Yu-Li Hsueh

A highly flexible and efficient passive optical network employing dynamic wavelength allocation

A novel and high-performance passive optical network (PON), the SUCCESS-DWA PON, employs dynamic wavelength allocation to provide bandwidth sharing across multiple physical PONs. In the downstream, tunable lasers, an arrayed waveguide grating, and coarse/fine filtering combine to create a flexible new optical access solution. In the upstream, several distributed and centralized schemes are proposed and investigated. The network performance is compared to conventional TDM-PONs under different traffic models, including the self-similar traffic model and the transaction-oriented model. Broadcast support and deployment issues are addressed. The networks excellent scalability can bridge the gap between conventional TDM-PONs and WDM-PONs. The powerful architecture is a promising candidate for next generation optical access networks.

Success PON demonstrator: experimental exploration of next-generation optical access networks

The deployment of passive optical networks for broadband access has been largely recognized as a promising solution to open the first-/last-mile bottleneck. We propose and demonstrate a new hybrid TDM/WDM PON architecture that jointly serves multiple physical PONs to enjoy statistical multiplexing gain as well as cost sharing. This article describes design and implementation issues of the key building blocks, including fast tunable lasers, burst-mode receivers, and scheduling algorithms with quality of service support. A prototype testbed is constructed, and transmission experiments are performed to show the effectiveness of the integrated system. Coexistence with current PONs and future evolutional paths are described as well. Experimental explorations of the new network architecture involve advanced photonic and electronic subsystems, which inspires developments of the next-generation optical access networks.

4-level direct-detection polarization shift-keying (DD-PolSK) system with phase modulators

We propose and demonstrate a novel 4-level DD-PolSK system with LiNbO/sub 3/-based phase modulator and alternative allocation of constellations, which lead to a greatly simplified transceiver architecture. A 5 Gb/s (2.5 GS/s) testbed has been build to demonstrate the feasibility of the 4-PolSK transceiver.

SUCCESS-DWA: a highly scalable and cost-effective optical access network

Passive optical networks have been identified as promising access solutions that can open the first-mile bottleneck, bringing gigabits-per-second data rates to end users. Current TDM PONs enjoy low cost by sharing resources in time, but suffer from limited capacity. In the future, WDM technology may be employed to achieve high performance. In this article we introduce a novel PON employing dynamic wavelength allocation to provide bandwidth sharing across multiple physical PONs. Tunable lasers, arrayed waveguide gratings, and coarse/fine filtering combine to create a flexible new optical access solution. The networks excellent scalability can bridge the gap between conventional TDM PONs and WDM PONs. The powerful architecture is a promising candidate for next-generation optical access networks.

A new media access control protocol guaranteeing fairness among users in Ethernet-based passive optical networks

We propose a new EPON MAC protocol guaranteeing fairness among users by allocating excess bandwidth proportional to their subscription rates. The novelty of the protocol is in the use of scalable per-subscription-rate-queuing with round-robin scheduling and packet reclassification at ONU.

Smooth upgrade of existing passive optical networks with spectral-shaping line-coding service overlay

A simple and cost-effective upgrade of existing passive optical networks (PONs) is proposed, which realizes service overlay by novel spectral-shaping line codes. A hierarchical coding procedure allows processing simplicity and achieves desired long-term spectral properties. Different code rates are supported, and the spectral shape can be properly tailored to adapt to different systems. The computation can be simplified by quantization of trigonometric functions. DC balance is achieved by passing the dc residual between processing windows. The proposed line codes tend to introduce bit transitions to avoid long consecutive identical bits and facilitate receiver clock recovery. Experiments demonstrate and compare several different optimized line codes. For a specific tolerable interference level, the optimal line code can easily be determined, which maximizes the data throughput. The service overlay using the line-coding technique leaves existing services and field-deployed fibers untouched but fully functional, providing a very flexible and economic way to upgrade existing PONs.

Demonstration and system analysis of the HORNET architecture

The HORNET architecture is a packet-over-wavelength-division-multiplexing ring network that utilizes fast-tunable packet transmitters and wavelength routing to enable it to scale cost-effectively to ultrahigh capacities. In this paper, we present the HORNET architecture and a novel control-channel-based media access control protocol. The survivability of the architecture is demonstrated with an experimental laboratory testbed. Mathematical analysis of the architecture shows that the wavelength routed network can scale to relatively large sizes ranging between 30 and 50 nodes, depending on the component performance. This is true even for arrangements that do not contain high-power optical amplifiers in every node.

Experimental demonstration of the HORNET survivable bi-directional ring architecture

In this work we demonstrate the HORNET 2FBPSR survivable architecture and the associated protocols. With simple intuition, we can see that this architecture performs up to twice as well as that of conventional ring architectures under normal conditions, and in the worst case the performance is equal after a cut occurs. We experimentally demonstrate that when a cut occurs, the maximum amount of time that any two nodes lose the ability to communicate is equal to the propagation delay of the fiber between them (less than 1 ms for a typical metro ring architecture). The demonstration of the HORNET testbed presented here is a major step towards making next generation high capacity packet-based MANs a reality.

Traffic grooming for WDM rings using optical burst transport

A sublambda traffic-grooming scheme on wavelength-division-multiplexed (WDM) rings, which is called optical burst transport (OBT), is proposed. The network protocol and architecture allow increased flexibility to tailor the transport network behavior for efficient delivery of bursty data traffic. Using different network parameters, its performance is analyzed via simulation, and the implementation issues including the media-access-control (MAC) protocol, tunable-filter controller, and burst-mode receiver are addressed. Finally, the feasibility of the OBT with an experimental testbed built by the authors is demonstrated and a streaming-video application is used to present its overall functionality.

OPN03-2: MARIN: Metro-Access Ring Integrated Network

We propose a novel metro-access integrated network that integrates hybrid TDM/WDM optical access networks into MAN, such that the capacity upgrade in both networks can be achieved simultaneously. By interconnecting multiple access ring networks, MARIN provides alternative paths for MAN traffic to be routed on it with high aggregated throughput. Thus it enables the deployed infrastructure, installed hardware, and available bandwidth of the optical access networks to be shared and leveraged by MAN. Cyclic wavelength selective switch, fast tunable laser, and optical parametric wavelength conversion are used in MARIN system for network reconfigurability, resource sharing in the central office, and wavelength set conversion, respectively. The key components are demonstrated with experimental testbed and their performance is evaluated.