OPTICAL FIBER NETWORK DESIGNAND

OPTICAL NOISE

Contents

• Introduction• Copper, fiber or wireless• Choosing transmission equipment• Planning the route• Choosing components• Link power budget• Documentation• Planning for install• Developing for test plan• Planning for restoration• What is noise in optical fiber• Disadvantages of noise• Method to reduce noise

Introduction

• Specialized processes leading to a successful installation and operation

• It includes determining the type of communication system(s) which will be carried over the network, the geographic layout, the transmission equipment required.

• We can consider actual component selection, placement, installation practices, testing, troubleshooting and network equipment installation and startup.

Copper, fiber or wireless

• Designing long distance or outside plant applications

• Cabling containing single mode (SM) fiber over all other media.

• Two buildings on opposite sides of a highway, a wireless network may be easier to use since they have lower cost of installation

• Telco systems that still use copper

• CATV companies use a high performance coax into the home, but it connects to a fiber optic backbone.

Choosing transmission equipment

• The distance and bandwidth

• Shorter telecom links will use 1310 nm lasers on regular single mode fiber

• Longer links will use operation with 1550 nm lasers

Planning The Route

• Physical locations• Architectural drawings(premises)• Local building codes• Google Maps(OSP)• Approval by local, state and federal authorities

Link power budget

• Link Loss Budget(expected loss of the cable plant )• Loss budget analysis (routing, circuit length, fiber

type, connectors and splices, wavelengths)• Attenuation• Multimode fiber bandwidth

Documentation

• Every thing should be documented• Estimating, purchase, installation and future reference.• Save time• Easier rerouting• Paths, Cable, Splice , termination points, connections

Planning for install

• Critical phase• Checklist• Inspection• Schedule

Developing for test plan

• Testing three times• Cost of installation is high• Standard test procedure OFSTP-14• Splices testing• Cable testing

Planning for restoration

• Geographic diversity

• Good documentation should developed

• OTDR (optical time-domain reflectometer )

• Fusion splicer

Noise in optical fiber

• Backbone of the communications infrastructure.

• Voice and data (internet) traffic is routed through terrestrial and submarine link.

• Wavelength-division multiplexing (WDM) technology

• Noise inherent part of all systems

• Nonlinearity of the optical fiber

• Micro and Macro bending.

Types of noise

• Laser noise

• Quantum noise

• Shot noise

• Thermal noise

• Dark current noise

• White noise

Disadvantages

• Error in data detection

• Delay in transmission

• Decrease in efficiency

• Increase in circuit complexity

• Sensitivity

Methods to reduce noise

• By increasing the intracavity power level

• By minimizing optical losses.

• By building a stable laser resonator

• By temperature stabilization

• By using a low-noise pump source

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