Transcript Telecommunications and Networking - University of Baltimore Home

Telecommunications
and Networking
Learning Objectives
1. Understand the concept of a network.
2. Apply Metcalfe’s law in understanding the
value of a network.
3. Identify several major developments and
trends in the industries, technologies, and
business applications of
telecommunications and Internet
technologies.
4. Examples of the business value of Internet,
intranet, and extranet applications.
Learning Objectives
5. Identify the basic components, functions,
and types of telecommunications networks
used in business.
6. Explain the functions of major components
of telecommunications network hardware,
software, media, and services.
7. Explain the concept of client/server
networking.
8. Understand the two forms of peer-to-peer
networking.
Learning Objectives
10.Identify the various transmission media
and topologies used in telecommunications
networks.
11.Understand the fundamentals of wireless
network technologies.
12.Explain the concepts behind TCP/IP.
13.Understand the seven layers of the OSI
network model.
Network Concepts
 Network
– An interconnected chain, group or system
 Number of possible connections on a
network is N * (N-1)/2
– Where N = number of nodes (points of
connections on the network)
– Example, if there are 10 computers on a
network, there are 10 * 9/2 = 45 possible
connections
Telecommunications
 Telecommunications
– Exchange of information in any form (voice,
data, text, images, audio, video) over networks
Basic concepts
 Communication protocols (TCP/IP)
 Data transmission methods
– Asynchronous
– Synchronous
 Connecting
– Modem
– Hardwired and remote
 Data transmission channels (bps)
– narrow bands: 5-30
– voice bands: 1,000-9,600
– broad bands: 100,000
 Types of communication lines
– simplex
– half-duplex
– duplex
Networks
 Concept
– "a group of interconnected computers, workstations, or computer devices
(such as printers and data storage systems).”
 Network topology
– bus
– star
–
ring
 Local-area networks
– bus: Ethernet, carrier sense multiple access (CSMA)
– ring: token passing method
 Distributed data processing
– "interconnects sites of one organization not only for communication of data
and messages but also for
the sharing of resources."
Open Systems
 Information systems that use common standards
for hardware, software, applications and networks
 Internet networking technologies are a common
standard for open systems
 Connectivity:
– Ability of networked computers to easily access and
communicate with each other and share information
 Interoperability:
– The ability of an open system to enable end user
applications to be accomplished using different
varieties of computer systems, software packages,
Middleware
 Any programming that serves to “glue
together” two separate programs
Internet2
 Next generation of the Internet
 High-performance network
 In use at 200 universities, scientific
institutions, communications corporations
Internet Service Provider
 ISP
– A company that specializes in providing easy
access to the Internet
– For a monthly fee, you get software, user name,
password and access
 ISPs are connect to one another through
network access points
An Intranet Also look at fig 6.8
 A network inside an organization
– That uses Internet technologies (such as Web
browsers and servers, TCP/IP protocols, HTML,
etc.)
– To provide an Internet-like environment within
the organization
– For information sharing, communications,
collaboration and support of business
processes
– Protected by security measures
– Can be accessed by authorized users through the Internet
Extranet (also look at fig 6.9)
 Network links that use Internet technologies
– To connect the Intranet of a business
– With the Intranets of its customers, suppliers or
other business partners
GPS
1. The global positioning system (GPS) is a major
technological achievement that has broadreaching implications for business. Using the
Internet,
– Can find other innovative uses for GPS.
– Good places to start familiarizing yourself with
current accomplishments are

The GPSWorld site at
http://www.gpsworld.com/gpsworld/
 The GPS Overview at
http://www.colorado.edu/geography/gcraft/notes/gps/g
ps_f.html
Telecommunications network
 Any arrangement where a sender transmits
a message to a receiver over a channel
consisting of some type of medium
Types of Networks




WAN
LAN
VPN
C/S
VPN
 Basically, a VPN is a private network that uses a
public network (usually the Internet) to connect
remote sites or users together. Instead of using a
dedicated, real-world connection such as leased
line, a VPN uses "virtual" connections routed
through the Internet from the company's private
network to the remote site or employee.
Source: computer.Howstuffworks.com
VPN
Internetwork Processors
 Switch – makes connections between
telecommunications circuits in a network
 Router – intelligent communications
processor that interconnects networks
based on different protocols
 Hub – a port switching communications
processor
 Gateway – connects networks using
different communications architectures
ROUTERS
Routers are specialized computers that send
your messages and those of every other
Internet user speeding to their destinations
along thousands of pathways.

