Bandwidth barrels beyond the leading edge
-- EDN, January 4, 2001
Using its Hyperfine technology, Essex Corp has demonstrated 1-GHz channel spacing with a 16-GHz design. The company hopes this year to demonstrate 50-GHz bandwidth capability. Hyperfine modules will subdivide standard DWDM (dense-wavelength-division-multiplexing) channels into 50- to 100-GHz channels, yielding as many as 4000 channels per fiber.
Cielo demonstrated a full transceiver link using 1.3-µm VCSEL (vertical-cavity-surface-emitting-laser) technology running on 20 km of single-mode fiber with a bit-error rate better than 1x1012. VCSELs offer several advantages, including faster modulation, smaller size, lower power consumption, and lower device cost, over standard edge-emitting lasers.
Symmetricom says that independent laboratory testing has confirmed that its GoLong loop extender increases the reach of ADSL by as much as 30,000 ft at data rates of 1.5 Mbps downstream and 128 kbps upstream. GoLong can also coexist with nonrepeating ADSL within the bounds of spectrum-management Class 5 (SMC 5) power-spectral density.
Cielo Communications, www.cieloinc.com. at www.rscahners.ims.ca/ednmag.
Essex Corp, www.essexcorp.com. at www.rscahners.ims.ca/ednmag.
Symmetricom, www.symmetricom.com.
-by Nicholas Cravotta
