Is there a difference between a Dual Standby and a Dual active phone?

By | April 5, 2014

Recently I went to an online shopping portal to buy Moto G for my sister and while glancing through the specs sheet something caught my eye. Moto G is a Dual SIM device and specs sheet on that website stated that it is a dual standby device. I was little confused at this as currently I’m using HTC Desire VC which is dual SIM dual active device, which literally means even if one SIM is busy other SIM can receive the call. But still I was confused about dual standby technology and I thought of fully acquainting myself about these two tech jargons before finally making a decision. So I conducted a research for some time and found my answer.

Now a days it is very common to see dual SIM devices being launched every other day and this phenomenon is much more prevalent in emerging markets. You also came here searching for “What is the difference between dual standby and dual active phone?”. So now let us see what are the set of features which separate dual SIM dual standby and a dual SIM dual active phone.Dual SIM Dual standby active

What does it mean by Dual Standby phone?

Generally speaking you will find dual standby technology in most of the budget or some mid range phones. As the name clearly suggests both the SIM’s are on standby or ready to act as and when they receive a call. But once a SIM is busy receiving a call the other SIM becomes inactive and if somebody calls on the inactive SIM at the same time they will hear “this phone is currently not reachable, please try later. I have personally experimented this on Moto G which is a dual standby smartphone and found this to be true.

Another problem encountered on a dual standby phone is that if you using data (2G/3G) on one SIM then the other SIM becomes inactive. However when I tested Moto G for this nothing of this sort took place. In fact I saw a full 5 minute Youtube video on MTNL 3g and simultaneously the second Airtel SIM was able to receive call for 2-3 times.

If you use both the SIM’s for voice calling then there is a work around for this problem. You need to forward calls from both the SIM’s to each other in case they are not reachable. So suppose if you are making a call from your SIM A and and someone is calling on your SIM B simultaneously. In normal circumstances SIM B would be unreachable to your caller, however after you forward SIM B to SIM A in case it is unreachable then SIM A will receive a call waiting notification. Similarly you have to forward the call from SIM A to SIM B to make this workaround work for you.

These phones use same transceiver to receive signals for both the SIM’s and hence consume lesser battery power as compared to dual active phones. Some examples are Samsung Galaxy Ace Plus S7500, Samsung Galaxy Ace Duos, Moto G etc

What does it mean by Dual Active phone?

Dual SIM Dual Active simply means both the SIM’s remain active all the time and it is relatively much more easier to understand. So in a nutshell when you are taking calls on one SIM second SIM can receive calls and messages. Apart from this you may also switch between calls by putting the one caller on hold, the way you used to do during call waiting on single SIM phones.

Dual active phones have two separate transceivers (antennae) for signal reception for each SIM and sometimes even processor cores are assigned for particular SIM. All these leads to excessive power usage and hence battery gets drained quickly in dual active phones. Some examples are LG P520, HTC Desire VC, HTC Desire XC, HTC One Dual SIM, HTC Desire 600c.