Telecommunications, the Internet, and Wireless Technology - PowerPoint PPT Presentation


Title: Telecommunications, the Internet, and Wireless Technology


1
Telecommunications, the Internet, and Wireless
Technology
  • Chapter Seven (10th ed)

2
Why Is Business Interested in Telecommunication
and Networking?
  • Declining transaction costs (benefits of B2C and
    B2B)
  • Declining agency costs because managers can
    monitor employees and markets remotely
  • Increased agility (connections with suppliers and
    customers enables managers to spot trends and
    take appropriate actions). Concepts like
    extranets, collaborative commerce, intranets
    support this idea.
  • Higher quality management decisions (access to
    more information in a timely manner)
  • Declining geographical barriers
  • Declining temporal barriers (software
    development, time-based competition)

3
Telecommunications and Networking in Todays
Business World
  • Prior to 1990 most business communication
  • Postal service
  • Telephone system (voice fax)
  • Today most business communication is
  • Computers and email using the Internet
  • Cellular telephones
  • Mobile computers using wireless connections
  • All business has become e-business

4
Magnitude of the Change
  • 1 billion instant messages per day
  • 4 billion e-mails each day
  • 65 million music files downloaded
  • Estimated 3.9 billion photos sent over the
    Internet
  • 769 billion spent in the United States on
    telecommunications equipment and services

5
Telecommunications spending in the United States,
20022007
Note differences between services and equipment
spending
6
Basic Network Components
  • A network consists of two or more connected
    computers.
  • A network interface device (NIC) is the
    connection point between one computer and the
    network
  • A network operating system (NOS) routes and
    manages communications on the network and
    coordinates network resources (saving or
    retrieving files on your hard drive versus a
    network drive)

7
Basic Network Components (continued)
  • Hubs connect network components, sending a packet
    of data to all other connected devices
  • A switch has more intelligence than a hub and can
    forward data to a specified device or
    destination. The switch is used within a given
    network to move information.
  • Unlike a switch, a router (bridge) is a special
    communications processor used to route packets of
    data through different networks, ensuring that
    the message sent gets to the correct address. A
    router connects a LAN to the Internet.

8
A Simple Network
9
Corporate Network Infrastructure
10
Pieces in the Corporate Infrastructure
  • Center piece is a collection of linked LANS that
    support a firm wide corporate network
  • A series of servers supporting a corporate web
    site linked to enterprise and legacy systems
  • Support for a mobile sales force
  • Separate telephone network (cell and landline)
  • Separate video conferencing system (not shown)
  • Currently no one vendor can supply all of the
    services required
  • How does a manager navigate through this complex
    environment and make the right decisions?

11
Data and Signals
  • Digital data (1s and 0s) are represented by a
    discrete non-continuous wave form.
  • Analog data is represented by a continuous wave
    form. The human voice, music, and noise are
    examples of analog data.
  • From a physical point of view, data can converted
    to an electric (carried over a wire) or
    electromagnetic (stream of photons) signal
  • Usually digital signals convey digital data and
    analog signals convey analog data.
  • In telecommunications there is a need to convert
    digital data to an analog signal and vice versa.
  • Computers emit digital data but parts of the
    telephone system only transmit analog signals, so
    digital data must be converted into an analog
    signal and vice versa (need for your modem)

12
More on Signals
  • All signals can be represented as a sine wave
    (curve).
  • The amplitude of a sine wave is the maximum
    height of the sine wave from the x-axis
  • The frequency of a sine wave is the number of
    times a sine wave makes a complete cycle within a
    given time frame.
  • Cycles per second is referred to as Hertz (Hz)
  • Digital data can be converted to a digital signal
    by using two different voltages.
  • Digital data can be converted to an analog signal
    by using either two different frequencies or two
    different amplitudes.
  • The greater the frequency of a signal, the higher
    the possible data transfer rate the higher the
    desired data transfer rate, the greater the need
    signal frequency.

13
Electromagnetic Signals
  • Electromagnetic signals can be described in terms
    of a stream of photons each traveling in a
    wave-like pattern, moving at the speed of light
    and carrying some amount of energy. The only
    difference between radio waves, visible light,
    and gamma-rays is the energy of the photons.
    Radio waves have photons with low energies,
    microwaves have a little more energy than radio
    waves, infrared has still more, then visible,
    X-rays, and gamma-rays. Low energy photons (such
    as radio) behave more like waves, while higher
    energy photons (such as X-rays) behave more like
    particles.
  • The electromagnetic spectrum can be expressed in
    terms of energy, wavelength, or frequency. Each
    way of thinking about the EM spectrum is related
    to the others in a precise mathematical way (see
    next slide).

