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Tuesday, July 24, 2007

Some more clarity on xG Technology's xMax

I had an update meeting this morning with the xMax management team, and got a chance to grill them a bit more deeply on the current plans & business model. I last met them in late 2005, so obviously there's a fair amount that's happened since then.

The first and most important takeout is what applications and customer types they're aiming at initially. It is absolutely evident that xMax is not aimed at service providers looking to compete head-to-head with dense, large-scale, telco-grade cellular networks with all the complicated machinery they require. Maybe on the far horizon if all goes fantastically well, but not right now or realistically within a 3-4 year view.

The target segment of operators is much more akin to a those that are happy with lowest-cost, best-efforts, ISP/VoIP provider approach. The base stations & infrastructure are aimed at competitive service providers wanting to create a bargain-basement, 'alternative' network that avoids the need to tackle complex wholesale and interconnect arrangements with incumbents (wired or wireless) except via Internet VoIP.

Now, there are quite a lot of service providers that would be happy to take the compromises involved - proprietary technology, no "name brand" handsets, little spectrum management, limited end-to-end QoS, no international roaming and so on. These are the same type of organisations that might also look at low-end WiMAX installations, or even the larger WiFi mesh approach. But it is important to stress that these are essentially wireless ISPs that also have a VoIP proposition - similar in many ways to WiMAX Telecom in Europe or niche UMTS-TDD players like Woosh in New Zealand. The difference is that those operators are starting with PCs (which can support VoIP) rather than phones.

All this is well and good - and may even enable 100's of thousands of subscribers in the US, where there's still a few million subscribers on regional cellular networks outside the 'Big 4' carriers. Many of these customers have limited service capabilities - even having to pay extra if they roam nationally out of their local area. But it's not going to quickly scale to millions of users per country for a variety of reasons.

The international story was also interesting, for example talking about its evaluation with Telefonica's Mexican arm. The angle there is to allow large players to enter into commercially challenging new markets at a low cost, not to replace their existing incumbent networks such as Telefonica's Spanish busines or O2. Fair enough as an entry strategy where it's hard (politically or regulatorily) to deal with incumbents, but again it's a bit of a lower-grade solution rather than a fully bulletproof one.

Less clear was the situation with other international markets outside North America, particularly with regard to spectrum. The company's position is that it expects its customers to have access to their own spectrum - but they were very vague about which bands were ideal, how much spectrum might be needed for a given application, or critically, how long it might take to support a new frequency band in the base stations or phones. I also found it slightly worrying that the execs were unclear whether necessary spectrum had to be designated for TDD or FDD use.

I specifically didn't go down the route of asking the company about the recent public spat with a Qualcomm employee (Phil Karn), who has aggressively been trying to 'debunk' some of the company's more high-profile claims for xMax. Nevertheless they proactively raised the issue & pondered on his motives. The execs didn't brandish statements about 'orders of magnitude' better performance but were keen to stress power efficiency. Given that nobody with an engineering background was in the meeting it wasn't a topic I wanted to focus on. Either way, I don't see worrying about xMax as exactly being #1 on Qualcomm's to-do list at the moment given its other predicaments, so I don't see Karn's mission as some weird conspiracy: I suspect he just likes an argument, although in my view there are better ways to win one than the route he's taking.

However.... the CEO did give me useful numbers which I hadn't heard before. Some other engineers may be able to get their teeth into these & yield some analysis.

Apparently, the 1st generation products should yield an aggregate of 17Mbit/s in 26MHz of spectrum in the US ISM band at 902-928MHz, after accounting for guard bands and overhead. Ultimately the company is aiming for 2 bits / Hz in this band, in what they refer to as a "4G" network. They are also intending to go for four sectors per site, yielding a total of 17x4=68MBit/s , or in later versions maybe 2x26x4=208Mbit/s
[edit - that's my calculation, and based on comments below I should have asked about spectrum reuse & probably a bunch of other stuff. Treat it as an upper bound, I guess]

If I'm reading the tables here correctly, that's good but not exceptional in terms of spectral efficiency. My engineering knowledge doesn't permit me to say anything about power consumption, though. Someone else may have a view on this. It's worth noting that range is a bit of a non-issue here as it simply spreads the given (fixed) capacity over a larger area. Again, possibly useful for a startup operator wanting to build up a best -effort network over time by adding base stations, but again that's not a viable proposition for a mainstream operator wanting to launch a large network on Day 1 without having to go back & acquire more lots cell sites subsequently while the network is already running.

