Offloading a Data Tsunami

The well-reported tsunami of IP data traffic hitting cellular networks from Wi-Fi-enabled devices of all kinds is driving mobile operators to scramble for solutions to handle the pressure. These high-end handsets multiply data traffic like rabbits on Viagra.

It's estimated that a single smart phone generates 10 times the volume of data traffic than a conventional cell phone while a laptop generates a whopping 1,300 times more.

A new report from Cisco (now doing its own market research and analysis because it can), forecasts that mobile data traffic will double every year through 2014, increasing 39 times between 2009 and 2014, reaching 3.6 exabytes per month by 2014. And over 60 percent of the world’s mobile data traffic, they say, will be IP-based video. 

So what are mobile operators planning in response to this wave of data? Because the capacity demand in urban markets is so great, leading operators in Asia, Europe, and the US will respond with ANY and EVERY tool they can get their hands on. Consequently, over the next couple years we'll see a flurry of activity by operators to:

• add more carriers to high-traffic sites,
  
• implement traffic management tools in the core,
  
• accelerate plans for LTE deployments,
  
• increase the bandwidth of backhaul links,
  
• acquire new or re-purposed spectrum,
  
• add femtocells in force, and (most importantly)
  
• embrace the technology that until recently was nearly a dirty word for mobile operators:  

Wi-Fi

Uncontrollable, unlicensed and unpredictable, Wi-Fi has historically been used as a way for carriers to provide convenient, best effort connectivity to users in hotspots. Now operators are taking a much more strategic view of the technology, looking for ways to leverage recent technical advances (such as 802.11n and dynamic beamforming) to help them ease coverage and congestion pains (the so-called 3G/4G offload problem).

But the answer isn't just throwing up a bunch of Wi-Fi access points in more hotspots. What's needed is a well-thought through architectural approach that spans the radio access network, backhaul and core cellular infrastructure - addressing issues like provisioning, traffic flow, seamless authentication, IP mobility, policy control and management. Just the "simple" task of ensuring users maintain the same IP address as they roam from a Wi-Fi to a GSM network is a major issue. Coordination on the backend is non-trivial.

Not to dismiss the importance of seamless network integration and management, fundamentally, mobile operators face two major tsunami challenges (quickly and affordably): 

1. scaling capacity and 
2. scaling coverage. 

Mobile operators use the same network to deal with high-value voice and messaging (that have real-time transmission characteristics), as well as lower-value Internet "browsing" data traffic. Meanwhile, dealing with the lack of fixed infrastructure or real customer demand can inhibit the buildout of expensive cellular infrastructure to provide ubiquitous voice and data services.

Sure, there's now Wi-Fi on more and more smart phones, but everything these phones talk to (eg.wireless LANs and 3G networks) are not equipped today to move that traffic off to Wi-Fi in a way that is seamless for the subscriber and manageable for the operator. We're talking about things like tracking traffic, individual policy control, lawful intercept and the like.

At Ruckus, we've been working with Tier 1 operators on ways to use Wi-Fi as an extension of their own networks and to sort out the best approach for integrating 802.11 WLANs into 3GPP networks. Ultimately, what's really needed is new reference architecture for 3GPP/WLAN internetworking that builds on Wi-Fi experience in the hotspot world and an intimate understanding of the 3GPP networks’ requirements.

The standards guys in the mobile industry's 3GPP club, but no one expects to see any implementations of it within the next three years -- during which time smart-phone traffic will continue to overrun their networks in ever taller waves. So any new reference architecture put forth in the short term must be ready for rapid implementation while anticipating the forthcoming 3GPP standard in the longer term.

Our practical, field-tested approach provides exactly that kind of immediate relief and forward-looking view, delivering seamless subscriber experiences while eliminating any incremental software requirements on phones (a requirement critical to subscriber adoption and fast deployment) and connecting efficiently into the established 3GPP/LTE core.

With such an architecture, we believe impatient smart phone users the world over can expect better, substantially higher-bandwidth experiences in the places where they pause to surf or watch small-screen videos quite soon.