14
The Relationship Between Wave Length and Frequency
15
Modulation
16
Frequency Spectrum for Electromagnetic Signals
TV 54M - 216 MHz
TV 220M - 500 MHz
AM 550K - 1650 KHz
FM 88M - 108 MHz
Navy/submarines
ELF
VLF
LF
MF
HF
VHF
UHF
Microwave
Optical
Hertz
100
1K
100K
1M1M
10M
100M
1G
10G
  • All waves behave similarly
  • Frequency differences
  • Amount of data
  • Distance
  • Interference / Noise

Public Safety 150M - 160 MHz
Public Safety 460M - 500 MHz
Cellular phones 800 MHz
Cordless phones (some) 900 MHz
PCS ET 2 GHz
Pers. Com. Sys (PCS) 1.85 G - 2.2 GHz
17
Client/Server Computing
  • The hardware side
  • The client
  • The server
  • The software side
  • Client/server software splits the processing of
    applications between the client and server to
    take advantage of strengths of each machine
  • E-mail and browsers are examples
  • Client/server computing has largely replaced
    centralized mainframe computing

18
Packet Switching
  • In packet-switched networks, messages are first
    broken down into small bundles of data called
    packets that are sent along different
    communication paths and then reassembled once
    they reach their destinations.
  • Packet switching makes more efficient use of the
    communications capacity of a network.
  • The packets include information for directing the
    packet to the right address and for checking
    transmission errors along with the data.
  • Always done on the Internet, but restricted to
    data now being used for voice (VoIP)

19
Packet Switching
20
TCP/IP
  • TCP/IP is the communications protocol used by the
    Internet and all Internet devices.
  • TCP (transmission control protocol) part
  • Handles the movement of data between computers
  • Establishes a connection between the computers,
    sequences the transfer of packets, and
    acknowledges the packets sent
  • IP (Internet protocol) part
  • Responsible for the delivery of packets
  • Includes the disassembling and reassembling of
    packets during transmission

21
Internet Protocol Numbers (IPv4)
  • Each device attached to the Internet has an IP
    number (some static/some dynamic)
  • Each IP number consists of four parts separated
    by periods. Each part contains a number between
    0 and 255 therefore each part can be represented
    by 8 bits or 32 bits for the entire IP number
    (e.g., 146.186.87.220).
  • Approximate number of devices able to be on the
    Internet is 232 or
  • 210 210 21022103103103221094 (4 billion)
  • The process of associating an IP number with a
    character based name is called domain name
    resolution. The domain name system (DNS) is the
    software that associates character based names
    with the IP number. Internet Service Providers
    (ISPs) usually dedicate a server to perform
    domain name resolution (i.e., a DNS server).
  • To determine speed of your connection
    http//www.ip-adress.com/speedtest/
  • To determine your IP number http//www.What
    ismyIpaddress.com

22
Transmission Media Wire Or Wireless
  • Wire media
  • Twisted Wire up to 100Mbps
  • Coaxial Cable up to 1 Gbps
  • Fiber Optics up to 6Tbps
  • Uses strands of glass and pulses of light
  • Most expansive of three can carry data, voice,
    and video efficiently
  • Wireless media
  • Terrestrial microwave 100 Mbps
  • Satellite microwave GEO (geostationary earth
    orbit) about 22,000 miles above earth
  • Satellite microwave LEO (low earth orbit) about
    400-1000 miles above earth

23
Transmission Speeds
  • Digital signal speeds are usually expressed in
    bits per second (Kbps, Mbps, and Gbps).
  • Analog signal speeds are usually expressed in
    frequency per second or Hertz (KHz, MHz, or GHz).
  • A simple relationship between bps and frequency
    is found in Nyquists theorem
  • C2f(log2)L where f is the frequency, L is the
    number of signal levels (often 2) and C is the
    capacity of the medium in bps
  • The range of frequencies accommodated on a
    particular medium is called its bandwidth. For
    example, current cell phones operate in a
    bandwidth between 1.85 GHz and 2.2 GHz

