Fiber based access networks are recognized as promising technologies for solving broadband bandwidth bottlenecks. TDM-PONs, which are passive and non-reconfigurable, are the most widely deployed type of fiber access networks today. However, due to their passive nature, TDM-PONs encounter several issues such as inflexible coverage, lack of intelligence for control, and inability to counter security attacks. Based on current issues in optical access networks, we propose a novel non-volatile, reconfiguration node. The proposed remote node can reconfigure the network to adapt to varying degrees of deployment conditions and/or network attacks. Moreover, the proposed remote node incorporates a novel quasi-passive device that reconfigures using remotely supplied energy from CO. This quasi-passive device technology does not consume any energy once it reconfigures into a new latching states. Therefore, the proposed remote node has very low energy consumption and does not require local power supply to preserve the passivity of the passive distribution network. In particular, the proposed quasi-passive device technology is implemented using a novel tri-state Micro- Electro-Mechanical System (MEMS) actuator structure and the device demonstrates very small energy consumption requirement to enable energy be remotely supplied from CO. Also, the MEMS structure is shown to demonstrate acceptable insertion losses to makes it suitable for flexible energy distribution. Simulation study shows the proposed reconfigurable device would outperform traditional passive splitter in terms of maximum number of supportable users under realistic deployment conditions.

This paper presents a novel hierarchical and grid based reconfigurable optical-wireless network (GROW-Net) architecture. GROW-Net supports scalable and flexible integration of a large scale wireless mesh network in a municipal environment. Under the GROW-Net architecture, a joint evolution strategy is proposed to allow graceful upgrades in both optical backbone and wireless mesh network. To alleviate the known throughput bottleneck in mesh networks, a capacity enhancing technique based on flexible cell-splitting is proposed. The technique allocates wavelength resources to unutilized dark fibers using the unique structure of GROW-Net's reconfigurable and colorless access gateways. To analyze the effectiveness of the approach, throughput performance of the wireless mesh network is analyzed using a high fidelity simulator. The wireless mesh network in the simulation employs a distributed and cooperative medium access control protocol within a time division multiple access and time division duplex framework. Through the high fidelity simulation, results show the degree of throughput enhancement by using cell splitting method. The evolution strategy further enables the backbone to scale its bandwidth and adapt to future high throughput and very high throughput wireless technologies. The performance of the proposed backbone is demonstrated experimentally over the optical testbed.

Various wireless and optical access technologies have been developed to address different issues in access networks. By combining the complementary characteristics of wireless and optical networks, a hybrid optical-wireless access network will enable broadband, ubiquitous, and cost-effective last-mile service to the users. In this paper, a reconfigurable optical backhaul leveraging both the standard Time Division Multiplexing Passive Optical Network (TDM-PON) technology and wavelength division multiplexed (WDM) ring is proposed to achieve a higher bandwidth efficiency than simply using point-to-point backhaul links. Furthermore, an integrated routing algorithm which can adapt to the change of overall demand among different service districts by taking advantage of the proposed optical backhaul is also proposed. An experimental testbed is implemented to evaluate the reconfigurable scheme and its feasibility. Also, simulation results show that the proposed integrated routing with load balancing can improve the performance in hybrid optical and wireless networks.

This paper presents a novel integrated metro and access network based on centralized resource sharing. In its access segment, MARIN adopts a flexible and scalable architecture that employs centralized tunable transmitters and passive cyclic wavelength router in the central office. A tunable transmitter and fixed receiver scheme is proposed in the hybrid metro edge router - access central office to simultaneously achieve access resource sharing and dynamic bandwidth allocation in the integrated network. A wavelength reservation scheme and QoS aware scheduling scheme are proposed and discussed. Then, the proposed network is simulated and compared against legacy buffer insertion ring, such as resilient packet ring. The results demonstrate enhanced throughput performance through statistical multiplexing gain. An experiment testbed is constructed to demonstrate the physical feasibility of the proposed architecture.

Driven by the aggressive progress of optical access network development and deployment, we envision that the bandwidth upgrade in the metro-area network (MAN) will take place in the near future. Instead of upgrading the system performance independently in the metro and access networks, we propose a highly integrated metro-access network - the metro-access ring integrated network (MARIN). With MARIN architecture, the optical access network is integrated into MAN, such that the capacity upgrade in both networks can be achieved simultaneously without interfering the operation of existing MAN system. By interconnecting multiple access ring networks, all-optical path can be formed to route the MAN traffic between any metro hubs connected to MARIN. Fast tunable lasers are used in the central office of each access ring network to form a hybrid TDM/WDM access network architecture, and facilitate resource sharing, desirable network scalability, and routing efficiency of the metro traffic, which is the focus of this paper. wavelength routed optical burst switching (WR-OBS) is employed for route management of metro traffic. In MARIN, each access ring network emulates a distributed optical burst switch, controlled by the local central office. With WR-OBS for bandwidth and route allocation, the simulation results show that using multiple tunable lasers for simultaneous burst transmission and high-speed reconfigurable device at the joint node, the network performance of MARIN can be significantly improved.

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.