The Application of Mathematical Programming to Loop Feeder Allocation

The loop network is divided into two components, distribution and feeder. The distinction is basically economic. Distribution is the portion of the network nearest to the customer. Each distribution cable serves a small, well-defined geographical area, resulting in a low ultimate demand for capacity. Thus, economies of scale imply that 479 cables should be sized according to the ultimate demand. Distribution cables are spliced into larger feeder cables that connect them to the central office. Since the cross-sectional demand increase is considerably greater, it becomes economically advantageous to add capacity periodically rather than all at once. An impending shortage of spare facilities (wire pairs) in some distribution cable is usually due to a shortage of feeder pairs which are spliced to that distribution cable. If similar scarcities of spare feeder pairs appear throughout the geographic area fed by that cable, then more feeder cable must be added to the route. However, if some areas have an excess of spare pairs, splicing operations can sometimes be performed to make those spare pairs available to the distribution cable in need of them. The economic management of existing facilities and planning for new facilities in the loop network has come to be called feeder administration. This paper is concerned with the management of existing facilities, also referred to as the allocation process.1 It describes a model of the physical feeder route and the craft activity required to connect subscribers to the central office.