Lecture 3 LAN Transmission Media Transmission Media - Aseel Alhadlaq

Transmission Media Transmission medium: the physical path between transmitter and receiver. Repeaters or amplifiers may be used to extend the length of the medium. Communication of electromagnetic waves is guided or unguided. Guided media :: waves are guided along a physical path (e.g, twisted pair, coaxial cable and optical fiber). Unguided media:: means for transmitting but not guiding electromagnetic waves (e.g., the atmosphere and outer space). Transmission Media - Aseel Alhadlaq

Transmission Media Choices Twisted pair Coaxial cable Optical fiber Wireless communications Transmission Media - Aseel Alhadlaq

Digital Transmission Media Bit Rates Transmission Media - Aseel Alhadlaq

Twisted Pair Consists of two insulated copper wires arranged in a regular spiral pattern to minimize the electromagnetic interference between adjacent pairs Often used at customer facilities and also over distances to carry voice as well as data communications Low frequency transmission medium Transmission Media - Aseel Alhadlaq

Twisted Pair Limited in distance, bandwidth and data rate due to problems with attenuation, interference and noise Issue: cross-talk due to interference from other signals “shielding” wire (shielded twisted pair (STP)) with metallic braid or sheathing reduces interference. “twisting” reduces crosstalk. Transmission Media - Aseel Alhadlaq

Types of Twisted Pair STP (shielded twisted pair) the pair is wrapped with metallic foil or braid to insulate the pair from electromagnetic interference UTP (unshielded twisted pair) each wire is insulated with plastic wrap, but the pair is encased in an outer covering Transmission Media - Aseel Alhadlaq

Ratings of Twisted Pair Category 3 UTP data rates of up to 16mbps are achievable Category 5 UTP data rates of up to 100mbps are achievable more tightly twisted than Category 3 cables more expensive, but better performance STP More expensive, harder to work with Transmission Media - Aseel Alhadlaq

UTP categories Category 1 Voice only (Telephone) Category 2 Data to 4 Mbps (Localtalk) Category 3 Data to 10Mbps (Ethernet) Category 4 Data to 20Mbps (Token ring) Category 5 Category 5e Data to 100Mbps (Fast Ethernet) Data to 1000Mbps (Gigabit Ethernet) Category 6 Data to 2500Mbps (Gigabit Ethernet) Transmission Media - Aseel Alhadlaq

Twisted Pair Advantages Inexpensive and readily available Flexible and light weight Easy to work with and install Transmission Media - Aseel Alhadlaq

Twisted Pair Disadvantages Susceptibility to interference and noise Attenuation problem For analog, repeaters needed every 5-6km For digital, repeaters needed every 2-3km Relatively low bandwidth (3000Hz) Transmission Media - Aseel Alhadlaq

Coaxial Cable (or Coax) Used for cable television, LANs, telephony Has an inner conductor surrounded by a braided mesh Both conductors share a common center axial, hence the term “co-axial” Traditionally used for LANs, but growth of twisted pair for local nets and optical fiber for larger nets has reduced coax use Transmission Media - Aseel Alhadlaq

Coaxial Cable Center conductor Dielectric Braided material Outer outer cover Copyright ©2000 The McGraw Hill Companies Leon-Garcia & Widjaja: Communication Networks Figure 3.39 Transmission Media - Aseel Alhadlaq

Coaxial Cable Divided into two basic categories for coax used in LANs: 50-ohm cable [baseband] 75-ohm cable [broadband or single channel baseband] In general, coax has better noise immunity for higher frequencies than twisted pair. Coaxial cable provides much higher bandwidth than twisted pair. However, cable is ‘bulky’. Transmission Media - Aseel Alhadlaq

Baseband Coax 50-ohm cable is used exclusively for digital transmissions Uses Manchester encoding, geographical limit is a few kilometers. 10Base5 Thick Ethernet :: thick (10 mm) coax 10 Mbps, 500 m. max segment length, 100 devices/segment, awkward to handle and install. 10Base2 Thin Ethernet :: thin (5 mm) coax 10 Mbps, 185 m. max segment length, 30 devices/segment, easier to handle, uses T-shaped connectors. Transmission Media - Aseel Alhadlaq

