8. Mobile Devices

Question 1

Mobile Terminal vs. Mobile Device

Answer 1

• MOBILE DEVICE = small, handheld computing device (can also be a watch but no car)
• MOBILE TERMINAL = emphasises the fact that mobile device represents end of a communication link or edge node of communication network (cars can indeed be mobile terminals )

Question 2

Development of device capabilities

Answer 2

near-field-communication module -> … -> sensors -> … -> SMS -> general telephony capabilities (increasing complexity)

Question 3

Categorization of Mobile Devices - technical

Answer 3

HARDWARE INDEPENDENCE: Independent devices, Devices with external communication, Devices with external security modules, Devices with external memory
OPERATING SYSTEM – CHARACTERISTICS: Memory security, file security, access control & Security module support, secure I/O, program & system integrity

Question 4

Categorization of Mobile Devices - Application Aspects

Answer 4

FUNCTIONAL COMPLETENESS (TO END-USER): Limitations due to device size
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SIZE OF DEVICE: Small/integrated devices, “pocket-sized”, “tablet-sized”, “laptop-sized” -> Size is determined by its input (e.g. keyboard) & output (e.g. display) facilities
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SECURITY FEATURES: Data integrity, encryption, Access control, authentication

Question 5

components of mobile devices

Answer 5

accumulators (for charging) – processors (power management, performance) – Memory & Storage (storage on server vs. storage on client) – Display (Liquid-Crystal-Displays (LCD) OR Organic Light Emitting Diodes (OLED)) – Means for I/O

Question 6

Display of mobile devices

Answer 6

LIQUID-CRYSTAL-DISPLAYS (LCD): widespread in market
-> Dual Scan Twisted Nematic (DSTN): passive matrix -> high latency (blurred image with frequently changing pictures
-> Thin-film-Transistor-Displays (TFT): active (idea: display can be rolled like paper)
———–
ORGANIC LIGHT EMITTING DIODES (OLED)
Polymers can convert electric energy to light -> self-lighting: no background lighting necessary, electric power consumption decreased, thinner device.
-> PMOLED: passive matrix OLED -> simpler electronics, lower cost (e.g. mp3 player)
-> AMOLED: active matrix OLED -> no restrictions on size/resolution, more costly (e.g. iPhone X)

Question 7

Input Solutions for mobile devices

Answer 7

• QUERTY-Keyboard
• PALM Graffiti (handwriting recognition)
• Tegic Communications T9 (Text on 9 keys)
• Octave (slide finger on button)
• SWYPE (slide finger on display/keyboard)
• Speech Recognition

Question 8

Personal Area Network (PAN)

Answer 8

= personal environment, short range – e.g. connect mobile device & printer

• -> INFRARED DATA ASSOCIATION (IrDA): wireless, range up to 10 meters, optical connection required, e.g. wireless printing
• -> BLUETOOTH: connection of periphery-devices (e.g. headsets), overcomes weaknesses of IrDA – allows setting up ad-hoc networks instead of point-to-point connections
• -> NEAR FIELD COMMUNICATION (NFC): based on existing radio-frenquency identification standards, range: 10cm or less