Design and Implementation of GMPLS-based Optical Slot Switching Access-distribution Network Using PLZT Ultra-high Speed Optical Switch M. Hayashitani 1 , T. Kasahara 1 , D. Ishii 1 , Y. Arakawa 1 , S. Okamoto 1 , N. Yamanaka 1 , N. Takezawa 2 , and K. Nashimoto 2 1 Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan 2 Nozomi Photonics Co., Ltd., KSP R&D C333, 3-2-1 Sakado, Takatsu-ku, Kawasaki, 213-0012, Japan 1 hayashitani@yamanaka.ics.keio.ac.jp, 2 knashimoto@nozomiphotonics.com Abstract: We design and implement a GMPLS-based optical slot switching access-distribution network using PLZT switches. Switching speed is better than 10 nsec and the network has a large scalability, 1000 users, compared to PON. c  2006 Optical Society of America OCIS codes: (060.4250) Networks; (999.9999) GMPLS 1. Introduction In Japan, FTTH (Fiber To The Home) subscribers exceeded 5 million in 2006 and will reach about 20 million in 2008[1]. The spread of ultra-high speed access networks will enable us to transfer bulk contents like HD (High Definition) movie files. We design and implement an optical slot switching network for bulk content transfer. We consider that the optical slot switching network is the best approach because a network user can, in a very short period, access large bandwidth. However, it is very difficult to realize the slot switching network with conventional optical switches like the MEMS (Micro Electro Mechanical System) switch. Because the switching time of the MEMS switch is several hundred msec and the overhead between slots is large, a network based on the MEMS switch cannot transfer contents efficiently. The PLZT ultra-high speed optical switch[2]-[4] can overcome this limitation. The PLZT switch can improve the bandwidth utilization by reducing the guard time between slots unlike the MEMS switch. In addition, we employ GMPLS (Generalized Multi-Protocol Label Switching)[5] extension protocol as the slot reservation scheme. Unlike TDM (Time Division Multiplexing), GMPLS enables the slot switching network to reserve and release slots dynamically, and it realizes the distributed control of optical switches in the network. We consider the application of the proposed network as an access network for content distribution. 2. Proposed Scheme Figure 1 shows our proposed access distribution network. The slot switching network consists of a control plane and a data plane, and it synchronizes the devices in the network. The control plane employs the GMPLS protocol and reserves optical slots based on [6]. The data plane is an all optical network based on the PLZT switches manufactured by Nozomi Photonics. This product is the result of a collaboration between Keio Univ. and Nozomi Photonics. We extend the TDM-LSP (Time Division Multiplexing-Label Switched Path) scheme in RSVP-TE (Resource ReserVation Protocol-Traffic Engineering)[7] and realize optical slot reservation. RSVP-TE is standardized as the GMPLS signaling protocol. Figure 2 shows an example of slot reservation in the slot switching network. Each vertical line is a time line, and each time line is divided into frames consisting of several slots. In Fig. 2, the number of slots in a frame is 3. We assume that Service Provider receives a content request from Client A. Service Provider sends a PATH message for Client A after receiving the request. Intermediate Nodes receiving the PATH message confirm whether there are vacant slots. If there are vacant slots, Intermediate Nodes store the information about vacant slots and send the PATH message to the next node. Upon receiving the PATH message, Client A selects Slot 2, the earliest slot among all available slots on all the links of the route, and sends a RESV message for Service Provider. Intermediate Nodes receiving the RESV message reserve Slot 2 and send the RESV message to the next node. Each Intermediate Node maintains information about the reserved slots and the corresponding output port in the PLZT switch. Upon receiving the RESV message, Service Provider transfers the content by using the reserved slots in each frame. Service Provider sends a Path Tear Down message for Client A and releases the slots after finishing content transfer. Each Intermediate Node sends a switch control signal to the PLZT switch based on the information about the a1179_1.pdf OWC4.pdf