1. Telecommunications, the Internet, and Wireless Technology
Chapter 7 (Part 1)
Telecommunications, the Internet, and Wireless Technology

2. Networking and Communication Trends
Convergence:
Telephone networks and computer networks converging into single digital network using Internet standards
E.g. Mobile phone operators in Bangladesh offer voice service, and internet access
Broadband wired internet access:
Digital Subscriber Line, Optical fiber etc.
Broadband wireless internet access:
Mobile broadband: GSM, EDGE, 3G, 4G (WiMAX)
WiMAX: Provided by Qubee, Banglalion. This technology also offers Wi-Fi
This slide discusses recent developments in networking technologies. Ask students to give other examples of convergence. How fast is broadband today? Do all of the students have broadband? Note that in 2000, typical Internet access speeds were 56 kbps over a telephone line, costing 25 cents per kilobit, while today broadband speeds are 1-15 mbps, costing less than 1 cent per kilobit. Are students aware of how fast their Internet connections are at home, school, or work? Ask students if they know the speed of their cell phone’s Internet connection. The point here is to try and raise student awareness of telecommunications systems, and their capacities.

3. What is a computer network?
A computer network consists of two or more connected computers
Major components in simple network
Client computer- Computers used by end users
Server computer- Central computer that provides connections to client computers, serves web pages, stores data, and stores Network Operating System
Network interfaces device (refer to the picture on next slide)
Connection medium- Telephone wire, Coaxial cable, Wi-Fi
Network operating system (NOS)- Routes and manages communications on the network
Hub or switch- Acts as a connection point between computers
Routers
Device used to route packets of data through different networks, ensuring that data sent gets to the correct address
This slide describes what a network is along with the components that you will find in a simple network (illustrated on the next slide.) Ask students to describe the function of a NIC. What is a connection “medium”? Ask students to describe the purpose of a hub, switch, and router.

4. Network Interface Device
This slide describes what a network is along with the components that you will find in a simple network (illustrated on the next slide.) Ask students to describe the function of a NIC. What is a connection “medium”? Ask students to describe the purpose of a hub, switch, and router.

5. Telecommunications and Networking in Today’s Business World
COMPONENTS OF A SIMPLE COMPUTER NETWORK
This graphic illustrates the components of a simple network. While the NOS is shown as part of the server, note that, depending on the type of software, an NOS may also be designed to reside on client computers. Do some students have a home computer network? Ask them to describe the elements of the network.
Illustrated here is a very simple computer network, consisting of computers, a network operating system residing on a dedicated server computer, cable (wiring) connecting the devices, network interface cards (NICs), switches, and a router.
FIGURE 7-1

6. Components of networks in large companies
Company grows and accumulates hundreds of small networks in each location
Hundreds of local area networks (LANs) can be linked to each other and to firm-wide corporate network on different locations
Various powerful servers support
Web site
Corporate intranet, extranet
Back-end systems
Mobile wireless LANs (Wi-Fi networks)
Videoconferencing system
Telephone network
Wireless cell phones
This slide looks at the additional components one might expect to find in the network of a large company that has many locations and thousands of employees (illustrated on the next slide). Ask students what is meant by “backend systems.” Note that many firms are dispensing with traditional landline telephone networks and using Internet telephones that run on existing internal data networks and the Internet.

7. Components of networks in large companies
This graphic illustrates the components of a large company’s network. Note the difference between the wireless LAN, which allows wireless access within the office, and the mobile Wi-Fi network, which allows Internet access to employees outside of offices. The advantage of telephone-based wireless systems is that they do not require a Wi-Fi hotspot to work, and in fact can connect users to the entire globe through their telephone networks. Cable networks – major competitors of telephone company Internet providers – do not really have a mobile option although Optimum Cable (Comcast) and several other firms are developing a Wi-Max capability that could potentially serve an entire metropolitan area. This development will take many years, and in 2010 many Wi-Max metropolitan experiments were behind schedule. Towerstream is one of the largest Wi-Max providers in the U.S. and in 2011 announced it was developing coverage for Middleton, Rhode Island, and starting an installation in Manhattan (New York City). You might ask a group of students to do research on Wi-Max in U.S. cities and report back to the class. Towerstream.com is a good place to start.
Today’s corporate network infrastructure is a collection of many different networks from the public switched telephone network, to the Internet, to corporate local area networks linking workgroups, departments, or office floors.
FIGURE 7-2

8. Key networking technologies
Client/server computing
Distributed computing model in which some of the processing power is located within client computers
Clients are linked to each other through a network controlled by a network server computer
Server sets rules of communication for network and provides every client with an address so others can find it on the network
Client/server computing is used among departments, factory floors etc.
This slide and following two slides look at the main technologies in use today for networks: client/server computing, packet switching, and TCP/IP. Ask students what advantages client/server computing has over centralized mainframe computing.

