POPs refers to population covered in the wireless industry - not "Point of Presence" in the typical ISP sense.
run a Howardforums search, and you'll see that POPs refers not to access points but persons covered by (but not necessarily subscribiding to) a cellular service. -- "What makes us omniscient? Have we a record of omniscience? ...If we can't persuade nations with comparable values of the merit of our cause, we'd better reexamine our reasoning." -United States Secretary of Defense (1961-1968) Robert S. McNamara