Mobiles nearby

Mobiles nearby tells you when a station that is moving comes close enough to be worth calling. It is meant for driving: another operator meeting you on the same road, coming up behind you, or working their way along a road a mile or two over.

Mobiles nearby is part of APRS Connect Pro. Seeing moving stations on the map is free; being told about them is the part Pro adds.

Turning it on

Settings → Mobiles nearby, or the Mobiles nearby entry in the More menu — while the alerts are off, that list shows the same controls rather than sending you elsewhere for them, and once they are on it keeps an Alert settings link back to them. There are three things either way: the switch, the range, and whether a station has to be advertising a frequency.

The alerts arrive as notifications on their own Android channel, so you can silence them in Android's settings without silencing message notifications. Tapping one opens the Mobiles nearby list, which is also in the More menu.

Read them stopped

This is the feature most likely to have you reaching for a phone in a moving vehicle, so it is worth saying plainly: don't. Reading or operating a phone while driving is dangerous and in most places illegal. Set the range before you leave, let the alerts arrive in your pocket, and pull over somewhere safe before you look. The same is said in the Terms of Use.

The range

The range is the circle you set, in your own units. Fifteen miles is the default — ordinary simplex range for a mobile.

There are two ways a station gets inside that circle, and the app alerts on both:

In range now. The station is inside the circle. This covers the parallel-road case: two stations a mile apart on different roads may never get any closer to each other, and are workable the whole time.
Closing. The station is outside the circle but heading in, and will be inside it within the next ten minutes. This is the early warning, and it is what makes the feature useful at highway speed — an oncoming station thirty miles out is about seven minutes from being workable, and knowing that before it happens is the point.

A station driving away is never alerted on, even at the same distance as one bearing down. The app works out whether the gap between you is opening or closing, using both stations' reported course and speed, rather than only how far apart you are right now.

What counts as moving

A station must be reporting a speed above about 6 mph. That is what keeps digipeaters, igates, weather stations and home stations out of the alerts — a fixed station is not worth a notification no matter how close it is, because it will still be there tomorrow.

The test is the reported speed, not the station's symbol. A mobile running whatever symbol its radio shipped with still counts, and a fixed station running a car symbol still does not.

The frequency filter

Many mobiles put their voice frequency in the position comment or the status, like 146.520MHz T088. The frequency filter has two settings:

Any — alert on every moving station in range. A station with no frequency published is still workable; you call them on the calling frequency like anyone else.
With one — only alert on stations advertising a frequency.

Either way, when a station has published a frequency it appears on the notification and in the list, with its tone if it sent one.

A bare number such as 146.520 with no unit after it is not read as a frequency. Comments carry version numbers, voltages and temperatures that look identical, and a wrong frequency is the kind of thing somebody acts on. 000.000MHz is not read as one either — that is what a radio sends when no frequency is set.

How often it interrupts you

One alert per encounter, not one per beacon. A station travelling alongside you for an hour produces one notification, not thirty. If they drop out of range and come back later, that is a fresh chance at a contact and it alerts again.

There is also a ceiling of six alerts an hour. On a busy road near a city the circle can hold a dozen mobiles at once, and past a certain point notifications stop being information. The Mobiles nearby list is never capped — it shows everyone who qualifies, whether or not they earned a notification.

Why a station might not alert

It is not moving, or it is not reporting a speed at all.
Its last position is more than twelve minutes old. The app carries a station forward along its last known course to work out where it is now, and beyond twelve minutes that is guesswork rather than a position.
The app does not know where you are. The alerts need your own position, which means location permission and a recent fix. If your position is more than a minute old the list shows nothing rather than showing a stale answer.
You blocked it, or it is one of your own SSIDs.
You never heard it. Over RF you hear what your radio hears. Over APRS-IS the app widens the server filter to cover the area around you while Mobiles nearby is on, so stations near you arrive even on a receive-only session — but a station with no igate coverage and out of your radio's reach is not on the air as far as your phone is concerned.

Battery

The alerts need your position continuously. When you are already beaconing they cost nothing extra — the beacon is watching location anyway, and the alerts ride that same stream. When you are not beaconing, the app opens its own location watch while the feature is on.

Alerts keep working with the app in the background as long as Background running is on. See Background and battery.

Last updated 4 September 2026