The Role Of Wi Fi

Published Date: 02 Nov 2017

In the last few years, a number of technologies have been created and developed to pave the way for the so-called anywhere, anytime communication. These technologies provide different levels of performance , maturity, adoption and cost. The exposure of these technologies is significantly different. Wi-Fi has emerged as a technology for wireless local area networks that uses the frequency spectrum of 2.4GHz and operates at up to 11 Mbps within a range of approximately 100 -1000 feet. Known by its marketing name "Wireless LAN" or "WLAN", Wi-Fi is based on the international standard 802.11b from the Institute of Electrical and Electronics Engineers (IEEE) and has now become a popular worldwide platform for setting up wireless local area networks in offices, homes and public spaces. The technology provides all the functionalities of wired local area network (LAN) with no physical connection. Wi-Fi devices convert data packets into radio waves that are sent directly to other wireless devices or to an access point, popularly known as "hot-spot", that serves as a gateway to the wired LAN or the Internet.

To better understand the role of Wi-Fi within the wireless data communication industry, it is imperative to distinguish private and public wireless networks. A public wireless system is a communication system that is owned, operated, and maintained by a commercial company that is available to the general public on a subscription basis. On the other hand, a private wireless system is typically a radio communication system that is owned, operated, and maintained by an enterprise for its internal use. A private wireless may be deployed as an extension of corporate LANs in cafeterias, meeting or conference rooms to facilitate communications and enables mobile applications throughout the work environment.

The growth of Wi-Fi is driven by unlicensed spectrum, standardization and the cost curves that derive from advanced silicon design and manufacturing. Paired with growth in smartphones, this has created conditions that have literally revolutionized the way in which mobile data services are consumed and how the industry is structured. Consider, for example, how advanced, high-end smartphone use cases (and by extension, subscriber value) have shifted to Wi-Fi. With rich-media applications such as Skype, Facetime, BBC iPlayer, Spotify and others being designed to run over Wi-Fi rather than 3G – and in some cases restricted to Wi-Fi because cellular traffic is too congested or expensive – it is clear that users derive value in this form of connectivity that is additive to the 3G wide-area experience. Reclaiming some of that usage and influence is strategically important for operators and is underpinning a renewed push to integrate Wi-Fi more effectively into their subscriber offers.

Wi-Fi has firmly established itself as the most heavily-used wireless technology ever deployed in terms of the volume of data traffic transmitted over networks using Wi-Fi. According to Thomas Wehmeier, principal analyst at Informa Telecoms & Media, "any network director seeking to efficiently and profitably manage the follow of data traffic across their network should be looking to include Wi-Fi as part of an holistic customer-centric network strategy". Connections to Wi-Fi networks have historically been dominated by the laptops of the mobile workforce, but the rise of smartphones means that they are set to take over as the primary device connecting to public Wi-Fi networks. Operators around the globe are reporting that the mix of devices connecting to their public Wi-Fi networks is changing rapidly on an almost daily basis and, according to the joint WBA/ Informa Telecoms & Media industry survey, connections from smartphones and tablets already account for almost 51% of the total on average. As the penetration of smartphones, tablets and other connected devices increases, there is a widespread expectation that almost all mobile operators will be required to enter the Wi-Fi space in some way to remain competitive. Mobile operators have chosen a variety of different strategies to meet customer demand for Wi-Fi with their choices typically dependent on the existing status of the local Wi-Fi market and their own market position and network strategy.

In addition to high-end applications, common use cases for Wi-Fi include in-home usage, office connectivity, "deep indoor" venues with poor cellular coverage (e.g., conferences) and as an affordable alternative to mobile data roaming. In all these cases, operators see strategic value in being able to participate in this usage and clear potential to use their capabilities to deliver a better Wi-Fi service to end users. This situation led one senior operator executive interviewd for this report to state that "Wi-Fi is the comeback story of the year." Like many other operators – and nearly all Tier 1s – it has a range of initiatives underway to evaluate and deploy Wi-Fi solutions.

High demand from smartphone users and widespread availability make Wi-Fi technology a "game-changer" for the mobile data industry; however, direct opportunities for operators are limited. Low-cost hardware, unlicensed spectrum and link-layer interoperability have propelled Wi-Fi's global reach, creating tremendous value for smartphone users. But these same growth drivers have resulted in many different types of Wi-Fi that are so diverse in configuration, performance and ownership that it is virtually impossible for mobile operators to develop broad-based Wi-Fi strategies. In particular, concern over the inevitable burden on customer support has deterred operators from actively engaging with Wi-Fi. To unlock value in Wi-Fi, operators will need to focus on specific opportunities and use cases – the dilemma being that reducing a Wi-Fi strategy to a more manageable scope risks forgoing many of the theoretical benefits. For users, Wi-Fi is ubiquitous and interoperable; for mobile operators, it is heterogeneous and complex.

It is intuitive to most people that Wi-Fi plays a major role in the smartphone experience. Certainly this is the case in developed markets where fixed-line broadband is reasonably widely deployed. And increasingly, there is empirical evidence to back up that feeling: According to usage statistics collected by Bango, a long established mobile analytics firm, at the start of 2011 Wi-Fi accounted for more than 50 percent of mobile user connections to Internet content – more than double the 23 percent it accounted for at the start of 2010.