Broadband Coax 75-ohm cable (CATV system standard) Used for both analog and digital signaling. Analog signaling – frequencies up to 500 MHZ are possible. For long-distance transmission of analog signals, amplifiers are needed every few kilometers. Transmission Media - Aseel Alhadlaq

Fiber Optic Cable Thin (2 to 125 µm), flexible medium capable of conducting an optical ray Advantages Greater capacity Smaller size/lighter weight Lower attenuation Electromagnetic isolation Attenuation in the fiber can be kept low by controlling the impurities in the glass. Transmission Media - Aseel Alhadlaq

Fiber Optic Layers plastic jacket glass or plastic cladding fiber core consists of three concentric sections plastic jacket glass or plastic cladding fiber core Transmission Media - Aseel Alhadlaq

Optical Fiber Three standard wavelengths : 850 nanometers (nm.), 1300 nm, 1500 nm. First-generation optical fiber :: 850 nm, 10’s Mbps using LED (light-emitting diode) sources. Second and third generation optical fiber :: 1300 and 1500 nm using ILD (injection laser diode) sources, gigabits/sec. Transmission Media - Aseel Alhadlaq

Optical Fiber Attenuation loss is lower at higher wavelengths. There are two types of detectors used at the receiving end to convert light into electrical energy (photo diodes): PIN detectors – less expensive, less sensitive APD detectors ASK is commonly used to transmit digital data over optical fiber {referred to as intensity modulation}. Transmission Media - Aseel Alhadlaq

Optical Fiber Three techniques: Multimode step-index Multimode graded-index Single-mode step-index Presence of multiple paths  differences in delay  optical rays interfere with each other. A narrow core can create a single direct path which yields higher speeds. WDM (Wavelength Division Multiplexing) yields more available capacity. Transmission Media - Aseel Alhadlaq

Fiber Optic Types multimode step-index fiber the reflective walls of the fiber move the light pulses to the receiver multimode graded-index fiber acts to refract the light toward the center of the fiber by variations in the density single mode fiber the light is guided down the center of an extremely narrow core Transmission Media - Aseel Alhadlaq

Fiber Optic Signals fiber optic multimode step-index graded-index fiber optic single mode Transmission Media - Aseel Alhadlaq

Structured Cabling System Transmission Media - Aseel Alhadlaq

Structured Cabling System Standards for cabling within a building (EIA/TIA-568 and ISO 11801) Includes cabling for all applications, including LANs, voice, video, etc Vendor and equipment independent Designed to encompass entire building, so that equipment can be easily relocated Provides guidance for pre-installation in new buildings and renovations Transmission Media - Aseel Alhadlaq

Structured Cabling Subsystems Six subsystems: Entrance Facilities are where the building interfaces with the outside world. Equipment Room:  A room with equipment that serves the users inside the building. Telecommunications Room: This room contains the telecommunications equipment that connects the backbone and horizontal cabling subsystems. Backbone Cabling: A system of cabling that connects the equipment rooms and telecommunications rooms. Horizontal Cabling: The system of cabling that connects telecommunications rooms to individual outlets or work areas on the floor. Work Area Components: These connect end-user equipment to outlets of the horizontal cabling system. Transmission Media - Aseel Alhadlaq

Transmission Media - Aseel Alhadlaq

Backbone Cabling The backbone cabling is also called vertical cabling or wiring. It provides interconnection between telecommunication rooms, equipment rooms and entrance facilities. These backbone cablings typically are done from floor to floor to floor. Cables: unshielded twisted-pair (UTP) cable, shielded twisted-pair (STP) cable, fiber optic cable, or coaxial cable. Equipment should be connected by cables of no more than 30 meters. Transmission Media - Aseel Alhadlaq

Horizontal Cabling The horizontal cabling system extends from the work area’s telecommunications information outlet to the telecommunications room. Horizontal cabling is usually installed in a star topology that connects each work area to the telecommunications room. Cables: Twisted pair and fiber optic cable can be used for horizontal cabling Transmission Media - Aseel Alhadlaq

Horizontal Cabling To comply with EIA/TIA wiring standards, individual cables should be limited to 90 meters in length between the outlet in the work area and the patch panels in the telecommunications room. Patch cords for connecting the patch panel to hubs and switches in the telecommunications room should be no longer than 6 meters total distance. Cables connecting users’ computers to outlets should be limited to 3 meters in length. Transmission Media - Aseel Alhadlaq

