Basic concepts of wireless communication system
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This document provides an overview of basic concepts in wireless communication systems, including definitions of computer networks, networking, transmission media, distributed systems, and client-server models. It describes common network devices, topologies, protocols, and the differences between local and wide area networks.
Basic concepts of wireless communication system
- 1. Basic Concepts of Wireless Communication System Prepared by: Mr. Gilbert De Castro
- 2. Computer Networking Data Communication Transmission Media Distributed System Objectives
- 3. Basic Principle of Networks Computer network Collection of computers and devices connected via communications devices and transmission media Bunch of computers hook together in some way Each particular message is usually routed to a particular computer
- 4. Basic Principle of Networks Networking Is the problem of delivering a message from a source to a destination The problem of giving meaning to these messages received is called communication
- 5. Use of Computer Networks Networks for Companies Resource sharing – Saves time and money. Dynamic rerouting – Having alternative source of supply data Basic Principle of Networks
- 6. Networks for people Access to remote information – Great source of information Person-to-person communication Interaction between a person and a database Person-to-person interaction Interactive entertainment Network gaming Video-on-demand Basic Principle of Networks
- 7. Advantages of networking Connectivity and communication Data sharing Hardware sharing Internet access Internet access sharing Data security and management Performance enhancement and balancing Entertainment Basic Principle of Networks
- 8. Basic Principle of Networks Communication channel Is a pathway over which information can be transferred Information sent over a channel has source (often called the transmitter), from which the information originates And destination (often called the receiver), to which the information is delivered Channel
- 9. Communication channels Any communication has a direction associated with it Simplex channel – is a channel whose direction of transmission is unchanging Half-duplex channel – is a channel in which the direction may be reversed, but the transmission does not occur at the same time Full-duplex channel – is a channel that allows simultaneous exchange in both directions Basic Principle of Networks
- 10. Types of Transmission Technologies Point-to-point network – consist of many connections to individual pairs of machines Broadcast networks – all the machines on the network share a single channel Basic Principle of Networks
- 11. Network Topologies Computer networks come in different shapes and sizes The network’s topology can be thought of as its “shape”, the way the computers on the network are connected Network topologies are categorized into the five basic types Basic Principle of Networks
- 12. Characteristics of effective data communication Delivery Accuracy Timeliness Basic Principle of Networks
- 13. Components of data communication Message Sender Receiver Medium Protocols Basic Principle of Networks
- 14. Protocol Formal description of set of rule sand conventions that govern how devices on a network communicate Control aspects of data communication, which include the following: How the physical data is built How computers connect to the network How the data is formatted for transmission How the data is sent How to deal with errors
- 15. Basic Principle of Networks Network Topologies Bus network A common channel connect all devices All computers and devices connect to central cable, or bus
- 16. Basic Principle of Networks Ring network All messages travel in a ring, either in clockwise or counterclockwise direction Cable forms closed ring, or loop, with all computers and devices arranged along ring Data travels from device to device around entire ring, in one direction
- 17. Basic Principle of Networks Star network All devices connect to a central device, called hub All data transferred from one computer to another passes through hub
- 18. Basic Principle of Networks Tree network - Integrates multiple star topologies together into a bus
- 19. Basic Principle of Networks Mesh network – involves the concept of routes, where a message is sent on the network can take any of several possible paths from source to destination Popular topologies are bus, ring, and star
- 20. Communications device Hardware component that enables a computer to send and receive data, instructions and information Occurs over cables, telephone lines, cellular radio networks, satellites, and other transmission media
- 21. Communication Devices Modem Network Card Gateway Router Wireless Access Point Hub
- 22. Modem • Converts digital signals to analog signals and vice versa Dial up modem ISDN and DSL modems Wireless modem
- 23. Network Card Adapter card, PC Card, or flash card that enables computer or device to access network Sometimes called network interface card (NIC)
- 24. Gateway Links network using different protocols Contain devices such as protocol translators
- 25. Router Connects multiple networks and determines the fastest route for sending data over the network
- 26. Wireless Access Point Connects wireless communication devices
- 27. Hub • Device that provides central point for cables in network
- 28. Communication Channel Transmission media on which data travels in communications system Transmission media - are materials capable of carrying one or more signals Bandwidth - amount of data that can travel over a communications channel Physical Transmission Media Wireless Transmission Media
- 29. Physical Transmission Media Wire, cable, and other tangible materials used to send communications signals Twisted-pair cable Coaxial Cable Fiber-optic cable
- 30. Twisted-pair cable Used for telephone systems and network cabling
- 31. Coaxial Cable Often used for cable television wiring
- 32. Fiber-optic cable Capable of carrying significantly more data at faster speeds than wire cables Less susceptible to interference (noise) and, therefore, more secure, Smaller size (thinner and lighter)
- 33. Wireless transmission media Radio Signal Microwaves Satellites IrDA Bluetooth Wi-Fi
- 34. Radio Signal Broadcast radio distributes radio signals over long and short distances Cellular radio is form of broadcast radio used for mobile communications
- 35. Microwaves Earth-based reflective dish used for microwave communications Must transmit in straight line with no obstructions
- 36. Satellites Space station that receives microwave signals from earth-based station, amplifies signals, and broadcasts signals back to any number of earth- based stations
- 37. IrDA ( Infrared Data Association) Physical specifications communications protocol standards for the short-range exchange of data over infrared light waves
- 38. Bluetooth Short-range radio waves transmit data between Bluetooth devices Short distance transmission of about 30 feet
- 39. Wi-Fi Wireless Fidelity Connecting electronic devices wirelessly
- 40. Basic Principle of Networks Distributed Systems There is considerable confusion between a computer network and a distributed system The key distinction is that in a distributed system, the existence of multiple autonomous computers is transparent to the user The user can type a command to run a program, and it runs It is up to the operating system to choose the best processor for the application, send the necessary data and place the result to the proper location
- 41. Basic Principle of Networks Client/Server Extension of distributed data processing wherein it provides the best of both centralized and distributed data processing Client – issues a request to a server to ask for work to be done Server – usually a host machine that provides database, printing, storage and communications
- 42. Basic Principle of Networks Types of network design The networking industry refers to nearly every type of network as an “area network”. Local Area Network (LAN) Wide Area Networks (WAN)
- 43. Basic Principle of Networks Local Area Network (LANs) Connect network devices over relatively short distances Usually owned by an individual or corporation Network in limited geographical area such as home or office building
- 44. Basic Principle of Networks Wide Area Networks (WANs) Span a large physical distance (geographically-dispersed collection of LANs) and mostly owned by any one organization but rather exist under collective or distributed ownership and management Network that covers large geographic area using many types of media Internet is world’s largest WAN