OnQ Blog

Crossing over between 3G/4G and Wi-Fi – Seamless and Robust

Apr 22, 2013

Qualcomm products mentioned within this post are offered by Qualcomm Technologies, Inc. and/or its subsidiaries.

Not a long ago, when we started talking about small cells, the first question we would always hear was “why do we need small cells, when we have Wi-Fi?” But that has rapidly evolved into “how can we ensure that the interworking between 3G/4G and Wi-Fi is robust and seamless?”

The interworking becomes even more crucial considering the looming 1000x challenge, in which Qualcomm envisions dense deployments of small cells, most of which are integrated with Wi-Fi.

The integration and interworking of 3G/4G/Wi-Fi is multidimensional. There are many different deployment models and multiple levels of interworking. Let’s look at some of these in detail. The most basic deployment model is standalone Wi-Fi networks operated by 3rd party providers with signaling connectivity to the authorization/authentication part of 3G/4G networks. The next level is Wi-Fi networks/service offered by 3G/4G operators themselves, often called as “Carrier Wi-Fi.” In such cases there is a likelihood that the connectivity between the two networks goes beyond signaling and may have data connectivity as well. The most integrated model is using converged solutions that offer both 3G/4G and Wi-Fi from the same box, for example, small cells based on Qualcomm’s converged AP solutions. This also is a more likely scenario for small cell deployments.

In terms of levels of integration, the basic level is 3G/4G devices autonomously discovering a Wi-Fi network and connecting to it, without any user intervention, say, using PasspointTM (a.k.a. Hotspot 2.0).

The next level is intelligent selection between 3G/4G and Wi-Fi links based on operator policy. For example, operators may want to route high QoS and their own services through 3G/4G and offload best effort such as browsing, downloads and OTT (over-the-top) services to Wi-Fi.

An even higher level of interworking is providing seamless service continuity between 3G/4G and Wi-Fi networks. This means that devices not only automatically discover and connect to Wi-Fi but also seamlessly transfer the data sessions between the networks without users even noticing it.

The next level of interworking is supporting all the cases mentioned before, additionally, combing the data from the two links/networks and making it even more tight and robust. 3GPP is working on such advanced features in Rel. 11 and beyond.

No matter what the deployment model is or the level of interworking supported, devices will always be in a unique position to select the best possible access among 3G/4G and the many Wi-Fi links that they might see at any given time.

Of course, there are standards and operator policies to do the selection, but there are also ample opportunities for vendors to offer differentiation by providing additional intelligence to further optimize selection. For example, Qualcomm’s CnE smart connectivity engine which is part of device chipsets, packs many more smart algorithms to select the best link.

So in essence, there are many features for effective 3G/4G-Wi-Fi interworking and a clear roadmap to make it even more robust and seamless. In my next blog, I will discuss how Qualcomm is bringing this vision to fruition. Meanwhile, please visit our webpage www.qualcomm.com/wi-fi or listen to our recent Wi-Fi Evolution webinar to learn more. 

Opinions expressed in the content posted here are the personal opinions of the original authors, and do not necessarily reflect those of Qualcomm Incorporated or its subsidiaries ("Qualcomm"). Qualcomm products mentioned within this post are offered by Qualcomm Technologies, Inc. and/or its subsidiaries. The content is provided for informational purposes only and is not meant to be an endorsement or representation by Qualcomm or any other party. This site may also provide links or references to non-Qualcomm sites and resources. Qualcomm makes no representations, warranties, or other commitments whatsoever about any non-Qualcomm sites or third-party resources that may be referenced, accessible from, or linked to this site.

Prakash Sangam

Director, Technical Marketing