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Going the Distance with Wi-Fi Direct

By Glenn Fleishman

The areas Wi-Fi Direct can best Bluetooth are on distance and speed: I've written a few articles already about Wi-Fi Direct, the new peer-to-peer mode that the Wi-Fi Alliance is finalizing and which will appear in updated and new hardware in mid-2010. This includes my analysis of why Bluetooth and Wi-Fi Direct serve related but not entirely overlapping purposes. But in that discussion, I only mentioned speed and distance in passing.

Bluetooth devices come in one of three varieties by signal output: Class 1, 2, or 3. Class 3 devices (1 meter, 1mW) were originally the most common, intended for low-power earpiece-to-phone communication. Class 2 (10 meters, 2.5 mW) became more common, and I believe now predominates. This allows communication within a room and sometimes beyond. Class 1 (100 meters, 100 mW) is rarely found in peripherals, although it's used in computers. The Callpod Dragon V2 headset ($99) is a rare peripheral exception, but the size and price have something to do with its ability to push out that much signal.

Wi-Fi, in contrast, is designed for whole home/whole office coverage, with 802.11n finally achieving that for many venues. Wi-Fi equipment makers used to, and some still do, put out nominal distance numbers, like 100 meters diameter or what have you, but I always thought these numbers were nonsense. Originally, these distances were based on minimal testing in simulations of the real world. Some companies and trade groups have houses that are designed to be testbeds, even.

In practice, 802.11g Wi-Fi was a one to two wall and one, maybe two floor solution. A lot of factors about building materials affected that. 802.11n penetrates far better, and can produce a far clearer signal (and thus higher speeds) through many more obstructions.

For Wi-Fi Direct, where you want to be able to peer easily to devices around you without fuss, the distance and penetration issues may be one important component of why people may turn to use that mode rather than Bluetooth. It's possible that some operating system makers or third-party software developers will make it simple for Wi-Fi Direct to become an ad hoc Internet access mode, bypassing the need for guest networks in access points, for instance.

Speed will also be a component depending on the uses to which Wi-Fi Direct is put, and how OS makers and device makers incorporate the mode. If Apple lets me use Wi-Fi Direct on an iPhone to transfer data from an Apple TV or a Mac or Windows system with iTunes installed (say, as an extension of the firm's new Home Sharing feature in iTunes), then I will surely want the 50 to 150 Mbps available with Wi-Fi Direct instead of the 2 Mbps of throughput from Bluetooth 2.1+EDR.

This draws me back to the application and profile issue I discussed in the previous article on Bluetooth competition. The usage Wi-Fi Direct beyond simple file transfer and Internet access and printing will depend heavily on having layers of functionality (tasks and purposes) put on top of connectivity.

Posted by Glenn Fleishman at 10:55 AM | Permanent Link | Categories: Bluetooth, Standards | No Comments

Is Wi-Fi Gunning for Bluetooth? Not Precisely

By Glenn Fleishman

Wi-Fi Direct is both parallel to and complementary of Bluetooth. Discuss: Today's announcement of Wi-Fi Direct, a peer-to-peer Wi-Fi transfer method, might seem to be firing across Bluetooth's bow. But it isn't quite. Intel's My WiFi is a much more direct threat, and even then may not materialize in quite the way that's being predicted. (Read my coverage, "Wi-Fi Alliance Peers into the Future with Ad Hoc Replacement.")

To review, Bluetooth is a PAN (personal area networking) technology in which devices under the control of the same person or computer communicate over short ranges and relatively low speeds. Bluetooth can create peer-to-peer connections or piconet networks, which comprise a host and up to seven clients. In a very standard configuration, a cell phone might use Bluetooth to communicate with a laptop, sharing its 3G mobile broadband connection, while at the same time a Bluetooth earpiece is paired with the phone to handle audio.

Bluetooth requires a pairing process, in which devices authenticate to each other and agree through a handshake (with optional encryption) to talk to one another. The SIG, device makers, and desktop and mobile OS developers have done a great job of simplifying this process down to typically entering a PIN--one of several options with the current security system, Secure Simple Pairing--instead of having 20 to 25 steps as it used to be.

Bluetooth's current release (2.1+HDR [high data rate]) encompasses a wireless spec for 3 Mbps data transfer (raw) using the 2.4 GHz band. The spec also includes application-layer elements, which are called profiles, and which define a large array of end-to-end tasks, like printing, file transfer, or acting as a modem. This allows any manufacturer to make a Bluetooth keyboard that talks the HID (human interface device) profile, and which is tested and certified as such, to talk to any other Bluetooth device with the HID profile.

The Bluetooth SIG, which maintains and develops the spec, isn't tied to its physical medium. It's tried to partner with other specs in process to extend itself, notably tying its cart at one point to both major ultrawideband (UWB) encodings, and then picking WiMedia, which was the "winner" in UWB. WiMedia disbanded, but handed off the Bluetooth component to the SIG; there may still be life in it. (Originally, Intel et al. wanted to stick one UWB radio in computers and devices, but have many different protocols run over that radio, such as Bluetooth, TCP/IP, Wireless USB, and video. UWB is currently shipping only as an instantiation of Wireless USB.)

While UWB fiddled and burned, however, the SIG worked on Bluetooth 3.0+HS (High Speed), which incorporates a high-speed transfer mode that allows a Bluetooth device to coordinate with a peer switching to use 802.11 for a bulk transfer, useful for large files or high-speed video streaming. The session is still within the structure of a Bluetooth PAN, and the use of 802.11 is entirely under the control of the Bluetooth session. The devices don't suddenly become ad hoc nodes or soft access points. Note the use of 802.11: this is a particular use of that protocol outside of any current Wi-Fi spec.

Wi-Fi Direct is an outgrowth of the interest by Intel and others in reducing the number of radio technologies and the level of complexity in devices, which can correspondingly reduce battery usage, while also developing a spec that's to their liking. Intel has a board seat on the Wi-Fi Alliance and the Bluetooth SIG, but still enjoys charting its own course.

Wi-Fi Direct is a peer-to-peer technology, at least the way it's being described initially. Wi-Fi devices that have services to offer (like printing, file sharing, etc.) can advertise those in a way that other equipped devices can access directly. This new method offers the speed and security of an infrastructure Wi-Fi network with an access point at the center without the overhead of joining such a network or making such networks public to allow access to specific resources. That is, someone can print to your printer without you giving them a key to your network. Wi-Fi Direct is built on top of 802.11n, so it can work in both 2.4 and 5 GHz, too.

The simplicity of Wi-Fi Direct is supposed to aid in devices without keyboards or easy data entry methods, much as Wi-Fi Protected Setup (WPS) was supposed to offer a one-click secure connection. With a peer-to-peer approach, a camcorder could hook up with a laptop to transfer data directly without you needing to enter a WPA2 Personal passphrase or even connect at all to an existing Wi-Fi network.

Beyond speed and security, Wi-Fi Direct will allow an adapter to be scanning and accessing peers while also maintaining a full infrastructure connection to a network. It's this feature that allows devices to ostensibly cut the Bluetooth "cord," although I'm still dubious about that as a general element, as I'll explain.

