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Archive for the ‘controversies’ Category

All you can eat?

Thursday, December 10th, 2009

The always good Rethink Wireless has an article AT&T sounds deathknell for unlimited mobile data.

It points out that with “3% of smartphone users now consuming 40% of network capacity,” the carrier has to draw a line. Presumably because if 30% of AT&T’s subscribers were to buy iPhones, they would consume 400% of the network’s capacity.

Wireless networks are badly bandwidth constrained. AT&T’s woes with the iPhone launch were caused by lack of backhaul (wired capacity to the cell towers), but the real problem is on the wireless link from the cell tower to the phone.

The problem here is one of setting expectations. Here’s an excerpt from AT&T’s promotional materials: “Customers with capable LaptopConnect products or phones, like the iPhone 3G S, can experience the 7.2 [megabit per second] speeds in coverage areas.” A reasonable person reading this might think that it is an invitation to do something like video streaming. Actually, a single user of this bandwidth would consume the entire capacity of a cell-tower sector:
HSPA ell capacity per sector per 5 MHz
Source: High Speed Radio Access for Mobile Communications, edited by Harri Holma and Antti Toskala.

This provokes a dilemma – not just for AT&T but for all wireless service providers. Ideally you want the network to be super responsive, for example when you are loading a web page. This requires a lot of bandwidth for short bursts. So imposing a bandwidth cap, throttling download speeds to some arbitrary maximum, would give users a worse experience. But users who use a lot of bandwidth continuously – streaming live TV for example – make things bad for everybody.

The cellular companies think of users like this as bad guys, taking more than their share. But actually they are innocently taking the carriers up on the promises in their ads. This is why the Rethink piece says “many observers think AT&T – and its rivals – will have to return to usage-based pricing, or a tiered tariff plan.”

Actually, AT&T already appears to have such a policy – reserving the right to charge more if you use more than 5GB per month. This is a lot, unless you are using your phone to stream video. For example, it’s over 10,000 average web pages or 10,000 minutes of VoIP. You can avoid running over this cap by limiting your streaming videos and your videophone calls to when you are in Wi-Fi coverage. You can still watch videos when you are out and about by downloading them in advance, iPod style.

This doesn’t seem particularly burdensome to me.

AT&T to open wireless data channel to VoIP

Wednesday, October 7th, 2009

In an earlier post, I discussed a comment AT&T made contemplating allowing VoIP on the cellular data channel. Today AT&T wrote a letter to the FCC saying that they have decided to go ahead with it.

This will make international calls much cheaper for people who are willing to put up with the latency issues of the data channel.

VoIP on the cellular data channel

Thursday, September 17th, 2009

In a recent letter to the FCC, AT&T said that it had no objection to VoIP applications on the iPhone that communicate over the Wi-Fi connection. It furthermore said:

Consistent with this approach, we plan to take a fresh look at possibly authorizing VoIP capabilities on the iPhone for use on AT&T’s 3G network.

So why would anybody want to do VoIP on the cellular data channel, when there is a cellular voice channel already? Wouldn’t voice on the data channel cost more? And since the voice channel is optimized for voice and the data channel isn’t, wouldn’t voice on the data channel sound even worse than cellular voice already does?

Let’s look at the “why bother?” question first. There are actually at least four reasons you might want to do voice on the cellular data channel:

  1. To save money. If your voice plan has some expensive types of call (for example international calls) you may want to use VoIP on the data channel for toll by-pass. The alternative to this is to use the voice channel to call a local access number for an international toll by-pass service (like RebTel.)
  2. To get better sound quality: the cellular voice codecs are very low bandwidth and sound horrible. You can choose which codec to run over the data network and even go wideband. At IT Expo West a couple of weeks ago David Frankel of ZipDX demoed a wideband voice call on his laptop going through a Sprint Wireless Data Card. The audio quality was excellent.
  3. To get additional service features: companies like DiVitas offer roaming between the cellular and Wi-Fi networks that makes your cell phone act as an extension behind your corporate PBX. All these solutions currently use the cellular voice channel when out of Wi-Fi range, but if they were to go to the data channel they could offer wideband codecs and other differentiating features.
  4. For cases where there is no voice channel. In the example of David Frankel’s demo, the wireless data card doesn’t offer a voice channel, so VoIP on the data channel is the only option for a voice connection.

