Telecommunication Systems DCIT426

Telecommunication Technologies

• PSTN (Public Switched Telephone Network): Traditional circuit-switched network primarily for voice communication.
• ISDN (Integrated Services Digital Network): Integrates voice, data, and video services over the same network.
• Broadband Technologies:
  • DSL (Digital Subscriber Line): High-speed internet over copper telephone lines.
  • Cable Broadband: Internet services delivered through coaxial cables from cable TV providers.

Mobile Communication Systems

• 2G: Introduced digital signals, allowing SMS and basic data services.
• 3G: Enhanced data capabilities for internet browsing and video calling.
• 4G: High-speed internet support, enabling HD video streaming.
• 5G: Latest technology with ultra-fast speeds and low latency for IoT devices.

Network Types

• LAN (Local Area Network): Connects computers and devices in a limited area, e.g., home Wi-Fi.
• WAN (Wide Area Network): Spans large geographic areas, connecting multiple LANs, e.g., the Internet.
• MAN (Metropolitan Area Network): Covers a city or large campus, connecting multiple buildings, e.g., a university network.

Multi-User Detection and Antenna Array Techniques

• Multi-User Detection (MUD): Techniques to detect multiple users’ signals simultaneously, reducing interference and improving capacity.
• Interference in Communication Systems:
  • Co-channel Interference: Signal degradation caused by overlapping frequency channels.
  • Near-Far Problem: Strong signals close to a base station overpower weaker ones, affecting detection.

MUD Techniques

• Single-User Detection (SUD): Each user's signal is detected independently, treating others as noise.
• Multi-User Detection (MUD): Joint detection of signals from multiple users enhances system performance.
• Linear Detectors:
  • Matched Filter (MF): Correlates received signals with known user codes.
  • Decorrelating Detector: Mitigates interference effects by decorrelating signals.

WiMAX Technology

• WiMAX (Worldwide Interoperability for Microwave Access): Wireless standard for high-speed internet over long distances, based on IEEE 802.16.
• WiMAX Standards:
  • 802.16d (Fixed WiMAX): Supports fixed broadband access for stationary users.
  • 802.16e (Mobile WiMAX): Enables connectivity for mobile users.
• WiMAX Architecture:
  • Base Station (BS): Central device providing connectivity to subscribers.
  • Subscriber Station (SS): Endpoint device for user access.
  • Network Backbone: Core infrastructure connecting base stations to the internet.
• WiMAX Features:
  • High Data Rates: Up to 70 Mbps depending on conditions.
  • Long Range: Coverage up to 30 miles for fixed and 10 miles for mobile.
  • Quality of Service (QoS): Robust mechanisms for diverse services.
  • Scalability: Supports numerous users and devices.

Applications of WiMAX

• Broadband Internet Access: High-speed connectivity for residential and commercial users.
• Backhaul: Links remote base stations to the core network.
• Public Safety: Reliable communication for emergency services.
• Rural Connectivity: Internet access in underserved areas.
• Enterprise Solutions: Wireless connectivity for businesses.

Fiber-to-the-x (FttX) Technologies

• FttX: Broadband using optical fiber to deliver high-speed internet to various termination points.
• Types of FttX Architectures:
  • FTTH (Fiber-to-the-Home): Direct fiber connection to residences.
  • FTTB (Fiber-to-the-Building): Fiber to buildings, then distribution via copper or wireless.
• Applications of FttX:
  • Smart Cities: Infrastructure for IoT and smart services.
  • Telemedicine: Reliable connections for remote healthcare.
  • Education: High-speed access supporting online learning.

Mobile Ad Hoc Networks (MANETs)

• MANET: Decentralized networks where mobile devices communicate without fixed infrastructure.
• Characteristics of MANETs:
  • Dynamic Topology: Nodes can frequently join or leave.
  • Limited Battery Power: Requires energy-efficient protocols.
  • Bandwidth Constraints: Typically operate on limited bandwidth links.

Routing Protocols in MANETs

• Proactive Routing Protocols: Maintain current routes by periodically sharing routing tables among nodes.

Explore the fundamentals of telecommunication technologies including PSTN and ISDN in this quiz based on the DCIT426 handout. Test your knowledge on circuit-switched communications and the integration of voice and data services.