And another article on the Gigamux from EE Times:
Networking Equipment -- Multiplexer cuts costs by eliminating active optical devices -- Osicom ships metro-based dense WDM system
Loring Wirbel
Santa Monica, Calif. - Osicom Technologies Inc. is ready to ship its passive optical transmission multiplexer based on dense wavelength-division multiplexing (DWDM). Because the company has removed active optical devices such as erbium-doped fiber amps, the GigaMux-designed strictly for local-exchange markets-slashes DWDM prices compared with systems designed for long-distance applications.
DWDM is an emerging technology for increasing the capacity of fiber networks by simultaneously transmitting several signals that are separated by the wavelength of the optical signal. A carrier could add more signals to a 2.5-Gbit (OC-48) Sonet transmission fiber, for example, instead of moving immediately to a 10-Gbit (OC-192) Sonet fiber. Most early entrants into the DWDM market-such as Lucent Technologies, Ciena and Alcatel Telecom-have designed systems strictly for long-haul fiber applications.
Jim True, vice president of marketing for Osicom, said that there are advantages beyond cost reduction in a passive optical system. Osicom offers transparent use of the 16 channels in a GigaMux system, which means users aren't confined to Sonet rates in choosing interfaces. They could bring in a switched Gigabit Ethernet channel at 1 Gbit/second, for example, or a serial digital HDTV channel at 1.48 Gbits/s.
The GigaMux system can separate a single fiber into as many as 16 channels, and can support total throughputs of up to 40 Gbits/s. It can use existing fiber infrastructures based on 1,310- and 1,550-nm systems. The multiplexer system is not a fixed size like existing DWDM systems, but can grow from a single channel to 16 channels on an incremental basis, further cutting costs of implementation for small users. This modularity makes GigaMux a simpler system than many DWDM schemes.
A standard chassis and management module offer Simple Network Management Protocol-based management agents. Add-ins include a transponder module for optical signals, a transmitter module for electrical signals, a receiver module, a mux/demux module, an expansion module and a protection-switching module. The latter allows optional redundancy features for optical fiber, letting GigaMux move to a secondary fiber on the loss of a primary one.
A special module, called the booster power amp, allows carriers to increase the span of the network to ranges in excess of 120 km using a minimum amount of optical amplification providing up to 15 dB of gain. Nevertheless, True stressed that GigaMux is designed for local and metro loops, and the booster is only meant to slightly expand a system's radius.
For management, GigaMux offers direct connectivity to Castle Rock or Hewlett-Packard OpenView SNMP management, and the system also can provide standard SNMP agents to Windows NT. "NT may be the most important management platform moving forward," said True, "because its embedded database makes it easy to drill down and observe the behavior of individual channels." Carriers can also use TMN (Telecommunications for Management of Networks) systems with a q3 interface.
Osicom has beta units in place and is taking orders for systems for delivery in early 1998. Prices start at $35,000 for single-channel muxers to $225,000 for a 16-channel system. |