Users are within Wi-Fi coverage 63 percent of the time during the day (70 percent over 24 hours), and each stay in a Wi-Fi zone lasts about two hours.

About 65 percent of traffic can be offloaded to Wi-Fi under typical usage conditions using on-the-spot offload. Greater offload performance can be achieved if the user is prepared to accept delayed offload (e.g., sync your videos or photos when you get home).

Wi-Fi provides connection speeds of 2 Mbit/s on average, which is skewed to 2.76 Mbit/s at night (probably home Wi-Fi) and 1.26 Mbit/s during the day (probably shared Wi-Fi).

Table 1 below is from a comScore survey which shows the differences in the ways iPhone and Android users in the US employ Wi-Fi to access Web content.

It is by no means a complete, but Table 2 below highlights just some of the major operators making substantial investment in Wi-Fi access networks. Typically Wi-Fi is not the major area of investment for these carriers, but it is nonetheless substantial and these initiatives are viewed as strategic over the long term

Wi-Fi works best in short-range, interference limited environments, such as homes and offices. How well it work sin metro environments is less clear, since interference is likely to be higher (unlicensed spectrum; not coordinated) and distances greater. In these cases Wi-Fi comes into competition with "small cells" operating in licensed spectrum, which can benefit from interference management smarts and higher output powers. This typically means that at ranges greater than 50 meters the licensed small cell will provide better performance, especially outdoors or in other environments with high levels of interference.

In a historical context, Wi-Fi is a little like the "Wild West," with such stark variations in performance, security, and usability that operators have preferred a loose association with the technology, distancing them from the customer support burden when things inevitably go wrong. From a mobile operator perspective, Wi-Fi is like the Wild West because of many reasons. There is little formal oversight, and survivial of the fittest rules. This relative lack of regulation and centralized control is a large part of the reason the technology grew so fast. The rapid growth, however, has resulted in lots of different types of Wi-Fi. Variations in performance, security, configuration and so on make it a an untamed environment compared to the well-defined, monitored and managed environments in the cellular realm. This makes implementation of a Wi-Fi strategy a complex activity for a mobile operator. The many types of Wi-Fi access can be broken down into: residential Wi-Fi, enterprise, paid hotspots, free Wi-Fi, residential and enterprise hotspots, and personal hotspots.

Making Wi-Fi into an operator friendly technology will require significant technology development. It may be cliché, but the characterization that "Cellular is from Venus, Wi-Fi is from Mars" has more than a grain of truth. The 3GPP World that defines 3G and LTE and the IEEE World that defines Ethernet and Wi-Fi do occasionally speak different languages, and both are therefore working to adapt their technologies for mobile operator Wi-Fi. Progress fortunately is good. Tables 3 and 4 below respectively show the 3GPP initiatives to include Wi-Fi into the cellular architecture and the IEEE initiatives to integrate Wi-Fi into the cellular network.

According to Informa Telecoms & Media, the number of public Hotspots is set to proliferate, growing from 0.8 million at the end of 2010 to 5.8 million by the end of 2015, (see fig 1.).

Much of this growth will come from emerging markets such as China, India and Brazil where some of the largest-ever mass deployments of public Wi-Fi are being undertaken by incumbent and new entrants to the market: The world’s largest mobile operator, China Mobile, is planning to deploy a total of one million Wi-Fi Hotspots throughout China. This spread of public Wi-Fi networks will be a truly global phenomenon and operators in all regions and all types of markets have declared their intention to move into Wi-Fi.

The expansion of public Hotspots is not only being led by the land grab for key venues, such as hotels, stadiums and airports, being witnessed in new markets, but also by the increasing density of Wi-Fi networks in established markets. Wi-Fi is increasingly moving beyond the traditional prime locations to the next generation of Hotspot locations, such as retail outlets, local- and wide-area outdoor Hot-zones, as merchants and Wi-Fi network operators alike begin to understand the variety of profitable business models that can be underpinned by deployment of Wi-Fi.

The next evolution of the Wi-Fi standard –802.11ac-- promises a faster connection and a higher data transfer rate than the current standard. The plan is for this to boost video distribution and uploading and downloading of large files. However, it will not replace Ethernet completely due to the cheaper cost of wired connections. An analyst at research firm NPD In-Stat, said the new specification boasts several advantages over the existing 802.11n standard to include aggregate connection speeds over 1Gbps as well aiding in power savings when used on mobile devices. The new standard also achieves this by extending the air interface concepts used by 802.11n such as wider bandwidth, more MIMO (multiple-input and multiple-output) spatial streams, and high-density modulation. Also, 802.11ac operates in the less-used 5GHz frequency band, which makes it a compelling option to expand home Wi-Fi networks' capacity as consumers increasingly adopt connected mobile devices and use data-hungry apps.

Challenges

Although the Wi-Fi experience has improved with the deployment of 802.11n and the implementation of authentication based on 802.1x, there is still much to be done to grow the adoption and usage further and to build a first- class user experience. Challenges that must still be overcome include simplifying the authentication and sign-on process, establishing a truly global roaming footprint and addressing concerns around security and privacy. Just as fixed and cellular technologies are not standing still, the common standards that underpin Wi-Fi technology are evolving in parallel, with sometimes interweaving paths. Vendor, operators and Wi-Fi industry bodies, such as the Wireless Broadband Alliance and the Wi-Fi Alliance, are responding to changing demands from end users to develop new standards and frameworks to further enhance the Wi-Fi user experience in terms of authentication, speed, capacity, security and user experience.

