Mobility Now

One feature that is usually found on mobile devices spec sheets is the amount of memory. Unfortunately, there’s often only one type of memory shown, and it’s not always obvious which type it is. In order to know exactly what a handset can support, it’s useful to know the different types of memory that each devices can have.

Asking how much memory a phone has can actually result in multiple, different answers, and to make things harder a lot of web sites confuse the different types. In general, these are the types of memory a phone can have:

• ROM: This is non writable memory, containing the basic operating system of the phone. When you do a hard reset and format the memory of the phone, what’s on the ROM is what stays and why your phone can always be reset to factory settings. The amount of ROM a phone has is irrelevant since you can’t add things to it.

• Flash / internal memory: The amount of internal memory, sometimes called flash memory, is the space inside the phone where programs reside and where you can store messages, contacts and files. It’s usually the number you see when you look at a phone description and it says, for example, that the Nokia 6620 has 12 Megs of memory. If you are trying to save data such as a game on your phone and your phone complains about memory issues, this is probably what it needs.

• RAM: This is the temporary memory used to run programs. It must not be confused with the flash, since it can’t be used to store data. The memory is cleaned every time the phone is turned off. This is very rarely written in descriptions, but it’s very important since it dictates how many programs you can run at once. Some tools can tell you the number, such as FExplorer for S60 phones. The 6620 has 26 Megs. In some devices, built in flash is used for both internal memory and RAM. When trying to run a program, if it complains of memory issues, or closes due to running out of memory, this is what it needs. Note that the operating system itself as well as other running applications use up RAM and it’s often possible to free some more memory by closing applications or sometimes with firmware updates.

• External memory: This is simply the external memory cards that can be added to the phone. Many phones have extension slots now, but you need to be aware of the maximum size they support (512Megs, 1G, 2G, 4G and so on), and also the type (MMC, MSD, MiniSD, MicroSD and so on). There are not a lot of differences between the various types other than physical size and power consumption. Some recent models also introduced some DRM (copy protection) capacities.

• SIM: A SIM card is the little card used in GSM phones to store your phone number and contact information. These cards also have memory that can be used to store information. Usually it’s limited to contacts and sometimes a small amount of messages. The memory size can be tiny, such as 64KBytes, but it can be useful to transfer contact lists between phones.

When shopping for a phone, especially a smartphone, it’s important to have all the numbers. For example, a Nokia N80 has less free RAM than a N73, and will have more problems running multiple applications, even if both are modern smartphones. It’s important to check for these numbers in specs sheets or reviews to know if the phone will meet your needs, and then you’ll be sure to never run out of memory.

Symbian-Freak has a quick comparison of the Nokia N95, N93 and the Sony F707 Digicam. The main question being, can the latest 5MPx smartphone do as good as a 5 years old Sony digital camera. They post comparison shots and come to the conclusion that no, the digital camera still comes out on top.

The thing to remember is that the quality of a picture is not only based on the amount of megapixels. It’s based also on the lenses and on the software that processes the raw image, as well as the compression of the resulting JPEG file. The N95 has good lenses, but Sony is known to make very good cameras. Also being a phone, the processing is done by some rather new software running on top of a smartphone operating system, while the Sony is an actual camera.

Still, if you take a look at some recent Flickr photos taken by phones, the quality is still very good for web shots and medium sized photos. For many people who don’t need the best quality photos, a recent camera phone is enough.

Choosing a phone is usually based on many factors: look, style, type of phone, recommendations from friends, and hopefully features. Many people forget features and go purely for look, but that’s for another time. One thing that the vast majority of consumers forget, is battery life. At most, we see a 4h talk time / 260h stand-by time listed on the box and don’t think twice about it. However, it’s the first thing that comes to haunt us when the phone dies on us while in the middle of a crucial operation.

One myth about batteries is that all phones are pretty much the same, with relatively poor battery life. This is not the case. Most phones will, with typical usage, last a couple of days, but there are extremes. Some will literally not last a single day, and will require charges every couple hours, unless left totally unused. Others will be usable for weeks, where you can actually spend a full 2 weeks without charging it.

There are 2 factors that determine battery life. First is the power of the battery, which is based on the size and the electric charge measured in milliampere-hour (mAh). If the phone is very small or thin, the battery will also be smaller. This means the battery will most likely not last long. If it’s a bigger device, and the manufacturer can put in a bigger battery, then chances are it will be able to power the device for longer. The electric charge of the battery can also vary, usually between 860mAh and 1500mAh for most phones. There is a very big difference between one extremity and the next. Also sometimes the manufacturer will offer a “standard” and an “extended” battery of the same size, and if you look at the specs, what changes is the electric charge.

So now that we know what the battery is capable of, the second factor to look at is the power consumption of the phone. Again, it varies greatly from one feature to the next. The operating system on the phone will take power, and having a smartphone with multiple applications running will of course drain the battery faster. Being connected to a GSM or CDMA cellular network takes very little power, but 3G requires slightly more. Using wi-fi, if your device handles it, will take a lot of power. Using built-in GPS is even worse. The screen is another thing that takes power, and as the screens get better, bigger and with higher resolutions, they require more power. Using a screen saver in this case is actually a bad idea because animating it takes power. The best thing is if the phone can shut down the screen after a few minutes of inactivity.

There are things that can be done to save battery life. If you only have access to a GSM or CDMA network and your phone supports 3G, going in the setting and turning 3G off is a good idea, because switching from 2G to 3G takes a lot of power. Switching wi-fi scanning off is also very good, because scanning using the wi-fi antenna every 15mins will drain the battery in no time. The same is true for GPS. Also any extra screen saver, animation or background application running will take more power.

Battery power is one thing everyone wishes would improve on mobile devices. For me it’s an important part of why I select a device, and on my Nokia E61i (with 3G off but using wi-fi) I can get a full week of battery life using it moderately, or a full 8h of browsing / messaging, because it has a large 1500mAh battery. Many older black and white phones also gave similar performances even with lower batteries simply because of the low demands of the phone. On the other hand, reading user comments from say the Nokia 6300 or Samsung X820, their latest thin phones, some people are reporting less than a single day of battery life when using it moderately, and only 4h of usage time. Some will say that battery life is not a huge issue, simply not using any of the phone features will solve the problem. I think that’s a fallacy since there’s no use paying for a high end phone with lots of features if the battery doesn’t support them.