Optical networks Flashcards
1
Q
WDM
A
Wavelength division multiplexing
Transmission of multiple lights signals on the same strand of fiber.
DWDM: Dense WDM
- Sophisticated and expensive
CWDM: Coarse WDM
- lower number of wavelenghts → cheaper
Initial application
- Increase transmission capacity o fiber
- Increase utilization
- Point to point configs.
- Trunk bandwidth
Step further
- Wavelength switching
2
Q
Interim WDM Application
A
Ring topologies with WDM add/drop multiplexers
Mostly static or semipermanent interconnection configurations.
3
Q
Ultimate WDM application
A
Wavelength switched networks
Arbitrary mesh topologies of wdm links and wavelength switches.
Potential to be simple, hence delivering at low cost per switched bit.
4
Q
Optical core
A
Deploy physical properties of materials to deflect light from incoming fiber to outgoing fiber
- Tilting mirrors
- micro-electro-mechanical systems
- voltage operated
- Holographic reflecting surfaces
- voltage operated
- Materials change properties with heat, pressure, voltace/current
- Properties:
- potentially inexpensive: material and process
- bit rate and signal independent
- low power consumption
- High production cost
- High attentuation, regeneration is not provided
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5
Q
Electrical core
A
Convert optical signal into an electric one and use circuit interconnection network
- optical-electrical conversion
- receive the bits and switch them
- It loses all the nice properties of an optical core
- bit-rate independnce
- low-power consumption
- low-cost
- Cheper than optical core currently
- Less complex/costly than packet switching
6
Q
Optical network deployment
A
Provisioning
- Router (ip/mpls) can request channel to the switch with RSVP
protection
- pre-determined action: non-optimal resource utilization
restoration: dynamically determined action
