No it doesnt send any affiliation packets, I have GPS enabled on all my XG100p's that have that feature with non registration trunking programmed on all of them and not one packet is sent. You just have to make sure your programming is done right in the system and groups to not send packets. The GPS in Harris is more like the GPS in your car just gives you your lat/long, altitude etc info and current satellite teathering and thats all for that specific radio. Now if you combine a bunch of 100's with in band GPS and have them connected on a system then you'll be able to see radios within a geographical area to you but they have to be linked. Kinda like radar, thats the 3rd screen in the GPS view folder, looks like a bullseye with a green dot in the center. Anyhow hope that helps any.