Both operators and users have come to rely on Wi-Fi, so it has been compelled to grow smarter. The focus today is on simplifying the Wi-Fi user experience and aligning it as closely as possible with the mobile experience in terms of connection management, authentication and sign-on, charging and billing, and importantly security and privacy.

Although authentication methods have improved in the latest Wi-Fi- enabled devices, evidence suggests that additional simplification and automation is needed to drive adoption of public Wi-Fi usage outside the home. As a result, support for SIM- based authentication is expected to proliferate with the strong support of the operator community. Standards such as EAP-SIM and EAP-AKA are set to be included in a greater variety of smartphones and tablets.

But whether used to offload services from 3G or enabling new services, Wi-Fi is still subject to regulators and especially the laws of physics. That means Wi-Fi must be designed to provide a good user experience, a challenge partly because it does not have spectrum licenses to help protect against interference. Another regulatory factor is the country-by-country variations in how many channels are allowed in a particular band, which affects both capacity and the ability to work around interference. These challenges have not dissuaded wireless carriers, owners of hotspots, and owners of public venues, such as hotels and airports, from aggressively building, buying and expanding wide-are Wi-Fi networks over the past several years. This trend is unlikely to abate anytime soon simply because, from a business standpoint, Wi-Fi has many benefits. For example, it is a way for multiple system operators (MSOs) to expand into the wireless market without the steep cost of spectrum and cellular infrastructure. For some, Wi-Fi is a wholesale and retail opportunity and reduces the need for expensive cellular infrastructure upgrades for wireless carriers.

The cellular industry is suffering from a "high class" problem. Customers’ demand for their mobile data services is insatiable, a good problem arising from the growing popularity of the Internet access from mobile devices. In many parts of the world both consumer and business subscribers are demanding mobile access from a smartphone or tablet with a data plan. However this data demand is at lower prices per GB causing revenue per GB to decline and erode profitability. As operators try to meet the expected data demand using only cellular technologies in the Radio Access Network, Costs per Gigabyte (GB) are slowly declining, but Revenues per GB are increasing (see Figure 2) forcing operators to dramatically reduce costs to maintain profitability of data services.

The cost of delivering mobile data is dominated by the incremental costs of backhaul and RAN. Even the new micro-cells and femto-cells that provide significant extra "hot zone" capacity generate expensive, increased backhaul requirements for each cell. The profitability of Mobile Internet services is at risk, and mobile operators need to look to new, complementary technologies that can serve data traffic with a dramatically lower cost curve than the traditional, cellular-only RAN and backhaul solution.This problem is fundamentally driven by the mobile subscribers’ exponential appetite for mobile data at very low prices per GB. In 2007 the iPhone revolutionized the mobile Internet business and demonstrated consumers would readily consume "Apps" (mobile data services). The use of mobile data services has doubled each year and most industry experts expect it to do so for the foreseeable future.

As with cellular, Wi-Fi QoS also partly depends on backhaul. Backhaul size and technology vary widely, from 1.5Mbit/s DSL in areas where the network typically supports only a few users at once, to fiber in heavily trafficked venues like airports and stadiums. If the venue operator makes Wi-Fi QoS a high priority – such as in the case of upscale hotels that cater to business travelers – sometimes the backhaul even has operator redundancy. Ownership is yet another QoS factor. Many wireless carriers providers do not own and operate the Wi-Fi infrastructure that serves their customers. Instead, they resell service from Wi-Fi aggregators, which also own little or no Wi-Fi Infrastructure. The result is that, although the wireless carrier might be the public face of the Wi-Fi service that it provides to its customers, the multiple layers of companies limit its insights into and control over QoS. The wireless carrier also cannot demand much of an SLA from its Wi-Fi partners because without license protections, Wi-Fi is ultimately a best-effort service. "There definitely is more of a push – and we're seeing this in Europe, among other places – toward mobile carriers wanting their own Wi-Fi infrastructure to control the network quality and brand experience," says Sheila Burpee Duncan, VP of marketing communications at BelAir Networks.

Until recently, carriers have not put significant capital into building hot-spots, creating coordinated networks or WLAN / WAN integration because there has not been enough potential revenue in this opportunity. Besides, an open scenario was existed where companies are free to set up hot-spots and, consequently, there’s been a proliferation of facility owners and small to medium- sized of Wireless Internet Service Providers (WISPs) providing stand-alone WLAN service. In this fragmented marketplace, QoS, security and billing issues threaten to be more challenging than in any other mobile environment. These circumstances have facilitated the early appearance of companies such as Boingo in the US market. Meanwhile, CDMA operators Verizon Wireless and Sprint have been more conservative in formulating public WLAN strategies. They have remained focused on establishing data business on their new 1X networks before integrating with WLAN. So that subscribers will have little incentive to use a hot-spot if they are content with the availability, speed and pricing of 1X service for data. Verizon is considering WLAN as a way to increase ADSL revenues and customer satisfaction.

