Dialogic Blog

Has Roaming Killed the 4G Star?

by Cristina Cocco

Aug 7, 2014 5:18:43 AM


It’s been a while since the major mobile network operators (MNOs) in Europe first started deploying LTE.

Over here in Italy, the MNOs advertising campaigns on their 4G/LTE networks have been endless. They started before the networks even launched and they have been promoting them long since they went live.

Even though 4G is not available in all areas, it is found in major cities and it is gradually expanding and getting new subscribers.

Anyone with an LTE device living in, working in, or temporarily accessing a 4G-covered area has become adjusted to the service experience, and I dare say, expects it to exist in the major urban areas whenever they roam abroad. Well, maybe I’m just speaking for myself.

When I crossed the Italian border and flew to Paris, the World Cup was still on. I was banking on fast data delivery in order to watch the matches on my smartphone, since I did not anticipate access to Wi-Fi hotspots.

To backtrack a little bit, before I switched my phone off and boarded the plane in Milan, I noted I was receiving a 4G signal, and needless to say, I was expecting it when I got to France. I anticipated as much because my provider was advertising it on the airport billboards.  But when I landed in Paris and switched on my phone, the device went to 3G, and I never got the slightest flicker of 4G. This is despite the fact that I was roaming on the network of one of the major domestic and international MNOs.

At first, I didn’t really give it a thought; I was at the airport, outside the city, and possibly in a 3G-only covered area. However, during my entire stay in the city, my phone only got 3G, EDGE or no service at all. And that happened in a touristy area of a city, not to mention in the midst of a very important quarter final World Cup match!

How was that possible when the likes of Vodafone, Orange, TIM, SFR, and 3, to name a few, not only have extensive 3G roaming agreements, but are adding more and more 4G agreements each day? 4G roaming is a hot topic with Dialogic’s service provider customers. Roaming relies on a complex interplay of signaling messages that can be incompatible between the visited and domestic providers due to differences in the underlying equipment used in their respective networks. When I roam in another operator’s network, my data has to go all the way back to my domestic operator to hit the Internet. While this not only costs the operators sizeable backhaul charges, it can also potentially degrade the response and speed that I’ve come to expect. So we’re starting to see operators considering “breaking out” the data closer to where I’m roaming (Local Break Out).  This means additional complex information sharing between networks regarding what I’m authorized to do and how much potential bandwidth I’m allowed to use.

On the flight home, I wondered how long it will take to get a consistent 4G roaming experience when abroad, especially in light of the new EU roaming guidelines that went into effect July 1, 2014. When I got back home, I checked with my operator’s customer care team, and they assured me that I should have had 4G service while roaming in Paris.

How was it that I was not able to use 4G through my roaming provider when I could easily get it from my domestic operator in Italy?  Why didn’t my domestic operator give me the choice of roaming either at 3G or 4G speeds? Was my inability to get 4G in Paris due to an authentication problem, or an incompatibility issue between my home network and the one in Paris? Could it be that the providers just did not have a roaming agreement that included 4G?

At Dialogic, we see questions on 4G-to-4G as well as 3G-to-4G data roaming interworking. Service providers are deploying platforms known as Diameter signaling controllers (DSCs) to make this interworking between networks that support data roaming more secure, consistent and a lot easier.

In the meantime, I have a new mobile service ads suggestion for my MNO: “Sorry, 4G may not be available when roaming.”

Tell Dialogic your roaming story by tweeting us at @Dialogic.