We have used PetSafe wireless system, and it works great. The system we have, you can make the signal 360 or 180 degrees, plus make the arc larger or smaller, which is nice. I have it mounted about 2 feet inside our basement door on the wall on the side of our front door. I have it set for 180 degrees that way she (our dog) does not go under the 5th wheel, or on the other side to the neighbors, without her getting a warning. Then, depending on where we were, I would step it off and reduce or increase the size of the arc between us and our other neighbor, so there is plenty of clearance. I also put our our flags for the dog to see. We are full-time and have changed from and small lots to larger lots with no problems, because she was used to "seeing" the flags and stops.
Hope this helps and God bless,