24
Multiplexing Concept
  • A channels is a path followed by a flow of
    information (stream of bits). The information is
    carried by a digital or analog signal.
  • Multiplexing involves using a single
    communications channel to carry simultaneous
    transmissions from multiple sources.
  • Examples
  • Frequency division multiplexing divides a high
    speed channel into multiple channels of slower
    speeds (FDMA code division multiple access)
  • Time division multiplexing assigns the sender
    transmitter a small slice of time to use the high
    speed channel (TDMA)
  • Code division multiplexing assigns each user a
    special code enabling multiple users on a single
    channel (CDMA)

25
Types of Networks by Geographic Scope
26
LANs
  • Typical LAN operating systems are Windows
    (based), Linux, or Novell each supports TCP/IP
    (ease of establishing an intranet)
  • Ethernet is a LAN standard contained on the NIC
  • LANs may use the client-server or peer-to-peer
    architecture (all computers can share resources
    directly)
  • In the client-server model
  • NOS is primarily on the server
  • Large LANs often have many servers each dedicated
    to a specific function (e.g., print server, file
    server, Web server)
  • LAN topologies (shapes)
  • Star
  • Bus
  • Ring
  • Wired LANs versus wireless LANs

27
LAN Topologies
28
Broadband Network Services and Technologies
  • These technologies are for high-speed
    transmission or access to the Internet and
    provided by telecom companies
  • Services
  • Frame relay is like packet switching but faster
  • Digital subscriber lines (DSL) operate over
    existing phone lines and carry voice, data, and
    video. Provided by phone company
  • Cable internet connection is provided by cable tv
    vendors using same wires used for cable tv
  • T1 lines are high speed high volume lines
    supplied by telephone companies that are used by
    firms to move large volumes of voice and data
    traffic with strong security and reliability

29
Broadband Network Services and Technologies
(continued)
  • Asynchronous transfer mode (ATM) is a packet
    switching technology that can pass data among
    computers from different vendors and handle data,
    video, and audio over the same network. ATM
    creates a fixed channel, or route, between two
    points whenever data transfer begins. This
    differs from TCP/IP, in which messages are
    divided into packets and each packet can take a
    different route from source to destination. This
    difference makes it easier to track and bill data
    usage across an ATM network, but it makes it less
    adaptable to sudden surges in network traffic.

30
Internet Governance
  • No one owns the Internet, but worldwide
    Internet policies are established by the
    following organizations
  • Internet Architecture Board (IAB)
  • Internet Corporation for Assigned Names and
    Numbers (www.ICANN.org )
  • Internet Network Information Center (InterNIC)
  • Internet Engineering Steering Group (IESG)
  • Internet Engineering Task Force (IETF)
  • Internet Society (ISOC)
  • World Wide Web Consortium -www.W3C.org

31
Future of the Internet
  • Internet Protocol version 6 (IPv6) 128-bit
    addresses, contains over a quadrillion possible
    unique addresses
  • Internet2 and Next-Generation Internet (NGI) are
    consortia working on the next generation

32
Internet Technologies with Business Implications
  • Chatting and instant messaging
  • Electronic discussion groups (Usenet)
  • Groupware
  • Electronic conferencing
  • Internet telephony
  • Virtual private networks

33
Unique Features of the Internet
34
The World Wide Web
Client/Server Computing on the Internet
35
The World Wide Web
  • Terms associated with the Web
  • HTML
  • HTTP
  • URL ttp//www.megacorp.com/content/features/0860
    2.html
  • www.megacorp.com is the name of a Web server
    holding the info
  • Content/features is the directory path
  • 08602.html is the name of the file and file
    format (html)
  • Search engines and search engine marketing
    (www.google.com)
  • Intelligent agents (shopping bots)
  • www.froogle.com or www.mysimon.com

36
The World Wide Web continued
  • Web 2.0 refers to second-generation interactive
    Internet based services
  • Mashups (see chapter 5)
  • Blog (short for Weblog) is a Web site where
    subscribing individuals can publish material and
    links to other Web sites of interest. Business
    applications? www.diabetesblognetwork.com
  • RSS (rich site summary) enables users to check
    for updates to a site. If a user subscribes to
    the RSS service of a site, then the site notifies
    the user about new content on the site
    (garageband.com)
  • Podcasting is like blogging except you are
    publishing sound (www.abc.com)
  • Wikis are like blogs but visitors can change the
    posted material (Wikipedia)

37
Intranets
  • An intranet is a computer network within an
    organization that uses Internet technologies for
    members of the organization only
  • If a company has an existing network, than
    establishing an intranet is very inexpensive.
    All that is required is the server software and
    browsers for clients.
  • Most of the technologies mentioned earlier are
    all available at no charge