GSM operators in USA, in the other hand, have been the first carriers to lead the way in supporting public WLAN and providing connectivity to their networks. Once having completed their GPRS network rollout, there are two main reasons for GSM carriers to be more inclined toward public WLAN than CDMA carriers: First, compared to 1X, GPRS appears to have speed limitations at the current stage of technological evolution so public WLAN is considered a complementary technology for certain locations (high density/low mobility) and might be more of a threat to GSM carriers if not adopted. Second, the estimated Capital expenditures (Capex) for GSM carriers to upgrade beyond GPRS is higher than it is for CDMA, meaning Wi-Fi might represent a more durable alternative for high speed data infrastructure.

As data traffic exceeds voice traffic, it now becomes the problem to solve (in 2009, global data traffic exceeded voice traffic on mobile networks). It takes many years and billions of dollars for mobile operators to acquire and build out new licensed spectrum. Unless mobile operators deploy more cost-effective technologies, the viability of the Mobile Internet service is at risk. Existing models for mobile service delivery are inadequate to satisfy demand. Operators cannot simply double their use of spectrum and double the number of cell sites in their network each successive year. If no changes are made, demand could exceed capacity within three to four years.

With today’s architecture, operators could rapidly run out of spectrum and money. Already they are struggling to keep up with demand, since the introduction of the iPhone, mobile operators AT&T Mobility and O2 have struggled to keep pace with the demands of iPhone users. Leading operators, focusing primarily on data services experience this problem even more severely than others in the industry; O2 reported that their data traffic was doubling not every year, but every three months.

Technical enhancements of the existing, cellular model will bring significant benefits, but not enough to offset the exponential growth. For example, Alcatel-Lucent recently announced a new cellular product technology that, when fully deployed, could reduce the Total Cost of Operations (TCO) by 50%. However, operators need more than a one-time 50% reduction to control their costs as they face 100% increases in capacity each year!

Global mobile data traffic was up more than double from 2010 according to research from Cisco Systems Inc. Mobile video traffic made up nearly 53% of the traffic last year which is up from just shy of 50% in 2010. Global data revenue for wireless carriers is expected reach $491 billion in 2014 which is up from $214 billion only 5yrs earlier. Mobile operators like AT&T Mobility have taken bold steps to address this problem. In 2008, ATT acquired Wayport for Wi-Fi data offload.19 In 2011, AT&T Mobility attempted to pay $39 billion to acquire T-Mobile USA, a move which would have significantly increased its amount of licensed cellular spectrum and radio coverage.

Mobile Operators Solutions

In the past several years cellular operators have begun utilizing Wi-Fi hotspots as a means to expand their high speed data footprints and to offload data traffic. As smartphones, tablets, and dongles have continued to see strong growth, operators have actively deployed Wi-Fi hotspots to expand mobile broadband coverage and as a means to keep pace with the backhaul required to drive data traffic to the core network. Most notably, AT&T has adopted Wi-Fi as a key to alleviating traffic chokepoints created by rapid iPhone adoption and now hosts a network of 24000, including extended "hotzones" in NYC, San Francisco, Chicago, Charlotte, and Austin. In NY AT&T is embarking on an aggressive 5yr initiative to provide free Wi-Fi service at 20 city parks. Even though it comes off as a good will gesture to local residents, the expansion of the Wi-Fi network clearly serves the secondary purpose of providing a means of offloading moble data traffic to park users. The mobile operators are not alone in the deployment of Wi-Fi connectivity, as cable and fixed operators have also been aggressive Wi-Fi deployers.

Over the past few years Cellular operators have increasingly expanded into Wi-Fi, either by partnering with Wi-Fi network operators and/or aggregators, or by building Wi-Fi netowrks. One recent example is China Mobile, which plans to build 1 million hotspots, including 20,000 in Beijing alone.

Wireless carriers like Wi-Fi because it is an effective way to keep up with mobile data usage trends and mitigate cellular radio access network (RAN) congestion:

The vast majority of smartphones, tablets, netbooks and other data-centric cellular devices in use today have an embedded Wi-Fi modem. Thus cariers can leverage a broad installed base of devices, instead of having to use financial carrots and sticks to convince customers to replace their devices with onese that use more spectrally efficient cellular technologies

There is also a large and growing installed base of companies that own or agregate Wi-Fi hotspots, such as Boingo, BT, Openzone, iPass, Towerstream and some MSOs. These companies free wireless carriers from the financial burden of building and operating extensive Wi-Fi hotspot networks. These companies are also potential carrier acquisitions, as AT&T's 2008 purchase of then-partner Wayport shows. One motivation for acquisition, discussed later, is to have control over the network and thus QoS.

For CDMA carriers, Wi-Fi is a way to provide voice and data services to customers that roam internationally, without the need for interstandard (CDMA-GSM) roaming agreements and multi-standard user devices. Of course, the appeal of this offering depends on whether end users are willing to hunt for a hotspot every time they need to make a call or check e-mail. That hurdle becomes less of an issue the more that the CDMA carrier and/or its hotspot partner(s) expand Wi-Fi coverage.

