C7- Telecommunications, The Internet, and Wireless Technology

Networking and Comm. Trends A networking and communications revolution led by Internet-based technologies Convergence of telephone and computer networks Voice and data communication networks are becoming faster, more portable, and less expensive Telecommunications and Networking in

7-3 What is a computer network? Consists of two or more connected computers Each computer contains a network interface card (NIC)‏ The connection medium –telephone wire, coaxial cable, or radio signal in the case of cell phone and wireless local area networks Network Operating System (NOS)‏ –Routes and manages communications on the network and coordinates network resources Dedicated server computer Hubs Routers

7-4 What is a computer network?... Most networks contain a switch or a hub acting as a connection point between the computers –Hubs are simple devices that send packets of data to all other connected devices –Switches can filter and forward data to specified locations with some intelligence Routers send packets of data though different networks

Figure 7-1 Where is the Client computers Network operating system Server computer Cable (wiring) Network interface cards (NICs) Switches, and a router. 7-5 A Simple Network

7-7 Corp. Network Infrastructure

Client/Server Computing A distributed processing model –some processing power is located within small, inexpensive client computers –The clients are linked to one another The network is controlled by a network server computer –The server sets the rules of communication for the network –provides every client with an address so others can find it on the network 7-8 Key Digital Network Technologies Client/Server Computing Packet Switching TCP/IP and Connectivity

Packet Switching 7-9 Key Digital Network Technologies 1.Message broken down to packets 2.Sent through different communication path 3.Reassembled at destination

TCP/IP Protocol TCP/IP uses a suite of protocols: –TCP: Transmission Control Protocol – establish a connection –IP: Internet Protocol – handles delivery of packets set of rules governing transmission of information- used by and all Internet devices TCP/IP provides for breaking up digital messages into packets, routing them to the proper addresses, and then reassembling them into coherent messages Key Digital Network Technologies

7-17 Communications Networks A WAN may take on a derivative name such as MAN (metropolitan area network) simply to describe its physical location.

7-25 The Global Internet It is a network –Links hundreds of thousands of individual networks all over the world –Composed of computers and other devices that are logically linked together by a unique address space based on Protocol –Where devices are able to support communications using TCP/IP –That provides high-level services layered on a communication and network infrastructure Most homes connect to the Internet by subscribing to an Internet Service Provider (ISP)‏

7-30 Internet Services & Comm. Tools Person-to-person messaging; document sharing Usenet newsgroups: Discussion groups on electronic bulletin boards Chatting and instant messaging: Interactive conversations VOIP: Telnet: Logging on to one computer system and doing work on another FTP: Transferring files from computer to computer World Wide Web: Retrieving, formatting, and displaying information (text, audio, video, graphics) using hypertext links

Internet Features Hypertext –Standard for Web pages HTML –Web browsers request web pages using HTTP protocol Searching information –Search engines –Intelligent agents shopping bots –Web logs (blogs)‏ –Semantic web

Technologies And Tools Intranets and Extranets Intranet: –an internal organizational network that provides access to data across the enterprise –Protected from public visits by firewalls Extranet: –Authorized visitors (vendors, customers) are given limited access to an internal intranet Virtual Private Networks (VPN) A private network configured within a public network to take advantage of economies of scale and facilities of larger networks Secure connection between two points on Less expensive, more flexible, greater bandwidth than non-IP networks For Communication And E-business

The Wireless Revolution Mobile phones are now platforms for delivering digital data, used for recording and downloading photos, video and music, Internet access, and transmitting payments An array of technologies provides high-speed wireless access to for PCs and other wireless handheld devices and cell phones Businesses increasingly use wireless to cut costs, increase flexibility, and create new products and services

Wireless Transmission Media and Devices All wireless media rely on various parts of the electromagnetic spectrum Microwave systems transmit high-frequency radio signals through the atmosphere Communication satellites are used for geographically dispersed organizations Blackberry: handheld PDAs: small handheld computers –electronic scheduler Cellphones: use radio waves to communicate with towers in cells –message passed from cell to cell Smartphones: can save information, access Internet

Mobile Wireless Standards for Web Access Wireless Application Protocol (WAP): Uses Wireless Markup Language (WML) and microbrowsers Bluetooth –Creates small Personal Area Networks (PAN) –Can link up to 8 devices in 10-m area –Low power requirements

Wi-Fi Three standards: a, b, g Infrastructure mode: Devices use access point to communicate with wired network Ad-hoc mode (peer- to-peer): Wireless devices communicate directly with each other Benefits of Wi-Fi –Low-cost to provide Internet access to conference rooms, workstations –Allows hot-spots in public areas such as university campuses, airports … Challenges –Security –Susceptibility to interference

An Wireless LAN

How RFID Works

Wireless in Heath Care Electronic Medical Record (EMR) retrieval Wireless note taking for patient charts Lab test results Prescription generation Medical databases

Wireless Technology In The Enterprise Pervasive Computing –Wireless technologies are pushing computing into every facet of life, including cars, homes, office buildings, tools and factories; providing connections anywhere and anytime Wireless sensor networks (WSNs) –Networks of interconnected wireless devices that are embedded into the physical environment to provide measurements of many points over large spaces