- A+B Transceiver:
Principle:
- A+B transceivers use two separate optical fibers, one for upstream data transmission (A channel) and the other for downstream data transmission (B channel).
- Upstream and downstream data transmissions are completely separated and do not interfere with each other. Advantages:
- Separated upstream and downstream data transmission ensures high transmission efficiency and strong anti-interference capability.
- Relatively simple design and implementation.
- Flexible selection of upstream and downstream speeds based on actual requirements. Disadvantages:
- Requires two optical fibers, resulting in low fiber resource utilization.
- Higher installation and cabling costs.
- Single-Fiber Bidirectional (BIDI) Transceiver:
Principle:
- Single-fiber bidirectional (BIDI) transceivers use a single optical fiber, with upstream and downstream data transmitted using different wavelengths.
- Wavelength division multiplexing technology is used to achieve bidirectional data transmission over a single fiber. Advantages:
- Requires only one optical fiber, resulting in high fiber resource utilization.
- Lower installation and cabling costs. Disadvantages:
- Upstream and downstream data share a single fiber, leading to potential interference.
- Upstream and downstream speeds are relatively limited, dependent on the optical wavelength characteristics.
- More complex design and implementation, resulting in higher costs.
In the context of Gigabit networks, the single-fiber bidirectional (BIDI) transceiver technology is particularly advantageous. Its stability and cost-effectiveness make it well-suited for large-scale deployments in FTTH (Fiber-to-the-Home) and enterprise campus networks. While it may face some interference between upstream and downstream data, the overall cost-benefit ratio is higher compared to A+B transceivers, which are more suitable for specialized applications with strict performance and reliability requirements.