Cellular Networks


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Cellular Networks

  1. 1. Cell Phone and Cellular Networks
  2. 2. The Basics <ul><li>Sending a call </li></ul><ul><ul><li>Sound is converted into radio waves </li></ul></ul><ul><ul><li>Travel thru the air until they reach a base station </li></ul></ul><ul><ul><li>Base station sends your call thru the telephone network </li></ul></ul><ul><li>Receiving a call </li></ul><ul><ul><li>Message travels thru the Telephone Network until it reaches a base station close to your wireless phone </li></ul></ul><ul><ul><li>Base station sends out radio waves detected by a receiver in your telephone </li></ul></ul><ul><ul><li>Telephone converts the signals into voice </li></ul></ul><ul><ul><li>Video on cell towers </li></ul></ul>
  3. 3. <ul><li>Communications, Information and Entertainment Device </li></ul><ul><li>Important technology device world wide </li></ul><ul><ul><li>80% of the world’s pop has coverage </li></ul></ul><ul><ul><li>Largest growth rate – Africa </li></ul></ul><ul><ul><li>Tremendous growth due to Pre-paid service </li></ul></ul><ul><ul><li> with no commitment to a long term contract </li></ul></ul><ul><ul><li>Developing countries have poor wire – line infrastructure, cost of computers, poor quality </li></ul></ul><ul><ul><li>of lines, lack of consistent electricity in areas </li></ul></ul><ul><li>Entrepreneur Opportunities in Developing Countries </li></ul><ul><ul><li>Selling phone services to villages on a per use basis. </li></ul></ul><ul><ul><li>Sellers of prepaid phone cards including poor urban youths and small business owners. </li></ul></ul><ul><ul><li>Users of phones who gain business and employment opportunities mentioned above. </li></ul></ul>International Telecommunication Union (ITU), The Economist 82 Million 2004 Cell Phone Users in Africa 51 Million 2003 28 Million 2002 2 Milliion 1998
  4. 4. Challenges/Solutions <ul><ul><li>Challenges </li></ul></ul><ul><ul><li>Cost of the handsets </li></ul></ul><ul><ul><li>Coverage is concentrated in cites and specific countries </li></ul></ul><ul><ul><li>Poverty </li></ul></ul><ul><ul><li>Governmental restrictions on information </li></ul></ul><ul><ul><li>Solutions </li></ul></ul><ul><ul><li>Motorola won a contract to supply 6 million handsets to African nations at a cost of $40/handset </li></ul></ul><ul><ul><li>Business/Governments working together </li></ul></ul><ul><ul><li>Recycled Phones </li></ul></ul>
  5. 5. Cellular Communications <ul><li>3G Cellular Technology(144 Kbps to 2.4 Mbps) </li></ul><ul><ul><li>Wireless Broadband </li></ul></ul><ul><ul><li>Browse the Web, watch video or TV, play games </li></ul></ul><ul><li>PCS (Personal Communications Services) </li></ul><ul><ul><li>Term used by US FCC – all wireless digital communications </li></ul></ul><ul><ul><li>Cellular telephones, PDAs, pages, fax machines </li></ul></ul><ul><ul><li>Services on these devices: Voice Mail, Call forwarding, faxing, caller ID, Email and Internet access </li></ul></ul><ul><li>Manufacturers of Cell Phones include </li></ul><ul><ul><li>Nokia (31% Q1 of 2007global market),Audiovox(UT Starcom, Motorola, Benefon,…… </li></ul></ul><ul><li>Choices : </li></ul><ul><ul><li>Carrier (Verizon, T-Mobile, Cingular/AT&T, Sprint/Nextel) </li></ul></ul><ul><li>Plan, phone, features and services </li></ul>
