Fiber Optic Reference Guide: A Practical Guide to Communications Technology, Third Edition
This guide is an ideal primer for newcomers to the fiber optics industry as well as a useful reference guide for seasoned fiber optics veterans.
TABLE OF CONTENTS Fiber Optic Reference Guide: A Practical Guide to Communications Technology, Third Edition
Chapter 10: System Design Considerations
SYSTEM DESIGN FACTORS
To achieve high-quality transmission, careful decisions based on operating parameters apply for each component of a fiber optic transmission system. The main questions, given in Table 10.1, involve data rates and bit error rates in digital systems, bandwidth, linearity, and signal-to-noise ratios in analog systems, and in all systems, transmission distances. These questions of how far, how good, and how fast define the basic application constraints. Once these are decided, it is time to evaluate the other factors involved.
| System Factor | Consideration/Choices |
|---|---|
| Type of Fiber | Single-mode or Multimode |
| Dispersion | Regenerators or Dispersion Compensation |
| Fiber Nonlinearities | Fiber Characteristics, Wavelengths, and Transmitter Power |
| Operating Wavelength | 780, 850, 1310, 1550 nm, and 1625 nm typical. |
| Transmitter Power | Typically expressed in dBm. |
| Source Type | LED or Laser |
| Receiver Sensitivity/Overload Characteristics | Typically expressed in dBm. |
| Detector Type | PIN Diode, APD, or IDP |
| Modulation Code | AM, FM, PCM, or Digital |
| Bit Error Rate (BER) (Digital Systems Only) | 10 -9, 10 -12 Typical |
| Signal-to-Noise Ratio | Specified in decibels (dB). |
| Number of Connectors | Loss increases with the number of connectors. |
| Number of Splices | Loss increases with the number of splices. |
| Environmental Requirements | Humidity, Temperature, Exposure to Sunlight |
| Mechanical Requirements | Flammability, Indoor/Outdoor Application |
Many of these considerations are directly related to other considerations. For example, detector choice will impact the receiver sensitivity which will affect the necessary transmitter output power. Output power impacts the transmitter light emitter type which will affect the usable fiber type...
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