There's a bunch of other issues I haven't touched on here that are also important especially around backhaul, standards, threats from US 700MHz services and regional exclusivity.

But my current bottom line is that it sounds like a solution for the "Wireless ISP with VoIP" market, but not a near- or mid-term threat to conventional cellular voice or data services. There may be some extra-clever stuff in how it does power management, but the rest of the solution is not 'telco grade', and it would take a long time to get there as there's no 'ecosystem' in place and no clear strategy to build one. Although they ultimately want to sell silicon, it's not obvious how (for example) Nokia might engage with the company to integrate xMax into its phones.

I've seen some recent comparisons between xMax and 3GPP LTE and major 802.16e WiMAX rollouts like Sprint's, and I think they're largely unfounded & unrealistic - they're completely different propositions aimed at different customer groups & usage cases. To my mind, xMax is more of a potential threat to low-end ISP-type WiMAX deployments, CDMA450 in rural areas, and the largest WiFi mesh implementations, especially in North America or anywhere else with 900MHz unlicenced spectrum. I'm unconvinced they've progressed much towards supporting other frequencies - they certainly don't seem to have any other obvious preferred 'profiles' for 2.6GHz or 700MHz or 2.3GHz or whatever, and given work I've done recently it would probably take a lot of time & effort to support even one of these to a reasonable degree.

(As with my previous posts on xMax, I'm going to be ruthless with comment moderation/deletion)


Anonymous said...


What are your opinions on the 4g ISP offering with roaming in the xMax network. Let´s say for 70 USD per month, a subscriber pays for all you can consume wireless communications including internet.

The ISP gets 55 USD per month, xG gets 15 USD per month, the costs to maintain the network are minimal. Revenues on 400,000 customers are 22 million dollars a month for the ISP and 6,000,000 per month for xG.

Anonymous said...

few million subscribers on regional cellular networks


Hey it´s Marc, Thanks for following up with Rick. Do you think it´s possible that again with a few networks up, xG can capture the few million on regional cellular networks with their offering of mobile internet high speed service as well. If they can, over a period of 5 years, its 45 million USD per month or 540,000,000 USD per year in Rev´s to xG, and 4 times more than that to the ISP´s. If that is the case, based on their US business alone the stock should be higher, much higher.

wirelessman said...

I posted on your last xMax post as either guest or anonymous (can't remember which). I was the one who trashed xMax (I believe the word "fraud" was thrown around). In any case, I'll use an actual handle for this (and subsequent) posts so that I can't be accused of hiding behind anonymity.

I appreciate the fact that you and the xMax folks you spoke to aren't techies but I think you're being a bit cavalier about the concerns about spectrum issues. The amount of spectrum required, the bands and the duplexing scheme are pretty central to the business case for any operator that buys this technology. You found it worrying that the execs weren't even sure about TDD vs FDD. I find it downright preposterous. Red flags abound here.

As far as the performance numbers go, you probably know well that the wireless industry is full of hype (recall WiMAX and 75 Mbps at 75 miles?). The first three numbers (for the 2.X G technologies) in the wiki article you mention are reasonably correct. Note that they are per site (i.e. a 3 sector cell). For HSDPA/HSUPA, you're looking at about 1 and 0.5 bps/Hz/site for the DL and UL respectively (this is based on my access to field data from deployed networks with many sites and thousands of subs). Mobile WiMAX with all the bells and whistles will come in at around 2 bps/hz/cell (these numbers are based on network simulations that I trust, though not on actual multi-cell deployments with large user populations). I expect LTE to match mobile WiMAX. These numbers reflect real deployments (i.e. in- building service with cells approximately a mile in radius).

Given that, what to make of the xMax numbers? Their per site bandwidth efficiency is 8 bps/hz/cell, which is pretty hard to believe. If they're using the same 26 MHz in each of the 4 sectors/site, that means they're doing true 1:1 reuse and it's very unlikely that they could get such high data rates. They can do better by limiting cell radius to a few hundred meters but at best, that'd get them to 3 or 4 bps/hz/cell. Given that mobile WiMAX and LTE will achieve 2 bps/hz/cell only through the use of the full spectrum of advanced antenna technologies (e.g. MIMO, beamforming, etc.), it's pretty hard to believe that xMAX could double their numbers (let alone quadruple them).

