---
title: "Emergency Notification Systems Without the Internet — BosNets"
description: "What is an emergency notification system? From AFAD public warnings to in-team alerts, selection criteria and options that work when the network goes down."
url: https://www.bosnets.com/en/blog/emergency-notification-system
lang: en
alternate: https://www.bosnets.com/blog/acil-durum-bildirim-sistemi
author: "Emir Tanrıver"
datePublished: 2026-11-06
dateModified: 2026-11-06
source: html
---

# Emergency Notification Systems: Types, Selection and Working Without the Internet

[Emir Tanrıver (LinkedIn, opens in a new tab)](https://www.linkedin.com/in/emirtnrvr/) 6 November 2026 14 min read

An emergency notification system is the infrastructure that gets the right message to the right people as fast as possible when danger strikes. In Türkiye the term covers two different things: the public systems through which AFAD warns the population with sirens and cell broadcasts to phones, and the operational systems through which an organisation sends location, messages and alarms to its own team. The first warns everyone one way; the second lets your team find each other, talk and keep a record in the field. And when the network goes down, what stays standing is a mesh network that runs from device to device.

## In short

- Public warning systems (AFAD’s İKAS, the national mobile alert system) warn the population one way and by region; they are not designed for team coordination.
- Team emergency notification has to be two-way: an alarm, live location, written messages and a record that can be reviewed afterwards.
- Cell broadcast, SMS and mobile apps depend on the network; when base stations go down, in-team communication needs a solution that does not rely on infrastructure.
- Under Turkish Law No. 6331, workplaces must set up emergency teams and hold at least one drill a year; the notification system is part of that plan.
- BosNets lets teams send messages, share location and raise emergency alerts in one system, over a mesh network that works without the internet.

## Contents

1. What is an emergency notification system?
1. Which channels does a warning reach your phone through?
1. Why public warnings do not do your team’s job
1. What to look for in mass and team notification
1. When the network fails: emergency notification without the internet
1. The legal framework at work: Law 6331 and emergency teams
1. How a team alert works in the field
1. Our view
1. A closed notification network for your team
1. Frequently asked questions
1. Sources

## What is an emergency notification system?

In its broadest sense, an emergency notification system is the set of tools that takes information about a hazard from its source and passes it to the people who will be affected. The [TS 102 182 specification on emergency communications](https://www.etsi.org/deliver/etsi_TS/102100_102199/102182/01.05.01_60/ts_102182v010501p.pdf) from ETSI, the body that sets European telecommunications standards, expects a good notification system to deliver at high speed, deliver within the planned time, give enough detail about the emergency, give clear instructions on what to do and reach the right people completely.

In practice there are two families:

- **Public warning systems:** Channels such as sirens, cell broadcast and SMS that the state uses to reach everyone in an area at once. The message flows top-down and the recipient does not reply.
- **Operational in-team notification systems:** Systems used within search and rescue teams, construction and mining crews, security units or event staff. Here the message is two-way: the person raising the alarm shares their location, the coordinator replies, and everyone can see who is where.

In search queries, “emergency warning system” and “emergency notification system” are often used interchangeably. The distinction matters, because the right investment for your organisation depends on which need you are meeting.

### Public warning infrastructure in Türkiye

The backbone of public warning in Türkiye is AFAD’s [Integrated Warning and Alarm System (İKAS)](https://www.afad.gov.tr/butunlesik-ikaz-alarm-sistemi-projesi-ikas0) project. Against air raids and chemical, biological, radiological and nuclear threats, the system relays information from the Air Force Command and from institutions that are sources of hazard information to the Provincial Disaster and Emergency Management Centres online. It has three components: the News Gathering and Dissemination System (HAY), the Warning and Alarm (Siren) System and the Message Warning System (MUS).

MUS sends messages on channel 112 by cell broadcast, through the GSM operators, to people in hazard zones where the sirens cannot be heard. In this structure, [developed jointly by TÜBİTAK BİLGEM and AFAD](https://tubitak.gov.tr/en/node/15650), warnings can spread through cell broadcast, SMS, mobile apps, television, radio and social networks; institutions such as the General Directorate of Meteorology, DSİ, the General Directorate of Forestry and TRT have been integrated into the system.

