Most of that wiring is no longer needed. With traditional copper lines, each phone needed its own pair of wires. Designed just for voice calls, they topped out at 56Kbps (bits per second). Later, T-1 lines (1.5Mbps) let companies link 24 phones to the outside world over just two pairs. But Wilson Meany expects most of the phones at 140 New Montgomery to use VoIP (Voice over Internet Protocol), which sends calls over an Ethernet LAN and then onto fiber. One fiber cable, which can bundle together hundreds of strands of fiber, can carry almost unlimited amounts of voice and data traffic. To meet traditional phone needs, Wilson Meany will keep one copper trunk with 1,800 to 2,400 pairs and give each floor enough wire for 24 individual phone lines.
The developer is using one fiber cable for its own use and will allow tenants to deploy their own cables. There are eight conduits up through the building, each four inches in diameter, for just this purpose.
"The biggest thing is to get the pathways in. That's what we've done. That gives everybody the ability to get what they want in the future," Burrows said. Even Yelp, which might have as many as 1,000 employees in the building, would only need one fiber cable to the outside world for all its voice and data traffic, he said. "To get an amazing fiber service, it's one fiber the size of your finger."
Tenants can bring that fiber to a wiring closet on each floor and connect it to an Ethernet LAN with wiring laid in trays hung from the exposed cement ceilings. That's typical today, but it's a departure from the wiring system that Pacific Bell installed when it built the building. PacBell ran its phone lines down pipes in the concrete floor, pulling it up to employees' desk phones through holes in the floor spaced every few feet. That system was on the cutting edge in 1925 and became common in later decades, but now internal wiring is typically laid above a dropped ceiling or in trays hung below an exposed ceiling, which 140 New Montgomery's tenants are expected to do.
Ensuring good wireless signals in a building built at the dawn of the radio age may be more of a challenge. The exterior walls of 140 New Montgomery are concrete, with brick filler on the inside, originally covered but now exposed for a historic look. Neither material is very friendly to wireless networks, and in retrofitting the structure for seismic safety, Wilson Meany added more concrete and 2 million pounds of reinforcing bars in the core of the building.