Unit 3: Network Media and Hardware 

Transmission media refers to the physical path or channel through which data is transmitted from one device to another in a computer network. 

Transmission media can be broadly categorized into two main types: guided and unguided media.

Guided media refer to physical pathways, such as cables or wires, that are used to transmit data signals between devices. Examples of guided media include:

1. Twisted-Pair Cable: Twisted-pair cable consists of two insulated copper wires that are twisted together to reduce interference. It is commonly used in local area networks (LANs) and telephone systems.

2. Coaxial Cable: Coaxial cable consists of a single copper core surrounded by insulation, a metal shield, and an outer insulation layer. It is commonly used for cable television (CATV) systems and broadband Internet connections.

3. Fiber Optic Cable: Fiber optic cable is made up of thin glass or plastic fibers that use light to transmit data signals. It is capable of transmitting data at very high speeds over long distances and is commonly used in wide area networks (WANs) and high-speed data communications.

Unguided media, on the other hand, do not rely on physical pathways and instead use airwaves or space to transmit data signals. Examples of unguided media include:

1. Wireless: Wireless transmission media, such as Wi-Fi, Bluetooth, and cellular networks, use radio waves or microwaves to transmit data signals over the air.

Wired transmission media refers to guided media, such as twisted-pair cable, coaxial cable, and fiber optic cable, that use physical pathways to transmit data signals.

Wireless transmission media refers to unguided media, such as Wi-Fi, Bluetooth, and cellular networks, that use airwaves or space to transmit data signals.

UTP (Unshielded Twisted-Pair) cable is a type of twisted-pair cable that is commonly used in LANs and other types of computer networks. It consists of two insulated copper wires that are twisted together to reduce interference, but does not have a metal shield to protect against electromagnetic interference (EMI).

Coaxial cable is a type of guided media that consists of a single copper core surrounded by insulation, a metal shield, and an outer insulation layer. It is commonly used for cable television (CATV) systems and broadband Internet connections.

Fiber optic cable is a type of guided media that is made up of thin glass or plastic fibers that use light to transmit data signals. It is capable of transmitting data at very high speeds over long distances and is commonly used in wide area networks (WANs) and high-speed data communications.

Guided transmission media and unguided transmission media have different characteristics that make them suited to different types of applications.

Guided transmission media refers to physical pathways, such as cables or wires, that are used to transmit data signals between devices. Some of the key characteristics of guided transmission media include:

1. Reliability: Guided transmission media is generally considered to be more reliable than unguided transmission media, as it is less susceptible to interference and does not rely on airwaves or space to transmit data signals.

2. Speed: Guided transmission media is capable of transmitting data at very high speeds, as the data signals are not subject to interference from other devices or environmental factors.

3. Security: Guided transmission media provides a more secure transmission path, as it is less susceptible to eavesdropping or tampering than unguided transmission media.

4. Cost: Guided transmission media can be more expensive than unguided transmission media, as it requires the physical installation of cable or wiring.

Unguided transmission media, on the other hand, do not rely on physical pathways and instead use airwaves or space to transmit data signals. Some of the key characteristics of unguided transmission media include:

1. Portability: Unguided transmission media allows devices to be connected wirelessly, making it more portable and flexible than guided transmission media.

2. Ease of installation: Unguided transmission media does not require the physical installation of cable or wiring, making it easier to install and less expensive than guided transmission media.

3. Interference: Unguided transmission media is susceptible to interference from other devices or environmental factors, which can affect the speed and reliability of data transmission.

4. Security: Unguided transmission media is more susceptible to eavesdropping or tampering than guided transmission media, as data signals transmitted over the air can be intercepted.

It is important to consider the characteristics of both guided and unguided transmission media when choosing a transmission medium for a particular application, as the suitability of each will depend on the specific requirements of the network.

UTP (Unshielded Twisted Pair) and coaxial cables are both commonly used types of cabling in networking and cable television applications. Here are some of their specifications:

UTP:

1. Cable construction: UTP cables consist of multiple pairs of thin, unshielded wires that are twisted together to reduce crosstalk and electromagnetic interference.