Moving on to the issue of cost, an iPhone unlimited data plan is $30 per month. “Unlimited” is AT&T’s euphemism for “limited to 5GB per month,” but translated to voice that’s a lot of minutes: even with IP packet overhead the bit-rate of compressed HD voice is going to be around 50K bits per second, which works out to about 13,000 minutes in 5GB. So using it for voice is unlikely to increase your bill. On the other hand, many voice plans are already effectively unlimited, what with rollover minutes, friend and family minutes, night and weekend minutes and whatnot, and you can’t get a phone without a voice plan. So for normal (non-international) use voice on the data channel is not going to reduce your bill, but it is unlikely to increase it, either.

Finally we come to the issue of whether voice sounds better on the voice channel or the data channel. The answer is, it depends on several factors, primarily the codec and the network QoS. With VoIP you can radically improve the sound quality of a call by using a wideband codec, but do impairments on the data channel nullify this benefit?

Technically, the answer is yes. The cellular data channel is not engineered for low latency. Variable delays are introduced by network routing decisions and by router queuing decisions. Latencies in the hundreds of milliseconds are not unusual. This will change with the advent of LTE, where the latencies will be of the order of 10 milliseconds. The available bandwidth is also highly variable, in contrast to the fixed bandwidth allocation of the voice channel. It can sometimes drop below what is needed for voice with even an aggressive variable rate codec.

In practice VoIP on the cellular data channel can sometimes sound much better than regular cellular voice. I mentioned above David Frankel’s demo at IT Expo West. I performed a similar experiment this morning with Michael Graves, with similarly good results. I was on a Polycom desk phone, Michael used Eyebeam on a laptop, and the codec was G.722. The latency on this call was appreciable – I estimated it at around 1 second round trip. There was also some packet loss – not bad for me, but it caused a sub-par experience for Michael. Earlier this week at Jeff Pulver’s HD Connect conference in New York, researchers from Qualcomm demoed a handset running on the Verizon network using EVRC-WB, transcoding to G.722 on Polycom and Gigaset phones in their lab in San Diego. The sound quality was excellent, but the latency was very high – I estimated it at around two seconds round trip.

The ITU addresses latency (delay) in Recommendation G.114. Delay is a problem because normal conversation depends on turn taking. Most people insert pauses of up to about 400 ms as they talk. If nobody else speaks during a pause, they continue. This means that if the one-way delay on a phone conversation is greater than 200 ms, the talker doesn’t hear an interruption within the 400 ms break, and starts talking again, causing frustrating collisions.
The ITU E-Model for call quality identifies a threshold at about 170 ms one-way at which latency becomes a problem. The E-Model also tells us that increasing latency amplifies other impairments – notably echo, which can be severe at low latencies without being a problem, but at high latencies even relatively quiet echo can severely disrupt a talker.

Some people may be able to handle long latencies better than others. Michael observed that he can get used to high latency echo after a few minutes of conversation.

Apple’s App-roval process

Friday, August 28th, 2009

I wrote earlier about AT&T’s responses to FCC’s questions concerning the iPhone App Store and Google Voice.

Now Apple has posted its responses to the same questions, which are basically the same as AT&T’s. Among the differences are that Apple’s responses contain some hard numbers on its controversial App Store approval process:

  • 80% of applications are approved as originally submitted.
  • 95% of applications are approved within 14 days of submission.
  • 65,000 applications have been approved.
  • 200,000 submissions and re-submissions have been made.
  • 8,500 submissions are coming in each week.
  • Each submission is reviewed by two reviewers.
  • There are 40 reviewers.