The My WiFi technology that Intel developed (apparently at least in part with Ozmo Devices) emphasizes more of the PAN aspect, talking about having eight devices associated with a laptop, for instance.

So, the question at the outset was whether Wi-Fi Direct is a competitor to Bluetooth?

Bluetooth and Wi-Fi Direct definitely compete head to head on trying to make the simplest network connection between two devices for a variety of straightforward purposes.

However, Wi-Fi Direct won't be backward compatible to the hundreds of millions of devices on the market that already have Bluetooth 1.x or 2.x. Bluetooth's later flavors (2.x and 3.x) are backwards compatible with those older devices.

And while Wi-Fi with a PAN mode could reduce circuit counts, most Wi-Fi chips that are being sold in the mobile market, and I believe in the desktop/laptop market, are integrated Bluetooth/Wi-Fi modules that often throw in other radios and circuitry as well.

Wi-Fi may eventually be appropriate to build into keyboards, mice, wireless headsets, earpieces, and other low-battery peripherals, but that's not really the case today. Bluetooth dominates there in hundreds of millions of installed devices.

Bluetooth's profiles also seem like an advantage to me. Kelly Davis-Felner, the Wi-Fi Alliance's marketing director, said that Wi-Fi Direct would not have application or task overlays, but would be focused on the networking and communication level, as with other Wi-Fi certifications.

Which means that if I connect my mobile phone with my computer to transfer music over, I still need an application on both sides that handles the file transfer. With Bluetooth, the profiles still need an interface on top, but a universally supported file-transfer method already exists. I can use a Bluetooth program under Windows and on the Mac and within various mobile phones to transfer files today.

If I want a method that synchronizes stored files and handles it automatically, then OS makers or third-party developers still do have to build an application on top of that. But with Bluetooth, they can rely on leveraging a well-supported mechanism. It's asymmetric, in that a desktop OS program for syncing MP3 files or photos doesn't require a corresponding program to be installed on a mobile phone that allows access to its storage via the Bluetooth profile.

Now, of course, I'm being a little disingenuous about profiles, because Wi-Fi Direct will create an IP-based network between the two parties, allowing existing service discovery methods to work just as they do over a wireless LAN today--including Apple's Bonjour and whatever the current name of Microsoft's technology. But none of these methods are supported across gadgets (like cameras). mobile operating systems, and desktop/laptop operating system platforms. That's going to be the challenge for Wi-Fi Direct.

In the end, I certainly see Wi-Fi Direct as provoking additional industry efforts to figure out precisely what's useful about PANs and sell those capabilities to consumers as solutions for frustration or a way to accomplish tasks they're unaware they need to accomplish.

The best thing about Wi-Fi Direct is that it enables a secure, high-speed ad hoc mode that will actually work among different devices, something that's long been needed.

One of the most interesting aspects of Wi-Fi Direct is that it could be used with Bluetooth, since many manufacturers participate actively in the Bluetooth SIG and Wi-Fi Alliance. Beyond Bluetooth 3.0+HS, there could be a convergence path for hand-in-hand networking, playing to each standard's strengths.

Posted by Glenn Fleishman at 11:23 AM | Permanent Link | Categories: 802.11n, Bluetooth, Standards | 4 Comments

Wi-Fi Alliance Peers into the Future with Ad Hoc Replacement

By Glenn Fleishman

Strong peer-to-peer mode added to Wi-Fi portfolio: The Wi-Fi Alliance has announced Wi-Fi Direct, a peer-to-peer wireless networking method that takes the group into a new realm of creating specifications de novo, instead of following IEEE groups. The spec will appear in hardware by mid-2010.

Wi-Fi Direct will allow any device to advertise itself as a combination of software access point and peer. Newer hardware--which will include some existing equipment with firmware upgrades--will be able to maintain a wireless LAN connection to a so-called infrastructure network (via an access point), while also creating a peer-to-peer link to a device like a printer, mouse or keyboard, computer, or handheld. This could be used for file transfers, printing, input, and synchronization, among other purposes.

The spec is backwards compatible with 802.11a and 802.11g, which will see the peering device as a software access point, if I understand that detail correctly.

Wi-Fi Direct will include mechanisms for advertising service availability without connecting, something like the Apple Bonjour method known generically as Zeroconf that uses DNS records to broadcast specific services over a LAN.

The new method is a wholesale replacement of the weak ad hoc networking mode that's part of 802.11, but never built out into a standardized, certified part of Wi-Fi. Ad hoc networks allow devices to exchange data with each other without an access point, but implementations almost universally offer poor security and degraded throughput.

Distinct from ad hoc networks are software access points, which mimic all the functionality of an infrastructure network, and must be operated in a continuous fashion on a computer.

The Wi-Fi Direct mode will not suffer from weaknesses of either type of quasi peer-to-peer methods, and will be rigidly tested for interoperability among devices. Kelly Davis-Felner, the alliance's marketing director, said in an interview that Wi-Fi Direct can preserve the full bandwidth of 802.11n, as well as use WPA2 encryption and WPS (Wi-Fi Protection Setup) secure key handling.

Davis-Felner also said that while the spec has a lot of consumer electronics and home user advantages, enterprise management was baked in as well. The spec requires "Wi-Fi Direct networks to be seen by enterprise APs, and, potentially to be shut down by them" to prevent rogue networks that violate policy, she said. The spec also includes optional mechanisms that allow enterprise access points to suggest channel assignments and power management choices. The spec was designed to be an "enterprise-acceptable solution," Davis-Felner said.

The alliance has pulled together support from many non-standardized PAN/WLAN hybrid modes that have been under development, most notably the Intel My WiFi personal area networking (PAN) extension of 802.11. Intel said via email that Wi-Fi Direct would be incorporated into Intel My WiFi, which has additional capabilities. (My WiFi supports up to eight devices in a PAN configuration, much like Bluetooth.)

Chipmaker Atheros also offers its Direct Connect mode (in addition to a soft access point feature), which it said via email can converge into Wi-Fi Direct. (Oddly, Atheros has no plain product briefing page on this mode.) Marvell has a similar hotspot-on-a-chip offering, and plans Wi-Fi Direct support.

And Ozmo Devices, a chipmaking and integration firm that worked with Intel on its PAN/WLAN technology, is also onboard, deeply involved in writing the spec.

"This has been by far one of the most dynamic and heavily participated in groups that we've had in the Alliance," Davis-Felner said.

Wi-Fi Direct is a bit of a departure for the Wi-Fi Alliance, which typically develops a set of parameters from IEEE standards that a Wi-Fi-compliant device should support, and then builds interoperability testing and certification around those parameters.

With the initial release of Wi-Fi Protected Access (WPA), the Wi-Fi Alliance reacted to the interminable delays at the 802.11i security task group by splitting the backwards-compatible components from all the future-looking elements. WPA was based on an interim 802.11i draft, but ultimately was updated to WPA2 to incorporate the final work of the group.

