Samsung launched the new Galaxy S 4 with great fanfare, but the greatest thing about that device is buried rather deep in the user's guide. It is the world's first smartphone to ship with Passpoint enabled!

Passpoint is the Wi-Fi Alliance's designation for devices and network equipment that support the Hotspot 2.0 standard. There is almost no amount of hype that goes far enough when talking about the impact that Hotspot 2.0 will have on the wireless world. Seriously.

Hotspot 2.0 has been a work in process by the Wi-Fi community for better than half a decade. The goal being to make the process of Wi-Fi roaming as easy to use and secure as with cellular. It's not an easy proposition, but that standard was finally completed in June of last year, and network equipment with the Passpoint certification began to ship in the fall. Then came the wait for smartphones vendors to start shipping Passpoint certified devices. Now that wait is finally over!

With Samsung starting to ship Passpoint on the Galaxy S 4, we can expect the other major smartphone vendors to follow suit in short order. Users will now be able to enjoy all the benefits of Hotspot 2.0 technology, and it's a long list.

What makes Passpoint such a big deal is that it heralds in a new era where users no longer have to think about SSIDs or authentication or fumble around with passwords. Instead they just get connected. Just as in the cellular world, all the complexity of roaming and getting connected will be hidden from the user. That's a network and device problem, and not a user problem.

All users care about is an always best-connected wireless experience. And Wi-Fi roaming can go far beyond the cellular experience. You don't need to leave the country or even leave town to enjoy the wonders of roaming.

A user can roam at a local coffee shop, at a football stadium across town, or an airport on the other side of the world. Roaming partners can include mobile operators, cable operators, wireline operators, large and small enterprises, large and small public venues, consumer brands, and the list goes on. Roaming is simply the magic behind the curtain that makes everything happen.

Think about a huge web of millions of Wi-Fi access points owned by tens of thousands of different entities, all of which can be accessed by the user courtesy of a web of behind the scenes roaming agreements.

And not only does it make the user's life a lot easier, it solves the network densification problem for mobile operators. With the arrival of Hotspot 2.0, Wi-Fi will begin to so weave itself into the fabric of the mobile experience that it will start to disappear from view. Hotspot 2.0's magic doesn't end with seamless roaming, the technology also provides an encrypted airlink.

Now when a user sits down in a coffee shop or airport they don't need to worry about the security of their over-the-air communications. This is a problem that plagues a lot of public hotspots.

Congratulations to Samsung for being the first vendor to ship Passpoint capable devices, and now the entire wireless user community worldwide can begin to enjoy an entirely new and even more compelling user experience.

Carriers are excited by the prospect of Hotspot 2.0 (HS2.0) not least because it takes many of today’s manual Wi-Fi tasks, like authentication, and automates them; it lets users roam without hassle and network operators to focus on more important things than simple administration.

It achieves this through a truly revolutionary overhaul of the Wi-Fi connection procedure. Using the new IEEE 802.11u protocols, HS2.0 allows the Wi-Fi client and infrastructure to have a pre-association "conversation" about the capabilities and AAA interconnects of a particular Wi-Fi network. The client then makes an automatic decision about whether or not to connect to this Wi-Fi network, or to another that might be in range.
 

The shared vision for HS2.0 is for the Wi-Fi user experience to replicate the cellular phone experience through secure connections, automated, and conforming to user and operator policy. The development has considerable multi-industry muscle behind it from the Wi-Fi Alliance (WFA) for certification under the Passpoint™ programme and organisations such as the Wireless Broadband Alliance (WBA) for interoperability.

Hotspot 2.0 makes possible links to a huge network of effectively random Wi-Fi access points through a web of interconnections, so that users can enjoy a seamless experience as they move between Wi-Fi networks from almost any location. It achieves this through a revolutionary overhaul of the Wi-Fi connection procedure, automating the manual configuration and decision-making process, as well as effectively automating security through the implementation of advanced WPA-2 airlink securing and client isolation. HS2.0 eliminates the hassle of users fiddling with their devices in order to associate to the hotspot. No more ‘SSID surfing’ or having to ask the barista for the Wi-Fi passphrase.

While HS2.0 has been developed and promoted predominately by carriers and equipment suppliers, it will have its greatest impact and appeal within the enterprise. That’s what will make it a game-changer.

HS2.0 will be about much more than the technology enablement of a better mobile user experience – it will shift relationships between carriers and building owners; those who want to provide the uninterrupted service as part of their continued strategy to deliver better subscriber experiences, and those who own the locations essential for providing the continuity of service. This commercial/cultural shift, combined with an important leap forward technologically is going to give HS2.0 its place in the Wi-Fi hall of fame.

Whose Line is it Anyway?

Two principle parties are interested in the provision of Wi-Fi services: the owner of the venue or building, and the service provider. Now their interests are coinciding. The balance of power is shifting; the ‘power’ being the ability to offer robust Wi-Fi connectivity with no signal drop-off.

