This looks like a tangled mess of Category 5 (blue) and Category 3 (white) cables. But its temporary placement is actually all part of a plan in a 40,000-square-foot building expansion that will house PennWell`s Advanced Technology Div. (atd--Nashua, NH), which publishes Cabling Installation & Maintenance. Instead of running along ceiling grid panels, voice and data cables are fed from floor to floor through structural columns outfitted with faceplates to feed desktop data and telephone lines. Each floor has a data-communications and telecommunications closet, with an intermediate distribution frame, while the main distribution frame for telephone lines is on the second floor. Bruce Demaine, computer information systems manager for atd, reports that finishing touches to the new building are progressing. Ceilings are being installed, walls painted, floors carpeted, and heating and ventilation systems fine-tuned.