What is Dual SIM and is it for me?
The answer to this question is surprisingly more complex than you might initially think. For many in the UK Dual SIM may be a term you’re not familiar with. This is because in the UK most phones sold in mainstream stores only have a single SIM slot.
If however you’re one of our Asian customers, you’ll probably be wondering how someone could survive with only one SIM card!
Reasons for having Dual SIM
Having a second phone number might seem like a reason in and of itself. But why might you want a second number? Isn’t one enough?
There are a number of practical uses for a second phone number so let’s take a look.
Difficulty moving between providers
As you would expect there are different requirements around the world in regards to network compatibility. This is often why dual SIM slot phones appear in some countries more than others.
In some countries in the past it has been difficult to reliably change between providers. One solution to this was to sign an agreement with a new provider and use the 2nd slot!
In the UK we have for a long time enjoyed the ability to freely move between mobile operators. We can also easily take our current number with us. This has been part of UK law since 2003, and has meant that it has been fairly easy to move between mobile providers.
This type of legislation has only recently been introduced in some countries, or in some cases not at all. So when customers in these areas have moved to a new network provider, they have to get a new card and contract. To make sure people can still contact them using their old number, they need to keep their existing SIM card running.
Issues with coverage
Another problem and reason for needing Dual SIM are issues of coverage.
Due to the size of some countries there is no one mobile network which has complete coverage. Even in heavily covered countries such as the UK this is still an issue in rural areas!
Having two SIM cards allows you take advantage of two network providers that may be available in different parts of the country. Although only larger countries in theory have this problem, I imagine many of our readers will no doubt comment that mobile coverage is not perfect in the UK.
Keeping work and home separate
Another reason for Dual SIM is wanting to keep your home life and work separate. This is particularly important for anyone who runs a business from one phone.
Having two SIM cards lets you keep calls and messages for two numbers separate. So you can give out your numbers to the appropriate people. Depending on the phone you can set it to prompt which number to call out on every time, or have defaults. For instance all outgoing calls on SIM 1 and all text messages on SIM 2.
There are of course other reasons for needing dual SIM card slots, these are just some examples. Dual SIM phones are a great way to make sure you are constantly available and easy to contact.
So are all Dual SIM phones the same?
There are in fact two main versions of Dual SIM phones ‘Passive’ and ‘Active’.
Passive Dual SIM
‘Passive’ (standby) is when a phone has a single, shared antenna for both SIM cards. As the name suggests both SIM cards spend most of their time being in a passive standby mode, waiting to be used.
When you start using one of the SIM cards for either voice or data, the other automatically becomes inactive. Only when you have finished using the first SIM card can you start using the second.
This means you are not able to simultaneously download data using one SIM card while making phone calls with the other. At first this does seems limiting, but in practice is unlikely to cause too many issues. Particularly as if a line isn’t available to accept a phone call, it is usually diverted to voicemail automatically by the network provider.
This is the more cost-effective solution for consumer Dual SIM smartphones, so by far the more common version you will see available.
We can now offer this type of Dual SIM phone from a variety of manufacturers including Motorola, Huawei, CAT, WileyFox, RugGear and Microsoft to name a few.
Active Dual SIM
‘Active’ refers to phones which benefit from having two antennae, one for each SIM slot. This means you can simultaneously use the two SIMs. For instance downloading content on SIM1, and making a phone call on SIM 2. You can even have two conversations, switching the calls and putting one on hold.
There are some disadvantages with this type of Dual SIM phone, the most obvious being cost. There is an extra cost in having two antennae built in to the phone. You also have increased battery consumption, as the power draw for cellular connections is effectively doubled.
Finally there is the problem of availability. In countries like the UK they are almost impossible to source. For instance HTC released a Desire 600 with Dual Active SIM card slots, but this was never available in the UK.
Generally if you specifically need an active Dual SIM phone you might sacrifice high end specifications, or buy from a brand you are not familiar with.
Other Things to Consider
When buying a Dual SIM phone we would recommend checking if both slots can use 3G/4G connections.
Not all phones have the this functionality available on the second SIM slot. Many cheaper Dual SIM phones only allow data on one SIM card and just calls/texts (2G) on the second.
Also many manufacturers combine the SD card and second SIM card slot to create a hybrid slot. This is typically done to save on space, when manufacturing a smooth, slim phone. This can help improve looks, but again limits functionality, as with this setup you need to choose between a second SIM card or expanding storage with an SD card.
Finally some basic setup is necessary to fully take advantage of the dual SIM capabilities. To make sure data connections and phone calls use the SIM card you prefer, you will need to manage your phone settings carefully.
There are some disadvantages with using Dual SIM, but for most people who need this type of phone the benefits are far more important.
You will be able to manage your calls and get the coverage you need in areas of poor reception. An increasing number of manufacturers now offer this type of phone.
Here at Clove Technology we offer a wide choice on our website. As we mostly source UK stock, some of the major brands are missing from the list, however in the future this feature will be available on more phones giving more choice to customers.