Wireless Broadband Alliance enable seamless cellular and Wi-Fi using Small Cells

Tiago RodriguesWi-Fi is being mandated for many public access small cells, with an product specification of a tri-mode 3G/LTE/Wi-Fi small cell commonly thought of as an ideal long term goal. Relatively low takeup of Service Provider Wi-Fi to date isn't helped by clunky, unintuitive and potentially insecure login screens.

Tiago Rodrigues, Program Director at the Wireless Broadband Alliance explains how the WBA has developed a solution which makes Wi-Fi access as easy as cellular roaming, where and how this could be rolled out, and what the WBA/Small Cell Forum partnership could deliver next.

A quick recap of the Wireless Broadband Alliance

The WBA was founded 10 years ago by a group of operators looking at the public Wi-Fi business. Over several years, this club of operators sorted out many aspects of interoperability between different public Wi-Fi networks. This has evolved over time and become quite a large organisation, involving not only operators but also all kinds of partners, device manufacturers, infrastructure vendors and others.

Operators wanted to understand all of the impacts surrounding public Wi-Fi access, not just the technical side but also aspects about how to manage the service, handle billing between operators and deal with customer care – often these issues aren't so much technical as operational.

Changing the customer experience

The WBA recognised that a major barrier to mass consumer takeup of Service Provider Wi-Fi is the ease of use for the end customer. Those of us who appreciate the simplicity of how mobile phone roaming works – just switch your phone on in almost any foreign country and start making/taking calls and emails immediately – are well aware of the clunky and confusing way to access new Wi-Fi networks. Entering a username/password combination for an unknown foreign operator is both potentially insecure and highly inconvenient.

Seamless authentication has always been seen as a relevant topic within the WBA, who started work to achieve this in 2005. There were various trials and tests, but it was really the Next Generation Hotspot (NGH) initiative instigated around 2010/2011 that will create the similar experience for end users as found in the cellular market today. The WBA put in place a program and engaged with the Wi-Fi Alliance to build on their HotSpot 2.0/Passpoint standards. After field trials using Passpoint prototype and now certified equipment, we are now seeing commercial equipment available in the market.

A joint initiative with the GSMA

In partnership with the GSMA, we did a huge gap analysis of roaming procedures – everything from billing, clearing, contracts etc. required to be put in place for commercial roaming agreements. Everyone now follows similar arrangements, whether using Wi-Fi or cellular radio technology. The billing/usage data is transferred using the same TAP file formats, and there are methods that allow operators who use other formats to convert them to TAP. This allows almost any operator to implement a roaming interworking agreement.

Today, Wi-Fi roaming is very much more straightforward than even a couple of years ago. Back then, if a cellular operator wanted to setup Wi-Fi roaming then they needed to employ a dedicated person to administer it because it was so different. With the alignment of procedures in place today, the same administration covers 2G/3G and Wi-Fi. Roaming templates are basically the same, all the billing rules are the same, calendar limits (e.g. how quickly billing data must be sent on to the home network) and timings are now all the same.

How and where is Next Generation Hotspot being rolled out?

In terms of commercial adoption, European operators are starting to deploy NGH already. They are typically not replacing entire networks, but are installing new hotspots with Passpoint Access Points and controllers. There are also some deployments in Asia and one new operator in the US who is planning an entire rollout of NGH pretty soon that we hope to announce shortly.

Currently, the vast majority of the market today is still using a username/password authentication, even if hidden behind dedicated smartphone apps. Operators are moving on to the new automatic experience and starting to take advantage of SIM card authentication on Wi-Fi. There are around 7 or 8 operators using SIM card authentication for their own customers in their own national markets. For example, Swisscom iPhones automatically switch over to Wi-Fi when entering Starbucks.

Roaming between networks will take a little more time, but we are starting to see initial contracts put in place in Asia.

Backward compatibility

NGH hotspots are backward compatible with legacy login screens/passwords in addition to the new protocols, making the transition to the new scheme fairly painless.

Devices, such as smartphones, also need to be compatible with the new NGH protocols. This depends a lot on the device manufacturer. The WBA has been working substantially with Samsung, for example they have a firmware update for the Galaxy S2/3 and their S4 already comes with Passpoint compatibility. LG is also coming out with two new devices that support Passpoint. Chipset vendors Intel and Qualcomm fully support the new standard.

How will NGH affect today's low usage of Service Provider Wi-Fi?

Firstly, it's important to understand the notion that mobile data traffic consumed on the go using 3G or Wi-Fi is a substantially smaller amount than when stationary. The majority of 3G activity is used when in the office, or at home or sitting down rather than when walking the street.

Once implementation of automatic/seamless transfer to Wi-Fi is in place, we expect to see the proportion of Service Provider Wi-Fi ramp up substantially. Smartphones will automatically switch over to use Wi-Fi whenever in a public place.
A couple of WBA members have implemented the automatic SIM and we are working with them on a case study to share their traffic figures. It will be important for the market to understand how the percentage traffic mix between cellular and Wi-Fi changes, and how much more is sent over Wi-Fi once these new systems are in place.

We could also expect NGH to be used within an Enterprise office, allowing integrated mobile/wireline operators such as AT&T to optimise the services they offer to the customer. For example, a bank could provide optimised service between Wi-Fi and cellular within their own building optimising their investment with a co-ordinated solution.

How are the WBA and Small Cell Forum working together?

The WBA and SCF are working on a joint activity, initially writing a white paper that looks at tri-mode small cells (3G/LTE/Wi-Fi). It's still work in progress, aiming to be published around June/July this year, and talks about the different use cases and business scenarios where this type of equipment would be used. It will make some recommendations about where to deploy it and justify the business case. AT&T has been very keen to adopt this technology, as is KT. They (KT) already have an SME (Small Medium Enterprise) market offer and are working on a solution for the residential segment.

We expect to see a rollout of these pretty soon.

A technical advantage of using a tri-mode small cell may be avoiding the need to re-authenticate when swapping between Wi-Fi and cellular modes. Once a trusted relationship has been established using either mode, then a smartphone device could handover between any of 3G/LTE/Wi-Fi without needing to re-authenticate itself each time. This provides more control for operators to move customers between radio interfaces depending on radio conditions and overall usage at the time.

Policy management is another area to consider. A home operator could setup a policy to decide which visited network to connect with depending on various parameters and preferences. This aligns with Passpoint 2.0 and ANDSF (Automatic Network Discovery and Selection Function) which is due to trial during Q4 2013.

Our work with the Small Cell Forum will follow on from the initial White Paper to work on common architectures and look at how operators will work with Wi-Fi and integrated services. We will develop a framework technical architecture and guidelines for operators to follow. Work on this will start around September/October 2013.

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#1 M ehdi said: 
a recent paper on the cellular WiFi integration can be found under:

0 Quote 2013-05-22 09:37
#2 Julie Snell said: 
Good to read the last news on the Small Cell Forum, the dream has been in the pipeline for some years and thanks to your continued drive is closer to reality, well done to all at the WBA & GSMA
0 Quote 2013-05-22 18:58
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