38
Information Most Frequently Found in Corporate
Intranets
  • Customer databases
  • Corporate policies and procedures (Winthrop)
  • Corporate phone directories
  • Human resource forms (Winthrop)
  • Training programs
  • Product catalogs and manuals (Winthrop)
  • Data warehouse and decision support access
  • Internal purchase orders (Winthrop)
  • Travel reservations
  • Knowledge management databases

39
Extranets
  • An extranet is similar to an intranet but it
    enables the firms business partners (e.g.,
    suppliers or customers) to access the firms
    intranet
  • Once an organization links its network to the
    Internet theoretically anyone can access the
    firms network. With respect to an extranet,
    firms want to restrict access to business
    partners. A virtual private network provides the
    security mechanism for accomplishing this. A VPN
    uses a combination of public and private lines to
    build a secure extranet. The link between the
    firms network and the Internet is often called a
    tunnel. A VPN provides a secure tunnel.
  • VPNs are also required for firms with extensive
    intranets (multi-site firms)

40
Extranet Applications
  • Managing the supply chain
  • Collaborating with other organizations in the
    development of new products/services
  • Sharing product catalogs exclusively with
    wholesalers
  • Sharing news and other information of shared
    interest exclusively with business partners
    (e.g., production schedules, forecasts)

41
Wireless Communications and Access to the Internet
  • Wireless devices
  • (A devices) Cell phones, handheld computers
    (PDA), email handhelds, and smart phones
  • (B devices) PCs (laptops or desktops)
  • Standards for A devices
  • Cell phone standards (voice)
  • Global System for Mobile Communication (GSM)is an
    international standard
  • Code division multiple access (CDMA) is a US
    standard
  • Short message service (SMS)
  • Cell phone standards for Internet access
  • Wireless application protocol (WAP)
  • Wireless markup language (WML)
  • I-mode from Japan

42
Standards for B Devices for Wireless Computer
Networks
  • Bluetooth (IEEE 802.15) for networks up to 8
    devices with a 10-meter area (PANS). Can be used
    with both A and B devices.
  • For LANs the dominant standards are 802.11b and
    802.11g know as Wi-Fi (wireless fidelity)
  • Laptops need a wireless network interface card
  • Wireless devices communicate with the LAN by
    communicating with an access point which is
    basically a radio receiver/transmitter. The
    access point (hotspot) is connect to a wired
    network or router
  • Wireless devices can also communicate directly
    with each other
  • If the access point connects to the Internet
    (e.g., through cable or DSL) then Wi-Fi also
    provides Internet access
  • Cards exist for laptops that can enable them to
    use cellular phone services (EV-DO)

43
Other Ways to Access the Internet
  • Limits of Wi-Fi access limited mobility,
    security, interference, or no access point to a
    broadband connection
  • WiMax is another family of IEEE standards
    (802.16)
  • Range of 31 miles compared to Wi-Fis 300 feet
  • Data transfer rate of 75 Mbps compared to 54 Mbps
    for Wi-Fi
  • Very good security and will support voice and
    video
  • Businesses/homes can install rooftop antennas to
    receive
  • Laptops require a special card users can work in
    vehicles

44
Wireless Applications
  • Radio frequency identification (RFID)
  • Wireless Sensor Networks (not covered)

45
Radio Frequency ID (RFID)
  • RFID tags consist of a microprocessor and an
    antenna. Some tags can transmit on their own
    others transmit through activation by a reader
    sending a signal to the chip
  • History
  • Technology was invented in 1934
  • Many different kinds of tags with many different
    capabilities such as range, storage capacity,
    alterability of data
  • RFID tag of primary interest are the EPC
    (electronic product code) chips
  • Designed to replace UPC codes
  • 96-bit storage capacity potential to give
    individual items a unique identifier operate in
    868-965 MHz
  • Signals can only be read if within a few feet of
    reader
  • Cost of tags is still high 5-10 cents per tag
    limited to large ticket items

46
RFID Tags (Continued)
  • Major applications of EPC chips (current and
    future)
  • Track and locate inventory
  • Track items as they move through a firms supply
    chain
  • Smart shelves
  • Privacy issues (EPC tags)
  • Notification of the presence of a tag
  • Killing the tag before you leave the store
  • Restrictions on the use of tag generated data