Here, the alliance isn't following the IEEE, which has no PAN/WLAN convergence group, but maintains separate WLAN (802.11) and PAN (802.15) efforts. The 802.15 group has famously suffered from mid-stream shifts in technology approaches and the disbanding of 802.15.3b (high-speed PAN using UWB).

Wi-Fi Direct could be seen as a challenge to Bluetooth, given that Bluetooth is designed entirely as a PAN, and has a specification that will soon see light that allows Bluetooth to trigger an 802.11-compatible bulk-transfer mode for large files at faster rates. Bluetooth had paired itself with UWB as its next-generation wireless medium, but generic UWB radios never reached market, although there's still some potential.

Posted by Glenn Fleishman at 10:11 AM | Permanent Link | Categories: Bluetooth, Standards | No Comments | No TrackBacks

Wi-Fi Alliance Starts Ratified 802.11n Certification

By Glenn Fleishman

The Wi-Fi Alliance announced this morning that it has started certifying fully compliant 802.11n devices, along with new optional elements: The group, which tests 802.11 gear for interoperability, is graduating from the Draft N trademark and testing to plain old N, with updates to logos and processes.

As noted in my earlier article, "The Fine Points of Optional Wi-Fi 802.11n Certification," 2009-08-07, the Wi-Fi Alliance added four additional optional certifications for a third spatial stream, better 2.4 GHz coexistence, space-time block coding, and packet aggregation. A few other tweaks are also added, described in that article.

The biggest change we'll see from the completion of the 802.11n standard and this certification update is three-stream N, which will allow raw data rates of 450 Mbps, along with the potential to simultaneously address three mobile devices at one time that are using single-stream 802.11n. This is likely to have much less impact in the home than in the enterprise, of course. Four-stream, 600 Mpbs devices are still in the future.

The alliance only releases new certification programs after testing with reference gear from major chipmakers, this time involving Atheros, Broadcom, Intel, Marvell, and Ralink. The companies involved all shot out press releases today describing their involvement, and how cool all this new gear will be.

It's likely that as the result of certifying new gear, older devices will see minor firmware updates as tweaks are made. The space-time block coding changes conceivably can be rolled into older devices, as well as some of the packet-aggregation updates. Both improve throughput depending on network conditions.

Posted by Glenn Fleishman at 2:39 PM | Permanent Link | Categories: 802.11n, Standards | No Comments

IEEE Ratifies 802.11n

By Glenn Fleishman

If I had larger type, I'd use it: The IEEE Standards Board has formally ratified the 802.11n standard (802.11n-2009, to be extraordinarily specific). It took seven years and involved 400 members from 20 countries. Somebody deserves a vacation.

Successor standards committee's are already underway, of course, but it's likely years before we see products based on 802.11ac (6 GHz and below) and 802.11ad (60 GHz), both of which aim for speeds of 1 Gbps and faster.

Somebody go put masking tape over the word "draft" on all those Wi-Fi boxes.

As far as any firmware revisions based on tweaky late changes to the spec, it's unlikely. From what I can tell from colleagues and the Wi-Fi Alliance, it's much more likely that newer devices will add features than current devices will see (or require) firmware changes.

On 7-August-2009, I wrote up the four major additional features coming to the Wi-Fi certification process, some of which were dependent on the late-stage draft changes in 802.11n. See "The Fine Points of Optional Wi-Fi 802.11n Certification."

The four new certification elements mostly, but not entirely, related to improving raw speed or net throughput.

Posted by Glenn Fleishman at 3:13 PM | Permanent Link | Categories: Standards | No Comments

The Fine Points of Optional Wi-Fi 802.11n Certification

By Glenn Fleishman

The Wi-Fi Alliance explains four optional 802.11n elements for future certification: The Wi-Fi trade group has over the last 10 years kept together the notion that every device with Wi-Fi on the label should work at the greatest point of agreement with one another. This has continued in spite of new elements and enhancements to the 802.11 family of standards, including 802.11n.

The recent news that the IEEE had approved 802.11n within the 802.11 Working Group, and ratification was likely a few months away, led the Wi-Fi Alliance to explain its roadmap for adding more steps to the certification process. When the Wi-Fi group certifies a device, it runs it through tests that are supposed to ensure that the equipment responds in a standard manner. (The group also does plugfests in which equipment makers bring lots of gear together outside of lab conditions.)

When the word hit, the alliance identified four optional areas of certification that it would add. I knew about some of these areas, but I spoke with the group today to clarify what this meant for both equipment makers and end users. The Wi-Fi Alliance said it would offer tests for coexistence in 2.4 GHz, space-time block coding, transmit MPDU, and three spatial streams. Scratching your head? After 8 years of covering Wi-Fi, I admit I was in that position over a couple of those.

Let's go through them with the help of Greg Ennis, the alliance's Technical Director, who--along with Kelly Davis-Felner, the group's marketing director--was kind enough to lead me through it.

Coexistence. I first wrote about 802.11n coexistence mechanisms in depth back in Feb. 2007, when I interviewed Atheros's CTO Bill McFarland when the Draft 2.0 approval was imminent (see "How Draft N Makes Nice with Neighbors; 5 GHz Averts Tragedy of the Commons," 16-Feb-2007).

Coexistence has to do with the use of double-wide channels--40 MHz instead of the roughly 20 MHz regular channels--in both 2.4 and 5 GHz bands. The 5 GHz band isn't a problem, because 20 MHz channels don't overlap; Wi-Fi selectable channels in 5 GHz are staggered by intervals of 4 band channels (5 MHz each), such as 36, 40, 44, and 48. In 2.4 GHz, channels are staggered only by a single 5 MHz band channel, meaning that the use of 40 MHz will nearly always conflict with other existing networks.

Ennis said that 2.4 GHz coexistence terms weren't fully settled until recently, even though manufacturers have built in some methods of using 40 MHz in 2.4 GHz. The Wi-Fi Alliance discouarged the use; Apple, for one, doesn't allow its gear to use wide channels in 2.4 GHz.

In the new testing regime, "not everybody is required to support 40 MHz operation--but if they do support 40 MHz operation, they must go through the testing that we've defined," Ennis said.

The mechanisms that require an access point backing off to 20 MHz channels are so broad and severe that it's unlikely you could use a wide channel in any environment in which other Wi-Fi networks operate. Still, Ennis says, it may be of use in enteprise situations, or with future gear that's all 802.11n with these modes enabled that can be more respectful of each other automatically.

Space-time block coding. This term makes my head hurt every time I read it. I go off to the Web and read up on the principle, and it's above my paygrade. All wireless communication has to allot slots in some fashion--through contention or scheduling--for bits to go through. That's the basis of all wireless standards.

What STBC does is extend that beyond time into the domain of space. An access point can, through some complicated encoding, send different information simultaneously using multiple spatial streams so that receivers (stations in Wi-Fi parlance) that have single-spatial stream receivers can separately but at the same time decode their unique package.

The utility of this complicated feature is that we're likely to start seeing lots of single-stream N devices, as I've written about in the past year. (See, for instance, "Does the iPhone Need 802.11n?", 26-March-2009.)

