Posts Tagged ‘Mobile’

Why do smart phones freeze (or hang or lock up)?

2014/04/22

Old Nokia phones (also known as dumb phones or features) almost never froze! I had a Nokia phone which froze only once (worked fine after restart) in 7 years of use! That is pretty impressive.

However, most smart phones often freeze. Some freeze quite often while some other freeze only occasionally.

Let us understand why it happens.

All smart phones are mini computers inside. They have an Operating System (OS) which interacts with the phone hardware. Users interact with the phone via application layers.

The core of OS is known as “kernel”. This is low level assembly language core which translates users’ requests (via apps) so that hardware can process it. For example, when you dial a number (via dialler app) the request is sent to kernel which instructs the hardware to perform the phone dialing operation. Both Android and iOS runs on highly customized flavors of Unix OS inside them.

The old dumb phones also had similar concept but there was a big difference. Those phones were only allowed to perform few predefined tasks like dialing a number, receiving phone calls and sending texts (along with alarm, calendar etc.).

But modern smart phones are expected to do a lot of things! As a result, it is often very difficult to predict what each app will request to kernel. There are just millions of instructions possible. When many apps send some instruction to kernel, it may get overloaded (takes too long to process which manifests as phone slow to respond) or just get confused (manifests as phone freezing). The freezing often happens due to kernel going into an infinite loop (and does not know how to come out of that) or just bogged down by too much work.

When you use heavy weight apps in lower end (or budget) smart phones, due to slow CPU and small amount of RAM, the hardware gets overloaded. So, those phones often become slow over times. When you install newer versions of apps, they usually take up more space and thus strains hardware even more!

Different manufactures try to handle this problem in different ways. Apple implements a strict control of what its apps are allowed to do and what hardware goes inside the phone. That’s why iOS is more restrictive and iOS users see less frequent freezing. Internally, iOS apps work in a sandbox mode. Each app gets a space in phone storage and it can’t access anything outside of its own sandbox. Once you delete the app, all its traces are gone. This is also the reason why users can’t access iOS file system (unless you jailbreak). Apple also doesn’t allow usage of external memory card which is often responsible for corrupt file systems and thus causing problems.

Android system (even though derived from Unix) is more like good old desktop Windows OS in its behavior. Apps can often access an equivalent of Windows registry style things. Various apps dump garbage in cache, which fills up phone’s internal storage (like hard disk) and phone becomes slower over time. Even if you install an app in SD card, it still leaves traces in internal storage space due to OS design. Android also allows access to file system (just like desktop PCs) which means users can fiddle with its system and may accidentally delete system files!

Microsoft has taken iOS like “sandbox” approach in its Windows phone system. So, in theory, Windows Phones are supposed to crash less! However, these still allow external SD cards so such issues will remain to some extent. Also, as Windows phones have less market share at present, it is difficult to predict if they are indeed superior to Android or iOS.

From empirical evidence, it can be stated that:

  • Apple phones crash the least. However, internet browsing is often unpredictable and quite often iOS browser just crashes but this does not usually lead to entire phone freezing up.
  • Blackberries and Android phones crash often. Lower end Android models crash more if you fiddle with them too much for the reason described in this article.
  • Less matured OS crashes more. For example, Windows phones OS have good architecture but it is still maturing so it may crash unexpectedly.
  • Poorly designed OS will crash often. This is why Nokia’s Symbian based smart phones were notorious for freezing!

If you are an Android user, make sure you clear cache often, manage your applications so that it does not store too much data in phone’s internal memory and refrain from heavy browsing or playing hardware heavy games. This should lead to less crash, especially in budget hardware Android models.

If you are an iOS user (iPhone or iPad), there is not much you can do to prevent freezing (if that happens at all). Sometimes one or two rogue apps may cause problem. In that case, simply get rid of those apps. Some apps when updated, tend to make use of newer features of latest OS. If your OS is older version, you may see apps crashing (but not entire device freezing up).

Windows phones are still maturing so nothing can be advised at this moment.

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Why Android phone users complaint about running out of internal memory?

2012/09/11

If you are an Android phone user, you might have seen “Internal memory full” message sometimes. If you left your smartphone as factory setting then you won’t see this but as long as you installed few apps, then you are likely to see this – if your phone’s internal memory is small.

A typical smart phone as 3 types of storage.

RAM = Random Access Memory, works same way as in your normal computer. For example, iPad 1 has 256 MB RAM.

Internal memory = This is equivalent to your hard disk in your computer. Size of this varies widely. Basic version of iPhone has 8 GB internal storage. Budget Android phones often have as low as 150 MB internal storage.

External memory = Usually in the form of micro SD card. Not all phones offer this option. This is equivalent to having an external hard disk in your computer.

One confusion many Android smartphone users face is that even after installing apps to SD card, it still consumes internal memory!

This is due to the way Android OS works. Even though you install an app into SD card, it still keeps a footprint (like cache etc.) into internal memory. So, you having a bigger SD card won’t allow you install hundreds of apps as you are still bounded by available storage space in your internal storage (i.e. hard disk).

The internal memory is further partitioned to store operating system files (firmware) and user files. The firmware bit is ROM i.e. can’t be erased by user (if you do, the phone will become a brick). Thus, the available space to user in internal storage is further reduced.

This explains, why Android users with budget devices complaint about running out of internal storage.

So, the advise is to buy an Android phone with large internal memory for users (if you get bigger storage but most of which is filled by firmware then it is not much of use).

The SD card is for storing of phones, videos, music etc. You can’t use it to load unlimited apps!

3G vs 4G

2012/06/02

4G is said to be the next big thing. But how exactly it will help you?

The G here represent Generation. 2G was a slow connection. 3G is much faster and 4G will be even faster.

Typical 3G connection speed is 1-2 Mbps. In 4G is will be 5-10 Mbps. This means 4G will be as fast as current home broadband speed. However to achieve 4G speed, your device hardware must support this and network provider must be able to send data at this speed. Only then you can reap the benefit of 4G.

How it is going to help you? You may not need home broadband anymore. Although mobile data plans are rarely unlimited, unlike home broadband in most cases.