Finally, consider the wireless ISP + VoIP market that you see xMax positioning itself in. I've designed VoIP over 3G systems and it's very hard to make voice sound decent (let alone good) without fairly sophisticated QoS mechanisms over wireless links. You state that they have "limited end-to-end QoS" and I find it hard to believe that an operator (even a wireless ISP) will deploy revenue generating VoIP without those mechanisms.

Turning things around, I fail to see what xMax has to offer over and above the other competing technologies. It only makes sense if it blows the other technologies out of the water in terms of BW efficiency, coverage or infrastructure costs. And those types of claims are very hard to believe.

One last thing, if they get those numbers in unlicensed spectrum, it's almost certainly without interference. What happens when there are a ton of other WiFi networks in the vicinity?

Dean Bubley said...

To be honest I don't know much about Tier 2/3 customers & regions in the US. I guess it depends on cost & availability of local DSL & cable. Also about what happens to broadband pricing if there's more competition - do the cable guys & Verizon start to squeeze down to the sorts of prices you see in more broadband competitive markets like France?

However, another big issue is capacity & backhaul here. If you had 400k broadband customers then I guess you'd need to dimension for 20:1 = 20k simultaneous users. Then depends on how much speed you want to give them & therefore how dense you need to make the cells. At the full-rate I reckon is 208Mbit/s per site you can support 2x100Mbit/s users, or 20x10Mbit/s users or 200x1Mbit/s and so on. You also need to factor in the opex for linking the cell site to the regional hub - which is fine if you've got dark fibre running past that site, but not if it's in a field or on a mountain-top or something. 200MBit/s backhaul ain't cheap....

Dean Bubley said...

Wirelessman - thanks.

The multiplications of 26x2x4 were mine, and I was aware that I was probably missing some factors. Spectrum re-use issues makes sense in retrospect, fair point.

I just hadn't heard the 17MBit/s in 26MHz number before, which is what they're claiming for current performance. The 2bits/hz was stated as a goal rather than nearterm reality, so read into that what you will. It also wasn't 100% clear if they have the 4-sector architecture available from Day 1.

At least parity or 4x current numbers is at least on the same planet, compared with the 'orders of magnitude' claims historically.

Fair points on the voice QoS - I didn't really get a chance to dig into this. Presumably it's going to very dependent on how much latency you're willing to stand.

wirelessman said...

the thing is, once you retreat from the ridiculous "orders of magnitude" claims of performance improvements, you then have just another air interface technology which is proprietary, has limited service level features and lacks the benefits of standardization associated with all the usual suspects (WiMAX, UMTS, 1xEvDO).

Anonymous said...

As "wirelessman" just said, it was xG's orders-of-magnitude claims that made them utterly ridiculous. In fact, it made them physically impossible, leading to quite reasonable questions about their competence and/or forthrightness. That's the only point I've been trying to make, and I'm disappointed that you didn't pin them down on this. The Shannon limit is not that hard to understand.

If they scale their claims down to what's physically possible, then they become just another wireless technology, albeit a proprietary one with unknown performance in the real world.

Phil Karn

Dean Bubley said...

I take your points. On the other hand at the moment there's no wide area wireless technology that's specifically aimed at best-efforts / unlicenced applications.

If WiMAX had a profile for unlicenced spectrum then fair enough, but at the moment the only other alternative at this end of the market is some sort of cludged-together longrange WiFi with Pringles-Can antennas.

From my point of view I'm not especially interested if their previous claims were exaggerated. Every tech company on the planet does that to some degree. What I'm interested in is whether it's going to be important, and if so in what context.

My conclusion at the moment is that it's not going to be important for large-scale, QoS-managed, properly-optimised networks for large carriers. But it may have a role to play in smaller, more grass-roots, local players that are happy with a low entry cost & best efforts wide area broadband.

Is it going to change the world? No I don't think so. Could it play a niche role and squeeze the larger guys' margins a bit? Maybe. It's a bit like a lot of VoIP startups - not about to take huge market share, but a pressure on incumbents' pricing nevertheless.

Anonymous said...

Dean, saying you're not interested in whether xG exaggerated their claims is a bit like saying you're not interested in whether Enron exaggerated their profits. It's the central issue!

