If you need to keep tabs on your dog in areas where there is no cell phone reception, then a radio transmission GPS tracking device is what you need. These systems are best suited for dog owners that live in rural areas where there is no cell reception, owners who take their dogs hiking and camping in remote areas, and for those who have sporting dogs used for hunting in remote areas. Unlike cell based tracking systems, you cannot set up a virtual geofence when using a radio transmission GPS tracker. These types of devices constantly track your dog and shows its location. The range of most of these systems is limited to about 9 miles at best, depending upon the terrain and line of sight. One advantage is that some radio transmission systems do not require a contract or monthly monitory fee. Some may charge for custom maps. Some of the features you want to look for in these systems are the collar and device’s weight, the number of dogs the system can accommodate, the life and cost of the battery, any contract and monitoring costs, the range of the system, and any mapping capabilities.
The products that fall into this category are RoamEO, Garmin Astro 320 T5, SportDog TEK-V1LT, and the SportDog TEK-V1L. The Garmin and SportDog TEK models are designed specifically for sporting dogs and hunting.
by 
