We propose the cost-effective bit-level coarse wavelength division multiplexing (CWDM)-based power budget extender (PBEx) that can provide a high link budget of 54dB in a symmetric-rate 10-Gbit/s Ethernet passive optical network (10/10G-EPON). The proposed CWDM-based PBEx comprises a 2R-based 10/10G-EPON central office terminal (COT) and 3R-based 10/10G-EPON remote terminal (RT). It can apply several conventional CWDM technologies at the feeder fiber to reduce the amount of optical fiber required and increase the link capacity. Thus, it mainly conducts a wavelength conversion and signal retiming, as well as an upstream burst-mode for a continuous-mode conversion. We experimentally demonstrate the feasibility of a CWDM-based PBEx through packet-level testing using a pre-commercialized 10/10G-EPON system. We can confirm that the proposed solution can support a 128-way split at a distance of over 40km per CWDM channel with an enlarged loss budget of 54dB. We can also satisfy loss-free service during a packet transmission of 1010 both downstream and upstream.

Although wavelength division multiplexing-passive optical network (WDM-PON) is known as a high-speed transfer, it creates high channel costs per subscriber and low bandwidth utilization due to the fact that a wavelength is dedicated to each subscriber. Thus, it is imperative to reduce channel costs per subscriber and improve the bandwidth utilization. To achieve these, we first adopt a existing WDM-PON, which uses the bidirectional transmission with a single source for cost-efficiency by employing a gain-saturated reflective semiconductor optical amplifier (RSOA). Secondly, based on the existing WDM-PON, we propose an enhanced hybrid WDM/TDM-PON, which can extend the number of subscribers supported in each wavelength with splitters in the physical layer and a shared-time division duplex (TDD) frame format in the media access control (MAC) layer. Moreover, it can adaptively control the bandwidth through a dynamic bandwidth allocation (DBA) scheme according to the volume of traffic. Compared to the non TDD-based hybrid WDM/TDM-PON, it can reduce channel costs per subscriber from the extended number of subscribers supported in each wavelength. Furthermore, due to the DBA, it can improve the total queueing delay and throughput, and thus increase the bandwidth utilization.

To overcome the demerits of two passive optical networks; the small link capacity of the TDM-PON, and the ineffective link utilization of the WDM-PON; we propose a novel access network architecture featuring a WDM-based feeder network and a TDM-based distribution network. In this paper, we examine the design issues of the key constituent of SWE-PON (Scalable WDM-based Ethernet hybrid-PON) to validate its economic and practical feasibility. For flawless network operation, the wavelength tuning rule is investigated so that it does not collide between wavelengths from the tunable lasers belonging to the WDM coupler. Also, the potential problem between the tunable laser and the reflective operational device is analyzed in detail. From the numerical analysis and simulation, we demonstrate the variation of the network performance in terms of the upstream traffic delay and throughput of the ONU in accordance with the sharing structure of distribution network and the number of tunable laser devices (TLDs) at the feeder network.