Chipmakers are most likely now delivering quantities of these lower-powered, cheaper 802.11n chips that can't offer two streams--and thus double the bandwidth--as laptop and desktop 802.11n modules can. With STBC, an access point can utilize the full available 802.11n bandwidth by splitting it spatially between two devices instead of halving bandwidth by speaking to a single-stream device solely.

Ennis noted that STBC also improves the signal-to-noise ratio, which makes faster rates and farther distances possible. "I think this is going to be a popular optional feature," he said.

Aggregation MPDUs (MAC Protocol Data Units). While sounding obscure, this is yet another way by which 802.11n can eke out improved speeds. For long sequences of data, aggregation MPDUs lets a Wi-Fi system create a long frame, reducing all the overhead required to send a packet. (Every packet has origin and destination information, a preamble, and other data that adds overhead.)

For video, for instance, Ennis says that this kind of aggregation can improve throughput, although probably not by double-digit percentages. "It's not as dramatic an improvement as say using more spatial streams, or using 40 MHz channels," he said.

Currently, the Wi-Fi Alliance tests aggregation only if a manufacturer's access point sends these aggregated frames; it checks that a station can properly receive such frames, which can be interpreted under earlier 802.11n drafts. The new optional certification tests for aggregated frames sent by both stations and access points. (If included, it must be tested.)

Three spatial streams. This last one is quite simple. The Wi-Fi Alliance can now test for devices that send three streams of data across space up from two streams of data. Ultimately, we should see devices that can handle four, with a maximum raw symbol rate of 600 Mbps with wide channels in 5 GHz.

Those are the technical bits. I asked Kelly Davis-Felner, marketing director, how all the above plus other specifications already available and other elements coming down the pipe would be presented to buyers. The a/b/g/draft n labeling can only go so far. She said that's her primary focus right now, and there should be more news on that front soon.

Posted by Glenn Fleishman at 2:41 PM | Permanent Link | Categories: 802.11n, Standards | No Comments

Wi-Fi Alliance Confirms No Changes to Its Draft N Tests

By Glenn Fleishman

The Wi-Fi Alliance won't modify its certification tests for the ratified version of 802.11n: Changes aren't needed, the group says. This was completely expected, but glad to put yet another check in a box. The 802.11n standard will finally move from draft to completed status in September, although a vote taken recently has already formally closed the process.

PC World notes, from a briefing with the alliance, that there are four optional elements to 802.11n that will be certified in the future. Those optional parts were where changes took place after the mandatory elements were settled more or less in January 2007.

Posted by Glenn Fleishman at 3:38 PM | Permanent Link | Categories: Standards | No Comments | No TrackBacks

802.11n Moves Closer to Ratification

By Glenn Fleishman

The 802.11n spec celebrates its seventh anniversary without ratification: The gears at the IEEE grind but slowly, and 802.11n is still not actually a ratified and published standard even though its been built (in "draft" form) into tens of millions of devices, and has a certification standard (Draft N, natch) at the Wi-Fi Alliance. (The alliance is separate from the IEEE, developing standards for testing interoperability of commercially produced devices using the IEEE standards as the basis.)

Wi-Fi guru Matthew Gast, author of 802.11 Wireless Networks: the Definitive Guide (foreword by yours truly), writes on his marvelously named blog that 802.11n has moved up a few rungs of the IEEE hierarchical process towards shedding its draft label.

The 802.11n spec was developed in a process that started with the High Throughput Study Group, which was turned into Task Group N within the 802.11 Working Group, which specializes in wireless LAN protocols. Matthew writes that the working group has now passed the spec upwards to higher-level groups, starting with the IEEE review committee, which meets 11-September-2009. Matthew notes that's exactly 7 years after the first meeting of the high-throughput group.

In practical terms, this is all institutional process, rather than anything that will result in changes. As far as I can tell, there have been no substantive changes to 802.11n in years, and the less-important changes occur on the driver side, Matthew said via email. It's also important to note that no device has appeared that implements all the optional parts of 802.11n, and some monkeying around has occurred in those areas.

The draft label should come off in September.

Posted by Glenn Fleishman at 11:20 AM | Permanent Link | Categories: 802.11n, Standards | No Comments

Wi-Fi Alliance Bumps Features, Enterprise Support

By Glenn Fleishman

Wi-Fi will expand to include new authentication methods, more enterprise support: The Wi-Fi Alliance, responsible for the brand name Wi-Fi and the certification and testing that stand behind it, will add two new authentication methods to the suite supported as part of WPA2: EAP-FAST and EAP-AKA. EAP (Extensible Authentication Protocol) is a generic method of sending messages between parties.

EAP-FAST (Flexible Authentication through Secure Tunneling) is a Cisco replacement for the long-deprecated LEAP (Lightweight EAP), which was broken back in 2004. Unlike PEAP and EAP-TTLS, popular ways of validating a WPA2 Enterprise session with server certificates and tunneling credentials, FAST uses certificates only as an option. (EAP-FAST is itself vulnerable, although those vulnerabilities can be avoided in a deployment.)

EAP-AKA (Authentication and Key Agreement) is the more critical of the two, an authentication system designed for use on 3G networks--both GMS and CDMA evolved system--with a lot of flexibility about the kind of credential that's used to authenticate a device to a network.

The alliance has long included testing of five other EAP methods, including TLS (per-device certificate), TTLS, PEAPv0 and PEAPv1, and SIM. EAP-SIM is used with 2G GSM devices.

Edgar Figueroa, the executive director of the Wi-Fi Alliance, said in an interview that EAP-AKA testing and certification goes along with the group's interest in Wi-Fi in handsets. "It's very much in alignment with our intent to continue to support convergence," he said.

Handsets need to be more capable of easily logging into Wi-Fi networks because of the constant increase in the scale of data being sent to handheld devices, coupled with the cost and limits of 3G data to subscribers. "Users may be cognizant they are paying for that data traffic really quickly if they don't get on that Wi-Fi network," Figueroa said.

I asked Figueroa about a related issue: the coming deluge of single-stream 802.11n devices which are aimed at handsets as a replacement for 802.11g. Single-stream N will use single antennas and a single radio chain, which means that the encoding speed could be much faster than 802.11g, but can't approach the 100 to 150 Mbps top rates possible with two-radio, wide-channel multi-stream 802.11n devices in laptops and base stations. (You can read more background about this in my article, "Does the iPhone Need 802.11n?", 26 March 2009.)

The potential for consumer confusion could be high, with two bands, multiple streams, and other options. "Simpler is better," he said. The alliance is discussing "how information is needed, and how much may be superfluous, and how much do we want to complicate our brand."

One item in the group's favor is that all the 802.11n devices I'm aware of that support the 5 GHz band also support 2.4 GHz. This could make 2.4 GHz the default mode for compatibility. An increasing number of consumer base stations are simultaneous dual band, too, which alleviates issues on the client side. (There may be some specialized enterprise gear that's 5 GHz 802.11a or 802.11n only.)

Unrelated to today's announcement, a minor security update is planned in the future for WPA2 to add 802.11w, which provides integrity for management frames. These specialized frames are used by access points to report various data or communicate messages without user data between an access point and client.

