The Mighty March

For many years now, rising data traffic has been setting unprecedented trends in the mobile industry. Although communication service providers/network operators have realized the ramifications underlying this deluge of mobile data, they have unfortunately been very sluggish to respond to it. The business reality as it prevails now is that traditional voice oriented business models have been replaced by data and voice now remains relatively less strategic in defining operators' revenue strategy. On the other hand, for mobile subscribers too, it's the availability of choice and personalization in mobile data services that commands their loyalty and keeps them satisfied.

As mobile data consumption continues growing stronger, it keeps ushering in massive transformation on myriad aspects concerning networks, business models, devices, mobile ecosystem, and subscribers too.

The scenario has drastically changed over the past 2 years. Now, operators across the globe, in both developed and emerging mobile broadband markets are finding that their precious networks resources are getting exhausted critically like never before. Several wireless carriers have reported that mobile data traffic over their networks have skyrocketed like never before.

The fast increase in mobile broadband services, rich digital content such as video streaming, online gaming, social networking, etc, as the impact of web 2.0 and eventually the arrival of iconic smartphones and connected devices such as Apple iPhone, Google android devices, the iPad, etc, have together generated an unprecedented level of stress on mobile networks, leaving network operators in anxiety and incapable to respond. In 2010, global mobile data traffic nearly tripled (2.6 times growth) for the 3rd year in a row, despite a slow economic recovery, increased traffic offload, and tiered pricing emerged as a new norm. Again, global mobile data traffic is expected to grow 26 times from 2010 to 2015, a 92% CAGR.

Mobile video traffic was 49.8% of total mobile data traffic at the end of 2010 and will account for 52.8% of traffic by the end of 2011. Also by 2015, 2/3rd of the world's mobile data traffic will be video. The flipside to this trend is that while data revenues are growing, the rate of expansion is nowhere near that of traffic growth in mobile data.

The non-linear relationship between revenue and traffic growth characterizes the cost related challenge mobile operators are facing now. At this juncture, mobile operators need to be wary of these challenges snowballing into bigger bottlenecks and thus need to make the right technology choices and choose strategic partners that enhance their reach and help grow their revenues.

As a counter measure to reduce the burden on their network, several tier-1 operators have cut unlimited data plans and launched tiered plans to ensure network performance, following a similar move by AT&T in the US. However operators do not find this as the only solution and do not want to lose a significant growing market smartphone users, looking for value added services. As a better practice and pragmatic method, operators are turning to mobile data offloading so as to relieve the network congestion and to monetize their 3G and 4G networks more effectively.

Mobile Data Offload

In their search to put an end to the growing strain on their networks, operators have begun experimenting with various forms of data offloading such as Wi-Fi and Femtocell. This will help reduce load in congested cells and can contribute to improved performance and slowed capacity upgrade expenditure. Data offloading represents the use of complementary network technologies for delivering data to mobile networks, in order to alleviate stress on existing precious networks.

As per a recent study mobile data offloading is likely to grow 3-fold in the next 5 years and is expected to reach about 48% by 2015, from today's rate of about 16%. Since data traffic itself is estimated to grow by a factor of 30, the total offloaded data will expand 100-fold. In terms of choosing an offload option, much depends on a given operator current mobile broadband traffic patterns, license, spectrum availability, and Wi-Fi footprint.

Wi-Fi: A Much Needed Succor

Wi-Fi, until now, has been long perceived as a mere extension of service providers' fixed broadband business or as an adjunct to their hotspot infrastructure. Key benefits of Wi-Fi such as unlicensed spectrum were never tapped to imagine it as a profitable extension of mobile broadband business.

Wi-Fi: A Much Needed Succor

Wi-Fi, until now, has been long perceived as a mere extension of service providers' fixed broadband business or as an adjunct to their hotspot infrastructure. Key benefits of Wi-Fi such as unlicensed spectrum were never tapped to imagine it as a profitable extension of mobile broadband business.

Wi-Fi, as an offload technology provides 3 obvious benefits to the cellular operator-

• Cost Effectiveness: Wi-Fi leverages unregulated bandwidth and ensures stronger connectivity. Many mass market hardware solutions too are available for setting up Wi-Fi access
• Wide Availability: Wi-Fi hotspots are on the rise and its access is being made available in many public as well as business locations. Also academic institutions and other establishments are facilitating Wi-Fi access
• Widely Used: The real picture with 3G services seems far from what the hype originally promised. Many in the industry have cited increasing usage of rich mobile data as the real problem. However it's actually the inadequate and scarce spectrum that has led to this sorry scenario in 3G services. This problem tends to aggravate when studied in the context of urban areas with extreme teledensity, as severe network congestion makes even a voice call extremely difficult during peak business hours. Subscribers wanting to access video download, video calls, and similar rich internet content using smartphones are experiencing poor service to their dismay. Also mobile data roaming seems extremely inconsistent or not available at times.

Against this, many operators have learned that Wi-Fi provides a much needed succor in presenting smartphone subscribers with a respectable wireless broadband experience. Since Wi-Fi spectrum requires no licence, it is free from the problems of spectrum auctions or limitations of a scarce spectrum. Wi-Fi, thus answers the problem by enabling a suitable path for operators to offload their congested networks by integrating a wireless solution with appropriate scalability. Interestingly, in a rapidly emerging market like India, many urban locations have fiber-optic cables/DSLs with very high bandwidth.

