Frank J. Janniello

A prototype circuit-switched multi-wavelength optical metropolitan-area network

A description is given of Rainbow, a prototype optical network based on wavelength-division multiaccess (WDMA). Rainbow supports full-duplex circuit-switched interconnection of up to 32 workstations over a diameter of 25 km, at sustained bit rates of up to 300 Mb/s per connection, allowing a total network capacity of 9.6 Gb/s. Different connections are transparent to each other and may use different protocols and bit rates. >

WiSAP: a wireless personal access network for handheld computing devices

New short-range wireless communication technologies would enable environment-aware, mobile, personal area networks. These new technologies will serve as enablers for ubiquitous, low-cost, low-complexity, small-sized information appliances. These appliances will serve as interaction tools between humans and computer-driven services and applications existing in either the close or distant vicinity of humans. The new application paradigms these new technologies will enable are explored. Furthermore, an experimental wireless personal access networking platform called WiSAP, developed to research these new technologies and applications paradigms, is presented. Finally, some of the experiences gained from WiSAP while designing a consumer-oriented portable wireless communication system suitable for wireless mobile personal access networks are also presented.

WDM protocol-transparent distance extension using R2 remodulation

In computer networks using wavelength-division multiplexing (WDM), it is often necessary to extend the length of a given WDM path beyond that of a single segment whose length Is limited by the link budget. While wavelength-flattened optical amplifiers are the most obvious solution, this paper calls attention to a simple (albeit less efficient) alternative that works for any number of wavelength channels, but only a modest number of segments and modest bit rates. This scheme substitutes for each optical amplifier stage a multiwavelength 2R remodulator consisting of a WDM demultiplexor, followed by wavelength-by-wavelength zero-crossing detectors, then remodulation wavelength by wavelength, and finally wavelength-division multiplexing back onto a single fiber. Theory and experimental results confirm the usefulness of this primitive technique, which can also be used for add-and-drop links, for wavelength routing or wavelength conversion in scalable wavelength routing networks, for internetwork gateways, and for other applications.

Geographically dispersed Parallel Sysplex architecture using optical wavelength-division multiplexing

Since its introduction in 1994, the Parallel Sysplex architecture for mainframe computer systems has attracted a great deal of interest because of its high performance, continuous availability, scalability, and lower cost of ownership. Recently, it has become possible to interconnect the building blocks of a Parallel Sysplex (host processor, coupling facility, sysplex timer, and disk storage) at extended distances using fiber optic data links. In particular, optical wavelength-division multiplexing (WDM) has been an enabling technology for the extension of this architecture to a geographically dispersed Parallel Sysplex (GDPS). We describe the use of WDM in GDPS configurations, including distance limitations and typical performance considerations. Experimental results of testing a GDPS with WDM channel extensions up to 40 km are presented, and some test results on the IBM 9729 Optical Wavelength Division Multiplexer used in these configurations are also discussed.