But, most critically, disassociation and deauthentication frames are sent in this fashion without any protection. A network attacker can disrupt a network by forging these requests, which aren't checked for validity. 802.11w uses an encryption method that prevents invalid requests from being carried out.

The minor flaw in the TKIP encryption method discovered last year won't have any impact on the security protocols or tests by the alliance, Figueroa said. "We have consistently advocated WPA2 as the protocol that people should be using"--a message echoed by all sensible security consultants, writers, and researchers.

On the enterprise side, Figueroa said the Wi-Fi Alliance had a few enterprise-oriented projects in the works with a timetable of about two years for reaching fruition.

One is WMM-Admission Control, which enhances the WMM (Wireless Multimedia) quality of service provisioning protocol (from 802.11e) with resource availability. WMM by itself allows data to be assigned one of several priority queues to ensure, for instance, that voice packets make it through.

The admission control addition would let a set of managed devices restrict a device from joining a given base station channel if the resources to support an additional call or stream weren't available. "If you allow that to happen otherwise, you end up having a non-elegant degradation for all who are using the network," Figueroa noted.

The ultimate protocol might include a form of "advice," in which a device was told a different channel to join that had resources free for what the device was intending to do.

A related future improvement is Voice-Enterprise, which will provide more robust testing of VoIP over Wi-Fi at the scale used in large networks. Currently VoIP testing by the alliance simulates a loaded network with four calls being placed; the enterprise flavor will test in a simulation of dozens of calls along with many access points in use and fast roaming among them.

Finally, Wireless Network Management will one day extend detailed network status information that's required for network monitoring and troubleshooting to network administrators. While Wi-Fi access points can report a fair amount of information today--and that varies by vendor and network design--the testing program would establish a baseline and interoperability parameters.

Posted by Glenn Fleishman at 6:01 AM | Permanent Link | Categories: Enterprise, Standards | 1 Comment

Latest 802.11 Standard Boosts Wi-Fi Power in New Band

By Glenn Fleishman

The nearly finished IEEE 802.11y could make Wi-Fi more practical over longer distances: Wi-Fi is a compromise. In the unlicensed bands in which it operates, it has to deal with interference from noise sources and other networks, while using very low power, and trying not to make a pest of itself. It's done very well. In the 2.4 GHz band and parts of 5 GHz, the maximum power from the radio is 1 watt (W), and the effective power (EIRP) is 4 W on an omnidirectional antenna. (You can push far more power if you narrow the antenna's beam. And parts of the 5 GHz band restrict radio power below 1 W. I wrote a long rundown of 5 GHz issues back in Jan-2007.)

But there's this lovely new segment of lightly licensed spectrum in the U.S., the 3.65 GHz band. It's a non-exclusive licensed band available only in parts of the country that don't have pre-existing ground-to-satellite or radar uses that overlap. This omits most of the eastern seaboard and most major cities; Seattle is one exception.

The licensing mechanism allows any number of operators to obtain inexpensive licenses, and register the base stations they use by location. If interference arises among base stations, operators are required to work out the problems themselves. I wrote extensively about this band and its rules on 9-May-2008 in profiling Azulstar, formerly a metro-scale Wi-Fi firm, but now a big proponent of WiMax in 3.65 GHz. I also went over the rules for the band on 11-June-2007 when the FCC announced the arrangement.

Several firms offer base station and customer premises equipment for this band now, so close to the 3.5 GHz band more commonly exclusively licensed in Europe and elsewhere. WiMax equipment is available because the 3.65 GHz band can be used with WiMax without any modifications to that protocol, although limited to just 25 MHz of the 50 MHz that the FCC set aside.

Equipment that conforms to a more stringent set of rules about contention and other factors can use the whole 50 MHz, and that's where 802.11y comes in. It's an extension of Wi-Fi to cope with the specific needs--and to open Wi-Fi technology up to 20 W EIRP, a vastly higher power output. This could allow connections over 5 km, the group says.

The Wikipedia entry on 802.11y, clearly written by someone involved with the specification, notes that three specific additions are needed: a tweak to support the way in which the FCC wants contention among competing devices to work; a method for an access point to tell a station (a connecting radio) that it's about to switch its channel or its channel's bandwidth, and the station should do likewise; and a mechanism to handle a base station allowing or revoking permission to use the spectrum without uniquely identifying the user's system or broadcasting its precise GPS-based location.

The standard is near completion and initial approval. I don't have any knowledge about whether any mainstream Wi-Fi equipment makers or metro-scale equipment makers are looking into building 802.11y into their gear.

The fact is that this could be a great technology for the mostly sub-metropolitan markets that 3.65 GHz is available in, although it has the same pain as WiMax: all new gear on the towers and all new adapters for customers.

Posted by Glenn Fleishman at 2:01 PM | Permanent Link | Categories: Metro-Scale Networks, Regulation, Standards | 1 Comment

Bluetooth Will Add 802.11 for Bulk Data Transfer

By Glenn Fleishman

The Bluetooth SIG says a 2009 standard will integrate Bluetooth and 802.11 in a tighter, more complementary relationship: The group that controls the Bluetooth standard continues the evolution towards agnosticism about underlying radio stuff. The latest move takes advantage of the side-by-side deployment of the "winning" wireless specifications: Bluetooth for PAN (Personal Area Networks) and Wi-Fi for WLAN (Wireless Local Area Networks). Bigger files will automatically be sent over Wi-Fi. Sounds simple, no?

"Bluetooth is great right now for sending some of these less bulky data files," said senior marketing manager Kevin Keating, but with the "bulk transfer of entertainment data, whether it's piles of MP3s or a bunch of vacation photos you want to move off your cameras or on your PC, it's not really built for that."

The SIG made this announcement this afternoon at the Mobile World Conference in Barcelona; Bluetooth is built into hundreds of millions of cell phones worldwide in its current form, and is near two billion devices shipped in all form factors. That number went from 1 to 2 billion in about two years.

The new standard, called Bluetooth High Speed, will allow a Bluetooth adapter and drivers to identify bulk transfers and move them from the lower-powered and slower Bluetooth radio technology to more battery intensive, but faster 802.11.

They're really talking about 802.11 and Wi-Fi nearly interchangably, but this standard doesn't yet have any formal involvement from the SIG's counterpart, the Wi-Fi Alliance, which controls the certification process for Wi-Fi and the trademark. Keating said, "Wi-Fi is its own brand, and we've talked."

It's important to remember that Bluetooth is both a set of profiles that define behavior--applications and schemas for data in those applications--and a radio standard. Bluetooth was originally developed with its own communications spec (the MAC and PHY, in technical terms) that worked at 1 Mbps; the 2.0+EDR and 2.1+EDR (Enhanced Data Rate) bumped that to 3 Mbps. (Version 2.1 also dramatically simplifies pairing between devices; it's rolling out widely now.)

These profiles include things like HID (Human Interface Device) for keyboards and input devices, DNP for dial-up networking, GOEP (Generic Object Exchange Profile) for file transfer, and so forth. The profiles are at a layer of abstraction above the interface and radio part, which makes it relatively simple to repurpose them across many radio standards.