Wi-Fi emerges as a natural choice for both operators and subscribers alike for several obvious reasons. Adding more network capacity is neither cost-effective nor does it ensure scalability for service providers. As substantial share of high-speed data service demand comes from Wi-Fi enabled smartphones, Wi-Fi easily becomes a preferred data-offloading technology for alleviating clogged networks.

Key Challenges

There are several key challenges in embracing Wi-Fi for mobile data offload-

• Subscriber Seamless Service Experience: Identifying/detecting secured WLAN and authenticating the session over WLAN using SIM credentials. Seamless Wi-Fi connection suggests that it ought to function almost identically to cellular radio and be coupled to the operators core network and policy infrastructure. The Wi-Fi equipped 3G smartphones such as iPhones, BlackBerry, and android come with inbuilt Wi-Fi features that enable a seamless switch over to Wi-Fi when they are in contact with Wi-Fi range and automatically disconnects from 3G network based on priority network setting.

It requires that the user puts network credentials only once and then whenever the user is in that Wi-Fi range, the smartphone would select the pre-configured Wi-Fi network over 3G. On the other hand, laptops do not enable a seamless switch from 3G to Wi-Fi. Laptops therefore need a connection manager/client that can detect Wi-Fi networks and disconnect the 3G network by enforcing suitable configuration.

The real challenge faced is that mobile users do not really like to keep Wi-Fi 'always on' in order to have longer battery life. Therefore, ideally when a UE moves to the cellular operator's Wi-Fi hotspot, network preference for the UE should be automatically connected to Wi-Fi. This is operationally too complex and expensive, for it requires the Wi-Fi hotspot to be EAP SIM compliant.

With a view to providing the much needed fillip to mobile operators, Wireless Broadband Alliance (WBA) came with an announcement of a new specification in their WISPr 2.0 draft. This new specification enables EAP SIM authentication over HTTPs method and is targeted at introducing an enabling intervention that allows EAP authentication by extending the current WISPr architecture. Traditionally Wi-Fi services are accessed via a captive portal but this is not a viable solution as most smartphone do not support multiple browsers nor is it convenient for subscribers.

However EAP SIM authentication over HTTPs will take time, besides this, operators can exploit alternative methods such as web self care, MACID, and manual SMS based authentication for enabling Wi-Fi offload.

• Integration with Operator's Existing Mobile Core: For smooth transition from 3G to Wi-Fi, it requires seamless integration of the operators existing mobile core with the Wi-Fi infrastructure. The subscriber credentials for 3G subscriber resides in HLR and Wi-Fi supports only AAA based authentications. This requires a 3GPP compliant AAA that integrates with operators HLR/HSS to authenticate the subscriber.

Even as transition towards packet core networks is gaining notable progress, this would not be true for many mobile operators. In the case of a mobile operator with a non-EPC core, a different set of integration efforts would be needed to bring billing, charging and policy activities in sync with Wi-Fi offloading mechanism. Billing will be another key aspect after authentication and operators need to be able to charge their subscribers as per their prepaid/postpaid status.

• Roaming & Partner Settlement: Subscriber should have seamless connectivity across all regions. With 3G enabled smartphones becoming a part of daily routine for millions of subscribers, expecting to be always on, and always connected. Making available Wi-Fi connectivity across a wide geographical spread therefore becomes important for telecom carriers.

However, no operator can afford to invest heavily in building self-managed Wi-Fi networks. This leads them to forge tie-ups with Wi-Fi hotspots providers. In creating such partnerships, operators have to factor in the aspects of integration and standardization efforts that would go in authentication, settlement, reporting, and other capabilities. This way not only they can offer seamless global connectivity but can also enable compelling user experience on Wi-Fi to their subscribers.

• Regulatory Compliance: Validating subscriber credentials and reducing cyber crime. In the wake of rising cyber crime, telecom regulators are enforcing a strong vigilance over the activities on cellular networks / WLANs. With WiFi hotspots coming up everywhere and as more and more smartphone users begin enjoying WiFi access, operators are required to look at the fragility involved in WiFi offload. As regulatory compliance makes lawful interception inevitable, telecom service providers have to assess the aspects of subscriber data confidentiality & integrity, authentication, access control and intrusion detection and prevention while implementing integrated WiFi access.
• Carrier Grade Scalability: Mobile networks have adopted WiFi offload as a strategic decision to heal their core networks at the same time being able to realize added value and revenue opportunities. Profusion of smart devices together with WiFi hotpots has again added an important angle to this network optimization method. As millions of subscribers turn to WiFi to meet their mobile data needs via smartphones, enabling engaging experience has surfaced as a critical challenge. Against this phenomenon, operators have to deploy solutions that can help monetize data offloading by providing the capabilities to:
• Manage exponential traffic
• Facilitate simpler authentication/roaming
• Provide satisfactory throughput

3G/4G-Wifi offload requires tying up with WiFi service providers as well as addressing Authentication, Billing, Charging integration for the operators.

Vaibhav Mehta
The author is VP, new business development, Elitecore Technologies
vadmail@cybermedia.co.in