Claiming that your wireless technology requires "vastly less" RF power than the competition -- and making this the centerpiece of your "value proposition" -- is not the kind of minor exaggeration that every tech company makes. Six decades of intensive research has reduced this number by less than a factor of 10, and an additional factor of two would now be considered huge.

It would also be impossible since the state of the art ("Turbo coding") is already about 12% from the absolute limit.

This isn't about slightly improving talk time. Cellular networks are interference limited, so modulation and coding that can use less power (or tolerate more noise) can also tolerate more interference. Halving the required signal-to-noise (and interference) ratio -- reducing it by 3 dB -- would nearly double the system capacity!

Your spectral efficiency figures are much too high for this reason; it's easy to get 2, 3 or more bps/Hz with one isolated cell and interference. But cellular is all about spectrum reuse, so the real trick is keeping these numbers high in a sea of interfering cells on the same channel. The answers have not always been intuitive; CDMA, for example, increases efficiency at the system level by deliberately spreading individual signals.

As wirelessman said, advanced antennas are the key to future improvements. Yet xG hasn't even mentioned the subject. They just claim their huge power savings, pointing to their Nov 2005 demonstration that used a single tall tower in flat Florida. Not only was this highly unrealistic for a cellular network, but calculations show their signal was so strong that almost anything would have worked!

You make a good point about targeting the wide area unlicensed environment. Even without a magic modem, maybe xG can still build a business on the 902-928 MHz band. But they'd probably do better switching back to WiFi. There are successful wide area WiFi networks that don't use Pringles cans. See hpwren.ucsd.edu.

And yes I'm only here because I do enjoy a good argument. Especially when I have math and physics solidly on my side. See also Ben Friedlander's blog.

Phil Karn

Dean Bubley said...


"saying you're not interested in whether xG exaggerated their claims is a bit like saying you're not interested in whether Enron exaggerated their profits. It's the central issue!"

The central issue for you maybe. But the reason I'm interested (and write this blog at all) is because I'm an industry analyst & consultant and earn money from advising people in the mobile industry.

While I also take an interest in wider trends & specific company strategies, there is no upside for me in entering into this specific debate, given the vitriol involved.

90% of my business is about predicting what may happen in the future. The other 10% is about what's happening now.

If one of my clients wants to pay me a large amount of money to dissect historical claims, then I'll happily change my stance.

On that commercial note: if any readers want a more full analysis of xMax, or indeed any area of the wireless broaband industry, then please contact me via consultingATdisruptive-analysis.com

wirelessman said...

Dean, I see your point about there being no upside for you in getting into this discussion. Clearly the minutiae of physical layer wireless technology is not everyone's cup of tea. Yet at the same time, the capabilities of the underlying technology are the key enablers for any services and associated business models that are layered on top of the technology.

Imagine you were evaluating some company claiming that they were going to offer wireless HDTV video on demand to homes and they built a nice broad story around this...yet it turns out that they're planning on using GSM. You would laugh them out of the room because their underlying technology can't possibly support their business model. The point is that the technology and its capabilities do matter.

To people with decent wireless backgrounds like Phil and myself, the statements and claims that xG makes about xMax are in the realm of perpetual motion machines (recall how Steorm's demo went recently). To us, this pretty much reduces their credibility to zero, on any topic.

As for you, I read your blog because I enjoy your views and insight and I feel that you have genuinely interesting things to say about the wireless industry. I don't want to sound critical but your apparent credulity in the fact of xMax's claims hurts your credibility in my eyes, especially in areas where I don't have expertise. The gory detail wireless stuff is my core strength and an area I understand well. To be blunt, I think you need a better bullshit detector in this area. I still quite like all your other material so it's not like I'm going to stop reading.

p.s. as side note, I think it's a mild ad hominum attack against Phil to emphasize his employment at Qualcomm as if it diminishes his arguments. I work in the WiMAX space where Qualcomm is widely considered to be the enemy yet I still agree with everything he has to say on this topic.

Dean Bubley said...

Wirelessman - you & I are actually more in agreement than you think.

Yes, I think they almost certainly have a modem that works, and may have been optimised for power consumption in certain application cases. I certainly don't believe it's 'magic' in any sense. But I also don't believe it'll prove utterly useless either.

