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Vanu Replacing Cell Tower Equipment With PCs
Dwight Schwartz writes "As reported in an
article on the ScienceDaily site, researchers from
Vanu, Inc. of Cambridge, MA,
have successfully tested a system, the Vanu Software Radio(tm), that can replace a cellular tower's room full of communications hardware with a
Pentium-based computer running Linux. The system
offers the hope of making cellular technology more affordable for small, rural communities." The systems have been tested for the last several months in parts of Texas, with wider adoption planned for the near future.
This is actually *newsworthy*. I was starting to have withdrawls.
This should have a big impact on small towns where expensive cellular equipment isn't cost effective.
You can't legislate goodness. Let each to his own destiny, by will of his freely made choices.
This is excellent. I live in South Africa, and there is a massive gulf between the poor and the few rich - this will help to connect all the poor people, and especially the ones in rural areas.
What makes me the happiest of all, is that the system runs Linux, and this is great in the light of the fact that the South African government has articulated its commitment to open source software (they have indicated that they may replace several government systems with Linux boxes! so I hope that it happenes)
It just shows what a bit of ingenuity can do.
"I hate people who fabricate unintelligent quotes to add to their work seemingly by some 'anon' sage" -- anon
How can a single Pentium-based computer handle the bandwidth of many simultaneous calls? Does it merely act as a router or as something more? I ask because the article wasn't clear.
A blog like any other.
Loads of great ideas that are going to change the world and it's not going to cost barely anything!
It's like 1998 all over again!
Have a look at the original release from the US National Science Foundation. With some nice pictures. :-)
But is the PC as reliable as a room full of communications hardware? I think not. As soon as your Hard Drive goes out 911 is out of commission.
Not only will this allow cellular rollouts in poorer countries, expect to start seeing this in small pico cell sites across the world. I work for a company that produces network management software, and I know how complex a rollout process for single cell site is. The lists of equipment are huge and costly, and we have an entire set of modules that allow companies to keep track of the hardware in each site and its configuration. In short, cells sites are complex, costly to build and hard to maintain.
Replacing all of that with a tower, antenna and a PC would be a huge saving, both in terms of planing, installation and maintainence. A single site could be rolled out in a matter of weeks, rather than months, and cost a fraction of what it costs now.
For us in Europe, maybe it could help reduce costs and get the debt-laden operators back on their feet. For those of you in the US, you could well see much better coverage on all networks.
Sounds sorta similar to GNU Radio. :-)
It's cool that as computers get faster, you can have software replace hardware
Hardware is generally far more difficult to compromise than software, esp' a known operating system (regardless of how much more secure it may be than other cough, doze, boxes) You'd want some very secure remote access if at all. Otherwise you could find yourself with a whole bunch of phones ringing a la lawn-mower man style in a country town near you.
I'm originally from Stephenville, Texas - just down the road from these two communities. There are no third-generation networks available out there. My Sprint PCS phone doesn't work there, either - not even in analog mode. But just 20 miles away I have full signal strength in Vision mode.
I still have some friends in the region using Mid-Tex, and they haven't mentioned anything odd about their service. I guess that means it's a success as far as consumers are concerned.
I'm a student of telecommunications at an university of technology in Finland, and we've had compact basestations gathering dust at a student lab facility for _years_. (one Nokia and one Siemens, if I remember right)
The unit was about two mid-tower cases of volume, had an integrated PC, integrated antennaes, the whole bunch. Everything you need for a GSM basestation. And it really is an old model. Modern models are at least more efficient (with directional tracking antennaes, etc) and more inconspicious (they can look like fake chimneys, parts of wall, etc, so that it doesn't disturb the landscape.)
Probably we're not even talking about the same things since calling a basestation unit a "tower" is ridiculous. Maybe they've replaced the switching centre with a PC? Though I doubt it, since a PC/Pentium would be severely bandlimited to handle thousands of connections. Perhaps with dedicated hardware which is merely controlled by a PC..
Voice calls are good, but wouldn't it be even better to also support Internet connectivity on the network.
Take a look at openggsn which is developing an open source GPRS core network. Maybe the Vanu people could use this to also allow Internet communications for their SW basestation.
At first, it seems that the solution portrayed in the article would make the deployment of GSM networks easier and cheaper. This would not only be a solution for developing countries, but also for rural areas in western countries. An illustration of this last point is readily made by comparing the GSM coverage of a densely populated country like The Netherlands (former state provider KPN) to that of a much more sparsely populated country like the US (AT&T wireless).
However, GSM is not the only cell-phone standard there is. Another standard which is often used in rural areas is CDMA. It seems this standard features larger cells, and fewer base stations (for, of course, a less densely populated cell). Indeed, Verizon has plans to convert parts of its network to CDMA: see here.
Does anybody have altual experience with deploying CDMA networks? (obviously, given the coverage map for GSM, I don't need that experience in Holland ;)
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Next, affordable handsets
And affordable customer service...and affordable billing systems...
This is good news, but there are many other expenses involved that new cell companies have to contend with.
The main reason why software defined radio (SDR) hasn't yet taken off is insufficient A/D performance. And it's not the sampling rate that's the issue; A/D's exist now with sampling rates in the gigahertz range.
