In last week’s blog, I wrote in general about mobile virtual network operators (MVNOs) and mobile virtual network enablers (MNVEs).  In this blog, I want to cover MVNOs and roaming in a little more detail. Some MVNOs started out by offering broadband services and then moved their subscribers to mobile offerings. Their value propositions to subscribers are the same whether they’re billing for broadband or mobile services, certainly on the data side, and perhaps even for voice services. In the world of LTE, this becomes even more important. One can envision an MVNO offering for data and voice services that easily combines LTE and WiFi.


But what about happens when subscribers roam? Even in the same country, a subscriber might roam to a place where the MNO has no LTE service, or the MVNO has no ISP/WiFi relationship. In this case, interworking to other MNOs offering LTE service, or to an MNO’s 3G service, would be required. This has been referred to in Europe as “national roaming,” and it has been a hot topic of conversation and an idea that has been adopted by many countries. In the U.S., if I’m an AT&T subscriber who goes to a place where there is no AT&T coverage, but there is Verizon coverage, I’m out of luck. (If I’m a Verizon subscriber or a Sprint subscriber, it’s the same story.) I need to drive around until I get a signal from my MNO.


So let’s go back to Europe and national roaming.  If I’m on an LTE network and lose coverage, but there is another competing LTE network, I could “roam” to that network.  But let’s say the Diameter signaling isn’t quite implemented the same way, so it’s not so simple. A Diameter-Diameter Interworking Function could enable this to occur and funnel revenue to both of the MNOs here. Additionally, think of a case where the MNO LTE network coverage ends, but there is only 3G service by a different MNO. National roaming could indeed occur again, but there would need to be Diameter-SS7/MAP Interworking required. However, whether the competing MNOs would be motivated to do that is debatable. Perhaps laws could enable that, or forward thinking MNOs could take the initiative.


However, think about if you are the MVNO in this scenario. The MVNO is using an MNO network. If the “home” MNO has no network coverage, what is stopping you from connecting to a network that does have coverage? Well, the MVNO contract with the “home” MNO may stop you, or maybe the phone the MVNO uses is tied to the “home” MNO network. But let’s say those small details are worked out. The MVNO could indeed offer roaming services, too, assuming it had infrastructure in place such as PDN gateways, GGSNs, CSCFs and Diameter Interworking Function signaling controllers. 


What about if you wanted to have your session roam from LTE to WiFi seamlessly, including the billing? You’d need to make sure the Diameter signaling in the LTE network is interworked with the Radius signaling in the WiFi network. Obviously there is investment required here, so this is where a MVNE could really offer services, benefiting both the MVNOs who use the MVNE and obviously the MVNE itself.  But more importantly, the subscriber would benefit since they’d be able to use some cool services.