Fujitsu GeoStream R980 industrial strength router
ROUTERS
configuration table. A configuration table is a collection of
information, including:
 Information on which connections lead to particular groups
of addresses
 Priorities for connections to be used
 Rules for handling both routine and special cases of traffic
A router, then, has two separate but related jobs:
 The router ensures that information doesn't go where it's
not needed. This is crucial for keeping large volumes of
data from clogging the connections of "innocent
bystanders."
 The router makes sure that information does make it to the
intended destination.
Computer.howstuffworks.com
Distributed data processing
TSS - Time Sharing Systems
PC
PC
PC
MAINFRAME
CSS - Client Server Systems
PC
Client/Server networks
 Clients: End user personal computers
or networked computers
 Interconnected by LANs
 Servers: manage networks
 Processing shared between clients and
servers
CSS architecture
Remote
Server
File
Server
Communications Server
Print
Server
LA N
PC
PC
PC
PC
Peer-to-peer networks (p 209)
 Networks that connect from one PC to another PC
Peer-to-peer networking enables or enhances the
following scenarios:
 Real-time communications (RTC)
 Collaboration
 Content distribution
 Distributed processing
 Improved Internet technologies
Source: www.microsoft.com
Wireless Technologies
 Terrestrial microwave
– Earthbound microwave systems that transmit
high-speed radio signals in a line-of-sight path
– Between relay systems spaced approximately
30-miles apart
 Communications satellites
– Satellite serves as relay stations for
communications signals
– Uses microwave radio signals
Wireless Technologies
 Cellular and PCS telephone and pager
systems
– Divide the geographic area into small areas or
cells
– Each cell has transmitter or radio relay antenna
to send message from one cell to another
 Wireless LANs
– Radio signals within an office or building
– Connect PCs to networks
 Bluetooth
Bluetooth
 Bluetooth is a standard developed by a group of
electronics manufacturers that allows any sort of
electronic equipment -- from computers and cell
phones to keyboards and headphones -- to make
its own connections, without wires, cables or any
direct action from a user.
 Bluetooth can connect up to eight devices
simultaneously. With all of those devices
in the same 10-meter (32-foot) radius
 http://www1.us.dell.com/content/topics/globa
l.aspx/solutions/en/truemobile?c=us&cs=04
&l=en&s=bsd
Cell Phones
 GSM (CDMA) vs TDMA
 Cell vs Mobile
GSM
CDMA
Digital
YES
YES
Network Type
P-GSM 900 (primary) 900MHz
band
CDMA 800 , 800MHz band (X1
is available.. but is not
being talked about here)
Maximum talk range from a tower (pls. note you will
need a carkit for your mobile to achieve these
numbers in some cases)
35KM (stock cell) 70KM ER , EER
105KM possible with
special towers
Approx 110KM
Background Noise suppression
YES (Included in EFR)
YES
Talk Time
Higher due to DTX and the
"pulse" nature of TDMA.
Lower due to
CDMA transmitting all
the time.
Standby Times
Higher due the "pulse" nature of
TDMA
High
International Roaming
YES (over 138 GSM countries
world wide)
VERY LOW 15?
World wide customers
200 Mil
35 Mil
SMS
YES
YES
Fax + Data
YES
YES
Built in "Intelligence"
HIGH
MEDIUM
EDI Concepts
 EDI is a mechanism for electronic trading
 EDI replaces paper flow with online transactions
 EDI architecture
----> see next slide
 EDI is for trading partners
 Implementation plan is a key factor
 Obstacles:

