Review Step 2c: Characteristics & Trade-offs
Optical Fiber (cont.)
Deployment costs for fibre backhaul vary widely and are affected mainly by the civil works and regulatory compliance costs. Fibre can cover a wide area, as the technology itself has a range of hundreds of kilometres. Another advantage of fibre is its very high capacity, with a single strand of optical fibre able to carry enough bandwidth to support the needs of multiple users. Passive optical network technology, particularly the gigabit version (GPON), is increasingly being deployed as a way for fibre-optic technology to reach end-user premises (home or office) in a more affordable manner, as the active network equipment extends only to a central exchange. Instead of deploying active equipment to handle each connection to an end user, a network can use a series of optical splitters to deliver bandwidth from a central exchange to multiple premises. Using this method, a single fibre-optic cable with eight paired strands (for a total of 16 fibre-optic strands) can service as many as 1 024 subscribers, making it easier to attain the economies of scale needed for business viability and lowering access costs for end users (see Figure 25).
Figure 25: How a 16-strand GB passive optical network can service 1,024 subscribers
Sources: Adapted from Brewer et al, “From Analog to Digital”