These numbers don’t really add up. So what Apple probably means is that 95% of the applications that have been approved were approved within 14 days of their final submission. Even so, each reviewer must look at an average of 425 submissions per week (8,500*2/40), which is 10 per hour per reviewer – an average of 12 minutes of reviewer time per submission, which doesn’t seem to justify the terms “comprehensive” and “rigorous” used in Apple’s description of the process:

Apple developed a comprehensive review process that looks at every iPhone application that is submitted to Apple. Applications and marketing text are submitted through a web interface. Submitted applications undergo a rigorous review process that tests for vulnerabilities such as software bugs, instability on the iPhone platform, and the use of unauthorized protocols. Applications are also reviewed to try to prevent privacy issues, safeguard children from exposure to inappropriate content, and avoid applications that degrade the core experience of the iPhone. There are more than 40 full-time trained reviewers, and at least two different reviewers study each application so that the review process is applied uniformly. Apple also established an App Store executive review board that determines procedures and sets policy for the review process, as well as reviews applications that are escalated to the board because they raise new or complex issues. The review board meets weekly and is comprised of senior management with responsibilities for the App Store. 95% of applications are approved within 14 days of being submitted.

Of course much of this might be automated, which would explain both the superhuman productivity of the reviewers and the alleged mindlessness of the decision-making.

AT&T, Apple and VoIP on the iPhone

Wednesday, August 26th, 2009

The phone OEMs are customer-driven, and I mean that in a bad way. They view service providers rather than consumers as their customers, and therefore have historically tended to be relatively uninterested in ease of use or performance, concentrating on packing in long checklists of features, many of which went unused by baffled consumers. Nokia seemed to have factions that were more user-oriented, but it took the chutzpah of Steve Jobs to really change the game.

A recent FCC inquiry has provoked a fascinating letter from AT&T on the background of the iPhone and AT&T’s relationship with Apple, including Voice over IP on the iPhone. On the topic of VoIP, the letter says that AT&T bound Apple to not create a VoIP capability for the iPhone, but Apple did not commit to prevent third parties from doing so. AT&T says that it never had any objection to iPhone VoIP applications that run over Wi-Fi, and that it is currently reconsidering its opposition to VoIP applications that run over the 3G data connection. Since the argument that AT&T presents in the letter in favor of restrictions on VoIP is weak, such a reconsideration seems in order.

The argument goes as follows: the explosion of the mobile Internet led by the iPhone was catalyzed by cheap iPhones. iPhones are cheap because of massive subsidies. The subsidies are paid for by the voice services. Therefore, AT&T is justified in protecting its voice service revenues because the subsidies they allow had such a great result: the flourishing of the mobile Internet. The reason this argument is weak is that voice service revenues are not the only way to recoup subsidies. AT&T has discovered that it can charge for the mobile Internet directly, and recoup its subsidies that way. It will not sell a subsidized iPhone without an unlimited data plan, and it increased the price of that mandatory plan by 50% last year. Even with this price increase iPhone sales continued to burgeon. In other words, AT&T may be able to recoup lost voice revenues by charging more for its data services.

This is exactly what the “dumb pipes” crowd has been advocating for over a decade now: connectivity providers should charge a realistic price for connectivity, and not try to subsidize it with unrealistic charges for other services.

Tsera, LLC v. Apple Inc. et al. Patent troll?

Thursday, July 23rd, 2009

Here’s a little fairy-tale about what might have happened: Chuang Li took an idea to his boss at Actiontec who determined that it wasn’t of interest to the company and told him the idea was all his if he wanted to pursue it. Chuang ultimately refined the idea into the user interface that would become ubiquitous on MP3 players. The Patent Office rejected his application on a technicality. Chuang labored for years patiently jumping through hoops for the patent examiner while educating him on the validity of his claims. When the patent was finally issued, Chuang took it to Apple and requested a reasonable compensation for his idea. Unable to reach agreement with Apple after five years of effort, Chuang found a reputable firm of New York lawyers who were willing to take the case on a contingency basis.

