Signals: Communication in telecom starts with signals. These can be analog or digital. Analog signals are continuous and can take any value within a range, while digital signals are discrete and have specific values.
Modulation/Demodulation: For efficient transmission, information is often modulated onto carrier signals. Modulation is the process of encoding information onto a carrier signal, and demodulation is the reverse process of extracting the original information.
Transmission Media:
Guided Media: Includes physical cables like copper wires (used in traditional telephone lines), fiber-optic cables (use light signals for high-speed data transmission), and coaxial cables.
Unguided Media: Wireless communication uses unguided media, such as radio waves, microwaves, and satellite signals.
Network Topologies:
Point-to-Point: A direct link between two devices.
Multipoint or Multidrop: Multiple devices share a single communication channel.
Mesh: Devices are interconnected, allowing multiple paths for communication.
Bus, Ring, Star: Different physical arrangements of devices in a network.
Switching Techniques:
Circuit Switching: Dedicated communication path established for the duration of the conversation.
Packet Switching: Data is divided into packets, which are sent independently and reassembled at the destination. Common in modern networks, including the internet.
Protocols:
OSI Model: The Open Systems Interconnection model divides the networking process into seven layers, each responsible for specific functions like physical transmission, data link, network, transport, session, presentation, and application layers.
TCP/IP: The Transmission Control Protocol/Internet Protocol is a suite of protocols that form the basis of the internet. It includes protocols like IP (Internet Protocol) for addressing and routing, and TCP (Transmission Control Protocol) for reliable data delivery.
Wireless Technologies:
Cellular Networks: Divided into cells, each served by a base station. Common generations include 2G, 3G, 4G, and 5G, each providing increased data speeds and capabilities.
Wi-Fi: Local wireless networking using radio waves. Common standards include 802.11a/b/g/n/ac.
VoIP (Voice over Internet Protocol):
Digitalization: Voice signals are converted into digital data for transmission over the internet.
Protocols: SIP (Session Initiation Protocol) and RTP (Real-time Transport Protocol) are commonly used for voice communication over IP networks.
Telecom Security:
Cryptography: Ensures secure communication by encoding information.
Firewalls and VPNs: Protect networks from unauthorized access and secure data transmission over the internet.
Emerging Technologies:
5G Networks: Providing faster data speeds, low latency, and support for a massive number of connected devices.
Internet of Things (IoT): Interconnected devices communicating and sharing data over the internet.