47
Current Uses of RFID
48
Future Uses of RFID
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Transcript and Presenter's Notes

Title: Telecommunications, the Internet, and Wireless Technology


1
Telecommunications, the Internet, and Wireless
Technology
  • Chapter Seven (10th ed)

2
Why Is Business Interested in Telecommunication
and Networking?
  • Declining transaction costs (benefits of B2C and
    B2B)
  • Declining agency costs because managers can
    monitor employees and markets remotely
  • Increased agility (connections with suppliers and
    customers enables managers to spot trends and
    take appropriate actions). Concepts like
    extranets, collaborative commerce, intranets
    support this idea.
  • Higher quality management decisions (access to
    more information in a timely manner)
  • Declining geographical barriers
  • Declining temporal barriers (software
    development, time-based competition)

3
Telecommunications and Networking in Todays
Business World
  • Prior to 1990 most business communication
  • Postal service
  • Telephone system (voice fax)
  • Today most business communication is
  • Computers and email using the Internet
  • Cellular telephones
  • Mobile computers using wireless connections
  • All business has become e-business

4
Magnitude of the Change
  • 1 billion instant messages per day
  • 4 billion e-mails each day
  • 65 million music files downloaded
  • Estimated 3.9 billion photos sent over the
    Internet
  • 769 billion spent in the United States on
    telecommunications equipment and services

5
Telecommunications spending in the United States,
20022007
Note differences between services and equipment
spending
6
Basic Network Components
  • A network consists of two or more connected
    computers.
  • A network interface device (NIC) is the
    connection point between one computer and the
    network
  • A network operating system (NOS) routes and
    manages communications on the network and
    coordinates network resources (saving or
    retrieving files on your hard drive versus a
    network drive)

7
Basic Network Components (continued)
  • Hubs connect network components, sending a packet
    of data to all other connected devices
  • A switch has more intelligence than a hub and can
    forward data to a specified device or
    destination. The switch is used within a given
    network to move information.
  • Unlike a switch, a router (bridge) is a special
    communications processor used to route packets of
    data through different networks, ensuring that
    the message sent gets to the correct address. A
    router connects a LAN to the Internet.

8
A Simple Network
9
Corporate Network Infrastructure
10
Pieces in the Corporate Infrastructure
  • Center piece is a collection of linked LANS that
    support a firm wide corporate network
  • A series of servers supporting a corporate web
    site linked to enterprise and legacy systems
  • Support for a mobile sales force
  • Separate telephone network (cell and landline)
  • Separate video conferencing system (not shown)
  • Currently no one vendor can supply all of the
    services required
  • How does a manager navigate through this complex
    environment and make the right decisions?

11
Data and Signals
  • Digital data (1s and 0s) are represented by a
    discrete non-continuous wave form.
  • Analog data is represented by a continuous wave
    form. The human voice, music, and noise are
    examples of analog data.
  • From a physical point of view, data can converted
    to an electric (carried over a wire) or
    electromagnetic (stream of photons) signal
  • Usually digital signals convey digital data and
    analog signals convey analog data.
  • In telecommunications there is a need to convert
    digital data to an analog signal and vice versa.
  • Computers emit digital data but parts of the
    telephone system only transmit analog signals, so
    digital data must be converted into an analog
    signal and vice versa (need for your modem)

12
More on Signals
  • All signals can be represented as a sine wave
    (curve).
  • The amplitude of a sine wave is the maximum
    height of the sine wave from the x-axis
  • The frequency of a sine wave is the number of
    times a sine wave makes a complete cycle within a
    given time frame.
  • Cycles per second is referred to as Hertz (Hz)
  • Digital data can be converted to a digital signal
    by using two different voltages.
  • Digital data can be converted to an analog signal
    by using either two different frequencies or two
    different amplitudes.
  • The greater the frequency of a signal, the higher
    the possible data transfer rate the higher the
    desired data transfer rate, the greater the need
    signal frequency.

13
Electromagnetic Signals
  • Electromagnetic signals can be described in terms
    of a stream of photons each traveling in a
    wave-like pattern, moving at the speed of light
    and carrying some amount of energy. The only
    difference between radio waves, visible light,
    and gamma-rays is the energy of the photons.
    Radio waves have photons with low energies,
    microwaves have a little more energy than radio
    waves, infrared has still more, then visible,
    X-rays, and gamma-rays. Low energy photons (such
    as radio) behave more like waves, while higher
    energy photons (such as X-rays) behave more like
    particles.
  • The electromagnetic spectrum can be expressed in
    terms of energy, wavelength, or frequency. Each
    way of thinking about the EM spectrum is related
    to the others in a precise mathematical way (see
    next slide).

