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NamUk KIM HyunHo YUN Tae-Yeon KIM Jeong-Ju YOO Byong-Whi KIM Minho KANG
One of the important issues of future convergence service design in access networks is the ability to support different kinds of video delivery services for high quality IP-TV and multicast Video on Demand (VoD). In this paper, we address how to efficiently allocate video transmission channels based on multicast management technology in shared wavelength division multiplexed-passive optical network (WDM-PON). The shared WDM-PON introduces a broadcast downstream wavelength to support multicast videos in the point-to-point WDM-PON. Based on the shared architecture and multicast management technologies, the proposed dynamic channel scheduling arbitrates transmission channels of videos. It uses the information of broadcast video share to maximize traffic share in the optical layer. By maintaining high video share, proposed algorithm supports the maximum number of high quality multicast videos without serious service interference to real-time videos, delay-able videos, and internet services. In addition, it also reduces the packet processing burden and buffer size of the optical line termination (OLT). The analytic and simulation results validate the effectiveness of the proposed algorithm.
Tae-Yeon KIM NamUk KIM Sang-Ho LEE Jeong-Ju YOO Byong-Whi KIM
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.
Bokrae JUNG Min-Gon KIM Byong-Whi KIM Minho KANG
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.