Presentation on different modes of data communication
- 1. Presentation Topic: The Different Modes Of Data Communication Presented by: Simranjeet Kaur (94972346431) Simranjeet Singh (94972346433) Sunil Singh (94972346445) Tafadzwa Gonera (94972346447)
- 2. Contents • Introduction the data communication • Protocol models of data communication • Communication channels • Wired communication • Wireless communication • Conclusion
- 3. Definition of data communication • It is the physical transfer of data (a digital bit stream) over a point to point to multipoint communication channel. • Examples of such: optical fibre, copper wires, wireless communication channels ,etc. • Data is represented as an electromagnetic signal, such as voltage, microwave, etc.
- 4. Protocol models • The Open Systems Interconnection (OSI Model) is a way of subdividing a communications system into smaller parts called layers • A layer is a collection of conceptually similar functions that provide services to the layer above it and receives services from the layer below it
- 5. TCP/IP Model • It is a description framework for computer network protocols created in the 1970s by DARPA • The TCP/IP model, or Internet Protocol Suite describes a set of general design guidelines and implementations of specific networking protocols
- 6. Definition of communication channel • It refers to either a physical transmission such as a wire or to a logical connection over a multiplexed medium such as a radio channel • A channel is way to convey a message • Modes of transmission are: simplex, half duplex or full duplex • Types of transmission are: parallel and serial
- 7. Wired communication • A type of LAN technology which is based on a special type of cable which is used to transfer data • The maximum data transfer rate of this technology is 10Mbps • The cables used to configure the network are special. Examples are Ethernet and wired LAN
- 8. Coaxial cables • It is an armored cable with sheathed plastic that contains two concentric conductors or wires • It is used primarily for TV standard-definition connection • It is used to implement computer networks like Ethernet • It is also used to connect radio networks
- 9. A diagram of a coaxial cable:
- 10. Advantages • It has sufficient frequency to support multiple channels • Each of the multiple channels offers substantial capacity • Inner conductor is in a Faraday shield, therefore noise immunity is reduced
- 11. Disadvantages • Signal leakage • Imperfect shield of coaxial cable can causes visible or audible interference • External current sources like switched-mode power supplies create a voltage across the inductance • Common mode current occurs when stray currents in the shield flow in the same direction as the current
- 12. Fiber optic cables • The fiber optical consists of several thin fibers of glass or plastic of 50 to 125 micrometers of diameter • They are used in fiber optic communications which permit transmission over longer distances and at higher bandwiths
- 13. A diagram of fiber optic cable:
- 14. Advantages • Data transmission is incredibly fast • Fiber optic cables are not susceptible to RF (Radio Frequency) interference • Fiber optic cables can transmit data over exceptionally long distances with much data loss • Wiretapping is more difficult compared to electrical connections
- 15. Disadvantages • Fiber optic cabling can cost more than double what a typical broadband connection costs • Fiber optic connections are not available in many areas. Currently, this is one of the biggest disadvantages
- 16. Twisted pair cables • Twisted pair cabling is a type of wiring in which two conductors (the forward and return conductors of a single) are twisted together to cancel electromagnetic interference • Unshielded twisted pairs (UTPs) are mainly used in Ethernet and telephone systems • They are also used for indoor applications
- 17. A diagram of twisted pair cable:
- 18. Advantages • It is thin, flexible cable that is easy to string between walls • More wires can be run through the same wiring ducts. • UTP costs less per meter/foot than any other type of LAN cable
- 19. Disadvantages • UTPs susceptibility to electromagnetic interference greatly depends on the pair twisting schemes • In video applications that send information across multiple parallel signal wires, twisted pair cabling can introduce signaling delays known as skew which results in color defects and ghosting
- 20. Wireless communication • Wireless communication uses radio frequencies (RF) or infrared (IR) waves to transmit data between devices on LAN • Key components are a wireless hub, or access point used for signal distribution • Wireless signals are electromagnetic waves that can travel through a vacuum of outer space
- 21. Bluetooth • It is a proprietary open wireless technology standard for accessing data over short distances • Bluetooth uses short wavelength radio transmission to create PANs • Range of data transfer is power dependent i.e. 100m,10m and 1m but ranges may vary
- 22. Uses • Wireless control of and communication between a mobile phone and a hands free headset • Wireless networking between PCs in a confined space • Wireless communication with PC IO devices • Transfer of files, contact details, calendar appointment and reminders between devices
- 23. Advantages • It has a high level of compatibility among devices • It will connect to devices that are not of the same model • It almost always avoids interference from other wireless devices • It is doesn’t a line of sight connection it provides ranges of up to 100meters
- 24. Disadvantages • Infrared has data rates of up to 4 Mbps while Bluetooth only offers 1 Mbps • The greater range and radio frequency (RF) of Bluetooth makes it susceptible to interception and attack
- 25. WiMAX • Worldwide Interoperability for Microwave Access is a telecommunications protocol that provides fixed and mobile internet access • It provides up to 40 Mbps with IEEE 802.16m expected to offer up to I Gbps • It’s a standards based technology enabling the delivery of last mile wireless broadband access
- 26. Uses • Provides portable mobile broadband connectivity across cities and countries • Provides a wireless alternative to cable and DSL for last mile broadband access • Provides data, telecommunication (VoIP) and IPTV services • Provides a source internet connectivity as part of a business continuity plan
- 27. Advantages • A single station can serve hundreds of users • Much faster deployment of new users comparing to wired networks • Speed of 10Mbps at 10kilometers within line- of-site • It is standardized, and the same frequency equipment should work together
- 28. Infrared • (IR) Infrared Light is electromagnetic radiation with a wavelength between 0.7 and 300 micrometers, which equates to a frequency range between approximately 1 and 430THz • IR wavelengths are longer than that visible light, but shorter than that of terahertz radiation microwaves
- 29. Uses • It is employed in short range communication among computer peripherals and PDAs • It is used for remote controls to command appliances
- 30. Advantages • Low power requirements: therefore ideal for laptops, PDAs and cellphones • Low circuitry cost • Installation is easy because no proprietary hardware is needed • Higher security • High noise immunity
- 31. Disadvantages • Performance drops off with longer distances • It is weather sensitive: data transmission is poor is direct sunlight, rain, fog, dust ,etc. • Data rate transmission is lower than typical wired transmission • Data transmission is possible in the line of sight: transmitters and receivers should be aligned
- 32. Wi-Fi • Wi-Fi is a wireless technology that uses radio waves to provide wireless high-speed internet and network connections • Wi-Fi alliance defines Wi-Fi as any “wireless local area network (WLAN) products that are based on the IEEE 802.11 standards” • The cornerstone of any wireless network is an access point (AP)
- 33. Advantages • Wi-Fi allows the deployment of LANs without wires for client devices • Deployment of WLANs reduces the costs of network deployment and expansion • Wi-Fi is becoming widespread and easily accessible in the corporate infrastructures • Different brands of access points and client network interfaces can interoperate
- 34. Advantages • Wi-Fi Alliance are backwards compatible • Current version Wi-Fi protected access encryption is considered secure • Powers saving mechanisms such as WMM power save improve battery operation
- 35. Disadvantages • Spectrum assignments and operational limitations are not consistent worldwide • The most common wireless encryption- standard, Wired Equivalent Privacy is not secure • Mobile use of Wi-Fi over wider range is limited • Congestion
- 36. Conclusion • Wired technology is more secure, reliable, cheaper and has higher data transmission rates over wireless technology but one huge advantage that has made wireless technology popular is mobility.
- 37. The End