In that vein, the Bluetooth SIG has already disclosed plans for its support for ultrawideband (UWB), whenever PCs with UWB or adapters start appearing in great provision, and their own ultra low power version of Bluetooth for things like heart-rate monitor, bike cyclometers sensors, and other low-data-rate devices.

The Bluetooth SIG says prototypes using the high-speed standard will be tested this year, with a published spec due in mid-2009, and devices presumably long before the end of 2009.

Posted by Glenn Fleishman at 9:00 AM | Permanent Link | Categories: Bluetooth, Future, Standards | No Comments | No TrackBacks

Bluetooth Group Adopts Better Pairing, Lower Power Rules

By Glenn Fleishman

The Bluetooth SIG's board of directors approved 2.1+EDR (Enhanced Data Rate): The revision of the short-range personal area networking standard will reduce power consumption and greatly ease pairing, the association between two Bluetooth devices. The changes can be applied to 2.0+EDR devices via firmware, the Bluetooth SIG told me, but many Bluetooth modules are now in devices that lack firmware upgrade ability. So computers, yes; phones, many; picture frames, perhaps not so much.

Pairing has been dramatically improved by reducing the number of steps and the complexity. For devices that require a passcode entry, version 2.1+EDR requires that one device in the paired set generates a six-digit PIN that is then entered in the other device. And you're done. (Apple created their own version of this years ago, but it worked only when devices were discoverable and paired by Mac OS X to a computer, and it was far less secure than the 2.1+EDR version.)

The PIN is generated, by the way, using an Elliptic Curve Diffie-Hellman algorithm, which avoids man-in-the-middle (MitM) attacks by using an out-of-band method to confirm a key exchange. In this case, the two Bluetooth 2.1+EDR devices generate and exchange their ECDH keys, and then one device generates a six-digit PIN which is part of a hash of the session key being used by the two devices. While an MitM can talk to both parties, they can't know that six-digit PIN.

The improvement in power usage is rather significant: the SIG reports a fivefold improvement in battery life by intermittently connected devices like sensors, and input devices that send very little actual information, like keyboards and mouses.

Posted by Glenn Fleishman at 4:34 PM | Permanent Link | Categories: Bluetooth, Standards | 1 Comment | No TrackBacks

Bluetooth Extends Usefulness with Wibree Inclusion

By Glenn Fleishman

The Bluetooth SIG will incorporate Nokia's wearable Wibree technology into its portfolio: Nokia sparked some interest when it unveiled Wibree last year because of the niche it filled: wireless technology with miserly power use that could fit in a tiny form factor, like wearable items. But there were also groans. With Bluetooth, ultrawideband, Wi-Fi, WiMax, and ZigBee already extant--not another technology standard, please!

Fortunately, Nokia is contributing Wibree to the Bluetooth SIG, and the Wibree Forum (which includes Broadcom and other firms) will become part of the fold, too. Contributing is the operative word: Nokia will allow the use of Wibree royalty free. Bluetooth itself was turned into a royalty-free offering to push its adoption.

Wibree-based products will be marketed as ultra-low-power Bluetooth, and have a goal of a year's battery life, 10-meter range, and 1 Mbps throughput. Current Bluetooth products have no battery-life target that I'm aware of, and can operate at ranges of 10 meters (Class 2) or 100 meters (Class 1), and up to 3 Mbps with Bluetooth 2.0+HDR (high data rate). Existing Bluetooth devices won't talk to Wibree equipment, but future Bluetooth standards can incorporate that ability, as Wibree uses 2.4 GHz frequency hopping radios.

This might seem to put the Bluetooth SIG in competition with the ZigBee Alliance, which products products that use the IEEE 802.15.4 standard for low-power, long-battery-life, short-range, low-speed wireless communication. (By the way, IEEE 802.15.1 is a subset of Bluetooth.) ZigBee, however, is focused on devices in the home and office like alarm and fire sensors, A/V equipment (like a TV remote control), and "white" appliances like refrigerators that might have something to say to its owner. Wibree's intent is centered around small, mobile devices where Bluetooth might be too bulky or power-intensive. We'll see if worlds collide.

Part of the Bluetooth SIG's real genius in recent years--and, yes, its director Mike Foley deserves to be credited--is embrace, adopt, extend. Bluetooth was clearly on a path to obsolescence with its specific radio technology, even as developers and hardware manufacturers continued to cram Bluetooth into everything mobile. It didn't have a good roadmap with a single offering with incremental improvements--like moving from 1 Mbps to 3 Mbps.

What's critical to know about Bluetooth is that it's a pile of specific application-layer tasks (which they call "profiles") combined with underlying radio technology. The radio technology is, frankly, irrelevant except insofar as the original and current Bluetooth standards codified a common way of exchanging low-speed data wirelessly. That's great, but there are a lot of methods, and there's nothing particularly special or important about Bluetooth's RF.

Rather, the value is in the profiles, like file transfer, printing, hands-free access, and dial-up networking. These profiles are abstracted from the radio, which means that programmers never have to think about the RF properties of the device in order to use profiles. (They might think about efficiency for bandwidth and battery usage, but not about radio-wave propagation.)

This has allowed the Bluetooth SIG to embrace ultrawideband (UWB) and Wibree without compromising its existing set of products or alienating developers. In fact, it's a boon to all electronics makers: a handset or smartphone maker could add or switch to UWB from the Bluetooth RF standard without losing Bluetooth's capabilities. (UWB is always next year's technology. Late last year, it looked like 2007 was going to be the year. But we're still waiting for the first real UWB products to hit the marketplace.)

Posted by Glenn Fleishman at 12:16 PM | Permanent Link | Categories: Bluetooth, Standards, ZigBee | No Comments | No TrackBacks

Wi-Fi Alliance Gives Draft N Certification Details

By Glenn Fleishman

The Wi-Fi Alliance still targets late June for completion of its certification of Draft N devices: Equipment that conforms to Draft 2.0 from the 802.11 Task Group N as tested through a suite developed by the alliance will be able to display a new logo that incorporates the Draft N motif. Atheros, Broadcom, Cisco, Intel, Marvell, and Ralink provided reference designs that were part of the certification process. These products are now Draft N certified, but they're reference designs--they can't be purchased. Rather, the changes to these designs to reach interoperability will now filter out from the chipmakers to their OEM partners, the companies that make end user gear, like Apple, Buffalo, Linksys, and others. These OEM devices will then, in turn, receive certification as they update the firmware necessary to achieve that state and submit their equipment for testing.

Posted by Glenn Fleishman at 10:32 PM | Permanent Link | Categories: 802.11n, Standards | No Comments | No TrackBacks

Wi-Fi Alliance Certifies Nearly 100 Phones

By Glenn Fleishman

The Wi-Fi Alliance says that nearly 100 handsets are certified: The group has certified 82 dual-mode handsets and 10 Wi-Fi-only phones. The idea of certifying voice handsets that incorporate Wi-Fi allows the alliance to ensure both interoperability and better performance. Frank Hanzlik, the alliance's executive director, said in an interview that this testing helps the manufacturer produce devices that function better in difficult RF environments, as well as align the phone's function relative to Wi-Fi gateways. The alliance has also been working closely with the CTIA, the cell industry's trade group.