Now here are some facts: the slashdotscape is alive with outrage about another patent lawsuit, this time filed by a company called Tsera LLC against Apple and 18 other companies over a touchpad interface to personal media player type devices (iPods).

Tsera was formed a couple of weeks ago on July 10th, and has filed no ownership or officer information with the Texas Secretary of State. Its registered agent is National Registered Agents, Inc. of New Jersey. Five days after the company was formed, Chuang Li, the inventor of US patent number 6,639,584 assigned that patent to Tsera. That same day Tsera filed suit in the notorious U.S. District Court for the Eastern District of Texas. Tsera’s attorneys are Kaye Scholer LLP of New York (specifically James S. Blank, Patricia A. Carson, Leora Ben-Ami, Oliver C. Bennett and Tsung-Lin Fu.) Tsera’s local counsel are Jack Wesley Hill and Otis W. Carroll of Ireland, Carroll and Kelley, P.C. of Tyler Texas.

The complaint reveals that Tsera has no parent corporation, and that no public company owns 10% or more of its stock.

The original application for patent 6,639,584 was made exactly ten years ago, on July 29, 1999. At that time (and still) the inventor, Chuang Li was apparently working for Actiontec Electronics, Inc. of Sunnyvale, CA. Chuang Li did not assign the patent to Actiontec, although other patents he applied for around that time were assigned to Actiontec. Companies like Actiontec normally require their workers to assign all the intellectual property they generate, especially when it is relevant to their business. Actiontec makes an MP3 player called the PocketRave.

Chuang Li’s application was rejected on October 9, 2001, just two weeks before Apple launched the first iPod (which did not have a touch-sensitive interface.) Three months later, on 28th January 2002, Chuang Li submitted an amended application, which was again rejected, in November 2002. In May of 2003 Chuang Li appealed the rejection and submitted another amendment. The appeal was ultimately successful, and the patent was issued on the 9th of October, 2003.

Looking at this chronology, you can see that the patent application was amended after the July 2002 launch of the touch-wheel iPod. Numerous rejections and resubmissions are common in the patent process, but they can be symptomatic of a “submarine patent,” where an inventor (famously Jerome H. Lemelson) files a vague patent and tweaks it over the course of several years to make it apply to some successful product that has appeared in the interim. The most egregious type of patent trolling is when the patent at issue is meritless, but the troll demands a settlement that the defending company determines is cheaper to pay than to go to court over.

The Tsera patent doesn’t cite as prior art Xerox’s US Patent 5596656, filed in 1995 and issued in January 1997. The basic idea of the Xerox patent is to replace a keyboard by forming strokes on a touch-pad, while the basic idea of the Tsera patent is to replace buttons and knobs on a portable electronic device by forming strokes on a touch-pad. The Xerox patent has a system of “unistrokes” on a touch-sensitive surface that can be performed “eyes free” and in which unistroke symbols can “correlate with user invokeable control functions.” The Tsera patent has a “device controlled by a user tracing a command pattern on the touch-sensitive surface with a finger,” “without requiring the user to view the portable electronic device,” with each of the “patterns corresponding to a predefined function of the portable electronic device.”

These descriptions actually apply better to the iPhone and the iPod Touch than they do to the canonical iPod touch-wheel, where the annular touch sensitive surface doesn’t really accommodate free-form strokes.

The Xerox patent was the subject of extensively reported litigation running from 1997 to 2006.

The Xerox patent, which is prior art to the Tsera patent, includes free-form touchpad strokes used as control functions. I am not a lawyer, but it seems to me that application of this same idea to portable devices would have to be non-obvious or the term “control functions” would have to be narrowly defined in order for the Tsera patent to be valid.

Is Tsera acting as a patent troll? You be the judge.

A not so perfect Storm

Wednesday, December 10th, 2008

The Verizon Storm may be heading for failure in more than one way. A raft of reviewers, led by David Pogue of the New York Times are trashing its usability. This means that even with the marketing might of Verizon behind it it may not fulfill its goal of being a bulwark against the iPhone in the enterprise.

