3. Entrance Facilities

Entrance facilities include the pathways for outside carrier services, interbuilding backbone, alternate entrance and antennae entrance pathways. The entrance facilities consist of a termination field interfacing any outside cabling to the intrabuilding backbone cabling. The local telephone carrier is typically required to terminate cabling within 50 feet of building penetration, and to provide primary voltage protection. In buildings larger than 20,000 usable square feet, a locked, dedicated, enclosed room is recommended. Beyond 70,000-square feet, a locked, dedicated room is required, with a plywood termination field provided on two walls. In buildings up to 100,000 usable square footage, a wall-mounted termination field may serve as the entrance facility, using 3/4-inch plywood, 8-feet high. Beyond 100,000-square feet, rack-mounted and free-standing frames may also be required. Minimum space requirements are given as follows:

Optical Fiber Cabling Media
Gross Building Floor Space (sq. ft.)	Plywood Field	Room Dimension
5,000	8' high X 39" wide
10,000	8' high X 39"
20,000	8' high X 42"	(A room recommended
40,000	8' high X 68"	beyond this level)
50,000	8' high X 90"
60,000	8' high X 96"	(A dedicated room req'd.)
80,000	8' high X 120"	12' X 6.3'
100,000	8' high X 2 walls	12' X 6.3'
200,000	8' high X 2 walls	12' X 9'
400,000	8' high X 2 walls	12' X 13'
500,000	8' high X 2 walls	12' X 15.6'
600,000	8' high X 2 walls	12' X 18.3'
800,000	8' high X 2 walls	12' X 22.3'
1,000,000	8' high X 2 walls	12' X 27.7'

Rule of Thumb: Allow one square foot of plywood wallmount for each 200 square-foot area of floor space.