2. Maximum distance: UTP cables can transmit data signals up to a maximum distance of 100 meters (328 feet) without the use of repeaters or other signal boosters.

3. Bandwidth: UTP cables have a bandwidth capacity of up to 100 MHz, making them suitable for high-speed data transmission and applications such as Ethernet and Fast Ethernet.

4. Cost: UTP cables are relatively inexpensive compared to other types of cabling, making them a popular choice for home and small business networks.

Coaxial Cable:

1. Cable construction: Coaxial cables consist of a single, shielded wire that is surrounded by a braided metal shield, an insulating material, and an outer jacket.

2. Maximum distance: Coaxial cables can transmit data signals over much longer distances than UTP cables, typically up to 500 meters (1,640 feet) or more, depending on the quality of the cable.

3. Bandwidth: Coaxial cables have a higher bandwidth capacity than UTP cables, typically in the range of several hundred MHz, making them suitable for high-speed data transmission and video applications.

4. Cost: Coaxial cables are more expensive than UTP cables, due to their higher bandwidth capacity and shielding.

It's important to note that the specifications of UTP and coaxial cables can vary depending on the manufacturer and quality of the cable. When choosing a cable, it's important to consider the specific requirements of your application, such as data transmission speed, distance, and cost, in order to choose the best type of cable for your needs.

Wired and wireless are two different ways to transmit data between devices. Here are some of their specifications:

Wired:

1. Physical Connection: Wired communication requires a physical connection, such as a cable, between the transmitting and receiving devices.

2. Bandwidth: Wired communication typically offers higher bandwidth compared to wireless communication, making it suitable for applications that require fast and reliable data transmission, such as video and audio streaming.

3. Security: Wired communication is generally considered to be more secure than wireless communication, as the data is transmitted over a physical cable that is difficult to access or intercept.

4. Cost: The cost of wired communication can vary depending on the type of cable used, but it is often more expensive than wireless communication, due to the need for physical installation and maintenance of cables.

Wireless:

1. Physical Connection: Wireless communication does not require a physical connection between the transmitting and receiving devices.

2. Bandwidth: The bandwidth of wireless communication can vary depending on the technology used, but it is typically lower than wired communication.

3. Security: Wireless communication is vulnerable to eavesdropping and interference, which can affect the security and reliability of data transmission.

4. Cost: Wireless communication is typically less expensive than wired communication, as it does not require physical installation and maintenance of cables.

It is important to consider the specific requirements of your application, such as data transmission speed, distance, security, and cost, when choosing between wired and wireless communication. In some cases, a combination of both wired and wireless communication may be the best option, as this can provide the benefits of both technologies.

Here are some commonly used types of connectors in networking and communication systems:

1. RJ-45: RJ-45 is a type of connector used for Ethernet cables, which are used to connect computers and other devices in local area networks (LANs). The RJ-45 connector has eight pins and is commonly used for 10/100/1000BASE-T networks.

2. RJ-11: RJ-11 is a type of connector used for telephone cables, which are used to connect telephones and other devices to telephone lines. The RJ-11 connector has four or six pins, depending on the type of telephone line being used.

3. BNC: BNC is a type of connector used for coaxial cables, which are used in cable television and local area networks (LANs). The BNC connector is commonly used for 10BASE2 and 10BASE5 Ethernet networks.

4. BNC-T: BNC-T is a type of connector used to connect coaxial cables in a T-shaped configuration. It is commonly used in networking and cable television applications.

5. BNC Terminator: BNC Terminator is a type of connector used to terminate the end of a coaxial cable in a network. It is used to prevent signal reflections and ensure proper data transmission.

6. SC Connector: SC (Subscriber Channel) is a type of connector used for fiber optic cables, which are used for high-speed data transmission over long distances. The SC connector is a popular choice for its compact size and ease of use.

7. ST Connector: ST (Straight Tip) is a type of connector used for fiber optic cables. It is similar to the SC connector, but is slightly larger and not as commonly used.

8. MT-RJ Connector: MT-RJ (Mechanical Transfer – Registered Jack) is a type of connector used for fiber optic cables. It is a compact connector that combines both the transmitter and receiver into one unit.