14
The Relationship Between Wave Length and Frequency
15
Modulation
16
Frequency Spectrum for Electromagnetic Signals
TV 54M - 216 MHz
TV 220M - 500 MHz
AM 550K - 1650 KHz
FM 88M - 108 MHz
Navy/submarines
ELF
VLF
LF
MF
HF
VHF
UHF
Microwave
Optical
Hertz
100
1K
100K
1M1M
10M
100M
1G
10G
  • All waves behave similarly
  • Frequency differences
  • Amount of data
  • Distance
  • Interference / Noise

Public Safety 150M - 160 MHz
Public Safety 460M - 500 MHz
Cellular phones 800 MHz
Cordless phones (some) 900 MHz
PCS ET 2 GHz
Pers. Com. Sys (PCS) 1.85 G - 2.2 GHz
17
Client/Server Computing
  • The hardware side
  • The client
  • The server
  • The software side
  • Client/server software splits the processing of
    applications between the client and server to
    take advantage of strengths of each machine
  • E-mail and browsers are examples
  • Client/server computing has largely replaced
    centralized mainframe computing

18
Packet Switching
  • In packet-switched networks, messages are first
    broken down into small bundles of data called
    packets that are sent along different
    communication paths and then reassembled once
    they reach their destinations.
  • Packet switching makes more efficient use of the
    communications capacity of a network.
  • The packets include information for directing the
    packet to the right address and for checking
    transmission errors along with the data.
  • Always done on the Internet, but restricted to
    data now being used for voice (VoIP)

19
Packet Switching
20
TCP/IP
  • TCP/IP is the communications protocol used by the
    Internet and all Internet devices.
  • TCP (transmission control protocol) part
  • Handles the movement of data between computers
  • Establishes a connection between the computers,
    sequences the transfer of packets, and
    acknowledges the packets sent
  • IP (Internet protocol) part
  • Responsible for the delivery of packets
  • Includes the disassembling and reassembling of
    packets during transmission

21
Internet Protocol Numbers (IPv4)
  • Each device attached to the Internet has an IP
    number (some static/some dynamic)
  • Each IP number consists of four parts separated
    by periods. Each part contains a number between
    0 and 255 therefore each part can be represented
    by 8 bits or 32 bits for the entire IP number
    (e.g., 146.186.87.220).
  • Approximate number of devices able to be on the
    Internet is 232 or
  • 210 210 21022103103103221094 (4 billion)
  • The process of associating an IP number with a
    character based name is called domain name
    resolution. The domain name system (DNS) is the
    software that associates character based names
    with the IP number. Internet Service Providers
    (ISPs) usually dedicate a server to perform
    domain name resolution (i.e., a DNS server).
  • To determine speed of your connection
    http//www.ip-adress.com/speedtest/
  • To determine your IP number http//www.What
    ismyIpaddress.com

22
Transmission Media Wire Or Wireless
  • Wire media
  • Twisted Wire up to 100Mbps
  • Coaxial Cable up to 1 Gbps
  • Fiber Optics up to 6Tbps
  • Uses strands of glass and pulses of light
  • Most expansive of three can carry data, voice,
    and video efficiently
  • Wireless media
  • Terrestrial microwave 100 Mbps
  • Satellite microwave GEO (geostationary earth
    orbit) about 22,000 miles above earth
  • Satellite microwave LEO (low earth orbit) about
    400-1000 miles above earth

23
Transmission Speeds
  • Digital signal speeds are usually expressed in
    bits per second (Kbps, Mbps, and Gbps).
  • Analog signal speeds are usually expressed in
    frequency per second or Hertz (KHz, MHz, or GHz).
  • A simple relationship between bps and frequency
    is found in Nyquists theorem
  • C2f(log2)L where f is the frequency, L is the
    number of signal levels (often 2) and C is the
    capacity of the medium in bps
  • The range of frequencies accommodated on a
    particular medium is called its bandwidth. For
    example, current cell phones operate in a
    bandwidth between 1.85 GHz and 2.2 GHz

