5 Communication and network.pdf

Announcement Test 1 - 25 September 2024 (Wednesday) Communicati...

Announcement Test 1 - 25 September 2024 (Wednesday) Communications Network Digital communication is the process in which two or more computers or Network is a collection of computers and devices connected together devices transfer data, instructions and information. via communication devices and transmission media. For a successful communication to happen, we need. Network can be internal to an organization or span the world by – sending device connecting to internet. – communication device Network facilitates communication among users and allows user to – communication channel, or a communication channel, on which the share resources with other users. data, instructions or information travel. Resources can be data, information, hardware and software. – communication device – receiving device LAN, MAN and WAN Local Area Network Network can be are classified as Local area network (LAN) is a network that connects computers and – Local Area Network (LAN) devices in a limited geographical area, such as home, school, office – Metropolitan Area Network (MAN) building. – Wide Area Network (MAN) Each computer or device on the network is called a node, where nodes are connected through cable. The main difference is their area of coverage. Often shares resources like printer, storage and program. WLAN (Wireless LAN) uses wireless connection, to connect computer and devices. Metropolitan area network Wide Area Network Metropolitan Area Network (MAN) is a high speed network that Wide area network (WAN) is a network that covers a large geographic connects local area networks in a metropolitan area. area, like city, country or the world. Usually as city or town, and handles the bulk of communications activity Uses wired and wireless transmission media. across that region. A WAN can be one large network or can consist of multiple LAN’s MAN us usually managed by a consortium of users or by a single connected together. network provider that sells the service to the users. The internet is the worlds largest WAN. Personal Area Network Network Architecture Personal area network (PAN) is a network that connects computers and Network architecture is the configuration of computers, devices and devices in an individuals workspace using wired and wireless media in a network. technology. It is a logical structural layout of a network design. Devices include smartphone, digital cameras, printers and more. The architecture can be categorized as Connect through router or USB cables, Bluetooth or WiFi. – client/ server or – peer to peer. Client/Server Peer to Peer In client/server architecture, one or more computer acts as server and Peer-to-peer (P2P) network is a simple, inexpensive network other computer on the network request for service from the server. architecture that typically connects fewer than 10 computer. The server control the access to hardware, software and other Each computer or mobile phone device are called peer. resources on the network and provides a centralized storage area for Each has equal responsibility and capabilities, sharing hardware, data program, data and information. or information with one other. The client are computers and mobiles devices on the network that rely Each peer share resource and files. on the server for its resources. Ideal for small business and home users. client server Peer 1 Peer 2 internet Network Topology Network topology Start network Bus Ring Intranet Standards and Protocols Network Communication Standards Protocols ANSI and Institute of Electrical and Electronic Engineers (IEEE) Protocol is a standard that outlines characteristics of how two network propose, develop, and approve network standards. devices communicate. Network standard defines guidelines that specify Hardware and software manufactures design their product based on – the way computer access the medium to which they are attached these guideline, that allow their device can communicate in network. – the type of medium used Network communication standards are: – the speeds used on different type of network – Ethernet, token ring, TCP/IP, Wi-Fi, Bluetooth, Ir-DA, RFID, WiMAX – the type of physical cable or wireless technology used and WAP. Ethernet Token Ring Ethernet is a network standard that specifies no central computer or Token ring standard specifies that computers and devices on the device on that network should control when data can be transmitted. network share or pass a special signal (token) in a unidirectional Collision occurs when two or more computer send data at same time. manner and in a preset order. Defines physical configuration of a network. Token is a special series of bits that functions like a ticket. Transfer rate ranges from 10 Mbps to 100 Gbps. A device with the token can transmit data over the network. Only one token exist in one network to ensure only one computer transmit data at a time. Transfer rate between 4 Mbps to 16 Mbps. https://en.wikipedia.org/wiki/Ethernet https://en.wikipedia.org/wiki/Token_Ring TCP/IP Wi-Fi OSI (Open System Interconnection) describes how computer system Wireless Fidelity (Wi-Fi) identifies any network based on the 802.11 communicates over network. standard. Transmission Control Protocol/Internet Protocol (TCP/IP) is a network Uses radio wave as communication medium protocol that defines how a message are routed in a network. 