DWDM: New Way to Build Networks David Devereaux-Weber

Definition Dense Wavelength Division Multiplexing permits multiple optical signals to travel on the same fiber at different optical wavelengths

How Do We Use DWDM? Purchase right to use (Indefeasible Right to Use or IRU) someone else's dark fiber - they maintain the jacket and own the fibers, you use the fiber. Install your own fiber – you maintain the jacket and use the fiber.

Why Use DWDM? In high-bandwidth situations, using DWDM saves cost compared to using multiple fiber pairs. Using optical amplification can extend the reach of an optical span, reducing or eliminating the need for electrical regeneration.

Further DWDM Savings Optical amplification can carry more than one optical bandwidth, sharing the cost of amplification over multiple circuits.

Dim Fiber In the dark fiber situation, you have access to the entire fiber and all the wavelengths it can carry; you furnish the DWDM equipment and the transport equipment for each wavelength. If you only need one optical wavelength, the carrier owns the DWDM equipment, furnishes dim fiber to you

Telecom Paradigm Shifts Carriers moving from tariffed to non- tariffed services. Price can drop more in non-tariffed environment. Changing from circuit provider to fiber caretaker

Datacom Paradigm Shifts Reducing intermediate layers, like ATM, Frame Relay or SONET. Reducing provisioning complexity