Horizontal Cabling Transmission Media - Aseel Alhadlaq

Backbone vs Horizontal Cabling Transmission Media - Aseel Alhadlaq

Backbone vs Horizontal Cabling The main difference between backbone cabling and horizontal cabling is that they cover different telecommunication service areas. Backebone cabling is to connect the entrance facilities, equipment rooms and telecommunication rooms. Horizontal cabling connects telecommunication rooms to individual outlets on the floors. Backbone runs between floors. While horizontal is on one floor. The cables used for backbone cabling have very different requirement from the horizontal cabling: Backbone cables must meet particular fire-rating specifications. Backbone cable must have sufficient strength to support its own weight. Horizontal cabling system cable will be simpler. Transmission Media - Aseel Alhadlaq

Ethernet Cable Transmission Media - Aseel Alhadlaq

Ethernet Cable The name, Ethernet Cable, always refers to the following category: Category 5 Category 5e Category 6 Or more than those categories. Transmission Media - Aseel Alhadlaq

Ethernet Cable It is composed of 4-pair twist wirings. Orange Green Blue Brown Transmission Media - Aseel Alhadlaq Cat5e cable http://www.cat5ecable.co.uk/

Ethernet Cable Color Pin (T568B) White/Orange 1 Orange 2 White/Green 3 Blue 4 White/Blue 5 Green 6 White/Brown 7 Brown 8 You can use the order of rainbow colors to memorize the order of this wiring. Transmission Media - Aseel Alhadlaq

Ethernet Cable Pin Usage 1 Transmission (Tx+) 2 Transmission (Tx-) 3 Receive (Rx+) 4 -- 5 6 Receive (Rx-) 7 8 We can use the concept to justify the order of the wiring colors of straight through and crossover. Transmission Media - Aseel Alhadlaq

How to wire Prepare the materials and tools. Cable & RJ-45 plugs Scissors Crimping tool Transmission Media - Aseel Alhadlaq For RJ-45 plug. Crimping tool

How to wire Strip off suitable length of the cable sheath. About 2-2.5 cm You can mark the position first. Transmission Media - Aseel Alhadlaq

How to wire Align the colored wires according to the specific order. (Later we will talk about.) 1 2 3 4 5 6 7 8 Transmission Media - Aseel Alhadlaq

Straight Through And Crossover Wiring Wiring within a twisted pair cable is configured as either Straight through, where each wire (or pin) is attached to the same contact point at each end Crossover, where transmit contacts on each end of the cable are connected to the receive contact at the other end Transmission Media - Aseel Alhadlaq

Straight Through Wiring Transmission Media - Aseel Alhadlaq

Crossover Wiring Transmission Media - Aseel Alhadlaq

How to wire 1→8 Straight Through All order of the wirings is the same as the other side. 1→8 1 2 3 4 5 6 7 8 Transmission Media - Aseel Alhadlaq

Straight Through Host A Host B Pin Usage Color 1 Tx+ 2 Tx- 3 Rx+ 4 -- 5 6 Rx- 7 8 Transmission Media - Aseel Alhadlaq

How to wire Crossover We need to change the order of the transmission and receiving wirings. 1→8 1 2 3 4 5 6 7 8 Transmission Media - Aseel Alhadlaq

Crossover Host A Host B Pin Usage Color 1 Tx+ 2 Tx- 3 Rx+ 4 -- 5 6 Rx- 7 8 Transmission Media - Aseel Alhadlaq

How to wire Trim all the wires to the same length. Transmission Media - Aseel Alhadlaq

How to wire Insert the wires into the RJ45 plug. Transmission Media - Aseel Alhadlaq

How to wire Crimp the RJ45 plug with the crimping tool. Transmission Media - Aseel Alhadlaq

How to wire Correct Incorrect Verify the order of the wires is correct and all the wires are correctly making good contact with the metal contacts in the RJ45 plug. Correct Incorrect Transmission Media - Aseel Alhadlaq

How to wire Cut the cable into suitable length and repeat the below steps for the other side. Please be sure what kind of the cable you are wiring. Testing Transmission Media - Aseel Alhadlaq