The bottleneck is in dynamic range -- there can be a large difference between the weakest and strongest signal in an channel (80 dB is one example). To sample with enough resolution to capture that dynamic range, you need a lot of bits. But the more bits you use, the slower you have to sample; it's a tradeoff.
Until A/D converters advance quite a bit more, SDR won't fulfill promise.
Vanu is the son of Amar Bose, founder of Bose, the maker of all of those great speakers. Another MIT wizkid.
It means we can have our own phone networks! Is there ANYTHING we can't have? I know! A GIRLFRIEND!
It's Christmas everyday with BitTorrent.
The poster should have included this link (pdf) - much more interesting.
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They don't have to "accept" it. It will be there if they accept it or not. They just need to understand that if they don't adapt to it, regardless of whether or not they "accept" it, it will flatten them.
This is just the tip of the iceberg. Improvements in the software could add support for USTDMA, iDEN, CDMA, and maybe even AMPS/TACS (analogue) phones, making the specific phone architecture irrelevant, and ending the existing format war.
An additional benefit is this: If service is made available to emergency services (which was implied), then the emergency services can get access to better networking than they do now. Of course, the inherent risk in outsourcing the network must be weighed.
www.wavefront-av.com
I'm CTO at Vanu, Inc. Here's some additional info that some posters to this thread have asked about.
- Linux version: we're using a Debian 2.4 release with the real time patches. All the signal processing code runs as an standard application level process.
- A/D and D/A: we're using an external RF front end that provides over 90 dB spurious free dynamic range. The poster who said these are big and hot was right; it's a little smaller than a PC case all by itself, with a hefty fan to dissipate the heat of the power amp. It covers 25 MHz worth of spectrum and costs a lot more than the HP server that does the signal processing.
- software features: the linux applications running on the HP server handle the complete transmit and receive chains. We go from raw digital samples on one side (exchanged with the A/D and D/A converters) to voice and data packets on the other. A separate HP server runs the Base Station Controller functions, which are the protocol logic, handover control, and similar functions.
- reliability: a huge advantage of building the GSM software on top of linux is that it's portable. Some operators want the level of reliability that comes with commercial grade servers; some want the level that comes with telco grade servers. The GSM basestation software runs on whatever they need.
It's great to see how much interest there is in the slashdot community about this.
-john chapin
The reason the US has a bad infrastructure is because of the sparse population. We have states that are bigger than some countries. And a cell network is expensive. Most companies don't want to put towers up in the middle of nowhere when they will hardly be used. So hopefully this technology will make it more feasable to cover the areas that aren't going to get much use.
"Researchers have successfully tested a system that can replace a cellular tower's room full of communications hardware with a single desk-top style computer, making the technology affordable for small, rural communities."
From http://www.nsf.gov/od/lpa/news/03/pr03117.htm which is the OFFICIAL PRESS RELEASE.
A single desktop. Sounds incredibly stupid to me. I mean, you gotta cough up the cash for the antenna and transmission equipment, why cheap out on the hardware? Sometimes saving money doesn't make sense.
Blar.
So if we're now able to make carrier-quality telecom equipment that runs on fairly run-of-the-mill PCs, why are we still paying $50/mo to our mobile phone companies? Think of the revolution that's happening with 802.11, and now imagine a Linksys GSM Router sitting at home next to your Wi-Fi box. Of course our governments would never allow this to take place; who would pay billions to claim stake to the airwaves if we could build our own homegrown networks?
In reality, we'd probably NOT have personal GSM routers as I mentioned above... instead, we'd have community organizations sponsoring local sites, paid for and maintained by their users. Interconnected with other communities, it would form a massive network of telecom co-ops. If linked by microwave, you might not even need to involve your local utilities one bit.
I'm not suggesting that we dismantle the existing mobile networks; however, they are truly OUR airwaves. If we could see to it that a mobile network running on hardware like this were to be built using non- or minimally-licensed (community licensed?) bandwidth, a couple of years of network instability and growth could build a true grass-roots, free-as-in-speech-AND-beer telecom network.
Who's with me?
It's neat that Vanu is doing this on Linux, but it's not like it's a revolutionary technology breakthrough.
There's still an analog RF radio involved; all the digital processing is at the IF frequency. Digital signal processing of raw RF in the gigahertz range is still a bit out of reach. (And it will require an A/D with huge dynamic range.)
It's not clear that it's a win to do this using commodity PC hardware. Most of the crunching is in tight signal-processing loops that don't use much memory. With custom boards, you can have more CPUs on a board. Squeezing the physical size down matters in this application. If you can put the gear in a box on the pole, instead of needing a little shed, that's a big win. PCs also tend to use more power, and thus generate more heat, than DSPs per MIPS. Cooling all the gear is a constant headache in the cellular business. It typically doubles the power consumption, and the air conditioners themselves are maintenance headaches. What the industry wants is gear that doesn't require air conditioning, at least for smaller sites. Qualicomm has been shipping pole-mounted CDMA base stations since 1997.
It's also not clear that introducing a network between the radios and the processors helps reliability. If the radios are flexible enough that one can take over the job of another, it's easier to fail out a radio/processor pair and switch in another one.
None of this matters all that much because the cellular base station equipment industry is in the tank. The industry overexpanded based on forecasts of huge needs for 3G gear, and that didn't happen.