9. Key networking technologies
Packet switching
Method of slicing digital messages into parcels (packets), sending packets along different communication paths as they become available, and then reassembling packets at destination
Previous circuit-switched networks required assembly of complete point-to-point circuit. This was very expensive. Example: Telephone system.
Routers are used for packet switching.
This slide continues the discussion of the three main networking technologies today, looking at the second, packet switching. Note that circuit-switched networks were expensive and wasted available communications capacity – the circuit had to be maintained whether data was being sent or not. It is also important to note that packet switching enables packets to follow many different paths. What is the advantage of this capability?

10. Telecommunications and Networking in Today’s Business World
PACKED-SWITCHED NETWORKS AND PACKET COMMUNICATIONS
This graphic illustrates how packet switching works, showing a message being split into three packets, sent along different routes, and then reassembled at the destination. Note that each packet contains a packet number, message number, and destination.
FIGURE 7-3
Data are grouped into small packets, which are transmitted independently over various communications channels and reassembled at their final destination.

11. Key networking technologies
TCP/IP and connectivity
Connectivity between computers enabled by protocols
Protocols: Rules that govern transmission of information between two points in a network. Before TCP/IP there were incompatible protocols from several vendors
Transmission Control Protocol/Internet Protocol (TCP/IP)
Common worldwide standard for Internet
TCP
-establishes a connection between the computers
-sequences the transfer of packets
-acknowledges the packets sent IP
-responsible for delivery of the packets
-includes disassembling and reassembling of packets during transmission
This slide continues the discussion of the three main networking technologies in use today, and looks at the third, TCP/IP. Note that in a network, there are typically many different types of hardware and software components that need to work together to transmit and receive information. Different components in a network communicate with each other only by adhering to a common set of rules called protocols. In the past, many diverse proprietary and incompatible protocols often forced business firms to purchase computing and communications equipment from a single vendor. But today corporate networks are increasingly using a single, common, worldwide standard called Transmission Control Protocol/Internet Protocol (TCP/IP). TCP/IP actually is a suite of protocols, the main ones of which are TCP and IP. Ask students what these two main protocols are responsible for.

12. Different types of networks
Local-area network (LAN)
It is used to connect computers and other devices within a meters distance. This is widely used in an office environment.
One computer is a dedicated network file server, providing users with access to shared computing resources in the network, including software and data files
The server controls user access
The router connects the LAN to other networks, which could be the internet or another corporate network. This way LAN can exchange information with external network.
Network Operating Systems (NOS) for LAN are Windows, Linux
LAN architectures
-Client/server architecture is for 11 or more computers
-Peer-to peer architecture is for 10 or fewer computers
This slide looks at the types of networks that organizations use. Ask students what the differences are between digital and analog signals. Another example of the difference between analog and digital signals is the difference between vinyl records and digital CDs and MP3s. Ask students to describe and distinguish between LANs, CANs, WANs, and MANs, and also to talk about their different range of operation. Note that a network can be defined by the way the clients interact (client/server vs. peer-to-peer); the type of physical medium to carry signals (Ethernet, Fast Ethernet, etc.), and the way in which computers are connected and send signals to each other (topology).

13. Different types of networks
Wide Area Networks (WANs)
It is a collection of multiple LANs. Cover broad geographical distances- an entire region, or the entire world. The most powerful WAN is internet.
Example of regional WAN: Network of ATMs
This slide looks at the types of networks that organizations use. Ask students what the differences are between digital and analog signals. Another example of the difference between analog and digital signals is the difference between vinyl records and digital CDs and MP3s. Ask students to describe and distinguish between LANs, CANs, WANs, and MANs, and also to talk about their different range of operation. Note that a network can be defined by the way the clients interact (client/server vs. peer-to-peer); the type of physical medium to carry signals (Ethernet, Fast Ethernet, etc.), and the way in which computers are connected and send signals to each other (topology).