What are WEA and CMAS? Why don’t they work in Turkey?

WEA and CMAS are wireless emergency alert systems developed back in 2012. Pretty simple acronyms actually — Wireless Emergency Alerts (WEA) and Commercial Mobile Alert System (CMAS). Some emergencies — tornados, heavy rainfall, you name it — are hazards that can be predicted ahead of time. Thanks to this system, you can easily avoid trouble before it hits. So how exactly does this WEA thing work?

WEA has one simple requirement: base station connection. That’s it. If your device doesn’t have a base station connection, you’re not getting WEA alerts. But wait — that’s not even enough. WEA technology only works on 4G and 5G networks. Since we don’t really *have* 5G in our country, that part doesn’t matter anyway (Not like we have much 4G either, but whatever — or should I say 4.5G :D ).

The working method is super simple. In any emergency, state institutions, health authorities, or disaster agencies like AFAD send out a WEA message to a specific region. Every GSM operator in that region is obligated to push the message through all towers, reaching every connected device. So let’s say there’s a flood warning just for Istanbul. It’d be pretty stupid if someone in Ankara got that alert. So how’s this managed? There are three base station technologies globally: BTS / eNodeB / gNodeB. BTS is ancient, so it's irrelevant here. eNodeB and gNodeB are the modern ones for 4G and 5G. When you turn on your phone, it doesn’t connect to just one tower — it connects to several. That’s how your location is detected too: if you’re connected to three different towers, you’re somewhere in the middle — just like a Venn diagram.

Phone calls are the best example. Let’s say you call someone with the number 12345, but their phone isn’t connected to any tower — that means the IMSI number tied to that phone can’t be found. So your call goes straight to voicemail. But if the phone *is* connected to a tower, the tower verifies the IMSI and rings the phone. Simple, right? SIM check → phone check → ring. And if someone cloned your number onto a different SIM, the IMSI wouldn’t match, and the phone wouldn’t ring. That’s why banks ask you to unblock your SIM if you change it. Your phone number doesn’t actually matter — it’s the IMSI that counts.

So how does WEA work?

The institutions I mentioned earlier — health agencies, AFAD, etc. — send regional alerts. These alerts are verified by a CBC (Cell Broadcast Center). CBC-approved alerts differ from SMS in one key way: they don’t require user verification. That means no IMSI, no IMEI, no SIM, no phone identity is needed. A region is selected — say, Istanbul — and all towers in that area push the signal to every device sending an IMSI nearby. Doesn’t even matter which SIM card you’re using.

And then comes the fun part: when your phone gets a WEA signal, it SCREAMS. In many countries, you’re not even allowed to disable this. Not the case in Turkey — but things are way worse here anyway.

Our barely functioning GSM operators haven’t integrated this technology. And since we don’t really have a competent government to manage the system either, it’s entirely inactive. It entered testing in 2023 but never got finished. Classic.

Okay, so what was that “earthquake near you” alert on Android then?

This is where things split into two: WEA vs PN. WEA doesn’t need the internet. You just need to be connected to a 4G or 5G signal. Note: I said connected to a 4G or 5G *signal*, not that you have 4G/5G internet. People in Turkey often mix that up. The number refers to the *generation* of your base station connection, not your internet speed. 4G means fourth-generation signal connection — you’re hooked up to a tower. So if the government pushes a WEA alert, and your phone is connected, you’re getting it regardless of internet access.

Then there’s PN — Push Notifications. And that tech isn’t nearly as simple. It’s actually pretty complex, but here’s what you need to know: every device has a token, and there are two main PN servers in the world — APNS (Apple Push Notification Service) and FCM (Firebase Cloud Messaging). PN is simple in concept — your phone has a special code, and that code is stored in one of these servers. When someone messages you on WhatsApp, WhatsApp tells FCM or APNS, “Hey, send this to token X.” The server finds the matching device and sends the message through the internet. Sounds simple, but that’s all you really need to know.

The earthquake notifications on Android? Not WEA. Those were sent via PN — over the internet. So if your phone wasn’t online at the time, you weren’t getting that alert. Same goes for earthquake apps on the app stores. They use PN to send alerts too.

So which one’s better — PN or WEA?

WEA, by far. First, it doesn’t need an active internet connection. Second, it’s lightning-fast and almost foolproof. If you’re not physically near a tower, you literally can’t get the alert. Think of it like this: imagine someone spraying water from a hose in the middle of a city. If you walk under it, you get soaked. If you don’t, you stay dry. That’s how it works. Push Notifications aren’t that easy. You can’t pinpoint someone’s location from just a token. I could update my phone location in Istanbul, hop on a flight to the Netherlands, and be gone in a few hours. That change has to be tracked and updated in real time. Which slows things down a lot. Maybe it's a 30-second delay, maybe just 10. But in the middle of an earthquake, even milliseconds can make a difference.

The Bottom Line?

The GSM operators you pay, the government you pay taxes to — they’re all still useless, just like they’ve been for the last 20 years. If this keeps up, in a few years when the big Istanbul quake hits, the survivors will cry out, “God, why didn’t you just take me too.” I’m just sad, honestly. Sad for the clueless people spreading misinformation on Twitter. Sad for the failed government. Just… sad.

⁃ Stay safe, Turkey.