These are just a few of the many types of connectors used in networking and communication systems. The type of connector used will depend on the specific requirements of the application, such as data transmission speed, distance, and cost.

A Network Interface Card (NIC) is a hardware component that allows a computer or other device to connect to a network. The NIC is responsible for transmitting and receiving data between the computer and the network. It is installed in the computer or device and typically connects to a cable or wireless network.

There are several types of NICs available, including wired and wireless NICs. Wired NICs use a physical cable to connect the computer to the network, while wireless NICs use radio signals to connect wirelessly.

1. ARCNET (Attached Resource Computer NETwork): ARCNET is a type of networking technology that was first developed in the late 1970s. It uses a token-passing method for data transmission and is commonly used in industrial and control systems. ARCNET supports data transmission speeds of up to 2.5 Mbps and uses a bus topology.

2. Ethernet: Ethernet is a type of networking technology that is used for local area networks (LANs) and wide area networks (WANs). Ethernet is based on a bus topology and uses a carrier sense multiple access/collision detection (CSMA/CD) method for data transmission. Ethernet is the most widely used networking technology and is commonly used for 10/100/1000BASE-T networks. Ethernet supports data transmission speeds of up to 10 Gbps and is used for a wide range of applications, including computer networking, the internet, and broadband connections.

In summary, the choice of NIC and networking technology will depend on the specific requirements of the network, such as data transmission speed, cost, and compatibility with other devices. Both ARCNET and Ethernet are widely used and offer different features and capabilities, making them suitable for different applications.

Here are some commonly used network connecting devices and their functions:

1. Repeater: A repeater is a device that amplifies signals in a network. It is used to extend the range of a network by regenerating signals that have become weak due to distance or other factors.

2. Hub: A hub is a simple networking device that connects multiple computers or devices in a network. It operates at the physical layer of the OSI model and simply repeats incoming data packets to all connected devices.

3. Bridge: A bridge is a device that connects two separate networks and allows data to be passed between them. Bridges operate at the data link layer of the OSI model and can be used to segment a network or connect different types of networks.

4. Switch: A switch is a network device that connects devices together in a local area network (LAN) and provides a higher level of functionality than a hub. Switches operate at the data link layer of the OSI model and allow data to be transmitted directly to its intended recipient, improving network performance.

5. Router: A router is a device that connects multiple networks and forwards data packets between them based on their destination addresses. Routers operate at the network layer of the OSI model and are used to route data between LANs and wide area networks (WANs).

6. Gateway: A gateway is a device that provides a connection between two separate networks and allows data to be passed between them. A gateway typically operates at the application layer of the OSI model and provides additional functions, such as firewall protection and protocol conversion.

7. Access point: An access point is a device that provides wireless connectivity to a wired network. It acts as a bridge between a wireless device and a wired network, allowing wireless devices to access network resources.

8. Wireless access point: A wireless access point (WAP) is a device that provides wireless connectivity to a network. It allows wireless devices to connect to the network and access network resources.

In summary, these network connecting devices play important roles in connecting and managing networks, and the choice of device will depend on the specific requirements of the network and the type of connections being used.

Servers are specialized computers that provide centralized resources, data, and services to clients over a network. Some of the common types of servers are:

1. File Server: A file server provides centralized storage and management of files and directories. This type of server is responsible for storing, organizing, and managing data files, allowing users to access, share, and collaborate on these files from multiple devices.

2. Print Server: A print server manages and routes print jobs from multiple clients to one or more printers. It allows clients to print to any printer connected to the network without having to install drivers on each client device.

3. Mail Server: A mail server is responsible for managing, routing, and storing electronic mail (email) messages. It acts as a central repository for email, allowing users to access and manage their email from any device connected to the network.

4. Proxy Server: A proxy server is a device that acts as an intermediary between clients and servers. It provides an additional layer of security and privacy by hiding the IP addresses of clients and filtering incoming and outgoing network traffic.

5. Web Server: A web server is responsible for serving web pages and providing access to web-based applications and services. It stores, processes, and serves up web content to clients, allowing users to access and interact with websites and web applications over the internet.

These are just a few of the common types of servers, and each type of server may have different features and functions. The choice of server will depend on the specific requirements of the network and the services being provided.