over the past month most of my calls drop off. the 3g and 1x either have one bar or no bars. I walk two hundred feet to the street but it does not get any better. visitors with iphones have the same problem. they are unable to send text messages many times. we have four cell towers within two miles in any direction and still the problem continues. it never used to be like this. is it a frontier problem? several business within the two mile radius are having internet connection problems. i an in zip code 92307 apple valley, ca where will i find any comments for this question?