Telecommunication Access Techniques

Study Notes

Evolution of access techniques utilized various client terminals aligned with specific needs.
Initial communication began with leaflets and progressed through semaphore systems.
Telegraph systems emerged with advancements in guided media, utilizing open wire communications.
Manual, electro-mechanical, and fully digital switching systems adapted to the growing need for reliable telecommunications.
Main access networks initially comprised copper cable networks, transitioning to optical fiber due to various overhead line limitations.

Optical fiber offers significant advantages such as higher bandwidth capability, improving from around 20Kbps to up to 1Gbps.
Immune to electromagnetic interference, making it suitable for high EMI areas.
Development of IP and MPLS technologies is resulting in more effective data communication systems.
Client terminals have converged to support voice, video, text, web, and multimedia capabilities.

Optical fiber is extensively used in telecommunications, from global networks to local desktop connections.
Applications include:
- Long-distance communication backbones
- Inter-exchange junctions
- Video transmission and broadband services
- Computer data communication (LANs, WANs)
- Use in high EMI environments
- Non-communication applications such as sensors

Optical fibers consist of two layers: core and cladding, where the core carries light.
Snell's law governs light propagation, reflecting internal angles leading to total internal reflection.
The cladding index is approximately 1% lower than that of the core to facilitate this reflection.

Two primary cable designs exist:
- Tight Buffer Tube Cable: Direct contact buffering material, suited for jumper cables linking outside plant cables to terminal equipment.
- Loose Buffer Tube Cable: Commonly used for outside-plant installations, housing multiple fibers with moisture-resistant protection.

Indoor Cables:
- Simplex Fiber Cables: A single fiber within a cable, available in various jacket sizes.
- Duplex Fiber Optic Cables: Contains two fibers, one for transmitting and one for receiving signals.
Outdoor Cables:
- Outdoor Loose Tube Fiber Optic Cables: Designed with moisture protection, suitable for external environments.
- Aerial/Self-Supporting: Optimized for being strung from utility poles, featuring internal stress members for fiber protection, enhancing installation efficiency.

The trend towards universal accessibility in applications reflects the demand for access networks to become agnostic.
Human interfaces have improved, integrating sensory signals into terminal designs for enhanced user experience.
Rapid innovations and competition have led to greater service delivery expectations, reducing service delays and fostering peer-to-peer connectivity.