Wearable connectivity and positioning explained

Two different jobs get muddled on every product page. Positioning is how a device works out where it is. Connectivity is how it tells you. A device can be excellent at one and useless at the other.

1. How it works out where it is

Method	Typical accuracy	Works indoors?	What it means for you
GNSS (GPS, Galileo, GLONASS)	3–10 m outdoors	Poorly or not at all	The default outdoors. Drifts badly near tall buildings, and a cold fix can take minutes.
Wi-Fi positioning	Room to building level	Yes — this is the indoor answer	The device scans nearby Wi-Fi networks and matches them against a global database. It does not join those networks.
Cell tower ID	100 m to several km	Yes	Coarse fallback. Enough to say which neighbourhood, rarely which street.
Crowdsourced mesh	Where a passing device saw it	Where other people are	Apple Find My, Amazon Sidewalk, Tile. No position at all until someone else walks past.

How Wi-Fi positioning actually works — and what it collects

This is the least understood technology in wearables, and the one doing most of the work whenever a device reports a location indoors.

The device scans for nearby Wi-Fi access points and records their MAC addresses — the unique hardware identifiers your router and your neighbours' routers broadcast constantly. It sends that list to its back-end platform, which queries a geolocation API. Those providers — Google, Skyhook (now part of Qualcomm), Combain and others — maintain databases mapping billions of access points to physical coordinates. Skyhook's network alone covered over 4.5 billion geolocated Wi-Fi hotspots and 180 million cell IDs.

The device never connects to those networks. It doesn't need a password and doesn't use them for data. It's listening, not joining.

Two things follow that are worth knowing:

It's why indoor tracking works at all. A tracker that reports a position inside a care home or a school is almost certainly doing this, not using GPS.
It sends a list of your neighbours' networks to a third party. Not your data exactly — but a record of the wireless environment around a child or an older adult, leaving the device and going to a geolocation provider most buyers have never heard of. Privacy policies rarely mention it.

A practical consequence: Wi-Fi positioning degrades where there are few networks to see. Rural areas, large open sites and new-build districts can leave a device falling back to cell ID and a location accurate to a kilometre.

2. How it sends that back to you

Technology	Data rate	Battery	Best suited to	What it means for you
Bluetooth LE Outside our scope	Short range	Excellent	Phone-tethered devices only	Needs a phone within about 10 metres to do anything. A device that relies on this can't report from anywhere on its own — which is why ViaMondo doesn't cover BLE-only wearables. Listed here so you can recognize one.
Crowdsourced mesh Outside our scope	Tiny payloads	Excellent — months	Item finding	Apple Find My, Amazon Sidewalk. Depends on strangers' phones passing by. No live tracking, no SOS, no independent connection.
NB-IoT	≤ 250 kbps	Longest of all	Infrequent, low-data reporting	Superb battery, weak for mobility and live tracking. Wrong for wandering alerts.
LTE-M (Cat-M1)	≤ 1 Mbps	Balanced	Wearable health, asset tracking	The sweet spot for most trackers — handles movement and real-time updates.
4G LTE (Cat-1 / Cat-4)	10–150 Mbps	Heaviest draw	Voice and video calling	What kids' calling watches use. Full LTE is why they need charging nightly.
5G RedCap	150 / 50 Mbps	Moderate	Data-rich wearables	Emerging. Omdia forecasts ~1bn connections by 2030.
Satellite (NTN)	Messaging	Varies	Off-grid emergencies	Garmin inReach messages anyone; Apple reaches emergency relay centers only. Decisive difference.

Also covered: GNSS drift and cold-fix times · geofencing · fall-detection sensors · heart rate, SpO2 and ECG · battery chemistry and real-world endurance · eSIM and carrier requirements · network sunsets.