For LTE carriers, Wi-Fi is a way to deal with LTE's global spectrum fragmentation, which spans more than 40 possible bands. So instead of complex, expensive devices that support several LTE band, carriers can offer ones that support only their own LTE band(s), falling back to Wi-Fi in areas where customers otherwise would have to roam on other opertators' LTE networks. Wi-Fi is also typically faster than 3G, so the fallback from LTE is not as noticeable when using bandwidth-intensive services, such as video.

Wi-Fi has significantly lower service-delivery costs than 3G and 4G. Exactly how much lower depends on what is being compared such as the cost of a cellular macro base station versus the dozens of Wi-Fi APs required to achieve the same coverage footprint.

Customer participation is another factor that makes it difficult to quantify Wi-Fi's effect on RAN congestion and a carrier's bottom line. There is a big difference between having Wi-Fi in a device and the customer actually using it. For carriers, the ideal situation would go like this: When the customer goes to perform a bandwidth-intensive task, such as downloading a video, something would force the device to turn on its Wi-Fi radio, which then would search for the carrier's/partner's hotspot service or the customer's WLAN. If either is available, the device would use Wi-Fi rather than cellular to perform the task and then switch off the Wi-Fi radio to save battery life. This scenario currently exists only in limited form. For example, when iPad owners try to use cellular to download or update an app that is larger than 20MB, they get a pop-up telling them to switch to Wi-Fi to complete the task. (Some iPhone carriers, such as AT&T, automatically authenticate when in range of an AT&T hotspot if the customer has Wi-Fi turned on.) The switch to Wi-Fi requires manual intervention by the customer, and in a public place this assumes that the customer is knowledgeable enough to choose from multiple available Wi-Fi signals, if an AT&T signal is not available. Picking the wrong one can be a security risk.

The switch is difficult to automate. On laptops and netbooks, connection-manager software often can be customer configured, such as by an enterprise's IT department, to prefer one network over another for reasons, such as saving money. But carriers cannot force a device to switch to Wi-Fi. One reason is because the necessary mechanisms do not exist in most devices. Carriers also would need to build this option into their rate plans and educate customers that they could be switched to a different network at any given time. Enterprise customers could perceive this carrier-controlled automated toggling as a negative from a security standpoint.

The good news for wireless carriers – and for the companies angling to sell them Wi-Fi infrastructure or services – is that even without automatic network switching, usage is high and still increasing. For example, in 2008, AT&T's customer base took a full year to hit 20 million Wi-Fi connections. They took only six months in 2009 and five weeks in 2010.

Wireless carrier interest in Wi-Fi has created a market for RAN equipment that can support Wi-Fi and cellular. For example, Xirrus' Wi-Fi equipment has a modular design, and the company says it is increasingly being asked for modules that can support cellular, too. Powerwave Technologies has a LTE picocell with an optional 802.11a/b/g/n unit, while the BelAir100LP LTE Picocell supports both LTE and 802.11n. Expect more such products as wireless carriers expand their reliance on Wi-Fi.

Some wireless carriers see Wi-Fi as another way for them to target the M2M space. One reason is because Wi-Fi modules and service-delivery costs are so inexpensive, which are major assets in the notoriously price-sensitive telemetry market. "So if those machines are located inside a Wi-Fi environment, for us, it's just [about] what is the right design that works for the customer," says AT&T's Whiteside. "We view Wi-Fi as part of our broadband wireless infrastructure. [But] I'll admit that we haven't actively pursued it yet."

The proliferation of Wi-Fi benefits wireless carriers because the more public places with a Wi-Fi signal, the more practical it is for their customers to switch to a hotspot, helping relieve RAN congestion. The big catch is that the hotspot market's size is matched by it's fragmentation, creating another type of connection problem: roaming. Although major aggregators like Boingo and iPass provide access to large numbers of hotspots, they are still not everywhere.

Public access hotspots are the most approachable Wi-Fi opportunity for mobile operators, with decent prospects for expansion in high-density and high-use locations. Operators are attracted to the hotspot market not because it fundamentally changes their economics or value proposition, but because it is an actionable opportunity. Subscribers see clear incremental benefit from having Wi-Fi bundled with their data plans, and operators can ensure reasonably predictable performance and add value for users via capabilities such as auto-login using SIM authentication. Because it is an operator-managed service, the customer support burden should be acceptable.

SIM authentication is the first "proper" step toward Wi-Fi integration with the mobile core, offering security and usability benefits. Together with the Next Generation Hotspot initiative, industry-wide procedures for automatically and securely connecting smartphones to appropriate access points (APs) are being developed. This will finally make Wi-Fi a "trusted access network" from the perspective of the mobile core network – a fundamental shift in operators' approach to Wi-Fi, laying the foundation for deeper integration and innovation in the future. Operators will also need to support tablets and correlate non-SIM certificates to authentication, authorization and accounting (AAA) in the mobile core to maintain a common experience and platform efficiencies.

Progressive operators will leverage Evolved Packet Core (EPC) installations to integrate user-plane traffic from trusted Wi-Fi access. So far, operators have been clear that there is no major need or driver for Wi-Fi user-planetraffic to pass through their mobile packet core network, even though to not do so means some value-added services may not be available. However, with EPC designed to be access-independent, operators will have the foundation to support common service delivery and session mobility across 3G/4G and Wi-Fi. This will enable more sophisticated traffic management, managed offload techniques and policy-based use cases. Ultimately EPC integration will provide the foundation for advanced features such as IP Flow Mobility (IFOM).