  6. 6. Technology <ul><li>2-way radio between mobile phones and base stations </li></ul><ul><li>Geographical area split into overlapping areas called cells </li></ul><ul><ul><li>Typically 10 square miles </li></ul></ul><ul><li>Each cell has a base station (tower and building containing equipment) </li></ul><ul><li>Tower includes antennas, amplifiers, transceivers/transmitters </li></ul><ul><ul><li>Antennas are on a tower not at ground level – restrict exposure to electromagnetic fields </li></ul></ul><ul><ul><li>Base station communicates with mobile phones thru a channel </li></ul></ul><ul><ul><li>Channel has 2 frequencies: transmitting data and receiving data </li></ul></ul><ul><li>MTSO (Mobile Telephone Switching Office ) </li></ul><ul><ul><li>Handles phone connections to land lines </li></ul></ul><ul><ul><li>Controls the base stations </li></ul></ul><ul><ul><li>Hand offs calls from one cell to another </li></ul></ul><ul><ul><li>Keeps track of the cell you are located in </li></ul></ul><ul><li>Cell phone codes </li></ul><ul><ul><li>Identify the phone, phones owner and the service provider </li></ul></ul><ul><ul><li>ESN (Electronic Serial Number ) programmed into the phone when manufactured, permanent code </li></ul></ul><ul><ul><li>MIN (Mobile Identification Number) - a 10-digit number derived from your phone's number , programmed in when you activate the phone </li></ul></ul><ul><ul><li>SID (System Identification Code), unique number assigned to each carrier </li></ul></ul>
  7. 7. Powering UP/Making a Call <ul><ul><li>Powering Up </li></ul></ul><ul><ul><li>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) </li></ul></ul><ul><ul><li>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 </li></ul></ul><ul><ul><li>MTSO decides on a frequency to use for your call </li></ul></ul><ul><ul><li>Making a call </li></ul></ul><ul><ul><li>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 </li></ul></ul><ul><ul><li>Cell service verifies you are a legitimate customer and sends a channel assignment </li></ul></ul><ul><ul><li>Cell phone tunes to the channel and begins the call </li></ul></ul><ul><ul><li>Call is connected (you are talking on a 2-way radio) </li></ul></ul><ul><ul><li>As you travel the signal is moved from cell to cell </li></ul></ul>
  8. 8. Technology <ul><li>Roaming </li></ul><ul><ul><li>Leaving an area covered by your service provider </li></ul></ul><ul><ul><li>MTOS offices communicate with each other to track your calls </li></ul></ul>
  9. 9. Cellular Technologies <ul><li>GSM: most popular worldwide </li></ul><ul><ul><li>Europe, Asia, Africa </li></ul></ul><ul><ul><li>Better International Service </li></ul></ul><ul><ul><li>Dominate the world market </li></ul></ul><ul><ul><li>Only on Digital Networks </li></ul></ul><ul><ul><li>5 hours of talk time on a a battery charge </li></ul></ul><ul><ul><li>GSM Phone SIM card </li></ul></ul><ul><ul><li>Cingular, T-Mobile </li></ul></ul><ul><li>CDMA: most prevalent in US and competes equally with GSM </li></ul><ul><ul><li>In US legislation does not require a specific standard </li></ul></ul><ul><ul><li>Better US coverage </li></ul></ul><ul><ul><li>Used in US, Canada, Australia and some south eastern countries </li></ul></ul><ul><ul><li>3 hours of talk time on a battery charge </li></ul></ul><ul><ul><li>Common Platform for 3G Services </li></ul></ul><ul><ul><li>Allows more subscribes to be connected at the same time </li></ul></ul><ul><ul><li>Slight edge in quality of service </li></ul></ul><ul><ul><li>Sprint PCS, Verizon and Virgin Mobile. </li></ul></ul>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
  10. 10. Service Plans <ul><li>“ Pay as you go” </li></ul><ul><li>Whenever, or anytime, minutes </li></ul><ul><li>Weeknight minutes </li></ul><ul><li>Weekend minutes </li></ul><ul><li>Rollover minutes </li></ul><ul><li>“ In calling” for free </li></ul><ul><li>Need to learn about hidden usage fees </li></ul><ul><ul><li>Additional minutes, roaming fees </li></ul></ul>