Hanzlik said that he has been working to raise awareness of the WMM (Wireless Multimedia) extensions that allow voice packets to achieve priority across a network, WPA2 security, and the special WMM Power Save mode, which can extend battery life by 25 to 40 percent on a handset through better management of unnecessary communications with a gateway. Hanzlik expects over time to see WMM and WMM Power Save in more gateways. WMM Power Save could be a simple upgrade for most routers, as it requires no changes in the radio. Incompatible power save modes can actually waste power, and the alliance would like all makers to move towards their certified version.

For large-scale hotspot networks, moving to WMM Power Save could dramatically improve the experience of mobile users making Wi-Fi calls. "When you look at these very, very large operators like T-Mobile here in the US, or some of the folks in the Wireless Broadband Alliance [a worldwide consortium of hotspot operators], we're trying to get the word out to these folks" to upgrade their networks or plan to include WMM Power Save from the beginning.

Posted by Glenn Fleishman at 10:00 PM | Permanent Link | Categories: Standards, Voice | No Comments | No TrackBacks

Intel Unveils N for Centrino, Partner Program

By Glenn Fleishman

On the heels of Apple's commitment to 802.11n, Intel gets in the act: The timing is no coincidence. Apple and Intel have been coordinating messages, and even though Apple won't be using Intel's chips--Atheros appears to be the anointed party--Intel wanted to wait until after the IEEE task group vote last week and after CES, too. Apple jumped the gun by a few days.

Notebook partners include Acer, Asus, Gateway, and Toshiba committed at this point, with systems available at the end of January using Centrino Duo. The Santa Rosa laptop chipset platform is due in the second quarter of 2007, at which point they expect more participation.

Like Apple, Intel says five times the throughput, twice the range, but only in comparison with their previous products--no actual specs on megabits per second or feet/meters. They do note that N will provide an hour more battery life under comparable circumstances with the previous Centrino flavor. They will support 2.4 GHz and 5 GHz N channels.

The announcement includes the Connect with Centrino program, in which access point makers commit to rigorous testing with Intel to ensure interoperability. This is clever, because it will go beyond the Wi-Fi Alliance tests, which focus on wireless protocols, and include the whole ecosystem of DHCP addressing and other factors. Asus, Belkin, Buffalo, D-Link, and NetGear are all part of this first wave of branding.

Posted by Glenn Fleishman at 2:31 PM | Permanent Link | Categories: 802.11n, Adapters, Hardware, Standards | 1 Comment | No TrackBacks

Another Silly Name for a Redundant Product: Wibree

By Glenn Fleishman

Nokia introduces Wibree, a low-power alternative to Bluetooth: No, no, no, no. We don't need another wireless standard with a silly name. Wibree supposedly uses one-tenth the power of Bluetooth to deliver 1 Mbps (1/3 of Bluetooth's current radio speed) over 10 meters. With Zigbee (extremely low bandwidth, extremely low power, short distances), ultrawideband (high bandwidth, low power, short distances), Bluetooth (low-to-medium bandwidth, low power, short distances), and Wi-Fi (medium bandwidth, medium power, medium distances), it's really hard to see how Wibree fits into this ecosystem.

Bluetooth has a billion embedded chips now, and is still growing, despite reports of its death every few weeks since before its actual first shipment. Bluetooth is morphing from an application plus radio standard into an application standard that can be overlaid with minimal effort onto many radio standards. In that sense, perhaps Bluetooth would be a layer over Wibree, which would be just radio technology.

Still, Nokia should have a hard time of it introducing yet-another-technology that appears to have a single unique attribute--lower power than Bluetooth. They will try to get it introduced into a standards process.

Posted by Glenn Fleishman at 12:24 PM | Permanent Link | Categories: Future, Standards, Unique | 2 Comments | No TrackBacks

Wi-Fi Certification for Draft N by June 2007

By Glenn Fleishman

The Wi-Fi Alliance said today it would offer a two-phase plan to keep 802.11n's innovation moving along: With the next potential draft approval of the faster wireless data standard from engineering standards group IEEE's Task Group N looking like it won't appear until March 2007, the Wi-Fi Alliance has chosen to step in to stabilize the market. The first phase of certification will confirm compliance to what they expect will be Draft 2.0 in March, the next letter ballot in which Task Group N voters agree to an extensive set of changes to Draft 1.0. The compliance will be coupled with interoperability testing, so that devices labeled with their phase 1 branding--yet to be determined--will work together at the right speeds.

The second phase will be tied to a ratified standard, which may come by spring 2008. Ratification usually takes up to six months after final technical details are decided on and approved within a task group, so the standard will likely be gelled by fall 2007. Wi-Fi Alliance managing director Frank Hanzlik said in an interview today that should the March 2007 meeting not produce another draft, the alliance would assemble the closest possible set of agreed-on ideas to produce their certification standard. (The news was scheduled to be released tomorrow morning; News.com broke the embargo this evening.)

Products that comply with phase 1 certification for draft 802.11n could be on the market--through firmware upgrades or new hardware releases--by June 2007, but it's likely that devices that start to hit the market by early 2007 will more and more closely conform with what will be certified. "We actually are doing a lot of formal interoperability testing within the alliance with pre-standard products," said Hanzlik, and this ongoing work should reduce the time between the draft's approval and certification approval. (The alliance has opened more worldwide testing labs in recent months, too, which should distribute its certification work for faster completion.)

Phase 1 products aren't guaranteed to be forward-compatible with phase 2 products. "The forward-compatibility part is certainly too hard to call at this point; it's not anything that the alliance is committing to," Hanzlik said. However, they are stressing that compatibility among the phase 1 and 2 products would be highly stressed.

Phase 1 products will almost certainly have none of the optional elements for 802.11n, such as larger antenna arrays that produce higher throughputs. Some of these optional elements remain points of discussion, and will be less settled until further drafts are developed. Another major issue outstanding is the manner by which 802.11n devices will interact with legacy adapters and legacy networks, whether on the same Wi-Fi network, same Wi-Fi channel, or on adjacent Wi-Fi channels. That is expected to be resolved for the next letter-ballotted draft, which should be Draft 2.0.

This intermediate approach to 802.11n certification echoes the earlier interim security measure, Wi-Fi Protected Access (WPA), that the alliance put into place when the work on 802.11i lingered far longer than the market and manufacturers would tolerate, with the failure of Wired Equivalent Privacy (WEP) as a reliable link encryption method. WPA was available a year before 802.11i's final ratification, and stabilized the security concerns of the market. The later WPA2, which included the strong AES encryption method, entered the industry with relative seamlessness.

Of course, WPA had more to do with retrofitting a security model to work on older devices without leaving newer devices with less protection, and was a good-enough security system; WPA2 almost serves a different market, in which government-grade encryption algorithms are required and fast handoff for authentication, mobile devices--like VoWLAN handsets--is critical.