802.11 is a series of network standard that specifies how two wireless It describe rule for dividing messages into small pieces, called packets. devices communicate over the air with one another. Each packets is provided address, error check and detection, Developed by IEEE sequencing packets and regulate flow of message across network. data transfer rate ranging from 11 Mbps to 7 Gbps. Used as network standard for internet communication. Wi-FI can easily integrate with Ethernet, and works in collaboration with Application Layer TCP/IP. Transport Layer Internet Layer Network Layer Bluetooth IrDA Bluetooth is a network protocol that defines how two Bluetooth devices Infrared Data Association (IrDA) standard to transmit data wirelesly to use short-range radio waves to transmit data. each other via infrared light wave. Data transfer rate is up to 3Mbps. transfer rate between 115 Kbps to 4 Mbps. Bluetooth Devices must be within 33 Feet (~10 meters) to line of sight transmission, the sending device and the receiving device communicate. mist be in line with each other so that nothing obstruct the path of the Most OS has built in Bluetooth support. infrared light wave. RFID RFID (radio frequency identification) is a protocol that defines how a network uses radio signals to communicate with a tag placed in or attached to an object. Tag is called transponder, has antenna and chip that contains information. Communication Line Communication Lines Cable Dedicated line is a type of always-on physical connection that is Cable television (CATV) network provides high-speed internet establish between two communication devices connection called cable internet service. It can be analog or digital. CATV signal enters building through single line, E.g. coaxial cable. Digital lines connect home and business to network because they are The cable connects to modem, which connects to computer via faster than analog lines. Ethernet cable. Dedicated lines include User are home and small business. – Cable Television lines, DSL, ISDN, FTTP, T-Carrier line and ATM. https://www.digitaltrends.com/computing/different-types-of-ethernet-cables-explained/ DSL FTTP DSL (Digital Subscriber Line) uses standard copper phone wiring to FTTP (fiber to the Premises) uses fiber-optic cable to provide extremely transmit. high speed Internet Access to user’s physical permanent location. Dial tone provide both voice and data communication – Fiber to the home (FTTH) internet access via fiber optic for home user Use filter to reduce noise interference. – Fiber to the Building (FTTH) for business User: small business and home user Optical terminal at user location receives the signal and transfer them to ADSL (Asymmetric digital subscriber line) is a router connected to a computer. a type of DSL that support faster downstream rates than upstream rates. ADSL is ideal for internet access because users download more than upload. T-Carrier ATM T-Carries line is any of several types of long distance digital phone ATM (Asynchronous transfer Mode) is a service that carries voice, data lines that carry multiple signals over a single communication line. and media at very high speed. standard phone line carries only one signal Phone network, the internet and other networks with large amount of Uses multiplexing so that multiple signal share the line.. traffic uses ATM. Offer vary fast data transfer rate. Expensive only large companies can afford T1 line and fractional T1 line. Internet backbone uses T3 lines 28 times faster than T1. https://networkencyclopedia.com/asynchronous-transfer-mode-atm/  Communication Devices Communication device any type of hardware capable of transmitting data, instructions and information between a sending device and a receiving device. Sending end, the device sends data, instruction or information from the sending device to transmission end. Communication Devices Receiving end, a communication device receives the signals from the transmission media. Type of communication devices: – Dial Up modem, digital modem (ISDNm DSL and Cable), wireless modem, network cards, wireless access point, routers Digital Modem Cable Modem Broad band modem or digital modem is a communication device that Cable modem is a broadband modem that sends and receive digital sends and receives data and information to and from a digital line. data over the CATV network. Three types of broadband modem are cable modem, DSL modem and CATV provider installs a splitter at home. ISDN modem. – one part of the cable goes to the TV Modem typically have built-in Wi-Fi connectivity. – another goes to cable modem provided during installation. Modem is an external device A cable is used to connect the modem and a port on a computer. DSL Modem Wireless modem DSL modem is a broadband modem that sends digital data and wireless modem uses a mobile service provides network to connect to information from a computer to a DSL line and receives digital data and the internet wirelessly from a computer or mobile device. information from a DSL line. Wireless mode have external or built in antenna ISDN (integrated Services Digital Network) modem is a broadband available as USB adapter and other device modem that sends digital data and information from a computer to an ISDN line and receives digital data and information from an ISDN line. smartphone can function as wireless modem called mobile hot spot. PC or mobile device in tethered to the smartphone. Wireless Access Points Router Wireless access point (WAP) is a central communication device that Router is a communication device that connects multiple computers or allows computers and devices to transfer data wireless among them self other routers together and transmits data to its correct destination on a or to a wired network using wireless technology like Wi-FI. network. Have high-quality internal or external antennas for optimal signal. Router can be used in network of any size. WAP either connect to a router via an Ethernet or other cable or is part On the largest scale, router along with the Internet