Sunday 4 October 2015

How to send and receive messages when you travel

WhatsApp went free on the App Store during the holiday season to contend the pushing competition from Viber, Line and others. Being able to text other users without having to pay is a treat that has attracted million of users from every platform, keeping WhatsApp as the king of the messengers for now. There's no charge to use the service, at least on iOS, but there's an associated cost to your connection. Is WhatsApp really free?


WhatsApp needs to access the internet to be able to work; some type of connection needs to be available to send and receiving messages. In the case of the iPhone, this boils down to two options you're already using.

Understanding cellular data vs. WiFi
Just to be clear, cellular data is the internet access you get from your mobile operator either on prepaid or contract from companies like AT@T, Verizon, Vodafone, T-Mobile, Orange, EE… Depending on your plan, you're likely to receive a certain amount of data — measured in MB — included every month or, perhaps, you pay directly for the usage. You know that bill every month with your smartphone calls, SMS and data? You will be able to use WhatsApp with the that data service provided by your mobile operator.
If you're at home, work or anywhere else with a wireless WiFi hotspot (like the Tube!), your iPhone can make use of it and stop using cellular data network. Wireless internet connection was originally meant for laptops and desktop PCs, but they've become super-convenient for smartphone users. If you're paying a broadband or cable company to give you internet access through an ugly router somewhere in your house, you can also use this service to use WhatsApp.
You can disable cellular data on iOS going into Settings > General > Cellular menu
Why would I spend two paragraphs explain things these basic? It turns out a lot of people ask why would you have to pay for WhatsApp not realising they're paying already for these two types of internet connection: on the mobile and at home.
When you travel, and most importantly, when you go to a different country, these two options become irrelevant. Walking some meters away from your home, the radius of the WiFi network will decrease until it disappears. Crossing the border to a different country will also affect your mobile service, eventually getting a message indicating that your company cannot provide coverage, offering you to use some of the local mobile operator partners — at a cost. 

What are those roaming charges?
And this is exactly what roaming means. Connecting and using the services of a mobile network you're not subscribed to. If you take the time to ask your provider before you travel, there will be additional charges to use mobile internet abroad on roaming, which are typically not included in your package.
The good news is that using roaming you can carry on using WhatsApp regardless of where you are. On a negative note, all the messaging you could do for free now needs to be paid, as you're using the mobile network of a carrier that you're not subscribed to. Your mobile operator takes care of that and will make sure those extra charges appear on the next monthly bill when you get home, labelled as roaming charges.
Just for the sake of comparison, let's illustrate the point using the mobile operators available in the UK. Let's say I'm going to spend the weekend in Paris, France, and I want to keep using my iPhone, which I have on a monthly contract. EE and T-Mobile are the cheapest at the time of this writing, offering one MB of data for 25p and 33p respectively. O2, Vodafone and Three go for around 69p each. You can also get small packages for the day ranging from 100MB to 10MB for prices under £3.

You do the math
Now that I know how much I need to pay, I need to figure out how much I'm going to use. How do you know the message size on Whatsapp? How many MB does the app use to work? I have contacted the company to enquire about this but I received no comment. There's a simple test on this post that you can try yourself.
From my data usage testing comparing Viber and WhatsApp: Messages have a low data consumption, ranging from 1.0 KB to 3.0 KB for both apps. I suspect WhatsApp uses more data since it runs in the background to verify who's online and update the latest messages – that was 13 KB in one launch.
Resetting the data counter to zero is the most realistic way to calculate how much WhatsApp uses. This menu is hidden in Settings > General > Usage > Cellular Usage
WhatsApp will keep running in the background to be able to tell you when someone has messaged you and update all the statuses and "last seen" labels for your contacts. Keeping the app running in standby for a day could be up to 400 KB. Each message will be as small as 1.0 KB, increasing if you attach a picture, which can go up to 30 KB. If you make the basic math, keeping WhatsApp running for a day (400 KB) and sending and receiving 20 messages with text only (1 KB) and five pictures (30 KB) would be account for 570KB.
Since one Megabyte equals 1024 Kilobytes, our sample usage described above is 0.56 MB. I haven't tried each mobile operator, but I'm certain they bill you per full MB, so you will pay for one MB even if you only use half of it — that's why they tell you the MB is for 24 hours. So there you go, using WhatsApp abroad while on roaming should be at least one MB per day.
Now it's down to you to compare the cost with standard SMS on roaming and the use you're going to make of other apps that require data service, such as email, web browsing or maps. Remember that you may find some WiFi spots when you travel, and that's the key difference to reduce extra charges for using your phone on roaming. Happy travelling!