Cell Phone and Cellular Networks

1. Cell Phone and Cellular Networks Laurie Shteir, CIS Department

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 world’s 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/AT&T, Sprint/Nextel) • Plan, phone, features and services

6. 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 Technology

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 • Don’t store sensitive information • Don’t 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 • Don’t 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 • Used by folks with bad credit, emergency phone, vacationing traveler, mechanism for limiting use • Law Enforcement Officials: Also used by Terrorists and Criminals • No contract, no credit check, no long term obligation • Difficult or impossible to track • Law Enforcement Officials – Disposable phones were used to detonate the bombs terrorists used in the Madrid train attacks in March 2004.