Mobile to WiFi roaming - threats and opportunities


The GSMA and Wireless Broadband Alliance (WBA) announced yesterday that they will be working together to enable easier and more integrated WiFi-cellular roaming, with the results of their efforts visible in commerical terms in 2013.

The programme will take advantage of existing work to enable SIM-based authentication onto WiFi networks, as carried out by the WBA and the WiFi Alliance in their aligned Next Generation Hotspot and Hotspot 2.0  programmes. Although device-level authentication is one aspect of the process that enables devices to roam between WiFi and cellular networks there are other technical and commercial issues to sort out, and this is really what the GSMA-WBA announcement is about.

Dan Warren, Technical Director of the GSMA, explains the technical challenges in terms of clashes and gaps - in that the GSMA-WBA work is about aligning items where the WFA and 3GPP standards do the same things differently, or where the WBA roaming model is missing elements that are present in the GSMA roaming structure. That way, instead of having two separate definitions, the industry works to a single definition.

One example of a clash, Warren said, is in the signalling that is used to attach WiFi and cellular access networks to core networks. In mobile networks the Diameter protocol is used to handle the core network signalling that enables operators to route and charge for traffic, and to manage policy enforcement. In the WiFi world, that process is defined with the Radius protocol. "They aren't dissimilar," Warren says, "but they need to be matched. 90% of that is right at the moment, though there's a little bit still to be exposed."

Once the technical interfaces are addressed, the issues then become about commercial practicalities. Although the WiFi world has its equivalent of the GRX — the cellular roaming exchange — the GSMA has more detail contained within its own roaming frameworks, and there it can fill gaps in the WRIX model.

"In terms of contracts there is detail in the GRX frameworks that is not included in WRIX frameworks. So we are aiming for a common set of documentation," Warren said. This would enable operators to form bilateral relationships using a common set of specifications, therefore bringing down barriers to roaming for many operators.

So what does this mean for the consumer experience, and for the industry itself? Who stands to benefit most from the ability of operators to strike easier interconnect deals for mobile-WiFi roaming, and to pass that functionality on to users?

This is where Warren, and the GSMA, bows out. "The standard GSMA answer is that what individual operators offer is their business - our work is about giving them the opportunity to offer something additional to their existing services in a standardised manner. How they implement that in commercial reality is entirely the individual operators' business," Warren said. Warren did add though, that the demarcation between the WRIX and GRX could "become a lot more blurred"

One provider of a WiFi roaming exchange service to carriers, iPass, said that it sees the work both as a threat and an opportunity.

Marcio Avillez, Vice President of Network Services, iPass adds, "We recently launched our OMX (Open Mobile Exchange) and one service there is an exchange. So we view this as new way to further monetise all the commercial relationships and technical interconnects we have already. We see it as a welcome event to create new opportunities for us. Starting with the level of interconnect we have globally, we think we can play a central role."

As the standards are combined, however, does iPass see a danger that much cellular-WiFi interconnect business could head over to the existing cellular roaming exchange operators?

"It is a threat but it's one that we are well positioned to face," Avillez said. "The challenges will be more difficult for the GRX players: first because there's dozens of them, and second because there is more technical integration required to the platform. We've added over 20 providers a year and are well positioned to defend our place in the market today."

"The complication is going to be on the policy side, where there are protocols like CNQP, ANDSF and 802.21 that are pointing in the same direction but are not coherent right now. One of the things that needs to be figured out is how policy will be provided and delivered."

Mary Clark, Senior Vice President, Roaming, at Syniverse, sees the technical burden as falling equally on the WRIX side. "Because Wi-Fi uses different infrastructure to GSM, enabling all the technology types to work together requires some architecture adaptations that most Wi-Fi networks do not currently have," she explains.

As for how mobile operators will benefit, Clark and Avillez agree that the core initial use case will be for domestic data offload - attaching mobile users automatically to available WiFi networks with any billing or charging aspects taken care of in the background.

"For mobile operators, the agreement helps them to optimise the end-user experience and increase satisfaction by creating simplified Wi-Fi connectivity. It also helps operators alleviate network constraints by enabling better data offload for domestic 3G bandwidth. Moreover, it strengthens operators' positions as valuable elements of the expanding Wi-Fi ecosystem," Clark says.

Avillez adds,"The challenge on the mobile operator side is how to take that technology solution and take it to market. A lot has been written about taking the friction out of WiFi authentication but, of course, sometimes having friction is a good thing. I think operators need to be able to provide the seamless experience where it makes sense - as in domestic data offload - but there are use cases where you would want to make the user more aware of what's going on."

That includes international roaming, of course, but also a use case such as where a customer has a WiFi subscription as part of his fixed line home broadband deal, but also has a separate contract with a mobile operator who may be attaching the subscriber automatically to its preferred networks. Does the user, the fixed line provider, or the mobile operator decide which networks to attach to, and when? Or do the fixed line and mobile provider take care of that in a separate commercial relationship.

That sort of potential conflict could give a fixed line provider an opportunity to derive greater "wallet share" of a mobile customer, especially as they are "unencumbered by being wedded to the SIM for iD management", to use Avillez's words. Indeed, Avillez thinks greater WiFi-cellular roaming interoperability could give fixed line and cable challengers retail and wholesale opportunities.