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WEDNESDAY FEBRUARY 13
SCV Communicaations Society
Subject: Networked Storage Architecture Considerations
Speaker: Arthur B. Edmonds, Jr. (Hitachi Data Systems)

WEDNESDAY SEPT 11

SCV Communications Society

Subject: Intelligent Metro Networking with Tunable Laser Technology

Speaker: Muckai Girish (Atoga Systems)

A great deal of attention has recently been given to metro area network systems incorporating the use of tunable DWDM lasers. Tunable lasers allow for more innovative usages extending beyond the traditional advantage of reducing the sparing need. [Read more.]

WEDNESDAY OCT 9

SCV Communications Society

Subject: Carrier Synchronization in OFDM

Speaker: Jaekyun Moon (Bermai, Inc.)

Orthogonal frequency division multiplexing (OFDM) has gained considerable popularity in recent years as a preferred modulation method in many digital communication applications. The applications range from digital audio/video broadcasting to high speed wireless local area network. [Read more.]

Wednesday, November 13, 2002

SCV Communications Society

Subject: Issues in Echo Cancellation for Packet Voice Networks

Speaker: Krishna V V (LSI Logic)

Line echo cancellation in telephony -- primarily a mid-80's technology -- is seeing a renewed interest due to new challenges posed by the on-going network evolution to accomodate packetized voice delivery. Partly as a consequence, the relevant ITU standard itself has been undergoing quite a few revisions. Telephone networks employ "hybrids" to connect the 2-wire and 4-wire segments together. Echo arises due to impedance mismatch at the hybrid, but is not a problem on its own. [Read more.]

The FCC issued a Report and Order on February 14, 2002, allocating 7,500MHz for unlicensed use for Ultra-wideband (UWB) transmitters. The FCC has imposed a limitation on the output power and the frequency range of UWB devices, and will re-examine UWB technology with the possibility of easing the restrictions.

Roberto Aillo will address this topic at the December 11 meeting of the Santa Clara Valley Communications Society. His talk will provide an introduction to UWB, a summary of technology's advantages and limitations, a status of the industry, and a description of the applications most companies are focusing on.

UWB technology is defined as a radio signal that occupies a bandwidth of more than 20% of a center frequency, or more than 500 MHz. Most UWB companies are developing systems based on transmission and detection of very short pulses, typically in the nanosecond range. Various modulation schemes are currently been developed, such as pulse position modulation, pulse amplitude modulation, bi-phase modulation and others.

UWB receivers can be very simple, directly converting a received RF signal into a baseband signal, resulting in a very simple architecture. The main advantage is that a UWB transceiver doesn't require high Q components and, therefore, leads well to high level of integration. However, design challenges for UWB transceivers do remain and some of these will be discussed.

UWB systems have same potential advantages as compared to continuous wave systems. These include large processing gains, superior multipath immunity and resistance from interference from other systems. Commercial systems are under development today for very high bit rate Wireless Personal Area Networks (+200Mbps) and very low power consumption (multi-year battery lifetime). IEEE Standards activities are under way to define an industry standard.

Dr. Aiello is the founder and CEO of Discrete Time Communications. He is a recognized leader in the UWB community. Dr. Aiello was previously founder, President and CEO at Fantasma Networks, a UWB product company. In less than a year Fantasma Networks grew to be one of the recognized leaders in Ultra Wideband (UWB) technology.

Prior to Fantasma, Dr. Aiello joined Interval Research, Paul Allen's research laboratory, in 1996 to work on advanced wireless technologies where he built the first documented UWB network. He previously held senior positions at the Stanford Linear Accelerator Center (SLAC) and the National Superconducting Super Collider Laboratory in Texas. Dr. Aiello holds a PhD degree in physics from the University of Trieste. He has authored 20 patents on UWB technology.