"the capabilities of the underlying technology are the key enablers for any services and associated business models that are layered on top of the technology"

This is why the business model I'm suggesting - best-efforts wide area wireless broadband in an unlicenced band - is one that is relatively undemanding, compared with a full-strength cellular or WiMAX network supported by a broad ecosystem.

Yes, I know that 'proper' VoIPo3G IS demanding (and something I've also researched a lot recently), but I'd imagine that if you're more flexible on the latency & QoS, and you have a relatively diffuse user base, then a VoIP service should be workable even over a not-so-special system. It'll probably have teething problems though - possibly quite major ones. I've written before that I thought wVoIP wasn't an ideal choice of first application. My BS detector has certainly pinged enough on that score. I certainly think they're going to have issues with making decent handsets. But if they're selling into the bits of the US market that still have TDMA or iDen phones or use minor local carriers, they've got a relatively unsophisticated target audience.

I'm much more skeptical of the '4G' and wireless broadband claims as even 200MBit/s shared among a large cell isn't going to worry ADSL or cable guys, let alone FTTH.

You & Phil should also be able to spot that xG have recently seemed to down-play some of the 'orders of magnitude' rhetoric. Let's hypothesise that they've realised it's not quite as revolutionary as they'd hoped, once they consider realworld deployment scenarios. They're unlikely to issue a press release saying "D'oh!" are they?

Incidentally - think about the fact they're offering 'licences' at $1 per head of population in a coverage area. Valuations per subscriber in cellular are typically in the range of hundreds of $. Vodafone paid about $800 per sub for its Indian acquisition. I infer that the sign-up targets for xG's operator customers are probably aimed at the sub-1% penetration level. Again, this points to relatively undemanding technical targets compared with full-fat cellular networks.

Lastly - read between the lines. I'm saying this might happen, not that it will. There are certainly issues with their current approach, and I suspect their packaging & pricing may end up needing to be reworked.

With regards to Phil - actually I've tried to imply that his employment if anything bolsters his credibility. My experience of Qualcomm people has been that they're generally smart guys.

Anonymous said...

Lets also assume that they toned their claims down because of the reaction that they got from those dedicated to the way things "used" to be.

Dean you seem to be downplaying the cost of operations which are significantly lower in xG´s case. In addition, you are downplaying the utilization of the phones...I have a pic of a new one, and Cambridge Consultants are doing the design so they will not be unattractive.

Who would not want all you can talk followed by all you can consume broadband for a low price?

I don´t think their target market is just the poor guy with no connection. As a matter of fact, I know you are going to be very surprised with the actual service as it is rolled out. As for Qualcomm and Phil, they have stolen before, and they will steal again. Keep in mind a lot of New Tech is fluff and press releases...it´s not really fair to believe one over the other.

For Wirelessman, we will see if you are right or wrong.

Anonymous said...

With regards to Phil - actually I've tried to imply that his employment if anything bolsters his credibility. My experience of Qualcomm people has been that they're generally smart guys.

Dean, this lowers your credibility in my book...Phil Karn´s employment at Qualcomm as a low level engineer in a company that cannot do any business because they steal IP and his 700 posts on an xG investor message board slamming xG shows a desperate pathetic man.

Dean Bubley said...

That's a yellow card, Marc. I'm not going to get sucked into moderating a mudslinging match here. Phil seems to know what he's talking about, but in my view is going over the top in trying to hammer his point home.

I'll wait to see the details on exactly what's in the 'all you can eat' pricing. Bear in mind that once a call (or data traffic) is off the radio, and in the core of the network, it's just an ordinary VoIP call. xG won't be getting better wholesale rates than Skype or Vonage. The current price plan also won't work in Europe, becase of mobile termination costs. ie an xMax-to-Vodafone call is going to incur a wholesale price of 10c a minute (or whatever), so anyone giving a flatrate is going to have to do their sums more carefully than in the US where fixed & mobile termination aren't distinguished.

I'm also not sure they've factored backhaul costs into their opex estimates, especially where there's no existing fibre going past a cell site.

Anonymous said...

I´ll accept the yellow card and I will get some info on the backhaul. That will be put into the ISP´s cost, not xG

By the way, Dean, I tried to call you to learn more about your services in reviewing xMax ie how much is "a lot" of money.

You can email me on marcdannenberg@mdmarketing.e.telefonica.net

Anonymous said...

