Question

Compare the file storage of two types of cell phones, such as an iPhone and an Android phone. Research the amount of system software that occupies main memory after the phone is completely powered on. If the amount of storage used by the system files are substantially different, explain why that may be the case, such as platform issues, features, and so on. Cite your sources.

Cell phone configuration doesn't matter. Can pick any two types of cell phone.

Answer 1

INTRODUCTION:An array of functions is performed on a mobile device –ranging from a simple telephone device to personal computers that are designed for mobility, relatively compact in size, lightweight and battery-powered. Mobile devices can be differentiated on a basic, comparable set of features and capabilities. They include the microprocessor, ROM, RAM, radio module, digital signal processor, microphone, speaker, the various hardware keys, interfaces, and LCD. The mobile operating system can either be stored in NAND or NOR memory. Meanwhile, the code execution occurs in RAM.

Today, mobile devices are equipped with the system level microprocessors, which reduce the count of supporting chips and increase the considerable internal memory capacity. Currently, this is up to 128GB (e.g., Stacked NAND). The Built-in Secure Digital (SD) memory card slots, includes micro Secure Digital eXtended Capacity (microSDXC), may support removable memory with different capacities from 64GB to 2TB of storage. All non-cellular wireless communications including infrared (i.e., IrDA), Bluetooth, Near Field Communication (NFC), and Wi-Fi used to exchange other data can be built into both the device and support synchronization protocols.

Mobile devices have altogether different technical and physical characteristics. They vary in size, weight, processor speed, and capacity of the memory. Mobile devices may likewise use diverse sorts of extension capacities to give extra usefulness. Also, mobile device capacities occasionally incorporate extra features –for example, handheld Global Positioning Systems (GPS), cameras (still and video), or computers. Generally speaking, mobile devices can be anything from simple feature phones that are essentially straightforward voice, up to specialized gadgets or smartphones that offer extended capabilities and administrations for interactive media, such as those of a computer. Table 1 highlights the generic equipment attributes of feature and smartphones which underscore these qualities.

This illustration should give a feeling of the scope of the equipment on the commercial market. After some time, qualities found in smartphones tend to show up in feature phones as smart phones develop innovations. In spite of the fact that the lines of depiction are fairly dynamic, the table is filled a general guide.

Smartphone	Feature Phone
Display	Large size color, 16.7 million (~24-bit)	Small size color, 4k – 260k (12-bit to 18-bit)
Memory	Superior capacity (~128GB)	Limited capacity (~5MB)
Camera	Still, Panoramic, and Video (HD)	Still, Video
Processor	Superior speed (~1.5- 2.5 GHz octa-core)	Limited speed (~52Mhz)
Text Input	Touch Screen, Handwriting Recognition, QWERTY-style keyboard	Numeric Keypad, QWERTY-style keyboard
Card Slots	MicroSDXC	None, Micro/Mini SD
Voice Input	Voice Recognition (Dialing and Control)	None
Positioning	GPS receiver	None, GPS receiver
Battery	Fixed/Removable, Rechargeable Li-Ion Polymer	Fixed/Removable, Rechargeable Li-Ion Polymer
Display	Large size color, 16.7 million (~24-bit)	Small size color, 4k – 260k (12-bit to 18-bit)
Cell Interface	Voice and High-Speed Data (4G LTE)	Voice and Limited Data

Feature phones and smartphones both support voice, messaging, and an arrangement of essential Personal Information Management (PIM) sort of applications, including phonebook and logbook applications. Smartphones include PC-like capacity for running a wide assortment of general and unique applications. Smartphones are relatively bigger than any feature phone, and can bolster higher video resolutions (e.g., ~300 PPI). Smartphones may also have a QWERTY keyboard or touch screen. Smartphones support numerous applications available.

Mobile devices contain both non-volatile and volatile memory. Volatile memory (RAM) is occupied for dynamic storage, and its contents are lost when power is drained from the mobile device. Non-volatile memory is persistent as its contents are not affected by the loss of power or overwriting data upon reboot. For example, solid-state drives (SSD) store persistent data on solid-state flash memory.

Mobile devices typically contain one or two different types of non-volatile flash memory. These types are NAND and NOR. NOR flash has faster read times and slower write times than NAND. NOR is nearly immune to corruption and bad blocks while allowing random access to any memory location. NAND flash offers higher memory storage capacities, is less stable, and only allows sequential access.

