Network Cabling and Connectivity Technologies Explained

Local Network Wiring

• Coaxial Cabling: A cable consisting of a central conductor wire, shielded from external electric currents by a copper mesh (now largely in disuse).
• UTP Cabling: This cable is made up of four pairs of wires within the same sheath; every pair is twisted to avoid electrical interference from other pairs.
• Fiber Optic Cabling: Carries light pulses through tiny glass fibers, making it immune to external electric currents. It consists of two strands of fiberglass.

Connection via Telephone Line

There are several ways to connect to the internet through a phone line, each requiring a specific device:

• Modems: Send or receive information through a conventional telephone line. Their mission is to convert the digital signal from the computer into an analog signal to be sent over the line, and demodulate the received analog signal back into a digital format.
• ISDN Cards: Offer higher transmission speeds as information travels digitally. They provide various channels, allowing for simultaneous telephone calls.
• ADSL Modems: Transfer data at different speeds, with increased reception speed compared to shipping. New improved versions of this technology allow telephone operators to provide digital television and high-quality video through the ADSL line.
• Router: Enables computers to connect as if they were using a hub. It is the standard way to network two or more computers. It is also responsible for sending information to a single addressee by choosing the fastest route.

Mobile Connection

The mobile telephone system has evolved to achieve higher rates of information transfer, allowing for both telephone and internet connectivity.

• GSM (Global System for Mobile Communications): A digital mobile communication standard using circuit-switched communication. Voice is converted into a digital signal, encoded, and transmitted to a terminal for decryption.
• GPRS: Based on packet communication rather than circuit switching. It is not necessary to have an exclusive channel for each user, as channels may be shared.
• UMTS: Works with a very high frequency that enables a data transmission rate of 2 Mbps. It is possible to transmit voice and data simultaneously, including TV and video signals. Transmission is performed by packet switching and allows for a permanent network connection.

Local Networks and Security

The connection of cables to each computer is done through a network card. Systems must have appropriate software, known as network software. The most used protocol was Ethernet, and it is becoming increasingly common to use TCP/IP. Networks that use this protocol are called intranets. Each computer is identified by a unique IP address within a specific range.

Virtual Private Networks (VPN)

VPNs are a special type of network that adds a series of security measures between connected computers so that their communication remains private.