– lack of transaction standardization
– high start-up costs
EDI third-party suppliers
– AT&T, Control Data, EDS, GE, Western Union, IBM, Martin Marietta
Data Systems, etc.
EDI architecture
Trading Partner 1
Trading Partner 2
CONFIRMATION
standard
transactions
Transaction
Converter
Transaction
Converter
Acquisition System
system
transactions
system
transactions
CONFIRMATION
Order Entry System
ORDER
ORDER
Network Topologies (p 219)
 Topology: structure of a network
 Star: ties end user computers to a central
computer
 Ring: ties local computer processors
together in a ring on a relatively equal basis
 Bus: local processors share the same
communications channel
Network Architectures &
Protocols
 Protocol: standard set of rules and
procedures for the control of
communications in a network
 Network Architecture:
– Master plan of standard protocols, hardware,
software and interfaces between end users and
computer systems
– Goal of promoting an open, simple, flexible, and
efficient telecommunications environment
OSI & TCP/IP Models (p 221)
 Open Systems Interconnection (OSI) Model
– A seven-layer model that serves as a standard
model for network architectures
– Model for how messages should be transmitted
between two points in a network
– Each layer adds functions
 Transmission Control Protocol / Internet
Protocol (TCP/IP)
– A five layer telecommunications protocol used
by the Internet
IP
Internet protocol
 Each system connected to the internet is identified by a 32-bit IP address
 Four numbers separated by a decimal
Each represented by octal (8 bits; hence 0-255)
 Ex: 168.212.226.204
Binary format:
10101000.11010100.11100010.11001100.
A new protocol IPv6 allows for 128 bit IP addresses
to look up an IP address :http://www.kloth.net/services/nslookup.php
to find info:
http://www.geobytes.com/IpLocator.htm
Basic Communications Model
Standards are needed at all Layers
User Layer
Application Layer
Computer (Transport) Layer
Transmission Layer
Internet Telephony
 Using an Internet connection to pass voice
data using IP
 Voice over IP (VoIP)
 Skips standard long-distance phone charges
VOIP (source www.fcc.gov)
Bandwidth
 Bandwidth
– Frequency range of a telecommunications
channel
– Determines transmission rate
– Classified in bits per second (bps)
 Transmission Rates:
– Narrow-band – low-speed
– Broadband – high-speed
WiFi
 WIreless FIdelity (WiFi)-- used generically when referring
of any type of 802.11
"Wi-Fi Certified" (a registered trademark) by the Wi-Fi Alliance
are interoperable with each other,
even if they are from different manufacturers. A user with a
"Wi-Fi Certified" product can use any
brand of access point with any other brand of client
hardware that also is certified
http://www.webopedia.com/TERM/W/Wi_Fi.html
Additional Readings
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Voice over data networks
Networking Hardware Quiz
abc of wireless LAN
ISDN Tutorial
Ethernet tutorial
Internet Protocol
Thin clients
UNIX/NT integration
Cell phones
RWC 1: SAIC, Hewlett-Packard, GE, and Others:
Wireless, Wireless Everywhere
What are some of the business benefits
associated with using wireless networks to
collect and transmit data?
Benefits would include”
 Superfast wireless connections to the Web.
 Cost is about one-fourth of existing costs for
connection to the Web.
 Productivity gains such as a 45% gain at UPS.
What are some of the challenges being faced in this use
of wireless technologies? What solutions can you
offer?
 Having everyone online in a meeting can be toxic to
productivity. “No laptop” policies for important meetings.
 Enormous pressure within companies to provide Wi-Fi in
all areas of the company. Which employees have
compelling needs for Wi-Fi access
 Cost exceeds the benefit to be gained by providing Wi-Fi
such as in a manufacturing plant that would require
numerous additional access points than usual.
 Security of information available via the Wi-Fi system.
Delay implementation until security assurances are met.
The use of wireless networking as
described in the case is both innovative and
useful. What other business uses can you
envision for this approach?
RWC 2: Maryland and Colorado: Serving
Its Citizens Without Using Wires
1. What is the business value of advanced mobile technologies to
Maryland’s emergency management services?

Direct agents toward places where their presence is required

Give notice of impending natural disasters with forecasts and
instructions on how to proceed.

Improve information gathering on the extent and magnitude of
devastation.

Reduce the amount of manual data-entry, leading to improved
response times and reduction of errors (i.e. address is automatically
captured and pop-up menus limit possible answers).
In what other government services could
GPS serve to provide business value?
Give some examples.
 States’ National Guards, to monitor and direct personnel in
case of an emergency.
 Emergency Services, to direct ambulances, firefighters,
etc.
 Department of Treasury / Federal Reserve, to track the
location of armored trucks both for regular traffic and in
case of a hijacking.
 The military in general, given that it has one of the largest
manpower and logistics network in the country.
Are there disadvantages or risks associated with
the deployment of GPS systems to monitor
the location of people? Explain.
 Invasions of privacy
 Limitation on the freedom of movement
 Could allow not only the government but
also private individuals to monitor other
people’s movements.