LAN CABLES

LAN cables

A comparative understanding of the types of Ethernet cables deployed in Local Area Networks

LAN, which stands for Local Area Network, is a private network consisting of networking equipment and media such as routers, cables, switches, and access points that allows and facilitates connection between network devices, servers, and other LANs using the WAN (Wide Area Network). A LAN cable allows network connection and transmission of broadband signals between networking devices and equipment such as computers, phones, switches, and printers, typically over small distances. Ethernet cables are the most common and straightforward way of setting up a LAN.

Types of LAN Cables

There are three main types of LAN cables in popular deployment:

• Coaxial cables
• Twisted-pair cables
• Fiber Optic Cables.

COAXIAL CABLES

Popularly referred to as coax cables, they have a copper conductor in the middle surrounded by a PVC or Teflon dielectric insulator. The dielectric insulator is surrounded by a braided conducting metallic shield, which reduces electromagnetic interference (EMI), making it ideal for transmitting high-frequency electrical signals with low losses over long distances. The metallic shield is then covered by a PVC or fire-resistant sheath.

Coaxial cables have a maximum transmission speed of 10 Mbps.

They’re most commonly used in telephone systems, cable TV, antenna systems, and Internet gateway devices like routers.

The design choice has a direct impact on the cable’s capacity for handling power as well as its flexibility, frequency performance, attenuation, physical size, strength, and price.

Types of coaxial cable

• Hard-line coaxial cables have a larger diameter than other forms of coaxial cables. The center conductor is constructed out of copper, aluminium, steel, or silver. They’re mostly used in high-strength signal transmission scenarios like long-distance telephone and internet transmission.
• Flexible coaxial cables are easily pliable to suit the configuration of the installation or application. Most commonly used in home video equipment like TVs and CCTV systems.
• Semi-rigid coaxial cables have a solid copper outer sheath for superior shielding effectiveness and a Teflon dielectric for enhanced high-frequency performance.
• Formable coaxial or non-conformable coaxial cables use a flexible metal sheath rather than a copper sheath.
• Rigid coaxial or rigid line cables consist of a central, insulated wire (the inner conductor) mounted inside a tubular outer conductor. The inner conductor is insulated from the outer conductor by insulating spacers or beads at fixed intervals.
• Twinaxial cables, or Twinax, have two central conductors in the core and a single outer core and dielectric, unlike most coaxial cables with one conductor. They’re best suited for low-frequency digital and video applications.
• Triaxial cables, or Triax, have an additional copper braid added, which functions as a shield and is grounded to pass any ground loop currents or field noise away from the inner core conductor. They provide increased bandwidth and interference rejection.
• Other types of coaxial cables include water-cooled and micro-coaxial cables.

Depending on cable type and applications, coaxial cables use one of the following types of connectors:

• BNC (Bayonet Neil Concelman)
• N-series Connectors
• F-type connectors
• SMA or Subminiature connector
• TNC (Threaded Neil Concelman), etc.

In residential applications, three categories of coaxial cables are most commonly used, denoted as RG or Radio Guide:

1. RG6: Most commonly used in short cable TV transmissions.
2. RG11: It’s thicker, less pliable, and more resilient than RG6 and is preferred for long-distance, high-frequency transmissions with less loss.
3. RG59: Most commonly used in short runs, specifically CCTV applications.

2. TWISTED PAIR CABLES

Twisted-pair cable is a copper wire cable in which two insulated copper wires are twisted around each other to reduce interference or crosstalk. The twisted copper wires can either be shielded by an insulator or unshielded. It’s by far the most popular Ethernet transmission medium.

There are two types of twisted-pair cables:

Unshielded Twisted Pair (UTP) Cable: UTP consists of two insulated copper wires that are twisted around one another, which helps in mitigating interference. It’s currently the most commonly deployed cable in modern computer networks.

Shielded Twisted Pair (STP) Cable: In STP, the wires are covered by a copper braid covering or a foil shield, which adds a layer that protects them against interference leaking into and out of the cable. For this reason, they are mainly deployed for higher transmission rates over long distances.

Twisted-pair cables come in different categories (abbreviated as Cat.) with each supporting different speeds and bandwidths.

• Cat.1 with a 1.4 MHz bandwidth, supports 1 Mbps and is mostly used in Telephone cabling
• Cat.2 with a bandwidth of 4 MHz supports 4 Mbps and is used in transmission lines
• Cat.3 with a 16 MHz bandwidth supports 16 Mbps and is used in 10BaseT Ethernet
• Cat.4 supports 20 Mbps with a 20 MHz bandwidth and is used in Token Ring
• Cat.5 is used in 100BaseT Ethernet and supports 100 Mbps with a 100 MHz bandwidth.
• Cat5e also has a 100 MHz bandwidth but supports 1 Gbps Gigabit Ethernet.
• Cat6 and Cat7 both support 10 Gbps Gigabit Ethernet but have a bandwidth of 250 MHz and 600 MHz, respectively.
• Cat7a with a 1 GHz bandwidth can support up to 10 Gbps Gigabit Ethernet.
• Cat 8, mostly used in data centers has a 2 GHz bandwidth and support 25 Gbps up to 40 Gbps.

3. FIBER OPTIC CABLES

Fiber optic cables use optical fibers made of glass cores and surrounded by cladding material, usually, PVC or Teflon, whose main function is to protect the cable from damage. They can have several layers of protective cladding depending on the application, for instance, in outdoor or underground installations.

They transmit data in the form of light signals and are thus not susceptible to interference issues, unlike other types of cable. Compared to other media, they can transmit over very long distances at incredibly high speeds, with a capacity of almost 26,000 times higher than Twisted Pair Cable.

Types of Fiber Optic Cables

1. Single-Mode Fiber (SMF): It uses one single ray of light for data transmission and is deployed in long-distance transmission applications, up to several kilometers. Single-mode mode can be categorized into OS1 and OS2 fiber.
2. Multi-Mode Fiber (MMF): It uses multiple rays for data transmission over shorter distances, up to 550 meters, and is less costly than Single-Mode Fiber. Multi-mode fiber is categorized into OM1, OM2, OM3, OM4 and OM5.

Depending on the application and cable type, there are four types of connectors used in fiber optic deployments;

· ST (Straight-tip) Connector

· FC (Fiber Channel) Connector

· SC (Subscriber) Connector

· LC (Lucent) Connector

Since different types of cable are well suited for various deployments, the application will determine which LAN cable should be used. The procurement, installation, and maintenance expenses, which include expansion costs, are additional factors to take into account when selecting a cable type.