Integrating residential Wi-Fi into the mobile operator environment could be transformative, but is challenging even for integrated fixed/mobile operators. Because most smartphone usage over Wi-Fi is at home, it has the most potential to offload traffic and "change the game" for monetization of subscriber data will be compromised if so much usage is lost to generic Wi-Fi. However, integrating residential Wi-Fi is complex for myriad reasons. One area that does appear to have near-term potential is the so-called "Fon model" being pursued by BT Openzone, Orange and others, in which residential APs can act simultaneously as a private network and as public hotspots; certainly, hotspot coverage can be extended very effectively in this manner.

The relationship between Wi-Fi and licensed 4G small cell products is not clear; the "Wi-Fi indoor"/"small cell outdoor" distinction looks perhaps most useful for now. Simulations suggest 4G-LTE small cells will provide better efficiency than 802.11n Wi-Fi at distances greater than 40 meters in low-interference environments, and even greater advantages in moderate-load environments; whereas for short-range indoor use, 802.11n is more efficient and less expensive. The difficulty is that 4G-LTE small cells are not on the market yet, and the "smarts" on which they rely for performance are costly in terms of R&D and (potentially) hardware and may impact the overall cost of the solution to point where unlicensed Wi-Fi, for all its challenges, is more cost-effective. Currently it appears that over a three to five-year view, 4G-LTE small cells will prove successful in the outdoor metro-zone market and possibly larger public spaces.

One thing to look at is the fact that since hotspots are not everywhere, there is a need for a cellular style roaming framework, with mechanisms for authentication and billing, to make the connection experience as fast and user-friendly as possible. The ideal situation would be where a user's connection manager would provide a list of available hotspots and their tariffs. The user then could connect and have the tariff charged to his or her cellular bill, instead of having to enter credit card information.

A cellular style roaming framework also could help make wide-area Wi-Fi more attractive to enterprises if they view it as an effective way to avoid the chances that their field force employees will unwittingly connect to rogue APs. Increased consumer and enterprise use of Wi-Fi would benefit wireless carriers not just in terms of alleviating RAN congestion, but also by providing alternatives to cellular roaming. For example, CDMA carriers could use Wi-Fi roaming to provide voice and data services in areas where there only GSM-based cellular networks. "Some of the providers in the CDMA space, not just here in the US but also globally, are starting to wake up to the fact that perhaps Wi-Fi can serve as a nice roaming complement, espeially in place where they'd have to negotiate an interstandard roaming agreement," says iPass' Avillez.

Over the years, the Wi-Fi industry has done some work on roaming such as 802.11r, but those attempts languished because Wi-Fi – let alone Wi-Fi roaming – was not a strategic focus for wireless carriers, so it was not a strategic focus for the vendors with the capabilities to pull it off.

To assist mobile operators to satisfy the exponential demand for mobile data services, the mobile industry has created a new program in the Wireless Broadband Alliance to offload a significant percentage of mobile data traffic automatically, securely, and efficiently via Wi-Fi hotspots and fixed backhaul. Wi-Fi has emerged as a valuable part of the Radio Access Network (RAN) of the mobile operator. Until now its use has been severely limited by the need for the subscriber to manually discover, select, and access each hotspot and the lack of operator visibility of Mobile users who "Roam onto Wi-Fi."

A new program called Next Generation Hotspot (NGH) - using the latest HotSpot 2.0 specification1 - allows a mobile subscriber to connect automatically and securely to Hotspots using his service provider credentials while maintaining roaming visibility for the operator. NGH enables operators to continuously monitor and manage "cellular-like" service over Wi-Fi domestically and internationally so as to enhance performance and meet the demand for mobile data services over heterogeneous RANs - cellular and Wi-Fi. This enables mobile operators to simultaneously optimize backhaul throughput, offload specific traffic rapidly (e.g. video) and achieve better economics than traditional, cellular-only solutions.

In July 2011, the Wireless Broadband Alliance (WBA) announced it will be launching trials of its next generation hotspot (NGH), which features enhanced security and authentication and simplifies network discovery and selection of network for seamless cellular data offload. WBA, whose members include major wireless carriers such as AT&T, BT, Orange and T-Mobile as well as Wi-Fi equipment vendors such as Cisco and Anuba, has dubbed the new phenomenon as "Hotspot 2.0". WBA reports that 27 operators, vendors, and roaming hub consolidators have signed up for the trials. Once completed by the end of 2011, WBA will begin to work closely with the 3GPP standards body to ensure that the hotspots are able to integrate with HSPA and LTE network architectures more seamlessly. They plan to work closely with the GSM Association this year, with a taskforce poised to make recommendations for how to best integrate NGHs into operator networks beginning in 2012, and Wi-Fi Alliance plans to introduce a hotspot certification program in the middle of the year. The new specification for NGH is known as 802.11u. It is intended to facilitate automatic network discovery and selection in a manner that the current SSID method does not. Customers will be able to use SIM cards to access the networks over Wi-Fi hotspots. Network operators will then be able to establish cross-roaming agreements, allowing Wi-Fi access and offload onto partner networks readily. Access across multiple hotspot networks will be automatically authenticated and seamless to the user.