The widespread and growing use of Wi-Fi across public venues such as hotels, schools, shopping centres, retail outlets, public transport, sports venues – in fact, anywhere where people gather and expect to use their mobile devices without encountering any problems – is both a responsibility and an opportunity for venue owners, and for the enterprise. These are usually the owners of the network infrastructure. Since operators want the Wi-Fi network access, the real opportunity will emerge for any enterprise or venue owner to wholesale their existing wireless LAN capacity to operators; charging them recurring fees for that access.

Mobile service providers want to automatically connect their subscribers to their own ‘branded broadband’ service through the venue’s available high-speed Wi-Fi network, and it’s this connection that HS2.0 will make possible; giving the Wi-Fi network an interconnection with subscribers’ ‘home’ service providers so the devices just carry on functioning in the way we all expect in the 21st century. These back-end connections might be direct, but more likely will be indirectly provided through third-party hubbing services.

Hotspot 2.0 at Work in the Enterprise

A single SSID will advertise automatic authentication to a large number of “home” service providers. The Access Network Query Protocol (ANQP) then lets the devices know which providers have roaming arrangements with the venue. Some providers will be included in the ANQP advertisements from the AP, while the mobile device may request the complete list. Providers may be listed using any or all of the following identifiers:

• PLMNID: Mobile Operator Country Code (MCC) + Network Code (MNC)
• NAI: Network Address ID (i.e. Domain Name), e.g. btwireless.com
• Roaming Consortium Organization Identifier: This is assigned by IEEE to a single entity or group of entities with pooled authentication An 802.1x authentication request from the mobile device is forwarded by the local venue WLAN to the home provider via RADIUS.

An essential element in the roaming process, the HLR (home location register) is the database within a GSM network that stores all the subscriber data. If the home provider is a fixed operator, the request could be cleared through their RADIUS infrastructure and subscriber management system. AAA accounting records can also be provided from the local WLAN to the home provider AAA server for billing purposes.

Enterprise WLANs involve large capital and operational expenses and HS2.0 offers the chance both to gain a return on the investment and to secure an on-going revenue stream. The WLAN will become a profit centre. As it does, enterprises will need to build out their wireless LAN networks – driving new requirements for higher capacity and more industrial strength equipment. Where it gets really interesting is when Google, Facebook and Amazon.com come into the picture as home provider, using HS2.0 to authenticate users anywhere against their own databases.

Most expect HS2.0 to go live around late 2013 and early 2014. Once it hits, full monty, enterprise Wi-Fi will never be the same again. 

One of the hottest areas of interest for the mobile industry at this year's Mobile World Congress isthe integration of Wi-Fi access points and LTE small cell radios into a single box.

Integrating these different radio access technologies into a single platform or node provides big value, such as greater densification and a broader set of services then either technology could provide on its own.

Yet obvious concerns remain:

While mobile operators are rushing Wi-Fi to address their capacity needs in very high-density (primarily) indoor locations, small cells are also viewed as a good way to boost cellular densification in high traffic outdoors areas. But is it really that black and white?  

Deploying a multi-RAN access points outdoors is typically much more challenging than deploying Wi-Fi indoors. Why?  Because power and backhaul (fiber, microwave or spectrum) is scarce, costly and cumbersome to provision - needlessly stretching out deployment schedules. And in both cases, there is a  requirement to get permission to install equipment from the entity that controls the site.

Some of the very best places to mount small cells are on street furniture, specifically traffic lights and light poles (see picture below). These are highly desirable locations because they are almost everywhere and come with AC power. However, they almost never have Ethernet or some fiber connection for backhauling traffic.

This introduces the potential for Wi-Fi APs to backhaul small cell traffic to a "wired" aggression point in close proximity. That addresses the first challenge with many outdoor small cell deployments, but certainly not the last.

The entity that controls access to street furniture (usually a city) often has very specific conditions that must be met for site acquisition:

1. It usually starts with a neutral host solution where a single operator is allowed onto their light poles and they must provide services for everyone.  Municipalities don't want a lot of clutter on their light poles.  Wi-Fi excels at providing a neutral host solution.  Services can be "free" to all users, operators can wholesale services to other operators, or Hotspot 2.0 can be used to enable roaming on that infrastructure.  
   
   
   
2. It usually ends with aesthetics.  How these devices look in the environment is a huge concern for many cities, stadiums and public venues. This is driven by the desire to, again, limit clutter. Consequently there is a premium on putting "everything" into one box.  Everything means the small cell radio, the Wi-Fi radio for neutral host, and the wireless backhaul solution. 

This suggests an approach that allows the mobile operator to lead with a Wi-Fi on the street furniture, as it is just easier to get that approved by the various municipalities that control access to these poles, and then add small cells where and when needed to further increase cellular densification.

Most mobile operators are moving to a model that gives them the most flexibility such as deploying devices that provide mechanical separation of the Wi-Fi APs and small cells. This ensures "flexible deployment options" as these units can effectively evolve at their own pace. And as faster 802.11ac radios emerge, they can be easily integrated into a multi-RAN node with virtually no impact to the small cell. And the converse is true.  As small cells are enhanced they don't impact the Wi-Fi AP.  It also makes it very easy for a 3rd party to deploy the Wi-Fi footprint and lease space on the back of these AP's to different MNOs that might use small cells from different RAN vendors.  The small cell bolts onto the back of the Wi-Fi AP and gets power and backhaul from the unit. The Ruckus SmartCell 8800 (above) is just one example of this new category of the multi-access RAN nodes.