The legal framework was set by a [regulation published in the Official Gazette](https://www.resmigazete.gov.tr/eskiler/2021/02/20210226-4.htm) on 26 February 2021. It defines the national mobile alert system as the system that delivers warnings to users in a given area, in disasters, emergencies and threats to public order, national security and cyber security, by at least one of CMAS, CBS, a pre-call announcement and SMS. Set-up and operation are coordinated by the Information and Communication Technologies Authority (BTK) together with the relevant public institutions.

## Which channels does a warning reach your phone through?

The strength of public systems comes from not depending on a single channel. ETSI’s [earlier version of TS 102 182](https://www.etsi.org/deliver/etsi_TS/102100_102199/102182/01.04.01_60/ts_102182v010401p.pdf) also stresses that fast and effective warning usually requires a strategy that combines several channels.

**Public warning channels and their dependence on the network**

| Channel | How it works | Who it reaches | Network dependence |
|---|---|---|---|
| Sirens and voice announcements | Sound broadcast from loudspeakers in the area | Everyone within hearing range | Needs power and a control line |
| Cell broadcast (CBS/CMAS) | The base station broadcasts the same message to every phone in its coverage | All compatible phones in the area | Needs the base station to be working |
| SMS | Number-based delivery through the operator | Numbers on the list | Needs the mobile network |
| Mobile app | Push notification over the internet | People who installed the app | Needs a data connection |
| TV, radio, social media | Broadcast and platform announcements | People watching or following | Needs broadcast infrastructure and the internet |

The regulation divides warnings sent over CMAS into four categories: government alerts, critical alerts, missing/abduction alerts and test alerts. Receiving government alerts cannot be blocked; in the other categories the user’s preference applies. CMAS messages can be sent in Turkish and in a second language.

The last column of the table stands out: almost all of these channels need power, a base station or the internet. That may be enough to warn the public; but for a team working in the field after an earthquake, flood or fire, the real work starts after the warning arrives.

## Why public warnings do not do your team’s job

A critical alert on a phone says “there is danger”. A search and rescue coordinator, however, needs answers to these questions: Where is my team? Who is asking for help? Which area has been searched? Who has which piece of information?

Even in AFAD’s own operations, public warning and team coordination run on separate systems. The agency’s [Disaster Management and Decision Support System (AYDES)](https://www.afad.gov.tr/afet-yonetim-ve-karar-destek-sistemi-projesi-aydes21) is a web-based application built on Geographic Information Systems; it passes incident reports to teams by SMS and e-mail, and service groups stay in touch through instant messaging and e-mail. On the citizen side, the [AFAD Emergency Call app](https://www.112.gov.tr/afad-acil-mobil-uygulamasi) sends the location and status of people affected by a disaster to the 112 Emergency Call Centres by voice and message over a data line.

Both examples have the same thing in common: SMS, e-mail and a data line. In other words, the systems work as long as the mobile network and the internet stay up. Team emergency notification needs four things:

1. **Two-way communication:** It must be possible to get back to the person who raised the alarm and send instructions.
1. **Live location:** The coordinator should see everyone on the map without having to ask “where are you?”. We covered this in detail in our post on [seeing where your team is](/en/blog/live-location-tracking).
1. **A record:** Who reported what, when and from where; a written trail for post-operation review and reporting.
1. **Independence from infrastructure:** The ability to work without a base station or the internet.

## What to look for in mass and team notification

The criteria that procurement and technical teams should put on the table when choosing an emergency notification system for their organisation come both from ETSI’s expectations and from real needs in the field. [ETSI TS 102 182](https://www.etsi.org/deliver/etsi_TS/102100_102199/102182/01.05.01_60/ts_102182v010501p.pdf) calls for protection of the system’s operational data, user authentication, authorisation and access management, and privacy of registered people’s data; for high availability it recommends minimising single points of failure.

