Michael Hickey

Implementation of STARNET: a WDM computer communications network

STARNET is a broadband backbone optical wavelength-division multiplexing (WDM) local area network (LAN). Based on a physical passive star topology, STARNET offers all users two logical subnetworks: a high-speed reconfigurable packet-switched data subnetwork and a moderate-speed fix-tuned packet-switched control subnetwork. Thus, STARNET supports traffic with a wide range of speed and continuity characteristics. We report the analysis and implementation of an entire STARNET two-node network, from the optical to the computer layer, at the Optical Communications Research Laboratory (OCRL) of Stanford University. To implement the two logical subnetworks, we designed and implemented two different techniques: combined modulation and multichannel subcarrier multiplexing (MSCM). OCRL has already demonstrated several combined modulation techniques such as phase shift-keyed and amplitude shift-keyed (PSK/ASK), and differential phase shift-keyed and amplitude shift-keyed (DPSK/ASK), yielding combined ASK/DPSK modulation receiver sensitivities better than -32 dBm. OCRL has designed and implemented a high-speed high-performance packet-switched STARNET computer interface which enables high-throughput transfer to/from host computer, low latency switching, traffic prioritization, and capability of multicasting and broadcasting. With this interface board, OCRL has achieved average transmit and receive throughputs of 685 Mb/s and 571 Mb/s, respectively, out of the 800 Mb/s theoretical maximum of the host computer bus. The incurred packet latency due to the interface for a specified multihop network configuration has been simulated to be 24 /spl mu/s. Using simulation and experimental results, it is shown that STARNET is highly suitable for high-speed multimedia network applications.

WDM local area networks

Services and possible network topologies are discussed. The technological issues related to the implementation of such topologies are investigated, covering optical transmitters and receivers, tunable lasers and filters, and polarization control. Some experimental implementations reported in the literature are described.<<ETX>>

The STARNET coherent WDM computer communication network: experimental transceiver employing a novel modulation format

We have designed, constructed, and investigated an experimental transceiver employing a novel combined PSK and ASK modulation format for the STARNET coherent WDM computer communication network. Using this experimental transceiver, we show that it is possible to transmit and receive 2.488 Gb/s PSK circuit-switched data and 125 Mb/s ASK packet-switched data on the same lightwave. The experimental transceiver employs a custom integrated-optic LiNbO/sub 3/ modulator with both phase and amplitude sections, a 2.488 Gb/s tunable PSK heterodyne receiver, and a 125 Mb/s ASK heterodyne receiver. Both receivers function properly with error rates less than 10/sup -9/ and a sensitivity of -32.1 dBm; the corresponding optimum ASK modulation depth is 0.57. The resulting network power budget is 26.6 dB. >

Combined frequency and amplitude modulation for the STARNET WDM computer communication network

STARNET is an experimental wavelength-division multiplexed computer communication network that makes use of combined modulation of a single transmitter laser to implement a virtual-ring control sub-network and a reconfigurable high-speed sub-network over a passive star architecture. In this letter, we demonstrate a new technique of combined modulation that works by direct frequency-shift keyed (FSK) modulation and external amplitude-shift keyed (ASK) modulation of a semiconductor laser. By adjusting the amplitude modulation depth to 0.8, both the 125 Mb/s ASK receiver and the 1.244 Gb/s FSK receiver operate with equal bit-error ratios less than 10/sup -9/ for a received signal power of -24 dBm.<<ETX>>

Experimental PSK/ASK transceiver for the STARNET WDM computer communication network

STARNET is an optical wavelength-division-multiplexed computer communication network that offers each user both a circuit-switched subnetwork and a packer-switched subnetwork. The authors constructed an experimental STARNET node transceiver. The transceiver uses one integrated phase and amplitude modulator to transmit 125 Mb/s amplitude-modulated packet-switched data and 2.488 Gb/s phase modulated circuit-switched data using the same lightwave. The transmitter has an output power of 5 dBm at 1.32 mu m. The receiver recovers the circuit-switched and packet-switched data using heterodyne detection and has a sensitivity of -25 dBm. The resulting system power budget is 30 dB.<<ETX>>