But the Storm was an experiment in another way by Verizon. The other three major American mobile network operators have capitulated to Wi-Fi in smartphones. Against the new conventional wisdom, Verizon decided to launch a new flagship smartphone without Wi-Fi. The Storm looks like a trial balloon to see whether Wi-Fi is optional in modern smartphones. If the Storm is a success, it will demonstrate that it is possible to have credible business smartphones without Wi-Fi. But if it turns out to be a flop because of other factors, it will not be a proof point for Wi-Fi either way.

But Wi-Fi is a closed issue by now for all the network operators, perhaps even including Verizon. Phones have lead times of the order of a year or so, and controversies active back then may now be resolved. Verizon covered its bets by launching three other smartphones around the same time as the Storm, all with Wi-Fi (HTC Touch Pro, Samsung Omnia, Samsung Saga).

Before its launch, AT&T hoped that the iPhone would stimulate use of the cellular data network. It succeeded in this, so far beyond AT&T’s hopes that it revealed a potential problem with the concept of 3G (and 4G) data. The network slows to a crawl if enough subscribers use data intensively in small areas like airports and conferences. Mobile network operators used to fear that if phones had Wi-Fi subscribers would use it instead of the cellular data network, causing a revenue leak. AT&T solved that problem with the iPhone by making a subscription to the data service obligatory. T-Mobile followed suit with the Google phone. So no revenue leak. With the data subscription in hand, Wi-Fi is a good thing for the network operators because it offloads the 3G network. In residences and businesses all the data that goes through Wi-Fi is a reduction in the potential load on the network. In other words, a savings in infrastructure investment, which translates to profit. This may be some of the thinking behind AT&T’s recent acquisition of Wayport. The bandwidth acquired with Wayport offloads the AT&T network relatively cheaply. AT&T’s enthusiasm for Wi-Fi is such that it is selling some new Wi-Fi phones without requiring a data subscription.

The enterprise market is one that mobile network operators have long neglected. It is small relative to the consumer market, and harder to fit into a one-size-fits-all model. Even so, in these times of scraping for revenue in every corner, and with the steady rise of the Blackberry, the network operators are taking a serious look at the enterprise market.

The device manufacturers are way ahead of the network operators on this issue: the iPhone now comes with a lot of enterprise readiness Kool-Aid; Windows Mobile makes manageability representations, as does Nokia with its Eseries handsets. RIM, the current king of the enterprise smartphone vendors also pitches its IT-friendliness.

Wi-Fi in smartphones has benefits and drawbacks for enterprises. One benefit is that you have another smart device on the corporate LAN to enhance productivity. A drawback is that you have another smart device on the corporate LAN ripe for viruses and other security breaches. But that issue is mitigated to some extent if smartphones don’t have Wi-Fi. So it’s arguable that the Storm may be more enterprise-friendly as a result of its lack of Wi-Fi. Again, if the Storm becomes a hit in enterprises that argument will turn out to hold water. If the Storm is a flop for other reasons, we still won’t know, and it will have failed as a trial balloon for Wi-Fi-less enterprise smartphones.

White Spaces Videos

Tuesday, October 21st, 2008

I found this “grass roots” video on Google’s Public Policy Blog. That blog also has some interesting posts on related issues by Richard Whitt and Vint Cerf.

Looking at this provoked me to go to YouTube and search for other White Spaces related videos. I was interested to find a coordinated (by Google) effort by the proponents of White Spaces, and on the other side basically nothing – just this incredibly lame video that takes 7 minutes to tell us that microphones are used in sports broadcasting (don’t waste your time watching more than a few seconds – it’s the same all the way through).

It’s odd that the main opponents of Whitespaces (NAB and MSTV) haven’t put rebuttal videos on YouTube yet, and even odder that they haven’t found a need to present any more thoughtful analyses of the issue, equivalent (but presumably opposite) to those of Chris Sacca or Tim Wu. Instead, I have the impression that their strategy rests on the two prongs of public fear-mongering and bare-knuckled political lobbying.