**Selection criteria for an emergency notification system**

| Criterion | Why it matters | Question to ask |
|---|---|---|
| Coverage | Teams also work where the network ends: mines, tunnels, rural land, collapse sites | How is a message delivered when there is no base station? |
| Single point of failure | If the central server goes down, the whole system goes silent | Does the system depend on a central server, or does it work between devices? |
| Mass notification | One alarm has to reach the whole team at the same time | Does a single action send an alarm to the whole team? |
| Location sharing | In rescue and evacuation, minutes are won with location | Are locations visible live on the coordinator’s screen? |
| Record and reporting | Post-operation analysis and legal obligations | Are messages and location history recorded? |
| Closed network and access | Operational data should not be open to unauthorised people | Is the network open only to the organisation’s devices? |
| Set-up speed | There is no time for set-up during a disaster | How many minutes does it take to be operational in the field? |

In this table, “Coverage” and “Single point of failure” are the criteria most organisations only notice at their first major outage. Bulk SMS or internet-based apps are fast under normal conditions; the problem is that they depend on infrastructure exactly when they are needed most.

## When the network fails: emergency notification without the internet

An [academic study on disaster warning systems](https://dergipark.org.tr/tr/download/article-file/1439864) published on DergiPark stresses that warning systems need reliable infrastructure and resilient communication networks to work effectively. The study groups warning systems into four classes, mobile, satellite-based, wireless-network-based and aircraft-assisted, and notes that traditional channels such as signs, sirens, loudspeakers, radio, television, landlines and the internet can only serve to inform.

Among wireless-network-based solutions, the most flexible in the field are mesh networks. The logic is simple: every device both sends messages and passes on the messages of nearby devices to the next one. There is no central base station or server; as the team grows and spreads out, the network grows with it. If one device drops out, the message reaches its destination by another route. You can find the basics of infrastructure-free communication in our post [what is infrastructure-free communication](/en/blog/what-is-infrastructure-free-communication), and its use in the field in our post on [team communication without a base station](/en/blog/direct-team-communication).

Three practices that make notification without the internet work better:

- **Plan relay points in advance:** Over large areas or rough terrain, a fixed relay station extends the network’s reach. A solar-powered station is not affected by power cuts.
- **Keep messages short and structured:** Location, status and need; three pieces of information that take seconds to read in an emergency.
- **Rehearse the no-internet scenario in drills:** A team that uses the system by reflex when there is no network saves time in a real incident.

## The legal framework at work: Law 6331 and emergency teams

This is not only a matter for disaster agencies. Under the [regulations under Turkish Occupational Health and Safety Law No. 6331](https://webim.tki.gov.tr/file/d46e2dff-52e9-4444-87bf-e103454e924b?download=), workplaces must prepare an emergency plan and set up firefighting, rescue, protection and first-aid teams. A list with the contact details of the support staff in the emergency teams must be displayed visibly in the workplace, and a drill must be held at least once a year.

On construction, mining and energy sites, in practice this obligation means that the “the team is notified” step in your emergency plan must also work in a gallery with a weak signal or on a rural construction site. When you write your notification system into the emergency plan, defining which channel takes over under which conditions makes both inspections and drills easier. Work out the details of your plan with your occupational safety specialist and workplace physician.

## How a team alert works in the field

With BosNets, a team emergency alert flows like this:

1. **Alarm**The person in the field sends an emergency alert from a portable [BosMag](/en/bosmag) device or the [BosApp](/en/bosapp) app on their phone. The [emergency button](/en/blog/emergency-button) is designed to alert the whole team with a single press.
1. **Delivery**The alert spreads from device to device over the mesh network, without the internet or the cellular network. When a connection is available, the system switches between the internet and the mesh network automatically.
1. **Extending reach**Over large or rough areas, the solar-powered [BosBase](/en/bosbase) relay station carries the network’s range further.
1. **Location**The person’s location is shared with the alert; teammates and the coordinator see them on the map.
1. **Coordination**The coordinator directs the team and keeps messaging going from the browser-based [BosLog](/en/boslog) management interface.
1. **Record**Written messages and operational data are recorded, so you have a trail for post-operation review and reporting.

## Our view

The sentence we hear most often in the field is this: “The warning came, and then we couldn’t reach anyone.” Public warning systems do very valuable work in keeping people informed; but what a team needs in a moment of danger goes beyond being informed: finding each other and acting together.

That is why we built BosNets so that it never needs central infrastructure. Our mesh network is designed to provide licence-free, uninterrupted communication between devices. If the base station is working we continue over the internet, and if it is not, from device to device; the user does not have to deal with the switch.

Our other priority is the record. Voice radio conversations are lost; written data remains. Who reported, when and from where: the person running the operation should be able to see this both at the time and afterwards. Private closed networks also keep operational data within the authorised team.