A multi-Gbit/s optical LAN utilizing a passive WDM star: towards an experimental prototype

The goals and basic node configuration of STARNET, an optical broadband local area network based on a physical passive star topology, are presented. Over a single physical network, STARNET offers all users both a moderate-speed packet network and a high-speed WDM circuit interconnect. Several topological and protocol solutions based on these two data transport facilities are available to the users. An ongoing experimental effort aimed at the realization of a STARNET prototype is described. The prototype nodes are FDDI and SONET OC-48 data-format-compatible. The first four network layers will be fully implemented and the nodes will serve high performance workstations.<<ETX>>

An experimental multi-Gb/s WDM broadband network

STARNET is an optical broadband network architecture based on a physical passive star topology. Over a single physical network, STARNET offers all users both a moderate-speed packet switched subnetwork and a high-speed wavelength division multiplexing (WDM) circuit switched subnetwork. Based on these two data transport facilities, several topological and protocol solutions are available to the users. As a result, STARNET supports traffic of widely different speed and continuity characteristics. An ongoing experimental effort aimed at the realization of a STARNET prototype at the Optical Communication Research Laboratory of Stanford University is described. The prototype nodes are fiber distributed data interface (FDDI) and synchronous optical network (SONET) OC-48 data rate compatible.<<ETX>>

Combined PSK/ASK modulation format for the STARNET WDM local-area network

STARNET is a coherent optical wavelength division multiplexed (WDM) local area network. In STARNET, the use of low level amplitude modulation of phase modulated light has been proposed to implement a packet-switched ring network in addition to a high speed circuit- switched network. To verify the feasibility and characterize the effects of amplitude shift- keyed (ASK) modulation on a phase shift-keyed (PSK) receiver, we have measured the sensitivity of a 1.244 Gb/s PSK synchronous heterodyne receiver in the presence of 125 Mb/s ASK modulation. The experiments show that the unmodified (i.e., designed for no ASK modulation) PSK receiver successfully operates with a bit error ratio less than 10-9 and maintains phase-lock in the presence of ASK modulation for ASK modulation indexes less than 0.5.

Towards implementation of multi-Gb/s optical networks

The basic technologies and feasibility of multi-Gb/s optical LAN/MANs have been demonstrated. Broadcast and select passive star networks with less than 100 users operating at Gb/s data rates are feasible at this time. More complex technoligies such as wavelength translation and wavelength routing may be required to build fully scalable MAN/WANs.<<ETX>>

MultiGbit/s optical LAN utilizing a passive WDM star: toward an experimental prototype

STARNET is an optical broadband local area network based on a physical passive star topology intended for backbone applications. Over a single physical network, STARNET offers all users both a moderate-speed packet switched subnetwork and a reconfigurable high- speed (up to 2.5 Gbps) Wavelength Division Multiplexed (WDM) circuit switched subnetwork. Based on these two data transport facilities, several topological and protocol solutions are available to the users. As a result, STARNET supports traffic of widely different speed and continuity characteristics. This paper describes an ongoing experimental effort aimed at the realization of a STARNET prototype network at the Optical Communication Research Laboratory of Stanford University. The prototype nodes are FDDI data rate and format compatible in the packet switched subnetwork and currently use 8B/10B encoded data at a rate of 1.25 Gbps in the circuit switched subnetwork. The STARNET network serves high performance workstations running distributed multimedia applications, including video- conferencing. In this paper, the electronic hardware which interfaces the workstation to the STARNET optics is described. The moderate-speed interface uses an off-the-shelf FDDI-on- copper module to interface to the STARNET optics; a custom high-speed interface module provides fast packet switching (electronic) over the circuit switched (wavelength) subnetwork.