c7- telecommunications, the internet, and wireless technology

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

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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

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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.

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A Simple Network

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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

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Key Digital Network

Technologies

Client/Server

Computing

Packet Switching

TCP/IP and Connectivity

Packet Switching

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Key Digital Network Technologies

1. Message broken down to packets2. Sent through different communication path3. 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

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Communications Networks

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

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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)

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Internet Services & Comm. Tools

• E-mail: 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: email 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: 802.11a, 802.11b, 802.11g

• 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 802.11 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