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