So, to summarise:

xG got a lot of attention because they made some very impressive claims.

*if* they could deliver on their claims, then they would have a powerful product an impressive business model.

Phil, wirelessman and just about everyone else who knows how to spell "laws of physics" ridiculed those claims.

xG have moved away from their more aggressive claims, and your own "back of the envelope" figurings show that there current claims are nothing special.

So xG is in the same category as Redline, Navini, SR, Airspan, Alvarion and all the other people who tried to do proprietary wide-area air-interfaces and hopied broadband or VoIP would be good.

"But those are all WiMAX companies" you say...

Because the economics of a propriatary air-interface (with low volumes) simply do not work. Some very smart people (and the ones above are very smart, with some very good air interface designs) have proved that. The only lever you can play is to use standards to drive volume up and cost down.

xG were interesting (ahem) because they claimed the impossible.

Now they are just another propriatary wireless standard, then who cares: the laws of physics hit the laws of economics.

Anonymous said...

"xG have moved away from their more aggressive claims, and your own "back of the envelope" figurings show that there current claims are nothing special"

Back of the envelope figuring won´t do in this situation. We will see very soon what "niche" they have.

Anonymous said...

Back of the envelope figuring won´t do in this situation. We will see very soon what "niche" they have.

You are right of course.

Dean's back of the envelope says this is nothing special.

And real world results (interference, frequency reuse, terrain, etc) are always worse than back of the envelope.

I guess "niche" is a polite synonym for "yet another company that went bust trying to doing a clever air interface"

Anonymous said...

Oh so now it´s not a scam, it´s just as good as some other companíes. You guys are too funny. It´s almost as good as CDMA but MUCH CHEAPER to deploy and own.

That is the game breaker...so sorry.

Beer is Life said...


Nice to see you here. Gentlefolk, Marc is referring to the BER vEb/No plot xG have put on their website:

It shows xMax is nothing special. The emperor has no clothes.

wirelessman said...

Actually, I never retracted my view that xMax is a scam. Start googling Bobier, iDigi, Island labs, etc. and you will wade into a morass of skulduggery that will trap you for hours (trust me, that was an afternoon of productivity that I'll never get back).

Anonymous @ 6:44 said "Oh so now it´s not a scam, it´s just as good as some other companies". Well not quite. Given that accusations of fraud really don't lead to fruitful discussion and don't contribute to the collegial debate in this forum that Dean has kindly made available to us, I thought it best to discuss xG as if they were a legitimate technology company. Hence a discussion of their technology and business case (as opposed to boiler rooms in Spain).

If anyone's interested in reading about xMax's sordid past, look up iDigi in the archives of the Sarasota (Florida) Herald Tribune. Alas the archived stories cost $2.95 a pop but they almost beat the latest Harry Potter in entertainment value.

I gotta say, ever since its first incarnation as VMSK in 1999, this meandering little story has sure had legs. As a professional in the wireless industry, I'm not sure whether I should be entertained or appalled. A bit of both I guess.

At the end of the day, we'll all see how this plays out. The investors in the London exchange are surely all grown-ups and will survive the inevitable sting of loss. Acrimony and lawsuits will fly. Hilarity will undoubtedly ensue. I wonder if a few years from now my company's CEO will frantically call me asking about a new wonder technology that's the latest incarnation of single-cycle modulation wizardry (it's happened twice already). good times :)

Anonymous said...

"If anyone's interested in reading about xMax's sordid past, look up iDigi in the archives of the Sarasota (Florida) Herald Tribune. Alas the archived stories cost $2.95 a pop but they almost beat the latest Harry Potter in entertainment value."

Free is even better value:


wirelessman said...

I actually know of that link but since I couldn't be sure that the content of the article hadn't been altered (though I have no reason to believe it has been), I decided not to link to it. Like I said, it's a damn good story.

Anonymous said...

Maybe xG will be cheaper than CDMA, maybe not.

But will it be cheaper than a $60 802.11g WiFi base station?

Anonymous said...

Here is the difference between you and I wirelessman, you read stories and I live directly in them. Your "fraud" claims are from events that happened in 1999-2001...a little outdated, and since Rick and Joe were never found do be doing anything wrong, I can only assume that you are a gossipy washwoman with an axe to grind. Your facts are not facts at all, and as it so often happens when you do superficial DD using Google or Messge Boards, you are dead wrong...but something tells me you don´t like facts that much. Anyway, we´ll see, and you can carry on with your scare tactics.

