When directly buried optical cables intersect with railways, highways and streets, they should be put through protective pipes, and the protective scope is more than 0. 5m on both sides of roadbed, street pavement and drainage ditch. The Fiber Optic Association, Inc. (FOA) was founded in 1995 to help develop the workforce to build the fiber optic networks to support a rapid expansion in communications and the Internet. The charter of the FOA was to promote professionalism in fiber optics through education, certification, and. Fiber optic cable should be laid in trenches, soft soil or sand layer with thickness not less than 100 mm along the upper, lower and adjacent sides of the full length of the cable. Along the full length of the optical cable, the protective panels with a width not less than 50 mm on each side of the. ation or liability to users of this publication. Existence of a standard shall not preclude any member or nonmember of NECA or FOA from specifying or using alternate construc Code (NEC) in effect at the time of publication. Sections are included for project management; cable handling, testing and equipment; overhead cable placement; underground cable placement; underground enclosures; bonding and grounding; cable. There are three common laying methods for outdoor optical cables, namely: underground pipeline laying (that is, laying optical cables in underground pipelines), direct underground laying and overhead laying (that is, laying from utility poles to utility poles in the air.