Switched Network Architecture Research Articles

Optical path cross-connect node architectures for photonic transport network

This paper explores the optical path cross-connect (OPXC) node architectures that are essential components of the optical path network. Optical path technologies will play a key role in the development of the platform on which the future bandwidth abundant B-ISDN should be created. This paper highlights the wavelength path (WP) and the virtual wavelength path (VWP) technologies, both of which can greatly enhance the path layer capability and the efficiency of network failure restoration. The OPXC, which handles optical paths, is constructed with an optical switching network. Various WDM-based switching networks, which are aimed at LAN applications, have been reported. On the other hand, few WDM-based switching networks for OPXC systems, which are applicable to the nationwide transport network, have been proposed. In this paper, we elucidate the functional conditions required to construct OPXC nodes for WP and VWP global networks. Next, we assess switching network architectures for their applicability to the transport network. It is shown that the OPXC architecture based on DC-switches (delivery and coupling switches) is superior to the other OPXC architectures in terms of optical losses, modularity, and upgradability. Finally, detailed evaluations of the DC-switch-based OPXC node are presented that confirm its feasibility.

An expandable time-division circuit switching LSI and network architecture for broadband ISDN

A broadband network architecture is proposed that integrates multimedia services, such as data, video, and telephony information, using 52-Mb/s based STM-paths at the user network interface (UNI). The user can access any new service via the STM-based access network via either synchronous transfer mode (STM) switching or asynchronous transfer mode (ATM) switching. STM circuit switching supports long duration, constant bandwidth data transfer services such as video and high-definition television (HDTV) distribution and will also be used for the crossconnect system. Circuit switching can provide transparent transmission during long connection periods. This paper also proposes an expandable time-division switch architecture, an expandable time-division switching LSI, and an expandable switching module for small to large size system applications. The proposed time-division switching LSI, module, and system handle 52-Mb/s bearer signals and have throughputs of 2.4 Gb/s, 10 Gb/s, and 40 Gb/s, respectively. The time-division switch realizes video distribution with 1:n connections. Finally, a local switching node that features an expandable 52-Mb/s time-division circuit switching network is shown for multimedia access networking.

Terahipas: a modular and expandable terabit/second hierarchically multiplexing photonic ATM switch architecture

A terabit/second hierarchically multiplexing photonic asynchronous transfer mode (ATM) switch network architecture, called Terahipas, is proposed. It combines the advantages of photonics (a large bandwidth for transport of cells) and electronics (advanced logical functions for controlling, processing, and routing). It uses a hierarchical photonic multiplexing structure in which several tens of channels with a relatively low bit rate, say 2.4 Gb/s, are first time-multiplexed on an optical highway by shrinking the interval between optical pulses, then a number of optical highways are wavelength-multiplexed (or space-division multiplexed). As a result, the switch capacity can be expanded from the order of 100 Gb/s to the order of 10 Tb/s in a modular fashion. A new implementation scheme for cell buffering is used for eliminating the bottleneck when receiving and storing concurrent optical cells at bit rates as high as 100 Gb/s. This new architecture can serve as the basis of a modular, expandable, high-performance ATM switching system for future broad band integrated service digital networks (B-ISDN's). >

Surface-emitting laser-based smart pixels for two-dimensional optical logic and reconfigurable optical interconnections

A monolithic smart pixel technology based on the integration of two-dimensional arrays of cascadable optical switches, optical logic gates, and optical switching nodes consisting of vertical-cavity surface-emitting lasers and heterojunction phototransistors or photothyristors is described. Different combinations of these components perform optical switching, logic, routing, memory, and regeneration. Latching, nonlatching, and bistable switches with high optical gain and contrast are demonstrated, along with all the simple single-stage Boolean optical logic functions. A 2*2 optical bypass-exchange node and a reconfigurable, multistage, two-dimensional optical switching network architecture are also described. >

A scalable ATM switching system architecture

The architecture of an asynchronous transfer mode (ATM) switching system for prototype applications is presented. The general concept to upgrade the existing ISDN switch with an ATM module is introduced, and the building blocks of this ATM module are described in detail. Switching of ATM cells is performed in a single application-specific integrated circuit (ASIC). ASICs can be cascaded to form large switching modules. Peripheral modules interface the ATM switch to external transmission systems and perform all ATM-related functions, including means for redundancy of the switching network. The redundancy scheme tolerates single failures without affecting the user information. A switching network architecture is shown to be capable of fulfilling varying demands in terms of the number of ports for ATM switches and cross connects, concentrators, and multiplexers. >

The dilated slipped Banyan switching network architecture for use in an all-optical local-area network

A modification of the classical banyan switching network architecture, called the dilated slipped banyan, is described. This architecture is recursive and switching networks of any size perform permutation switching under a simple switching rule. They also exhibit column-control and dilation, properties that are particularly relevant to guided-wave and free-space photonic technologies. A photonic switching network, with this dilated slipped banyan architecture, is proposed as the hub of an all-optical active-star local-area network. The switching assignment at this hub is time-multiplexed on a fixed schedule that is known to all the terminals. This all-optical local-area network provides the equivalent of full-connectivity with high simultaneous data rates between every pair of terminals. A 16-terminal local-area network with 100 Mb/s of contention-free bandwidth between every pair of terminals is described.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A 2 Gb/s expandable space-division switching LSI and network architecture for gigabit-rate broad-band circuit switching

An expandable space-division (SD) switch architecture and a bipolar circuit design for gigabit-per-second crosspoint-switch LSIs are described. An expandable 2-Gb/s 16*16 crosspoint switch LSI which employs a novel switch structure, a novel circuit design, and a super self-aligned process (SST-1A) is developed. A switching module and partial 1:n nonblock, full 1:1 nonblock switching network architecture are also presented. Using the LSI and the switching network architecture, an experimental 620-Mb/s network system is demonstrated. >

A PCM frame switching concept leading to burst switching network architecture

A PCM frame switching concept leading to burst switching network architecture