards, a power bank and a designated relay work with Briar on Android, with a Meshtastic radio per person, or with no app at all and a whistle. What OSHI adds is that the plan lives in the app people already use online, so the group, the contacts and the map are there on the day. Compare the options in best offline messenger apps and LoRa messengers compared.

Frequently asked questions