24
Multiplexing Concept
  • A channels is a path followed by a flow of
    information (stream of bits). The information is
    carried by a digital or analog signal.
  • Multiplexing involves using a single
    communications channel to carry simultaneous
    transmissions from multiple sources.
  • Examples
  • Frequency division multiplexing divides a high
    speed channel into multiple channels of slower
    speeds (FDMA code division multiple access)
  • Time division multiplexing assigns the sender
    transmitter a small slice of time to use the high
    speed channel (TDMA)
  • Code division multiplexing assigns each user a
    special code enabling multiple users on a single
    channel (CDMA)

25
Types of Networks by Geographic Scope
26
LANs
  • Typical LAN operating systems are Windows
    (based), Linux, or Novell each supports TCP/IP
    (ease of establishing an intranet)
  • Ethernet is a LAN standard contained on the NIC
  • LANs may use the client-server or peer-to-peer
    architecture (all computers can share resources
    directly)
  • In the client-server model
  • NOS is primarily on the server
  • Large LANs often have many servers each dedicated
    to a specific function (e.g., print server, file
    server, Web server)
  • LAN topologies (shapes)
  • Star
  • Bus
  • Ring
  • Wired LANs versus wireless LANs

27
LAN Topologies
28
Broadband Network Services and Technologies
  • These technologies are for high-speed
    transmission or access to the Internet and
    provided by telecom companies
  • Services
  • Frame relay is like packet switching but faster
  • Digital subscriber lines (DSL) operate over
    existing phone lines and carry voice, data, and
    video. Provided by phone company
  • Cable internet connection is provided by cable tv
    vendors using same wires used for cable tv
  • T1 lines are high speed high volume lines
    supplied by telephone companies that are used by
    firms to move large volumes of voice and data
    traffic with strong security and reliability

29
Broadband Network Services and Technologies
(continued)
  • Asynchronous transfer mode (ATM) is a packet
    switching technology that can pass data among
    computers from different vendors and handle data,
    video, and audio over the same network. ATM
    creates a fixed channel, or route, between two
    points whenever data transfer begins. This
    differs from TCP/IP, in which messages are
    divided into packets and each packet can take a
    different route from source to destination. This
    difference makes it easier to track and bill data
    usage across an ATM network, but it makes it less
    adaptable to sudden surges in network traffic.

30
Internet Governance
  • No one owns the Internet, but worldwide
    Internet policies are established by the
    following organizations
  • Internet Architecture Board (IAB)
  • Internet Corporation for Assigned Names and
    Numbers (www.ICANN.org )
  • Internet Network Information Center (InterNIC)
  • Internet Engineering Steering Group (IESG)
  • Internet Engineering Task Force (IETF)
  • Internet Society (ISOC)
  • World Wide Web Consortium -www.W3C.org

31
Future of the Internet
  • Internet Protocol version 6 (IPv6) 128-bit
    addresses, contains over a quadrillion possible
    unique addresses
  • Internet2 and Next-Generation Internet (NGI) are
    consortia working on the next generation

32
Internet Technologies with Business Implications
  • Chatting and instant messaging
  • Electronic discussion groups (Usenet)
  • Groupware
  • Electronic conferencing
  • Internet telephony
  • Virtual private networks

33
Unique Features of the Internet
34
The World Wide Web
Client/Server Computing on the Internet
35
The World Wide Web
  • Terms associated with the Web
  • HTML
  • HTTP
  • URL ttp//www.megacorp.com/content/features/0860
    2.html
  • www.megacorp.com is the name of a Web server
    holding the info
  • Content/features is the directory path
  • 08602.html is the name of the file and file
    format (html)
  • Search engines and search engine marketing
    (www.google.com)
  • Intelligent agents (shopping bots)
  • www.froogle.com or www.mysimon.com

36
The World Wide Web continued
  • Web 2.0 refers to second-generation interactive
    Internet based services
  • Mashups (see chapter 5)
  • Blog (short for Weblog) is a Web site where
    subscribing individuals can publish material and
    links to other Web sites of interest. Business
    applications? www.diabetesblognetwork.com
  • RSS (rich site summary) enables users to check
    for updates to a site. If a user subscribes to
    the RSS service of a site, then the site notifies
    the user about new content on the site
    (garageband.com)
  • Podcasting is like blogging except you are
    publishing sound (www.abc.com)
  • Wikis are like blogs but visitors can change the
    posted material (Wikipedia)

37
Intranets
  • An intranet is a computer network within an
    organization that uses Internet technologies for
    members of the organization only
  • If a company has an existing network, than
    establishing an intranet is very inexpensive.
    All that is required is the server software and
    browsers for clients.
  • Most of the technologies mentioned earlier are
    all available at no charge