By the way, it costs xG 2700 USD per base station so yest, they will beat the pants off any other pricing.

Dean Bubley said...

I agree that most companies with proprietary air interfaces tend to struggle, even if their ideas are clever. Many have moved over to do WiMAX, Flarion was acquired by Qualcomm and IPwireless by NextWave.

I actually suggested during my meeting with xG that they probably need to think about pushing xMax to become sort of standard, in order to catalyse the creation of an ecosystem. If they keep too tight a lid on the technology they won't get support from device builders, test equipment, and so on.

There are a couple of differences here perhaps - use of the 900MHz ISM band, and the focus on creating phones. Flarion has a prototype one but never really pushed hard there. And we've also now crossed over into an era when VoIP is a massmarket proposition, WiFi is used widely, and we have a better understanding of consumers' real attitude to QoS vs best-efforts.

In many cases, best-effort is good enough - I reckon there's a lot of 'unnecessary overengineered QoS' around - IMS being a prime culprit in the core.

So it's possible that there is indeed a worthwhile niche for a new proprietary technology. Not easy, for sure, but WiFi has already demonstrated that there is demand for a second tier of wireless infrastructure.

In a way, it's shame that the WiFi industry has focussed on going toward ever-faster speeds like 802.11n, rather than optimising for range or other variables. That said, I notice that Intel is working on this: http://news.cnet.co.uk/networking/0,39029686,49288788,00.htm

Offtopic - Wirelessman, I'd be very interested to talk to you about your other work. If you contact me I'll respect your anonymity.

Rupert said...


There have been people trying to use unlicensed before: this was the roots of both APERTO and PROXIM technology; I spent a number of painful months trying to get WipLL (was Marconi, now Airspan) to work in ISM band.

Nothing new there.

The reason it doesn't work is simple: unlicensed band is low power (by law) and noisy (by definition). As such, range, coverage & quality all suffer compared to licensed band.

There really is nothing unusual about that.

This isn't too different from what Tropos, Belair, etc do - except they have they cost advantage of dirt cheap modem chips.

To summarise the summary:
If you change the laws of physics you can make it work.
xG were interesting because they claimed the impossible.

Nothing impossible, nothing interesting.


(PS A couple of the anonymous were me)

Rupert said...

I take it back.

There is something interesting about xG.

Something fascinating even.

And that is the attention paid, and the credibility given to them.

One might imagine that the bar was higher for difficult claims, that people would not just say "show me" but would assk hard questions...

And yet, and yet...

Like Steorn, xG deserves a whole new chapter in the -thoroughly recommended- "Extraordinary Popular Delusions and the Madness of Crowds"

Fascinating indeed


Anonymous said...

The reason it doesn't work is simple: unlicensed band is low power (by law) and noisy (by definition). As such, range, coverage & quality all suffer compared to licensed band.

Wrong Rupert, the tech works.

Anonymous said...

There have been people trying to use unlicensed before: this was the roots of both APERTO and PROXIM technology; I spent a number of painful months trying to get WipLL (was Marconi, now Airspan) to work in ISM band.

Trying is not doing, Rupert, but you don´t know much about doing....so if xMax succeeds it will be NEW.

wirelessman said...

Well I've never been called a washwoman before (is that even a real insult or did you just make that up?). I don't feel I have any particular axe to grind but I guess that's in the eye of the beholder. I do attend WiMAX forum and IEEE meetings and one thing I can tell you is that xMax is a running joke in those venues, good for a few laughs over pints at the bar. Most of us don't bother commenting publicly on it though the efforts of people like Phil Karn and Prof. Ben Friedlander, who do bother, is well appreciated (if for no other reason than we can point people in their direction when the occasional xMax question comes up).

Dean, I set up a temporary e-mail alias at mailexpire. It's:


it'll forward to my real e-mail for 24 hours before expiring. cheers.

Anonymous said...

WIMAX is a JOKE, been around since 2002 and NOTHING!!

What do you do at those forums, drink coffee and eat donuts, cause with Wimax there is not much to discuss.

Good joke though.

