Towards Technologically and Competitively Neutral Fiber to the Home (FTTH) Infrastructure
journal contributionposted on 01.02.2012, 00:00 authored by Anupam Banerjee, Marvin SirbuMarvin Sirbu
This paper provides a framework for understanding competition and industry structure in the context of Fiber to the Home (FTTH). We present engineering cost models, which indicate that FTTH is a decreasing cost industry, thereby making facilities based competition an unlikely outcome. Non-facilities based competition (or service level competition) in FTTH can happen in data-link layer (or transport) services via unbundled dark fiber (i.e. unbundled network elements) and in higher layer (voice, video and data) services via logical layer unbundling (or open access). FTTH architectures differ in the extent to which they support unbundling and therefore the extent of non-facilities based competition in FTTH depends on the architecture of the shared network over which multiple service providers offer service. Among the four different FTTH architectures considered, the curbside single-wavelength Passive Optical Network architecture (PON) that has isolated pole-mounted splitters has the most economical fiber plant but permits unbundling only at the logical layer. Consequently, though a PON supports ‘open access’ based competition in higher layer services like voice, data and switched digital video, it does not facilitate competition in data-link layer services or in the provision of analog broadcast video services. In complete contrast, the Home Run architecture has the highest initial (fiber related) capital cost, but permits unbundling of both the physical plant and at the logical layer. The Home Run architecture therefore supports a per subscriber choice of data-link layer services (via UNE based competition) as well as competition in higher layer voice, video and data services (via open access). This work further identifies deployment strategies, which can facilitate physical plant unbundling at costs much lower than the Home Run architecture. Physical plant unbundling is made possible by establishing Optimal Fiber Aggregation Points (OFAPs) that aggregate multiple distribution fibers (or homes). Unbundling is achieved at the cost of longer distribution loop lengths (vis-à-vis a curbside PON). Ideally, both passive splitters and active electronics can be deployed at an OFAP. OFAP architectures further lead to higher utilization of splitter and Optical Line Termination (OLT) ports in markets that have less than 100% penetration thereby providing the service provider with a real option to (i) defer investment in OLT ports (ii) deploy multiple data-link layer technologies and (iii) effectively phase in new technologies - under both monopoly and competition.