38
Information Most Frequently Found in Corporate
Intranets
  • Customer databases
  • Corporate policies and procedures (Winthrop)
  • Corporate phone directories
  • Human resource forms (Winthrop)
  • Training programs
  • Product catalogs and manuals (Winthrop)
  • Data warehouse and decision support access
  • Internal purchase orders (Winthrop)
  • Travel reservations
  • Knowledge management databases

39
Extranets
  • An extranet is similar to an intranet but it
    enables the firms business partners (e.g.,
    suppliers or customers) to access the firms
    intranet
  • Once an organization links its network to the
    Internet theoretically anyone can access the
    firms network. With respect to an extranet,
    firms want to restrict access to business
    partners. A virtual private network provides the
    security mechanism for accomplishing this. A VPN
    uses a combination of public and private lines to
    build a secure extranet. The link between the
    firms network and the Internet is often called a
    tunnel. A VPN provides a secure tunnel.
  • VPNs are also required for firms with extensive
    intranets (multi-site firms)

40
Extranet Applications
  • Managing the supply chain
  • Collaborating with other organizations in the
    development of new products/services
  • Sharing product catalogs exclusively with
    wholesalers
  • Sharing news and other information of shared
    interest exclusively with business partners
    (e.g., production schedules, forecasts)

41
Wireless Communications and Access to the Internet
  • Wireless devices
  • (A devices) Cell phones, handheld computers
    (PDA), email handhelds, and smart phones
  • (B devices) PCs (laptops or desktops)
  • Standards for A devices
  • Cell phone standards (voice)
  • Global System for Mobile Communication (GSM)is an
    international standard
  • Code division multiple access (CDMA) is a US
    standard
  • Short message service (SMS)
  • Cell phone standards for Internet access
  • Wireless application protocol (WAP)
  • Wireless markup language (WML)
  • I-mode from Japan

42
Standards for B Devices for Wireless Computer
Networks
  • Bluetooth (IEEE 802.15) for networks up to 8
    devices with a 10-meter area (PANS). Can be used
    with both A and B devices.
  • For LANs the dominant standards are 802.11b and
    802.11g know as Wi-Fi (wireless fidelity)
  • Laptops need a wireless network interface card
  • Wireless devices communicate with the LAN by
    communicating with an access point which is
    basically a radio receiver/transmitter. The
    access point (hotspot) is connect to a wired
    network or router
  • Wireless devices can also communicate directly
    with each other
  • If the access point connects to the Internet
    (e.g., through cable or DSL) then Wi-Fi also
    provides Internet access
  • Cards exist for laptops that can enable them to
    use cellular phone services (EV-DO)

43
Other Ways to Access the Internet
  • Limits of Wi-Fi access limited mobility,
    security, interference, or no access point to a
    broadband connection
  • WiMax is another family of IEEE standards
    (802.16)
  • Range of 31 miles compared to Wi-Fis 300 feet
  • Data transfer rate of 75 Mbps compared to 54 Mbps
    for Wi-Fi
  • Very good security and will support voice and
    video
  • Businesses/homes can install rooftop antennas to
    receive
  • Laptops require a special card users can work in
    vehicles

44
Wireless Applications
  • Radio frequency identification (RFID)
  • Wireless Sensor Networks (not covered)

45
Radio Frequency ID (RFID)
  • RFID tags consist of a microprocessor and an
    antenna. Some tags can transmit on their own
    others transmit through activation by a reader
    sending a signal to the chip
  • History
  • Technology was invented in 1934
  • Many different kinds of tags with many different
    capabilities such as range, storage capacity,
    alterability of data
  • RFID tag of primary interest are the EPC
    (electronic product code) chips
  • Designed to replace UPC codes
  • 96-bit storage capacity potential to give
    individual items a unique identifier operate in
    868-965 MHz
  • Signals can only be read if within a few feet of
    reader
  • Cost of tags is still high 5-10 cents per tag
    limited to large ticket items

46
RFID Tags (Continued)
  • Major applications of EPC chips (current and
    future)
  • Track and locate inventory
  • Track items as they move through a firms supply
    chain
  • Smart shelves
  • Privacy issues (EPC tags)
  • Notification of the presence of a tag
  • Killing the tag before you leave the store
  • Restrictions on the use of tag generated data

47
Current Uses of RFID
48
Future Uses of RFID
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