With 802.11n, the standard has to work on the lowliest to most sophisticated device, and there's a lot of hardwiring in silicon that can't be fixed later, so the standard has to be right when devices are released. That's been one of my primary objections to Draft N gear.

I have consistently said that you should not buy Draft N gear because there are significant advantages for most users. Buying MIMO gateways makes a lot of sense if you want better 802.11g speeds over greater areas. That technology is now relatively mature, relatively compatible, and relatively cheap. Draft N devices are quite expensive (Atheros aims to fix that by year's end), don't seem to deliver range and speed in testing (see this latest PC World showdown), and have no guarantee of full upgradability when the final 802.11n standard is delivered. (Intel said today they'd include Draft N support in their Santa Rosa platform in the first half of 2007, but Intel is on the board of the Wi-Fi Alliance, and thus knew this certification was coming when they made this statement.)

This process set up by the Wi-Fi Alliance answers my concerns.

First, with 802.11n's ratification pushed back nearly a year from the expectation just a few months ago, there's now a reason to bring today's capabilities into today's equipment. When ratification was just a few months away, having an entire generation of equipment that would be potentially incapable of forward compatibility or upgrade seemed ridiculous. Now, it's a reasonable market choice given a 12-to-18-month lifespan for the right kind of user. (The equipment will obviously continue to work after the ratification, too, and have its own value as it will retain interoperability and other benefits that current Draft N devices can't guarantee.)

Second, the Wi-Fi Alliance is waiting for Draft 2.0 or its equivalent. This allows a host of compromises to be made in the year between Draft 1.0 and 2.0, and technical problems to be solved. There should be an ocean of difference from Draft 1.0 to 2.0 in terms of basic problems being solved. Today's Draft N devices promise compliance to a draft that will be superceded, and offer no hardware upgrade promise when and if that happens if firmware upgrades fail to suffice.

Third, the alliance will offer a brand that I confirmed with Hanzlik will be clearly differentiated in phase 1 and 2. This won't offer consumers or businesses any implicit promise about forward compatibility. This reduces confusion in the marketplace and provides a clear message to equipment buyers that they are buying gear that may be superceded later, but has value now.

Fourth, the interoperability and conformance testing by the Wi-Fi Alliance will smooth out the rough spots in using devices from different manufacturers together. Some early equipment plays very poorly with its friends (similar devices from other makers) and neighbors (nearby networks). The alliance's process has worked in the past.

So, I can't say right now, go out and buy Phase One gear, because it has no name and doesn't exist. But I will predict with some degree of certainty that devices that start shipping in late winter 2007 will likely offer enough carrots for those who need higher performance or greater area networks to start thinking about purchase, and what's for sale by June 2007 (and certified) will be good investments in the next generation of Wi-Fi.

Posted by Glenn Fleishman at 5:46 PM | Permanent Link | Categories: 802.11n, Standards | No Comments | No TrackBacks

China Appeals WAPI Decision

By Glenn Fleishman

China has reportedly filed an appeal with the ISO standards body over its proprietary wireless LAN encryption algorithm: WAPI (Wired Authentication and Privacy Infrastructure) continues to make waves in international security and standards circles. The Chinese official news agency Xinhua reported today that a domestic industry trade group filed appeals in April and May with the international ISO standards body over ethics issues involved in the fast-track rejection of WAPI alongside IEEE 802.11i.

The Xinhua agency reports that the China Broadband Wireless IP Standard Group (BWIPS)--the recently formed WAPI Industrial Union isn't mentioned here--has collected 49 pieces of evidence proving ethics violations. The 802.11i standard was fast-tracked for consideration of approval; WAPI was rejected, in part, according to reports in March of this year, that China failed to disclosed key portions of the specification, including cryptography.

The group of 22 firms that are involved with WAPI's future were earlier reported to include many with government and military investments and control, which is a typical occurrence in China.

I've written a lot about WAPI; you can find earlier posts here. My ongoing concern, shared by many Wi-Fi industry insiders, is that without WAPI being fully published for examination, there's no way to determine the strength and integrity of the protocol--including whether backdoors are part of the standard. I've been told by some readers this is a paranoid attitude, but I'd suggest that events of the last six months make it clear that China wants to be able to monitor all data traversing its local networks and the Internet.

Update: PC Magazine provides a little more background detail on the dispute which centers on the IEEE recommending its own amendment to the ISO standard to IEEE international members, where the Chinese standards' backers believe the IEEE should have presented its members with an impartial representation of the two amendments.

A University of New Haven School of Business professor with a background in Chinese business operations sides with my take on WAPI. She says in this article, "China's WAPI standard could allow backdoor access to the technology, which is not really allowed. And China has no motivation to prevent backdoor access to the technology so this is one of the tussles. It's very characteristic of Chinese business. China has all kinds of on-the-books and off-the-books trade barriers."

Posted by Glenn Fleishman at 12:55 PM | Permanent Link | Categories: International, Security, Standards | 6 Comments | No TrackBacks

802.11n Slides Further into the Future

By Glenn Fleishman

An IEEE member informed me that the Task Group N schedule has slipped considerably: The group received 12,000 comments on the Draft 1.0 proposal that was accepted as a working draft in March, and which failed to achieve in May anywhere near the 75 percent required (it received under 50 percent) to make it a final draft that would head to ratification. What wasn't expected is that instead of perhaps 2,000 comments on the draft, a typical occurrence after drafts are sent around for review by IEEE voting members, 12,000 comments came in.

I can't say whether this is unprecedented--I simply don't know--but it should undermine the confidence of Atheros, Broadcom, and Marvell in producing silicon based on Draft 1.0 and calling it Draft N compliant. It's possible that none of the 12,000 comments will result in significant changes that require modification beyond what's achievable with firmware. Because none of the manufacturers shipping Draft N devices will guarantee that their shipping equipment will be upgradable for full functionality and Wi-Fi certified interoperability to the final, ratified version of Draft N, this is yet another sign that buying Draft N equipment right now is senseless.

To avoid confusion, Draft N encompass a set of technical changes that could boost speeds to 150 Mbps of net throughput or more. Multiple in, multiple-out (MIMO) antenna and processing technology is one part of that, and a significant part, but there are hundreds of other details. If you want a broader coverage area, buy current generation MIMO gear. If you want higher speeds, wait a few months at least. I was predicting July or September for a stable draft, but my source says things will slip, which could mean November or even January before a draft is reached that one would have confidence solves all the existing problems with legacy networks and which could be etched onto silicon wafers forever.

Some blame the IEEE for the slow pace of introducing new standards. I can't blame the group's process, but its pace is based on a certain frequency of general meetings that doesn't hold up to the demands of the marketplace. This is why gear now regularly ships far ahead of any standard, and why standards like the ultrawideband physical layer for personal area networks (802.15.3a) disbanded in disunity.

Again, if you want range, buy MIMO. If you want speed, wait. And whatever you do, don't buy Draft N. The premium you pay isn't worth the uncertainty and the many, many upgrades you'll have to apply.

Posted by Glenn Fleishman at 3:16 PM | Permanent Link | Categories: 802.11n, Standards | No Comments | No TrackBacks