1. Mobile Devices: How they Operate
Computer Maintenance
Mobile Devices: How they Operate
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Trade & Industrial Education

2. Course Objectives Define and identify what constitutes a mobile device
Demonstrate a working knowledge of mobile device operation
Understand and explain how mobile devices communicate
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3. Mobile Devices
Mobile device: a small, hand-held computing device that typically weighs less than 2 pounds
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4. Types of Mobile Devices
Cell phones
Smart phones
Personal data assistants
Tablet (more recently)
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5. Mobile Devices
Devices contain an operating system that allows them to run smaller applications called apps.
Wireless connectivity is built into the device
Wi-Fi
Bluetooth
Cellular
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6. Mobile Device Interface
Touch: Device interaction by touch can happen in many different ways:
Touchscreen
Stylus
Mechanical keyboard & finger track pad/ball
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7. Mobile Device Interface
Touchscreen: Screen of the device contains layers with the LCD being on the bottom and the subsequent layers above house the touch sensors
Two most widely used systems in mobile devices: Resistive and Capacitive Touch
The screen is comprised of a large grid that signals the coordinates of the user’s input
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8. Mobile Device Interface
Resistive Touch: Two thin layers where one is electrically charged and the other senses the charge when the two are pressed together
This is an older version of the touchscreen technology.
Pressing firmly on the screen and using a stylus were the two most common means of using this technology
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9. Mobile Device Interface
Capacitive Touch: An insulator (glass) is coated with a grid of conductors that emit an electrostatic field that when touched allows the grid to locate where the field is being disrupted
This is the current standard for touchscreen interfaces (smartphones, tablets, and other current mobile devices).
Doesn’t require firm presses—merely a light touch
Requires touch with skin (conductive) to function
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10. Operating a Mobile Device
Device Operation (Smartphone):
Power button
Turns the device on/off
Home button – Usually located on a central part of the device
Turns the screen on
Exits an application
May be a Back button
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11. Operating a Mobile Device
Device Operation (Smartphone) Cont’d:
Back button (may also be the home button)
Exits an application / Reverts to a previous screen
Track pad – Some devices have this option also located in a central part of the device.
Utilized to navigate on devices without a touchscreen
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12. Mobile Devices – How They Communicate
Mobile devices use three means of wireless communication: Wi-Fi, cellular, and Bluetooth
Wi-Fi is used for small coverage areas
Residential
Businesses
Cellular is used for large geographical areas
Deployed by large telecom companies
Bluetooth is for the smallest coverage areas
Often utilized as an accessory device alongside mobile devices (ex. Bluetooth headset)
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13. Mobile Devices – Wi-Fi
Wi-Fi: Wireless technology that allows electronic devices to exchange data
Wi-Fi (a.k.a. WLAN) was developed in the mid to late 1990s
Developed by the technology that allows devices to transmit and receive data wirelessly through radio frequencies
Requires an Internet source to function as a router (hub) and offers Internet connectivity to wireless devices
Utilizes a standard that can connect with almost all mobile wireless devices
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14. Mobile Devices – Wi-FI The different speeds of Wi-Fi
802.11b - Single Band
Late 90s technology – 2.4 Ghz - 11 Mbits/s
802.11g – Dual Band Unified b/g
2003 standard – 2.4 Ghz – 54 Mbits/s
802.11n – Dual Band
2009 amendment – 2.4 & 5 Ghz – 54 to 600 Mbits/s
802.11ac – Fifth Generation of Wi-Fi – An emerging standard
5 Ghz – At least 1 gigabit per second
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15. Mobile Devices – Wi-Fi Wi-Fi Security
Wired Equivalent Privacy (WEP): Initial form of Wi-Fi security; introduced in 1999 and outdated by 2003 due to security concerns (least secure)
Wi-Fi Protected Access (WPA): 2003 security implementation designed to make wireless networks more secure
Wi-Fi Protected Access 2 (WPA2): Current security standard that employs a 256 bit encryption (most secure)
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16. Mobile Devices – Wi-FI Wi-Fi Security: Connecting to the network
Select network name
Identify security type
Mobile device should auto detect the security type
Enter password
Join
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17. Mobile Devices – Cellular
Cellular wireless: Wireless connectivity via cellular radio towers that are deployed across an extensive geographic area
Providers utilize different technologies that can allow devices to work with one provider and not another
Current cellular technologies are CDMA and GSM and LTE
Cellular wireless speeds are increasing rapidly due to the benefits of the newest technology, LTE
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18. Mobile Devices – Cellular
Cellular wireless cont’d:
Broadcast from the 450 Mhz frequency up to the 21 MHz frequency
FCC oversees who owns what frequencies a cellular provider may utilize
Lower frequencies allow a cellular radio tower a greater radius of range
Lower frequencies also improve reception in buildings
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19. Mobile Devices – Cellular
Cellular wireless types:
Code Division Multiple Access (CDMA):
Aging 3G standard for wireless devices used for data and voice and is the dominant technology in the U.S.
Global Systems for Mobile Communications (GSM):
Newer 3G to 3.5G wireless technology; is the dominant technology utilized worldwide
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20. Mobile Devices – Cellular
Cellular wireless types cont’d:
Long Term Evolution (LTE):
4G or 4th generation of cellular wireless technology
The next evolution of GSM; is being widely adopted
Speeds currently are 2-10 times faster than 3G technology
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21. Mobile Devices – Bluetooth
Bluetooth: Wireless standard for exchanging data over short distances in the Mhz range
Developed in 1994 as an alternative to data cables
Must be paired with a compatible device to function
Is used for data sharing and voice communications
Uses low power (benefit)
Examples of devices a mobile device can pair with:
Smartphone, PDA, headset, printer, keyboard, and PC
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