Types of Network Media Classification | UTP | fiber optic

Types of Network Media Classification:

In this post we briefly discuss the types of network media of the Physical Layer which are

• Copper wiring / UTP
• Fiber optic 
• Wireless media.

There are three basic formats of network media: copper cable, fiber optic cable and wireless connection. Now we go on to detail each one of them.

COPPER CABLE

The networks use copper media because they are economical and easy to install , and have low resistance to electric current. However, copper media is limited by distance and signal interference such as:

• Electromagnetic interference (EMI) or radio frequency interference (RFI): Possible sources of EMI and RFI include radio waves and electromagnetic devices such as fluorescent lights or electric motors.
• Crosstalk : this is a disturbance caused by the electric or magnetic fields of a signal from a wire to the signal from an adjacent wire.

To counteract the negative effects of EMI and RFI, some types of copper wires are packaged with a metal shield and require proper grounding.

Within copper media there are three main types of copper media that are used in networks:

1. Unshielded twisted pair (UTP)
2. Shielded Twisted Pair (STP)
3. Coaxial

UNSHIELDED TWISTED PAIR (UTP) CABLE

UTP cabling is used to interconnect network hosts with intermediary network devices, such as switches and routers.
In LAN networks, the UTP cable consists of four pairs of color-coded wires that are twisted together and coated with a flexible plastic sheath that protects them from minor physical damage. The braiding of the wires helps to protect against interference from signals from other wires.

Types of UTP cables:

Depending on the different situations, UTP cables may need to be armed according to different wiring conventions.

• Direct Ethernet cable : Usually used to interconnect a host with a switch and a switch with a router.
• Ethernet crossover cable: cable used to interconnect similar devices. For example, switch to a switch, a host to a host or a router to a router.
• Console cable: Cisco-exclusive cable used to connect a workstation to a console port of a router or switch.

SHIELDED TWISTED PAIR (STP) CABLE

Shielded twisted pair (STP) provides better noise protection than UTP wiring. However, compared to the UTP cable, the STP cable is much more expensive and difficult to install . Like the UTP cable, the STP uses an RJ-45 connector.

The STP cable combines shielding techniques to counteract EMI and RFI , and wire braiding to counteract crosstalk . For maximum shielding benefits, STP cables are terminated with special shielded STP data connectors. If the cable is not properly grounded, the shield can act as an antenna and pick up unwanted signals.

COAXIAL CABLE

The coaxial, coaxcable or coax cable gets its name from the fact that there are two conductors that share the same axis (two concentric conductors). While the UTP cable essentially replaced the coaxial cable in modern Ethernet installations, the coaxial cable design was adapted for wireless installations and cable Internet installations.

FIBER OPTIC CABLE

Currently, fiber optic cabling is used in four types of industries:

• Business networks : fiber optic is used for trunk cabling applications and for interconnecting infrastructure devices.
• Fiber-to-the-Home (FTTH) : Fiber to the home is used to provide always active broadband services to homes and small businesses.
• Long-range networks : service providers use them to connect countries and cities.
• Underwater cable networks : they are used to provide reliable high speed and high capacity solutions that can survive in adverse underwater environments over transoceanic distances.

Among the properties of fiber optic cabling, the following stand out:

• It transmits data over longer distances and bandwidths greater than any other network media
• It transmits signals with less attenuation and is totally immune EMI and RFI.
• Flexible but thin fiberglass threads extremely thin and transparent very pure glass, not much thicker than human hair.
• The bits are encoded in the fiber as pulses of light. The fiber optic cable acts as a waveguide, or a "light pipe", to transmit light between the two ends with minimal signal loss.

TYPES OF FIBER OPTIC CABLES

The types of fiber optic media are as follows:

• Single mode fiber optic (SMF) : it consists of a very small core and uses expensive laser technology to send a single beam of light, as shown in figure 1. It is widely used in long-distance situations that cover hundreds of kilometers, as applications Cable TV and long distance telephony.
• Multimode fiber optic (MMF) : consists of a larger core and uses LED emitters to send pulses of light. In particular, the light of an LED enters the multimode fiber at different angles.

One of the prominent differences between multimode and singlemode fiber optics is the amount of scattering, which refers to the extent of light pulses over time. The more dispersion there is, the greater the loss of signal power

 WIRELESS MEDIA

These data communications are made using radio and microwave frequencies. Wireless technology is important in the following areas:

• Coverage area: There are certain construction materials used in buildings and structures, in addition to local land, which limit effective coverage.
• Interference : may be affected by common devices such as home cordless phones, some types of fluorescent lights, microwave ovens and other wireless communications.
• Security : devices and users without authorization to access the network can gain access to the transmission.
• Shared media: WLAN operates in half-duplex, which means that only one device can send or receive at a time. The wireless medium is shared among all wireless users. The more users that need access to the WLAN simultaneously, each will get less bandwidth

TYPES OF WIRELESS MEDIA

• Wi-Fi (IEEE 802.11 Standard): Wireless network technologies (WLAN) use a contention protocol called multiple carrier carrier collision prevention access (CSMA / CA)
• Bluetooth (IEEE 802.15 Standard): Wireless Personal Area Network Standard (WPAN) uses a device pairing process between a distance of 1-100 meters.
• Wi-Max  (IEEE 802.16 Standard): Known as Global Interoperability for Microwave Access (WiMax). It uses a point-to-multipoint topology to provide wireless broadband access.

WIRELESS LAN

In general, a wireless LAN requires the following network devices:

• Wireless Access Point (AP): concentrates users' wireless signals and connects to the existing copper-based network infrastructure, such as Ethernet. Home and small business wireless routers integrate the functions of a router, a switch and an access point into a single device.
• Wireless NIC adapters : provide wireless communication capability to each host in the network.