There are two primary services, analog and digital mobile. The analog standard was established by cell phone pioneer Motorola in the very early 1980's. In the early 1990's digital cell phones began to come onto the scene. All phones produced now are either entirely digital or handle both digital and analog cell phone signals. I doubt that new phone manufacturers today are even concerned with analog signal technology and probably do not build that kind of yesterday's tech into their phones.

However, should you still have one of these ancient phones, you'll need to replace it by the end of the year 2007 to avoid service interruptions.