Laurie Shteir, CIS Department

1
Cell Phone and Cellular Networks
2
The Basics

• Sending a call
• Sound is converted into radio waves
• Travel thru the air until they reach a base
  station
• Base station sends your call thru the telephone
  network
• Receiving a call
• Message travels thru the Telephone Network until
  it reaches a base station close to your wireless
  phone
• Base station sends out radio waves detected by a
  receiver in your telephone
• Telephone converts the signals into voice
• Video on cell towers

3

• Communications, Information and Entertainment
  Device
• Important technology device world wide
• 80 of the worlds pop has coverage
• Largest growth rate Africa
• Tremendous growth due to Pre-paid service
• with no commitment to a long term contract
• Developing countries have poor wire line
  infrastructure, cost of computers, poor quality
• of lines, lack of consistent electricity in
  areas
• Entrepreneur Opportunities in Developing
  Countries
• Selling phone services to villages on a per use
  basis.
• Sellers of prepaid phone cards including poor
  urban youths and small business owners.
• Users of phones who gain business and employment
  opportunities mentioned above.

4
Challenges/Solutions

• Challenges
• Cost of the handsets
• Coverage is concentrated in cites and specific
  countries
• Poverty
• Governmental restrictions on information
• Solutions
• Motorola won a contract to supply 6 million
  handsets to African nations at a cost of
  40/handset
• Business/Governments working together
• Recycled Phones

5
Cellular Communications

• 3G Cellular Technology(144 Kbps to 2.4 Mbps)
• Wireless Broadband
• Browse the Web, watch video or TV, play games
• PCS (Personal Communications Services)
• Term used by US FCC all wireless digital
  communications
• Cellular telephones, PDAs, pages, fax machines
• Services on these devices Voice Mail, Call
  forwarding, faxing, caller ID, Email and Internet
  access
• Manufacturers of Cell Phones include
• Nokia (31 Q1 of 2007global market),Audiovox(UT
  Starcom, Motorola, Benefon,
• Choices
• Carrier (Verizon, T-Mobile, Cingular/ATT,
  Sprint/Nextel)
• Plan, phone, features and services

6
Technology

• 2-way radio between mobile phones and base
  stations
• Geographical area split into overlapping areas
  called cells
• Typically 10 square miles
• Each cell has a base station (tower and
  building containing equipment)
• Tower includes antennas, amplifiers,
  transceivers/transmitters
• Antennas are on a tower not at ground level
  restrict exposure to electromagnetic fields
• Base station communicates with mobile phones thru
  a channel
• Channel has 2 frequencies transmitting data and
  receiving data
• MTSO (Mobile Telephone Switching Office)
• Handles phone connections to land lines
• Controls the base stations
• Hand offs calls from one cell to another
• Keeps track of the cell you are located in
• Cell phone codes
• Identify the phone, phones owner and the service
  provider
• ESN (Electronic Serial Number) programmed into
  the phone when manufactured, permanent code
• MIN (Mobile Identification Number) - a 10-digit
  number derived from your phone's number ,
  programmed in when you activate the phone
• SID (System Identification Code), unique number
  assigned to each carrier

7
Powering UP/Making a Call

• Powering Up
• Power is turned on, phone registers a unique
  identifier System Identification Code (SID) - to
  the Mobile Switching Office thru a control
  channel (special frequency used to communicate)
• Phone transmits a registration request which the
  MTSO keeps track of to identify the cell you are
  in when it wants to ring the phone
• MTSO decides on a frequency to use for your call
• Making a call
• Cell phone identifies the closest base station,
  determines the strongest channel, phone
  transmits MIN (your cell phone number) its ESN,
  and the number you are dialing
• Cell service verifies you are a legitimate
  customer and sends a channel assignment
• Cell phone tunes to the channel and begins the
  call
• Call is connected (you are talking on a 2-way
  radio)
• As you travel the signal is moved from cell to
  cell

8
Technology

• Roaming
• Leaving an area covered by your service provider
• MTOS offices communicate with each other to track
  your calls

9
Cellular Technologies
Can I take my US Phone to Europe and make
calls? Only if you have a Triband Phone or a
Quad Band Phone (world phone) Motorola
Sony Nokia Samsung

• GSM most popular worldwide
• Europe, Asia, Africa
• Better International Service
• Dominate the world market
• Only on Digital Networks
• 5 hours of talk time on a a battery charge
• GSM Phone SIM card
• Cingular, T-Mobile
• CDMA most prevalent in US and competes equally
  with GSM
• In US legislation does not require a specific
  standard
• Better US coverage
• Used in US, Canada, Australia and some south
  eastern countries
• 3 hours of talk time on a battery charge
• Common Platform for 3G Services
• Allows more subscribes to be connected at the
  same time
• Slight edge in quality of service
• Sprint PCS, Verizon and Virgin Mobile.

10
Service Plans

• Pay as you go
• Whenever, or anytime, minutes
• Weeknight minutes
• Weekend minutes
• Rollover minutes
• In calling for free
• Need to learn about hidden usage fees
• Additional minutes, roaming fees

11
Health Concerns

• Problems with cell phones
• Non repairable corrosion of parts
• Inability to provide 100 service
• Interference
• Extreme Heat damage battery of components of
  cell phone
• Health Concerns
• Support needed research into possible biological
  effects of RF (radio frequency)of the type
  emitted by wireless phones
• Design wireless phones in a way that minimizes
  any RF exposure to the user that is not necessary
  for device function and
• Cooperate in providing users of wireless phones
  with the best possible information on possible
  effects of wireless phone use on human health
• FCC operates a website to determine the SAR value
  of cell phones
• http//www.fcc.gov/cgb/sar/

12
Suggestions for Securing a Cell Phone

• Dont store sensitive information
• Dont trust the cell phone company to keep your
  data secure
• Check Billing for Fraud, Cell phone signals can
  be intercepted and cloned,
• tumbling (one bogus call here and there)
• Assign passwords when possible, cell phones are
  small and easy to loose
• Report loss immediately to your provider
• Ask for confirmation in writing that device has
  been disabled
• Dont be fooled by cell phone insurance only
  covers the device, not charges for calls
• Careful if you recycle your old phone
• Turn off Bluetooth signal to non-discoverable
• Viruses for cell phones infancy stage, hidden in
  applications for cell phones
• Kill your battery
• Make costly calls
• Send text messages
• Better Business Bureau reports cell phone
  providers are the number 1 complaint among
  consumers

13
Ethical Considerations

• Cell Journalism
• Authenticity of pictures
• Having pictures taken, video and voice recorded
  without permission
• Classroom use
• Highschool and College
• Location Information
• 3G phones with integrated GPS
• E-911 standard from the FCC
• sensor networks able to determine locations
  within buildings.
• Slippery-Slope, Privacy, Ethics
• Security
• Generally non-secure
• Cell Phone Voice Mail is easily hacked by certain
  provider
• Spoofing caller ID
• Disposable Phones ( A Phone You can Loose)
• Very little audit trail no way to track the
  specific owner