Ultimately the convergence of Wi-Fi and small cells is a very compelling idea with lots of industry momentum, but it is probably best if Wi-Fi leads in this dance.

But when he rears his ugly nose into our business we get, well....all up IN it.  

Sometimes things can get a little complex, technical and confusing. We're big on simplifying things and being brutally honest about technlogy and it's real value - whether it's ours or not. So here goes.

Cisco's new whitepaper "All_Beamforming Solutions are not Equal" is at best misleading and at worst mythology.

In this paper, Cisco effectively got two things right:
1) they spelled the word "beamforming" properly and
2) they used the appropriate Cisco corporate logo.

FUDDING UP

Cisco is clearly going out of their way to give the impression that Ruckus-patented BeamFlex and digital signal processing (DSP)-based beamforming (often called chip-based transmit beamforming or TxBF) techniques are categorically similar. This is patentedly false.

BeamFlex and TxBF are radically different in function, benefit, and usefulness. What’s more important is that product vendors with only DSP-based TxBF would like to suggest that adaptive antenna switching somehow prevents supporting chip-based TxBF as well. 

Ruckus supports both. The benefits of BeamFlex sit on top of those brought by chip-based beamforming. The gain of these techniques is cumulative. Why pretend that customers must pick one or the other when they can get both? 

For IT managers, administrators, and engineers alike, 802.11n’s MIMO techniques and all this other WI-Fi technical mumbo jumbo can be both complex and confusing – making vendor marketing (admittedly) an opaque fog.  To that end here's some absoute truth (facts that are true for all people, at all times, in all places) that should help.

Customer have LOTS of choices and can be easily deceived by supplier marketing.  Yet at the end of the day, customers just want the truth. 

SAFETY TIP: If you want to avoide reading further, just download, read and memorize this document.

FOR THE TECHNICALLY MINDED 
(you know who you are)

Cisco’s ClientLink uses a type of chip-based beamforming with implicit client feedback. In theory, implicit transmit beamforming (TxBF) such as ClientLink allows an AP to create multiple downlink beams that constructively add together at the client to improve the overall signal. To do this successfully, the AP relies on what it hears from the client (the “implicit” feedback, which is really no feedback at all) to determine how best to steer the beams. 

1. ClientLink is a chip-based MIMO technique that cannot be used on the same antenna at the same time as other chip-based MIMO techniques like Spatial Multiplexing (SM), Space-Time Block Coding (STBC), and Cyclic Delay Diversity (CDD), so TxBF comes with a tradeoff from the start. 
   
2. ClientLink forms its beams based on how the AP “hears” and not based on how the client “hears.” 
   
3. Implicit beamforming uses received signals to determine the relative signal offset for each downlink beam. Theoretically, this works fine for fixed clients, but for mobile clients, every downlink frame will be optimized for the client’s previous location, and not for its current location. 
   
4. TxBF such as ClientLink requires incredibly precise phase and amplitude weights for constructive gain to occur exactly at the client location. When the weights are not accurate, destructive interference occurs and can actually reduce signal quality instead of improving it. 

Perhaps the actions of the IEEE’s 802.11 working group— removing implicit beamforming entirely—speak the loudest. For more evidence on this topic, researchers from leading universities readily acknowledge the problem of non-reciprocity and the faults in implicit beamforming.

For beamforming to work successfully, transmitted signals from the AP must constructively combine at the client’s antenna(s). What happens if a client device has more than one antenna? In such a case, it is not possible for the AP to determine which client antenna(s) the AP heard from. Given that almost all notebooks and tablets as well as most mobile phones (even ones with a single Tx/Rx chain) have multiple antennas, ClientLink is becoming applicable to an ever-dwindling minority of clients— SISO devices without antenna diversity—such as the old iPhone4 with the well-documented “antennagate” problem.

Also, it's important to note that the throughputs in Cisco's plot are north of 200Mbps. This means that the client is at least a three-stream MIMO 802.11n client. But ClientLink can't work with multi-antenna clients because it needs the channel state information (CSI) between EACH antenna combination. And with multi-antenna clients it's simply NOT physically possible to get the per antenna CSI without client cooperation (and client cooperation requires standardization).

 Finally, Cisco attempts to dismiss the gains of PD-MRC, but this is simply because their brand of beamforming can't support it. IEEE channel models measure PD-MRC gains in the 7-15 dB range for LOS conditions and in the 3-5 dB range for NLOS conditions. 

Ultimately marketing is relatively simple. But building RF features that truly impact real clients in everyday networks isn't. End-users need to review third-party testing that includes both Cisco and Ruckus products. Better yet, test both products in your own environment, with your expected client devices and applications.

At the end of the day, the worst thing about being lied to is knowing you're not worth the truth.