NEW YORK -- Cell phone companies say their networks are largely up and running after a blizzard dumped up to 3 feet of snow on New England.Not all cell towers have backup power, so natural disasters can take out cell service through power outages. Last fall's Superstorm Sandy had a major impact on cell service in flooded areas of the Northeast. This week's snowstorm had much less effect. AT&T ( T) says the "vast majority" of its cell towers in the hardest-hit states are operating fine, and work is under way to restore service in some areas. Verizon Wireless ( VZ), which prides itself on providing backup power to nearly all sites, says its network is performing well. Sprint Nextel ( S) says the storm's impact was "minimal."