What we see in the field, at events such as the [AFAD Drone Search Competition](/en/blog/afad-drone-search-competition-samsun), is always the same: a system that sets up fast, stays simple and does not depend on infrastructure keeps the team from falling apart in the hardest conditions.

— Emir Tanrıver, co-founder of BosNets

## A closed notification network for your team

From search and rescue teams to construction and mining crews, from security units to event organisations, BosNets brings your team’s messaging, location sharing and emergency alerts together in one system on every site where the network is not enough. The BosMag device, the BosApp app, the BosBase relay station and the BosLog management interface work together.

For a set-up built around your organisation, you can request a quote and a demo from our [pricing page](/en/pricing); our post on a [private closed communication network](/en/blog/private-closed-communication-network) also describes this set-up. Teams focused on disaster scenarios can look at our [disaster and emergency communication system](/en/disaster-emergency-communication) page, and those running field operations at our [field and operational communication](/en/operational-communication) solution.

## Frequently asked questions

### An emergency alert arrived on my phone. What should I do?

Read the message to the end and follow its instructions. In a real hazard warning, follow the official channels of AFAD and local authorities, and know your assembly area in advance. Do not share unverified information, so as not to cause panic.

### Can critical alert notifications be turned off?

Under the [2021 regulation](https://www.resmigazete.gov.tr/eskiler/2021/02/20210226-4.htm), receiving government alerts cannot be blocked. In the critical, missing/abduction and test categories the user’s preference applies; these settings are in your phone’s notifications or emergency alerts menu. For your safety, keeping critical alerts on is recommended.

### Can an emergency alert be sent when there is no internet or network?

Cell broadcast, SMS and internet-based apps need the network. Mesh network systems that work from device to device, however, can carry messages, location and alarms within a team even without a base station. BosNets was designed for exactly this.

### Why does our organisation need a separate system when there is a public warning system?

Public systems send a one-way warning to everyone in an area; they do not let your team see who is where, reply to each other or keep a record. In addition, workplace emergency plans under Law No. 6331 require in-team communication to work. The two systems complement each other.

## Sources

- [AFAD: Integrated Warning and Alarm System Project (İKAS), in Turkish](https://www.afad.gov.tr/butunlesik-ikaz-alarm-sistemi-projesi-ikas0)
- [AFAD: Disaster Management and Decision Support System (AYDES), in Turkish](https://www.afad.gov.tr/afet-yonetim-ve-karar-destek-sistemi-projesi-aydes21)
- [Official Gazette, 26 February 2021: regulation on the mobile alert system, in Turkish](https://www.resmigazete.gov.tr/eskiler/2021/02/20210226-4.htm)
- [TÜBİTAK: Warning citizens in war and natural disasters](https://tubitak.gov.tr/en/node/15650)
- [112 Emergency Call Centre: AFAD Emergency mobile app, in Turkish](https://www.112.gov.tr/afad-acil-mobil-uygulamasi)
- [ETSI TS 102 182 V1.5.1 (2020)](https://www.etsi.org/deliver/etsi_TS/102100_102199/102182/01.05.01_60/ts_102182v010501p.pdf)
- [ETSI TS 102 182 V1.4.1 (2010)](https://www.etsi.org/deliver/etsi_TS/102100_102199/102182/01.04.01_60/ts_102182v010401p.pdf)
- [DergiPark: academic study on disaster warning systems, in Turkish](https://dergipark.org.tr/tr/download/article-file/1439864)
- [Workplace emergency regulations under Law No. 6331, in Turkish](https://webim.tki.gov.tr/file/d46e2dff-52e9-4444-87bf-e103454e924b?download=)

- Emergency Notification
- Disaster Communication
- Mesh Network
- Occupational Safety
- Field Operations

## Related pages

- [Emergency button: alert the whole team with one press](/en/blog/emergency-button)
- [Disaster and emergency communication system](/en/disaster-emergency-communication)
- [What is infrastructure-free communication?](/en/blog/what-is-infrastructure-free-communication)
- [Field communication system buyer’s guide](/en/field-communication-system-buyers-guide)

## Stay in touch with your team without a network

Tell us what your operation needs and we will plan a demo together.

[Get in Touch](/en/contact)
[All posts](/en/blog/)