  11. 11. Health Concerns <ul><li>Problems with cell phones </li></ul><ul><ul><li>Non repairable corrosion of parts </li></ul></ul><ul><ul><li>Inability to provide 100% service </li></ul></ul><ul><ul><li>Interference </li></ul></ul><ul><ul><li>Extreme Heat – damage battery of components of cell phone </li></ul></ul><ul><ul><li>Health Concerns </li></ul></ul><ul><ul><ul><li>Support needed research into possible biological effects of RF (radio frequency)of the type emitted by wireless phones </li></ul></ul></ul><ul><ul><ul><li>Design wireless phones in a way that minimizes any RF exposure to the user that is not necessary for device function; and </li></ul></ul></ul><ul><ul><ul><li>Cooperate in providing users of wireless phones with the best possible information on possible effects of wireless phone use on human health </li></ul></ul></ul><ul><ul><ul><li>FCC operates a website to determine the SAR value of cell phones </li></ul></ul></ul><ul><ul><ul><li>http://www.fcc.gov/cgb/sar/ </li></ul></ul></ul>
  12. 12. Suggestions for Securing a Cell Phone <ul><li>Don’t store sensitive information </li></ul><ul><li>Don’t trust the cell phone company to keep your data secure </li></ul><ul><li>Check Billing for Fraud, Cell phone signals can be intercepted and cloned, </li></ul><ul><ul><li>“ tumbling” (one bogus call here and there) </li></ul></ul><ul><li>Assign passwords when possible, cell phones are small and easy to loose </li></ul><ul><li>Report loss immediately to your provider </li></ul><ul><ul><li>Ask for confirmation in writing that device has been disabled </li></ul></ul><ul><li>Don’t be fooled by cell phone insurance: only covers the device, not charges for calls </li></ul><ul><li>Careful if you recycle your old phone </li></ul><ul><li>Turn off Bluetooth signal to non-discoverable </li></ul><ul><li>Viruses for cell phones infancy stage, hidden in applications for cell phones </li></ul><ul><ul><li>Kill your battery </li></ul></ul><ul><ul><li>Make costly calls </li></ul></ul><ul><ul><li>Send text messages </li></ul></ul><ul><ul><li>Better Business Bureau reports: cell phone providers are the number 1 complaint among consumers </li></ul></ul>
  13. 13. Ethical Considerations <ul><li>Cell Journalism </li></ul><ul><li>Authenticity of pictures </li></ul><ul><li>Having pictures taken, video and voice recorded without permission </li></ul><ul><li>Classroom use </li></ul><ul><ul><li>Highschool and College </li></ul></ul><ul><li>Location Information </li></ul><ul><li>3G phones with integrated GPS </li></ul><ul><li>E-911 standard from the FCC </li></ul><ul><li>sensor networks able to determine locations within buildings. </li></ul><ul><li>Slippery-Slope, Privacy, Ethics </li></ul><ul><li>Security </li></ul><ul><ul><li>Generally non-secure </li></ul></ul><ul><ul><li>Cell Phone Voice Mail is easily hacked by certain provider </li></ul></ul><ul><li>Spoofing caller ID </li></ul><ul><li>Disposable Phones ( A Phone You can Loose) </li></ul><ul><ul><li>Very little audit trail – no way to track the specific owner </li></ul></ul><ul><ul><li>Used by folks with bad credit, emergency phone, vacationing traveler, mechanism for limiting use </li></ul></ul><ul><ul><li>Law Enforcement Officials: Also used by Terrorists and Criminals </li></ul></ul><ul><ul><li>No contract, no credit check, no long term obligation </li></ul></ul><ul><ul><li>Difficult or impossible to track </li></ul></ul><ul><ul><li>Law Enforcement Officials – Disposable phones were used to detonate the bombs terrorists used in the Madrid train attacks in March 2004. </li></ul></ul>