& cplSiteName &


Light Reading
The Buzz Bin
Light Reading

Current-generation ROADMs are limited by fixed add/drop transceivers and wavelength assignments. When a wavelength is assigned, a transceiver must be physically connected to the correct mux-demux port at the add/drop site. Even if the transceiver is tunable, it still must be manually moved.

A colorless ROADM allows this process to be automated. But to achieve this, several wavelength-selective switches (WSSs) are needed at the add port. The number of WSSs used is set by the port count: For an 80-wavelength add, up to nine 1x9 WSSs are used. Higher-degree 1x23 WSSs will reduce the units needed while also potentially lowering the cost-per-port.

On the receiver (or 'drop') side, vendors use multiple WSS ports or power splitters. But with the emergence of tunable coherent receivers at 40 Gbit/s and 100 Gbit/s, colorless demultiplexing using a coherent receiver to select the desired channel is possible, simplifying the ROADM design.

Regardless of the architecture, the end result of a colorless design is that any wavelength (color) can be assigned to any port of the add/drop site using software, and without a technician having to be on site.

(1)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View        ADD A COMMENT
User Rank: Light Beer
12/5/2012 | 4:18:35 PM
re: Colorless

The next one should be channel spacing independency.

So that no matter what the channel spacing is (50 GHz or 100 GHz) ADD or DROP can happen anytime.

Perhaps, tunable filter technology should be deployed then.


Featured Video
From The Founder
Light Reading founder Steve Saunders recently visited the University of North Carolina Charlotte (UNCC) where Cisco's Tetration application is providing data center analytics, simplifying SDN, helping with cloud migration and overseeing white-list security policy.
Flash Poll
Upcoming Live Events
March 20-22, 2018, Denver Marriott Tech Center
March 22, 2018, Denver, Colorado | Denver Marriott Tech Center
March 28, 2018, Kansas City Convention Center
April 4, 2018, The Westin Dallas Downtown, Dallas
April 9, 2018, Las Vegas Convention Center
May 14-16, 2018, Austin Convention Center
May 14, 2018, Brazos Hall, Austin, Texas
September 24-26, 2018, Westin Westminster, Denver
October 9, 2018, The Westin Times Square, New York
October 23, 2018, Georgia World Congress Centre, Atlanta, GA
November 7-8, 2018, London, United Kingdom
November 8, 2018, The Montcalm by Marble Arch, London
November 15, 2018, The Westin Times Square, New York
December 4-6, 2018, Lisbon, Portugal
All Upcoming Live Events
Hot Topics
AT&T Likens DoJ Suit to Shaved Persian Cat
Mari Silbey, Senior Editor, Cable/Video, 3/12/2018
Trump Blocks Broadcom's Qualcomm Acquisition
Dan Jones, Mobile Editor, 3/12/2018
John Deere Bets the Farm on AI, IoT
Scott Ferguson, Editor, Enterprise Cloud, 3/12/2018
Rumor Mill: SoftBank Still Eyeing Charter
Mari Silbey, Senior Editor, Cable/Video, 3/12/2018
Animals with Phones
Live Digital Audio

A CSP's digital transformation involves so much more than technology. Crucial – and often most challenging – is the cultural transformation that goes along with it. As Sigma's Chief Technology Officer, Catherine Michel has extensive experience with technology as she leads the company's entire product portfolio and strategy. But she's also no stranger to merging technology and culture, having taken a company — Tribold — from inception to acquisition (by Sigma in 2013), and she continues to advise service providers on how to drive their own transformations. This impressive female leader and vocal advocate for other women in the industry will join Women in Comms for a live radio show to discuss all things digital transformation, including the cultural transformation that goes along with it.

Like Us on Facebook
Twitter Feed