The NGH standard will allow mobile operators to ensure the same level of QoS and security as they currently offer on their networks now. The new standard will also offer greater visibility into network traffic and the ability to establish roaming relationships with other hotspot providers similar to arrangements that currently govern cellular traffic roaming onto partner networks. In conjunction with the developments around NGH, vendors are also making enhancements in the antenna technology that supports these large-scale Wi-Fi roll-outs. As a result of increased smartphone usage in stadiums, conference centers, and other high-traffic venues, the need for supporting large numbers of mobile devices continues to increase. Using directional antenna technology allows these deployments to specifically target users in specific sections or areas and also provide better support for low-powered Wi-Fi clients. Operators will welcome these new enhancements that will go a long way not just in cellular offload but in improving the overall subscriber experience.

According to CiscoVisual Networking Index, in 2010 global mobile data traffic nearly tripled (it grew to be 2.6 times larger than the previous year) for the third year in a row, despite a slow economic recovery, increased traffic offload, and the advent of tiered pricing. By 2015, global mobile data traffic will reach an annual run rate of 75 exabytes per year. 75 exabytes is equal to 75 times more than all IP traffic generated in 2000.This demand increase began because of the popularity of the Apple iPhone, Research In Motion’s Blackberry, and subsequently Android-based phones. Tablets, gaming consoles, laptops and netbooks, and non-smartphones are only adding to the demand. Mobile operators are looking for solutions to offload this data traffic from their cellular networks. Offloading data to hotspots is an economically attractive alternative, because many carriers already operate a substantial number of hotspots. Mobile operators would like to provide a user experience on Wi-Fi networks similar to that provided on 3rd Generation networks. This means making Wi-Fi as easy to use as cellular and providing it with cryptographically equivalent mutual authentication and link-layer security.

In 2011, there were about 290.9 million wireless subscriptions in the United States. At the same time, more than 2.7 trillion SMS and MMS messages were sent over the course of the year.

Next Generation Hotspot (NGH)

Work started on making Wi-Fi part of the mobile ecosystem back when it first became a mass-market proposition, around 2003. Most notable is the work in the standards bodies, and specifically the 3rd Generation Partnership Project (3GPP) "I-WLAN" specifications, which remain the basis for cellular/Wi-Fi integration efforts today. The Institute of Electrical and Electronics Engineers (IEEE) and associations such as the Wi-Fi Alliance have similarly been working to evolve Wi-Fi for use on mobile environments and make it a trusted part of the mobile network. The current work on the Next Generation Hotspot initiative is one good example.

To enable mobile operators to offload data onto Wi-Fi and remove some known barriers to use, the Wi-Fi and Mobile industry have collaborated to create the Next Generation Hotspot (NGH) program. In 2010, industry leaders formed the Hotspot 2.0 Task Group in the Wi-Fi Alliance and the Wireless Broadband Alliance embraced Hotspot 2.0 as the foundation technology for authentication and roaming for the Next Generation Hotspot (NGH). The goals of Next Generation Hotspot are simplicity and security. For example, a customer walks into any Hotspot in the world that has a roaming agreement with their mobile service provider and gets automatic and secure internet access. The HotSpot 2.0 specification solves several key problems that have been barriers to widespread use of Wi-Fi. Next Generation Hotspots (NGH) use the "HotSpot 2.0" specification to accelerate the utility of Wi-Fi for mobile operators by allowing more subscribers automatic access, and minimizing network changes for the operator to connect to a different technology. Hotspot 2.0 is the technical specification being developed in the Wi-Fi Alliance for seamless and secure access. NGH is the program in the Wireless Broadband Alliance that uses Hotspot 2.0 and other technologies to enable operators to make their Wi-Fi networks interoperable and create a global Wi-Fi roaming system complementing GSM.

There have been a number of previous product offerings that started to provide Wi-Fi as an "alternative RAN." However, these efforts used proprietary solutions and did not allow the operator the desired visibility, cost control and ease of use.

There are three technology pillars to Next-Generation Hotspot:

IEEE 802.11u which is an amendment addressing interworking with external networks. It was completed in mid-2010 and approved by the IEEE for publication in February 2011. The purpose of the amendment is to provide an effective interface between an IEEE 802.11 access network and carrier networks. The amendment adds to IEEE 802.11 network discovery that provides for the discovery of suitable networks through the advertisement of access network type , roaming consortium, and venue information. Also, Provides Access Network Query Protocol (ANQP),which is a query and response protocol used by a mobile device to discover a range of information, including roaming partners accessible through the hotspot along with their credential type and EAP method supported for authentication; IP address type availability (for example, IPv4, IPv6); the hotspot operator’s name; and other metadata useful in a mobile device’s network selection process.

WPA2-Enterprise is required for certification because it provides a consistent security level that both service providers and subscribers can rely on to protect the network, the devices, and the transmitted data.

WPA2-Enterprise meets enterprise and government security requirements. It leverages Authentication, Authorization, Accounting (AAA) functionality to monitor and manage traffic, and to define user-specific authentication levels, using multiple EAP methods for authentication. WPA2-Enterprise certification is widely available in Wi-Fi CERTIFIED mobile devices and laptops. Legacy clients that are certified for WPA2-Enteprise support the same level of security as the new Passpoint equipment, and can use the new Passpoint authentication process if they have WPA2-Enterprise enabled.

