Roundtable: Cellular/Wi-Fi Integration

There is a disconnect between the approach that 3GPP is taking with ANDSF and what the Wi-Fi Alliance is taking with hotspot, discovery and policy delivery technologies.  There have been statements made that these do not necessarily work together well. I wanted to ask you what your perspective is on this issue and how would you think the industry and standards organizations involved in delivering these solutions will evolve?

Allan:   I don’t think these are competing but rather complimentary architectures.  How they leverage each other is going to become more apparent over time--probably over the next year. With regard to policy, it’s really being able to tie it back into rules and use cases that consider subscriber entitlements, current location and network conditions. Hotspot 2.0 can provide local decisions on selection of Wi-Fi networks based on information from access points. The ANDSF policy server can add additional value with further decisions based on the overall network conditions, the cellular network and Wi-Fi, including the aggregate traffic. The policy server can also base decisions on the subscriber’s service plan, their entitlements and preferences. So, this can be policy rules-driven and Hotspot 2.0 is not necessarily focused on that.

One use case, for example, is where Hotspot 2.0 provides some network loading at a particular access point. And that information can also be used within the ANDSF architecture in a couple of ways.  Clients, for example, may use that network loading information that’s received from the access point directly. For example, they might use that to make some decisions as to when to offload or not offload. And so that can be complimentary and then there’s a couple of potential ways that over time, even that information can be made available back into the ANDSF server. I would say that some of the capabilities of Hotspot 2.0 we’ll see being leveraged into the ANDSF approach or architecture.

Alex:   I want to switch gears a little bit and go back to some things that Todd talked about in his opening statement regarding the integration of Wi-Fi access point capability at home or elsewhere that RadiSys and InterDigital are working on, and also the integration of access for Wi-Fi and the security gateway that RadiSys is working on. What I want to ask is how important do both of you think physical integration of Wi-Fi and cellular is going to be? I’m talking about integration within a single device and probably the question is most important for devices that are at the edge of the network: the Femto access points and the Wi-Fi access points. Right now most of the implementations out there are separate. We’ve collaborated with RadiSys and others to bring them together, but the question is whether you see that kind of a physical integration as an important trend going forward. And it probably makes sense to start with Todd on this one.

Todd: Yes, I do see it as an important step. I’ll go back to the survey I mentioned earlier. In that survey we asked a similar question regarding which type of small cell, focusing only on public access type small cell versus a home solution, is most interesting to the operators that we surveyed. And the response options were single-mode 3G, single-mode LTE, 3G plus Wi-Fi, LTE plus Wi-Fi, and 3G plus LTE. And out of the respondents the largest majority was 3G plus LTE but right behind that was LTE plus Wi-Fi and 3G plus Wi-Fi.

There are very few companies really pushing towards just 3G or just LTE. From where we sit today there isn’t a significant amount of integration that’s deployed yet, but we are starting to see some of it. For example, Telefonica in the UK has deployed a hotspot network throughout London in support of the Olympics that has Wi-Fi as well as 3G capabilities in a single box. So, it is starting. I think it’s important to get to this carrier-managed approach. There’s only so many lamp poles and so many locations that you can deploy small cells, so taking advantage of some of just the most base logistical benefits and cost savings from a converged deployment, and then building upon that to provide a carrier-grade of services and load balance things across the different networks becomes very valuable.

I don’t think that you can assume that it’s a no-brainer and that in every deployment scenario you should have the two of them physically integrated. It will vary, but we certainly see a significant drive toward physical integration with the two technologies. And you can see it happening in the ecosystem, too. If you look at what Qualcomm is doing with the Atheros acquisition, they are building a strong position in Wi-Fi to deliver an integrated solution between Wi-Fi and the licensed technologies. Broadcom is playing heavily in the small cell market. So, we’re seeing the silicon vendors looking to have a strong Wi-Fi portfolio, or certainly make significant investment to bring those capabilities together. That’s a good sign for the market’s move towards dual-mode.

Alex:   I want to switch topic and bring up one issue that we have not talked about. That’s the issue of session continuity, the ability to seamlessly move application flows to and from Wi-Fi or between Wi-Fi and cellular. It seems to us at InterDigital that ultimately session continuity provides the likely glue and plumbing that will enable the full integration of Wi-Fi into cellular networks that we’ve been discussing. At the same time what we see is a very, very limited adoption of these kinds of session continuity technologies in the industry. What your opinion and where do you see this going? Why do you think the adoption today is fairly limited? Perhaps we can start with Allan on this one.

Allan:   Yes. I agree session continuity is key to improving the user experience and we’re seeing a lot of CAPEX decisions on WLAN gateways with a key value being session continuity.  It’s a core functionality of our 7750 gateway platform that is getting a lot of traction. So, the adoption is just beginning but certainly, operators want to have session continuity inclusive in their carrier Wi-Fi service.

Todd: I agree. I think it’s a matter of the time it takes to get from testing and trials before actually delivering the service. I think that’s one of the first things the industry tried to tackle regarding session continuity. Operators are starting to adopt it now.

I think there would be some reticence to allow folks to migrate between Wi-Fi and 3G or other technologies and in a more seamless way from a mobile operator’s perspective if there wasn’t much managed capability on the Wi-Fi network. They go hand-in-hand.  We are experiencing this today where we see Wi-Fi gateway functionality built into our converged Security Gateway product.

In the real world it doesn’t happen super-fast, or as fast as any of us want it to, but in the relatively near future we’ll start seeing more service offerings provided to the market. This will be especially true for those operators that have a lot of their own Wi-Fi hotspots. There are operators out there that have 30-40,000 Wi-Fi hotspots under management. They’ll certainly be the first to deliver that type of service.

Alex:   I want to thank both of you for taking the time to participate in this discussion. Before we conclude our roundtable, I want you an opportunity to make some concluding remarks.

Allan:   I think over the next few years we’re going to see a lot of creativity focused around Wi-Fi and how it’s integrated with 3G and 4G technologies. Certainly expect significant technical advances, and advances and variation in business and marketing approaches and creativity around how Wi-Fi is used in conjunction with 3G/4G technologies.

Todd: I’d like to echo that. From Radisys’ perspective, our main focus is helping our customers to enable operators to deal with the huge influx of data traffic and manage and monetize that traffic. It may be through our support of small cells and Wi-Fi-related technologies, policy enforcement and policy-managed type applications, or through intelligent edge solutions. We do see Wi-Fi as a key component and something that we see really marrying well with our small cell strategy and security gateway products.

Alex Reznik is a Senior Principal Engineer at InterDigital where he currently leads a team that focuses on innovation and systems design in the area of heterogeneous networks, IP mobility and the evolution of these technologies for the future mobile Internet.

Allan Jerrett from Alcatel-Lucent is Director of Product Management in Network and Services Management, IP Division.  His responsibilities include the 5780 dynamic service controller, which is a platform and a portfolio of control applications, including policy control: PCRF and the ANDSF or Access and Network Discovery and Selection Function.

Todd Mersch is Director of Product line Management in the Software and Solutions group for RadiSys. Todd’s area of oversight includes SIPware-branded software products as well as professional services and solutions within the company.