Anonymous said...

xMax is a running joke in those venues, good for a few laughs over pints at the bar. Most of us don't bother commenting publicly on it though the efforts of people like Phil Karn and Prof. Ben Friedlander, who do bother, is well appreciated (if for no other reason than we can point people in their direction when the occasional xMax question comes up).

Looks like you are just another drunk cable guy. Is xMax a running joke or is it an occasional question? Are you there wirelessman?

Anonymous said...

Hey Wirelessman, I hope you and your drunk buddies paid attention to Sergio Verdu in Nice last month... http://blogs.princeton.edu/eqn/2007/06/sergio_verdu_a_giant_in.html

I like this bit..Verdú’s talk tomorrow is playfully titled “teaching it” — “it” being information theory. Verdú is part of Princeton Engineering’s peerless powerhouse in information theory, a group of formidable theorists who are as renowned for their teaching as for their scholarship. This group includes H. Vincent Poor, Princeton’s dean of engineering, who is giving today’s plenary talk at the conference in Nice. A world-class authority on wireless, Poor will be talking about two different models of wireless networks: competitive and collaborative. At Princeton, Poor’s collaborators include Stuart Schwartz, Mung Chiang, and Sanjeev Kulkarni, who by the way has written a book with philosopher Gilbert Harman that has just been published by MIT Press.

You know who Stuart Schwartz is advising, right Wirelessman?

I think you need to stop drinking.

Anonymous said...

What I am worried about is this company Far Reach that is supposed to roll out this service. Who are they, does anybody know?

Anonymous said...

I know. Why are you worried about them? Is your name Ketil and did you just call Far Reach saying you were from somewhere other than what the truth is?

Don´t play games, its so easy to do that.

What do you want to know?

Dean Bubley said...

Just to throw something random into the discussion - long-range voice in the unlicenced 900MHz band ain't entirely new....


It's an old-school cordless phone working at up to 10km @ 500 milliwatts....

Now sure it's not VoIP and it's certainly not carrier-grade, but it's an interesting counterpoint to some of the xMax vs WiFi range arguments.

Separately, this is a wireless module for 902-928MHz (one of many intended for telemetry & other applications), which cites a range of 35 miles. Again not intended for voice, but the point remains that long-distance unlicenced-band communications isn't new.

Anonymous said...

A few comments on the person called Marc who makes comments on this blog:

His connection to XG, see blog post from August 1 - http://marconig.wordpress.com/

This is a quote from a post he made on an xg forum, http://www.iii.co.uk/investment/detail?code=cotn%3AXGT.L&display=discussion&action=list, where he claims to act on the behalf of xg His username on this forum is Marcsanpedro and he is very outspoken about that.

Dean Bubley said...


I'm familiar with the iii forum and have mentioned it on this blog before. To my knowledge, Marc doesn't speak 'on behalf' of xG, he's more of a very noisy (and often 'outspoken') investor.

I'm not interested in having the iii flame war spill over onto here.

His link to Far Reach wasn't known to me, however.

Anonymous said...

Check again, boys, there is no link with me and Far Reach....see what happens when you make mountains out of molehills.


Now what are you washwomen (not you Dean) going to talk about?

Anonymous said...

That link to sunbiz.org has a link to August 2007 filing that include Marc's name and list him as Office and Director....I'm confused.

Anonymous said...

Of course you are confused, you have been sucked in to a pointless soap opera without having any knowledge of the facts.

Now he´s there, now he´s not!!
Meaningless bull**** just to disparage xG.

Sad really.

Anonymous said...

Did it, really? Where is it?
and more importantly, now that Okey, the owner of the co. for 16 years is the "Prez", what did it all mean before?

This is washwoman gossiply housewife behavior...you boys should be ashamed of yourselves.
Not you Dean.

Anonymous said...

I myself work in the wireless industry as a marketing director for a company that is a major player in wireless technologies, so I will keep the technical aspects of this discussion aside.

Commercially what are the biggest problems for any potential green field ISP/VoIP provider?

- No spectrum available... or at least no money to buy spectrum
- High per sub costs (CAPEX + OPEX costs)

If xMax break this paradigm and offers a cheap alternative for green field operations to be started without the massive costs of a traditional carrier grade network, then we are completely ok with the compromises in QoS, bandwidth, etc...

I feel that eliminating the spectrum problem is already a compelling enough issue to justify any investments in xMax development.

my 2 cents!