EAP-based authentication. In order to take full advantage of next-generation hotspot capabilities, carriers and users alike require an easy-to-use authentication mechanism. Network selection by a mobile device and authentication to the selected network should be carried out autonomously by the device without the need for user intervention (for example, the user entering a username and password). The natural choice for GSM carriers is to use the subscriber identity module (SIM) credentials already carried in their subscribers’ mobile devices, combined with EAP-SIM authentication. Similarly, the natural choice for Universal Mobile Telecommunications Service (UMTS) carriers is to use USIM credentials in conjunction with Extensible Authentication Protocol Method for UMTS Authentication and Key Agreement (EAP-AKA). Indeed, the Wi-Fi Alliance’s WPA2-Enterprise certification already provides an option for EAP-SIM and EAP-AKA interoperability testing.

(NGH) Solution for Wi-Fi Roaming

As mobile operators have learned over the last 25 years of operating mobile networks, roaming is an excellent solution to obtaining coverage, since it is not feasible to construct your own network everywhere that your subscribers may wish to obtain service. Although it may be feasible in some areas for the operator to build their own network with traditional RAN or Wi-Fi, this option is not available in all locations. Roaming, in contrast, multiplies the home operator’s coverage outside of their home market, without requiring capital investment in the build-out. Operators will want to employ Wi-Fi to reduce their costs and use roaming to increase their coverage. In combination, Wi-Fi will become a roaming network ("Wi-Fi Roaming") to complement the operator’s own 3G or 4G network. Operators can use Wi-Fi networks as roaming partners, just as they do other mobile operators networks today. In fact, in the NGH, operators can use the same technology and processes to roam using Wi-Fi, without requiring the operator to change the way it operates. Just like the GSM standardized roaming across cellular operators, we envision NGH to provide a Wi- Fi Roaming system that is similarly integrated and available across GSM operators. HotSpot 2.0 is designed to allow mobile service providers to employ Wi-Fi without changing the way they operate. As with subscribers, the goal is to make the use of Wi-Fi transparent: seamless and automatic. In the case of mobile operators, having their subscribers "roam" onto selected Wi-Fi networks is just like roaming onto another 3G network.

Other Opportunities for Success

Meanwhile, Wi-Fi's technological and regulatory challenges are opportunities for vendors to differentiate their products. On the infrastructure side, one way is by using smart antennas on the access point (AP) to focus the downlink signal and to improve uplink reception. This architecture also helps deal with the fact that many Wi-Fi user devices are mediocre performers for reasons that include an emphasis on getting their price as low as possible and antennas typically being an afterthought among device vendors.

Some challenges cannot be overcome by a single company. One example is roaming, where the Wi-Fi Alliance is among the organizations working to make it easier for users to connect to Wi-Fi networks other than the one owned by their primary service provider. Another example is an upcoming 3rd Generation Partnership Project (3GPP) standard, Release 10, that enables simultaneous connections to Long Term Evolution (LTE) and W-Fi networks so devices can quickly and automatically switch between the two, based on factors such as cost and bandwidth

Conclusion

Wi-Fi networks are an essential component to meet the ever-growing demand for mobile broadband. The business value of Wi-Fi will continue to expand by offering users consistent, portable connectivity. What’s more, that business value will be realized via seamless authentication, provisioning, and roaming. Next-Generation Hotspot strategy which is based on IEEE 802.11u, WPA2-Enterprise, standards-based EAP methods enables carriers to optimize their networks by offering Wi-Fi as an additional mechanism for secure mobile access of data traffic, while also helping to ensure a superior user experience. The strategy moves the Wi-Fi network from an untrusted network to a trusted and integral part of a carrier’s network. The Next Generation Hotspot provides a platform for delivering a host of new features that enhance the end-user experience with unique, context-aware services and web-based applications to increase revenue and market share through subscriber retention.

NGH is a critical component of a solution that is easy for mobile operators to implement, since the HotSpot 2.0 specification includes the mobile operator’s existing method for authenticating a mobile network subscriber. Previously, a mobile subscriber that desired to use a commercial hotspot was forced to establish a separate subscription with the hotspot provider. Authentication and authorization for the use of the hotspot did not go to the home operator, creating additional work and complexity for the subscriber, severing the link that allowed the home operator to control and safeguard roaming use.

With NGH, the home operator stays in control. Authentication and service authorization requests are sent to their subscriber database (HLR/HSS). Similarly, billing is promptly reported to their network, and all roaming use can be controlled and monitored. All of this is achieved using the same methods the operator currently uses for 3G roaming, so Wi-Fi is now totally integrated into their operation. With HotSpot 2.0, Wi-Fi is no longer an alien network but works as part of the home operator’s roaming system.

Considering how many wireless carriers are using or considering using Wi-Fi offload, it is no surprise that the vendors offering solutions reads like a who's who of telecom. Besides the companies already mentioned, others include Motorola Solutions, whose controllers and Aps are interoperable with IntelliNet Technologies' Wireless Services Gateway; Kineto Wireless, whose customers include T-Mobile USA; and PCTEL, which white-labels antenna systems to vendors including BelAir. This is just a representative sampling, not a comprehensive list of Wi-Fi vendors.