backbone forward of a router. data packets to their destination using the fastest available path. In smaller networks, router allows computers and devices to share a single broadband internet connection. Network cards Hubs and Switches Network card or network interface card (NIC) is a communication device Hub or switch is a device that provides a central point for cables in a that enables a computer or device that does not have built-in networking network. capability to access a network. Larger networks typically use hub, while smaller networks use switch. The card coordinates the transmission and receipt of data, instructions Some Hub and switch may include router. and information to and from the computer or device containing the network card. The hub or switch receives data from many directions and the forwards it to one or more destination. Network card for desktop is an adapter card, and for mobile is USB adapter. Transmission media Transmission media (communication channel) consist of materials or substances capable of carrying one or more communication signals. When a data send, the signal that carries the signal may travel over various transmission media. Transmission Media Broadband Latency Broadband media transmit multiple signals simultaneously. the amount latency is the time it takes a signal to travel from one location to another of data, instruction and information that can travel over transmission on a network. media sometimes is called bandwidth. Factors that affect latency is distance, transmission media type and The higher the bandwidth the more data is transmitted. number of node. For best performance, bandwidth must be high and latency should be low. Physical Transmission media Twisted Pair Cable Includes wire, cable and other tangible materials twisted pair cable is widely used transmission media for network. Used underground or within buildings. Also used in landline phone system. Ethernet and token ring uses this type of media It consist of two or more twisted pair wires bundled together. Types: each pair consist of two separate insulated copper wire. – Twisted Pair cable, coaxial cable and Fiber-optic cable Wires are twisted together to reduce noise. Noise is electrical disturbance which can degrade communication. Coaxial Cable Fiber Optic Cable Coaxial cable consist of single copper wire surrounded by at least three Fiber optic use light to transmit signals over dozens or hundreds of this layers. stands of glass or plastic. – insulating material Each strand is called optical fiber as thin as human hair with protecting – woven or braided metal coating. – plastic outer coating. Advantage: CATV network wiring often uses coaxial cable because it can cabled – Capable of carry more signal than wire cable over longer distance than twisted pair. – Faster data transmission Current network don’t use coaxial because fiber optic can transmit – Less susceptible to noise signal at faster rate. – better security and – smaller in size Wireless transmission media Infrared Wireless transmission media send communication signals through the Infrared (IR) is a wireless transmission medium that sends signals using air and space. infrared light waves. More convenient than installing cables Mobile computers and devices, such as mouse, printer, and Used in location where cable are impossible to be installed. smartphone, may have IrDA port that enable the transfer of data from one device to another. Types are infrared, broadcast radio, cellular radio, microwaves and communication satellite. Maximum transfer rate 115 Kbps to 4 Mbps. Broadcast Radio Cellular Radio Broadcast Radio is a wireless transmission medium that distributes is a type of broadcast radio that is in wide use for mobile radio signal through air over long distance or short distance. communication. transmitter to send the radio signal and receiver to accept it. wireless modem and mobile phones. Network use transceiver which send and receive signals from wireless Mobile phone uses high frequency radio waves to transmit voice and digital data messages. device. Categories of cellular radio transmission are; Broadcast radio is slower and more susceptible to noise. – 1G Provides flexibility and portability. – 2G (9.6 Kbps to 144Kbps) Example, Bluetooth, UWB and WiFi – 3G (144 Kbps to 3.84 Mbps) – 4G (Up to 100 Mbps) – 5G Microwaves Communication Satellite Microwaves are radio waves that provides a high speed signal Communication satellite is a space station that receives microwaves transmission. signals from an earth based station, amplifies the signal and Fixed wireless broadcaster signals back over a wide area to any number of earth based stations. send signal from one microwave station to another each based station can be microwave station, smartphone and GPS microwave station is an earth based reflective dish that contains the receivers. antenna, transceivers and necessary equipment. Up-link is transmission from earth based station to a satellite Like infrared, microwave uses line of sight transmission. Down-link is transmission from satellite to earth based station. Situated on top on building or mountains to avoid obstruction. Transfer rate: up to 2.56 Tbps Transfer rate: up to 10 Gbps Cont.. Summary Application that uses communication satellite are: Various types of networks and communication technologies air navigation, television and radio broadcast, weather forecast, video Network architectures conferencing, paging, GPS and Internet connections. Standards and protocols Satellite modem together with satellite dish, allows user to access the Communication lines and communication devices internet using satellite technology. Transmission media. Satellite internet connection is used in remote areas and expensive.