Learning Resource

Mobile Device Characeristics

Mobile devices perform an array of functions ranging from a simple telephony device to those of a personal computer. Designed for mobility, they are compact, battery-powered, and lightweight. Most mobile devices have a basic set of comparable features and capabilities. They house a microprocessor, read-only memory (ROM), random-access memory (RAM), a radio module, a digital signal processor, a microphone and speaker, a variety of hardware keys and interfaces and a liquid crystal display (LCD). The operating system (OS) of a mobile device may be stored in either NAND or NOR memory while code execution typically occurs in RAM.

Currently, mobile devices are equipped with system-level microprocessors that reduce the number of supporting chips required and include considerable internal memory capacity currently up to 64GB (e.g., Stacked NAND). Built-in Secure Digital (SD) memory card slots, such as one for the micro Secure Digital eXtended Capacity (microSDXC), may support removable memory with capacities ranging from 64GB to 2TB of storage. Noncellular wireless communications such as infrared (i.e., IrDA), Bluetooth, Near Field Communication (NFC), and Wi-Fi may also be built into the device and support synchronization protocols to exchange other data (e.g., graphics, audio, and video file formats).

Different mobile devices have different technical and physical characteristics (e.g., size, weight, processor speed, memory capacity). Mobile devices may also use different types of expansion capabilities to provide additional functionality. Furthermore, mobile device capabilities sometimes include those of other devices such as handheld global positioning systems (GPS), cameras (still and video) or personal computers. Overall, mobile devices can be classified as feature phones that are primarily simple voice and messaging communication devices or smartphones that offer more advanced capabilities and services for multimedia, similar to those of a personal computer. The table below highlights the general hardware characteristics of feature and smartphone models, which underscore this diversity.

The classification scheme is illustrative and intended to give a sense of the range of hardware characteristics in the marketplace. Over time, characteristics found in smartphones tend to appear in feature phones as new technology is introduced to smartphones. Though the lines of delineation are somewhat fuzzy and dynamic, the classification scheme nevertheless serves as a general guide.

Hardware Characterization
 Feature PhoneSmartphone
Processorlimited speed  (~52Mhz)superior speed (~1GHz dual-core)
Memorylimited capacity (~5MB)superior capacity (~128GB)
Displaysmall size color, 4k – 260k (12-bit to 18-bit)large size color, 16.7 million (~24-bit)
Card Slotsnone, MicroSDMicroSDXC
Camera

still, video

still, panoramic, and video (HD)
Text Inputnumeric keypad, QWERTY-style keyboardtouch screen, handwriting recognition, QWERTY-style keyboard
Voice Inputnonevoice recognition (dialing and control)
Cell Interfacevoice and limited datavoice and high speed data (4G LTE)
Positioningnone, GPS receiverGPS receiver
WirelessIrDA, BluetoothBluetooth, Wi-Fi, and NFC
Batteryfixed/removable, rechargeable Li-Ion polymerfixed/removable, rechargeable Li-Ion polymer

Both feature phones and smartphones support voice, text messaging, and a set of basic personal information management (PIM) type applications, including phonebook and calendar facilities. Smartphones add PC-like capability for running a variety of general and special-purpose applications. Smartphones are typically larger than feature phones, support higher video resolutions (e.g., ~300 PPI) and may have an integrated QWERTY keyboard or touch-sensitive screen. Smartphones generally support an array of applications, available through an application storefront. The table below lists the differences in software capabilities found on these device classes.

Software Characterization
 Feature PhoneSmartphone
OS

closed

Android, BlackBerry OS, iOS, Symbian, WebOS and Windows Phone

PIM (Personal Information Management)phonebook, calendar and reminder listphonebook, calendar and reminder list
Applicationsminimal (e.g., games, Notepad)applications (e.g., games, office productivity and social media)
Callvoicevoice, video
Messagingtext messaging, MMStext, enhanced text, full multimedia messaging
Chatinstant messagingenhanced instant messaging
E-mailvia text messagingvia POP or IMAP server
Webvia WAP gatewaydirect HTTP

Feature phones typically use a closed operating system with no published documentation. A number of companies specializing in embedded software also offer real-time operating system solutions for manufacturers of mobile devices. Smartphones generally use either a proprietary or an open source operating system. Nearly all smartphones use one of the following operating systems: Android, BlackBerry OS, iOS, Symbian, WebOS or Windows Phone. Unlike the more limited kernels in feature phones, these operating systems are multitasking and full-featured, designed specifically to match the capabilities of high-end mobile devices. Many smartphone operating systems manufacturers offer a software development kit (SDK), e.g., the Android (Android Studio, n.d.), or iOS (Apple, n.d.) SDKs.

References

Android Studio. (n.d.). Retrieved from https://developer.android.com/studio/index.html

Apple. (n.d.). Retrieved from https://developer.apple.com/devcenter/ios/index.action

Licenses and Attributions

Guidelines on Mobile Device Forensics by Rick Ayers, Sam Brothers, and Wayne Jansen comprises public domain material from the National Institute of Standards and Technology, U.S. Department of Commerce. UMGC has modified this work.