Check which carriers a tracker uses and look at their coverage maps for your home, walks and trips. Single-network trackers (Fi Series 3+ on AT&T LTE-M) are fine where that carrier is strong; multi-carrier trackers (Tractive on AT&T, Verizon and T-Mobile) help in patchy areas; satellite-capable collars (Fi Ultra) reach further.
What LTE-M is
LTE-M is a low-power slice of 4G built for small devices. It sends little data but reaches further into buildings and uses less battery, which is why trackers like the Fi Series 3+ can last weeks or months per charge.
Single network vs several
| Tracker | Network (maker) |
|---|---|
| Fi Series 3+ | AT&T LTE-M |
| Tractive DOG 6 | AT&T, Verizon and T-Mobile LTE (U.S.) |
| Fi Ultra | T-Satellite with Starlink |
| Halo Collar 5 | Major carriers incl. AT&T, Verizon, T-Mobile |
A tracker that can use several networks, like Tractive DOG 6, has a better chance of finding signal in a weak spot. Fi Ultra adds satellite to reach areas without towers.
Checking your area
- Look up each carrier's coverage map for your home, regular walks and places you travel.
- Ask neighbors which carrier works on your road; maps are optimistic.
- In remote country, a radio system such as Dogtra PATHFINDER2 works with no cell signal at all, within range of you.


