Finding the right technology to cover the last few miles of any network has always been a problematic challenge for service providers. Whether wireless, copper or optical links are to be used, there's inevitably a set of competing technologies to choose from. Finding the optimum solution can be a complex process, with numerous interlinked factors to be taken into account. In this context, developments underway in the world's market around the use of high speed Passive Optical Networks (PONs) are going to be particularly significant - especially as far as the role of Gigabit PON (GPON) systems are concerned. The newly standardized ITU-T G.984 GPON technology, is delivering extremely high bit rates while still supporting the transmission of native formats such as IP and TDM at extremely high levels of efficiency. Due to its unprecedented offered bandwidth, GPON is the ideal technology for large-scale FTTH applications where multiple end-users are requiring an ever-growing bandwidth. Moreover, in areas populated by both business and residential customers, GPON is the most cost-effective solution.
Proc. SPIE. 5282, Network Architectures, Management, and Applications
KEYWORDS: Fiber to the x, Green fluorescent protein, Networks, Passive optical networks, Optical networks, Time division multiplexing, Error control coding, Network architectures, Standards development, Asynchronous transfer mode
This paper contains a comprehensive review of the various Passive Optical Network (PON) technologies in the marketplace today, namely APON, EPON and GPON, and draws an in-depth comparison between them.
Following a review of the history of the various PON flavors, as well as the service requirements set forth by service providers, the emerging Gigabit PON (GPON) technology is examined in detail. System performance between the various protocols is compared using efficiency and scalability factors, and conclusions are drawn as to the overall throughput efficiency of and cost influence on the solution. GPON carries a two-fold promise of both higher bit rates and higher efficiency when carrying multiple services over the PON. It offers a scalable framing structure from 622Mb/s to 2.5Gb/s, as well as support for asymmetric bit rates, exceptionally high bandwidth utilization for any type of service and a variant of standard ITU-T Generic Framing Protocol (GFP) encapsulation of any type of service (both TDM and packet) onto a synchronous transport protocol. It is shown that in the worst-case scenario, based upon the most conservative assumptions regarding traffic distribution, GPON is substantially more efficient, with an overall efficiency of 93% compared to 71% with APON and 49% with EPON. Using a more detailed analysis based upon a traffic model provided by the service providers within the full service access networks (FSAN) consortium, it is shown in quantitative terms that GPON offers exceptionally higher bandwidth for the entire range of applications when compared to both APON and, especially, EPON, resulting in substantially lower cost per bit and a much faster payback period.