Feature phones were among the primary type of devices, which contained NOR flash and RAM. System and user data are stored in NOR and replicated to RAM on booting for faster and quicker code execution and access. This is called first generation mobile device memory configuration.

Initially, when smartphones were released, memory configuration evolved, including NAND flash memory. This development of NOR, NAND and RAM memory is considered second generation. This generation of memory configuration stores system files in NOR flash, user files in NAND and RAM is utilized for code execution.

The recent smartphones contain just NAND and RAM memory which is known to be part of third generation, because of increasing transaction speed, more storage density, and lower cost. To encourage the miniaturization on mobile device motherboards and the interest for higher density in storage space (i.e., 2GB – 128GB) the new Embedded MultiMedia Cards (eMMC) style chips are available in almost each smartphone. The figure beneath depicts a variety of memory configurations across mobile devices.

RAM is hardest to capture accurately because of its volatile nature. Since RAM is ordinarily utilized for program execution, information or data might be valuable to the examiner, for instance, configuration files or passwords, etc. RAM acquisition tools for mobile devices are starting to be accessible.

NOR flash memory incorporates system data; for example, operating system code, kernel, drivers, system libraries, memory used in the execution of an application running on the operating system and the user application execution instructions. In data accumulation for first generation memory configuration devices, NOR flash is the best location.

NAND flash memory contains the following: PIM data, graphics, audio files, video files, and other user files. This kind of memory in most cases gives the examiner the most valuable data or information. NAND flash memory may forgo various duplicates of transaction based files like logs and database, because of wear leveling algorithms and garbage collection routines. However, NAND flash memory cells can be re-utilized for just a restricted time period before becoming unreliable, wear leveling algorithms are utilized to expand the life expectancy of Flash memory storage, by organizing data so that re-writes are disseminated equally over the SSD.

Garbage collection happens because, NAND flash memory cannot overwrite existing data, the data should first be deleted before writing in the similar cell.

iphone:

Storage on an iPhone or iPad refers to the amount of solid-state flash memory available for storing apps, music, documents, videos, games, and photos. The amount of storage available is described in GB, or gigabytes, and iPhone storage on current devices ranges from 32 GB to 512 GB. Apple's Operating System (iOS) typically takes up some of that space, so it won't all be available to you.

This is a storage problem that afflicts all computing devices. For some reason, device manufactures count 1GB differently from how it is counted by a machine using intelligent software. This means a 320GB laptop never has 320GB internal storage. A 1TB hard disk never has usable 1TB storage. And a 16GB phone never has 16GB usable space.

This happens because phone makers count 1GB = 1000MBs. But the software treats it differently. It counts 1GB = 1024MBs. So when a phone makers gives you 1GB, you actually get only 1000MBs and not 1024MBs.

Or in other words, device manufacturers use decimal system to measure capacity. But software uses binary units to measure it.

Apple explains it best on its website. It says (to avoid lawsuits),"1GB = 1 billion bytes; actual formatted capacity less."

So how much is the actual formatted capacity of a iPhone, or for that matter any other phone, that has 16GB specified storage?

According to binary method 1GB = 1073741824 bytes. This means if a device like iPhone has 16 billion bytes internal storage, the actual capacity that software has access to is:

16,000,000,000 divided by 1073741824 = 14.9GB

So, a 16GB iPhone actually has 14.9GB internal storage.

The 14.9GB internal storage that you have on your phone has to be shared with the operating system. The Android or iOS that is installed on your phone is using the same storage. So depending on the size of the OS, you will get less storage than 14.9GB for your photos, music and apps etc.

How less depends on what kind of operating system you are using. For example, on Nexus 5 running Android Lollipop users get access to 12.5GB space so around 2.4GB is taken by the core software installed on the phone.

But because different companies use different (and modified) versions of Android, the size of the core software tends to be different. For example, on Galaxy S5 running Android 4.4 with Samsung's Touchwiz user interface, the available space is slightly less than 9GB. On the RedMi Note with 8GB internal storage, users get a little over 6GB space.

Considering every phone nowadays uses somewhat modified or different version of core Android software, the available internal storage is different in every phone even if they all have "16GB internal storage".

So next time you are buying a phone, don't just go by what is printed on the specification sheet. Even with the same 16GB storage, one phone may give you 12GB of usable while other may limit you to just 9GB.