Posts Tagged ‘Nokia’

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.