Green light for White Spaces

Wednesday, October 15th, 2008

The eagerly awaited White Spaces test report of the Office of Engineering and Technology of the FCC came out on Wednesday. The operational paragraph in the Executive Summary reads:

We are satisfied that spectrum sensing in combination with geo-location and database access techniques can be used to authorize equipment today under appropriate technical standards and that issues regarding future development and approval of any additional devices, including devices relying on sensing alone, can be addressed.

It is huge that the FCC leaves the door open to devices relying on sensing alone, because even Google had begun to back off from this idea.

As expected, the report is a little more enthusiastic about fixed wireless Internet access, the kind of use advocated by the IEEE 802.22 working group, than it is about the personal and portable use advocated by Microsoft and Google, among others:

It will… allow the development of new and innovative types of unlicensed devices that provide broadband data and other services for businesses and consumers without disrupting the incumbent television and other authorized services that operate in the TV bands. The Commission is considering whether to also allow “personal/portable” WSDs to operate in the TV spectrum.

I have been following the White Spaces saga for some time (click on the “White Spaces” tag below, and the links to the right of this column); it is a great idea in theory, and if it turns out to work as hoped, the concept could eventually be extended across much more spectrum, leading to a nirvana of effectively unlimited cheap wireless bandwidth.

The commissioners plan to discuss White Spaces at their November 4th meeting.

Verizon’s basic VoIP patents ruled invalid

Tuesday, October 7th, 2008

Back in 2007, Verizon sued Vonage over three basic VoIP patents, and Vonage ended up settling for $120 million. It was a complicated story. Three US patents were involved: 6,104,711, 6,282,574 and 6,359,880. Verizon won that case, and was awarded $58 million plus a 5.5% royalty on Vonage’s future business. Vonage appealed, and the appeals court vacated the $58 million damages award and the 5.5% royalty. But it was on a minor point:

We hold that the district court did not err in its construction of disputed claim terms of the ’574 and ’711 patents. Therefore, we affirm the judgment of infringement with respect to those claims. However, we hold that the district court improperly construed one of the disputed terms in the ’880 patent, and accordingly vacate the judgment of infringement with respect to the ’880 patent and remand for a new trial… We vacate in its entirety the award of $58,000,000 in damages and the 5.5% royalty and remand to the district court for further proceedings.

But the case never went back to the district court! Verizon and Vonage had settled before the verdict, and under the terms of the settlement the verdict triggered a $120 million payment from Vonage to Verizon. Vonage went on to settle similar patent issues with AT&T for $39 million and Sprint for $80 million.

This year Verizon sued Cox on similar issues in the same court, Judge Claude Hilton’s court in the Eastern Virginia Federal District. This time Verizon lost. The jury found the claims of the ‘711 and ‘574 patents to be invalid, and Cox not guilty of infringing the others. Here is my summary of the claims that were found to be invalid:

US patent 6,104,711:
Claim 1 – A DNS (or similar) server translating an address based on a condition
Claim 3 – Like claim 1, where the condition is the status of an endpoint
Claim 11 – Like claim 1, where the condition is a query of an endpoint

US patent 6,282,574:
Claim 5 – Like 711.1, where the server returns a phone number (but no condition is involved)
Claim 6 – Like 574.5, where the server returns a phone number plus an IP (or similar) address

Presumably Verizon will appeal, but to this layman they seem unlikely to win. Their previous victory over Vonage was pyrrhic; the definitions returned by the Markman hearing in that case and the reasoning of the appeal court ruling broadened the scope of the patents to the extent that they encompassed a ton of prior art, as you probably expected when you saw the claim summaries above.

There are numerous patents covering VoIP, and numerous patent holders wanting a slice of the pie. James Surowiecki wrote a characteristically good piece on this type of situation in the New Yorker in August.