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19 megabits on 3G
haligan writes "Bell Labs research arm announced the development of two prototype chips that would allow mobile devices to receive more than 19 megabits of data per second on 3G networks." Power consumption is low enough for cel phone type applications.
see, the funny thing is, there's more than just bandwidth to hosting a website.
i could set up a p60 at work on a university t3, but i don't think it would survive a "slashdotting", since the fucking machine would melt under the load.
idiot.
-4 not fucking funny.
Bell Labs BLAST Off With New 3G Chips
By Ryan Naraine
Lucent's (Quote, Company Info, News) Bell Labs research arm on Thursday announced the development of two prototype chips that would allow mobile devices to receive more than 19 megabits of data per second on 3G (define) networks.
The Murray Hill, N.J.-based telecommunications equipment maker said the new chips are part of its Bell Labs Layered Space-Time (BLAST) wireless technology.
Lucent, which is working to introduce the multiple input/multiple output (MIMO) technology for commercial use, said the BLAST chops conform to industry standards for size and power consumption and passed lab tests to deliver data on 3G networks at higher speeds.
The fastest third generation (3G) network today offers maximum data transfer speeds of about 2.5 Megabits per second (Mbps) but Lucent said tests prove the new chips can allow data delivery at 19.2 Mbps.
Lucent plans to license the chips' designs to mobile handset, PC card and other device makers looking to integrate MIMO into future 3G products. It also plans to deploy the technology on its family of Flexent OneBTS base stations as part of plans to push commercial implementation.
"The two chips have been tested successfully in four-antenna terminal configuration that also uses four transmit antennas at the base station. These chips, one for detecting BLAST signals and the other for decoding them, are small enough and consume so little power that they could be used in cell phones or laptop computers with minimal impact on battery life," Lucent said.
Bell Labs researchers in Australia and New Jersey designed BLAST, which splits a single user's data stream into multiple sub-streams and uses multiple antennas at the terminal and base stations to transmit the wireless signals at ultra-high speeds.
"All the sub-streams are transmitted in the same frequency band, so spectrum is used very efficiently. At the receiver, an array of antennas is again used to pick up the multiple transmitted sub-streams. Using the multiple antenna technique, the rate of transmission is increased roughly in proportion to the number of antennas used to transmit the signal," the company explained.
On the Minneapolis Wireless Airport network, you get the first day of access free! Everyday after that is $10 tho, but still if you have a long lay over the $10 is more than worth it. I've used the network several times before and the download speeds aren't too slow(usually 125k and up).
Acording to the lecture i attended last year by a very sensior vodaphone engineer this bandwidth is the maximum available. It isnt all used for data in fact they reserve a few channels for voice and a few for data (depending on the area past usage etc) also if you are the only user then things get faster still. However it wtill wont be that fast most 3g implementations relie on doing TCP/IP on top of TCP/IP on top of another protocol or 5 yes there are 2 tcp/ip stacks. This is so the phone network can keep you inside there network
A couple of points about this technique:
a.) I'd call this a 4G demonstration. Maximum data rates in the 3G specs/proposals (WCDMA, cdma2000, etc...) are much lower than 19 Mbps. e.g. 2-3 Mbps. e.g. By transmitting at 19 Mbps, they're not using WCDMA protocols.
b.) In a multiple Tx configuration, you're increasing the amount of interference. With 4 Tx antennas, the amount of interference seen by other users just went up by a factor of 4. This means your overall capacity just dropped by a factor of 4.
c.) Tranmitting at a higher data rate in WCDMA limits the number of other users you can have on the channel. You can only have a few users in a WCDMA cell transmitting at near maximum data rate.
FPGA, Wireless, ASIC, Verilog, VHDL, HW, 10yr exp, Team Lead, Ottawa (More? Email above. slashdotusername=dgmartin98 )
People tend to forget that sending out ACK packets upstream greatly effects the download speed of a connection. Asychronous connections with low upstreams often become saturated and drag down the downstream to unbearable levels.
>It's not the copper wire that's the real limiting factor, it's the way you're trying to send and receive data over it.
Some of us live almost 10 miles from an exchange too, don't forget.
In the UK a 'sensible' and 'affordable' pricing scheme sets the price for GPRS data at around 4UKP per Mb. (Cheaper if you buy a lot in advance). Most of the work involved in getting content to the phones is making sure as little data as possible is actually transmitted. This is to both make the access feel faster (works) and reduce the cost to the user (sorta works) or at least make the barefaced robbery a little less obvious.
19Mbit per second seems to me like I'd be sucking down a little over 2Mb/s (2 3/8) for a present cost of about 8UKP/s. Sheesh.
I can live with paying 5p per minute for GSM net access, perhaps with 3G for 20p p/m but it's stacking up to (non-sensationalist) about 400UKP/m. Even if I was willing to pay 40p p/m I am looking to massively debt-ridden companies to drop their data rate by 3 orders of magnitude... (I'm actually looking forwards to the arguments surrounding the relative pricing of data access on the networks...)
I realise the public won't stand for the extremes of pricing you get using that kind of math but I fear the pricing for these services are gonna remain on the high side of acceptable for a long time after they are available...
It's not that I'm Anti-American - I'm Pro-Freedom
I'm not going to tell you that you're stupid, just that you misunderstand the technology. 802.11B wireless ethernet is designed for high reliability at high transfer rates over a short distance. The speed isnt really an issue. (hence why 802.11A and g (54 Mbps) have yet to make any kind of showing) The 19Mbps cell phone networking they are speaking of has teh hurdle of distance to overcome, as you may be several miles from a tower, inside a building, in the rain or whatever. To get the range and penetration, a different frequency is used (900MHz I think). At these lower frequencies, only a limited quantity of data can be sent by conventional means. This technology allows simultaneous usage of multiple channels to achieve a higher bandwidth. (somebody correct me if I'm talking out of my ass) In theory, the technology (MIMO) COULD be used for something like WLAN, but there isnt the same need. It takes a LOT to saturate an 802.11B network.
People who think they know everything really piss off those of us that actually do.
Actually, the 4 antennas do use the same channel---the same frequency band. BLAST uses space-time coding techniques to increase the capacity of a single channel. Each antenna transmits a different signal on the same frequency band; the signal processing on the receive end separates them out.
In general it works well, although it's quite nonintuitive for a number of reasons.
For example, you might imagine that you could achieve similar data rates if you just transmitted 4 times the power with a single antenna instead. Unfortunately, due to multipath (reflections off buildings, trees, etc.), the average received power will vary so much that you can't be as aggressive with your data rate. With 4 antennas, the average received power will be much more even; when one antenna isn't coming in too well, the other three are likely not to have the same problem.
Secondly, amplifier costs don't scale linearly with power. So at those power levels, multiple lower-power amps can be significantly cheaper than one higher-power amp. The cost difference can be large enough that it's worth all the extra signal processing.
Finally, FCC rules are often kinder to systems which distribute power across multiple antennas than they are with a single antenna transmitting the same power. I don't know if that's the case with 3G but I can imagine so.
Those of you who study this please forgive the oversimplification.
I'm not sure about other countries,, but i live in Canada, and all the cell towers in my area have fiber connections, and i live in a small 2000 pop. villeage...
Reece,
TCP/IP on top of TCP/IP? Not really. What you'll find is that yes, there are lots of layers involved in your usual cell telecoms network. For (traditional) data, you would likely have:
1) Top layers from the OSI Model
2) TCP/IP
3) Air-Interface (E.g. TDMA, GSM, CDMA)
4) PDH (E.g. a T1 line from the base station controller to the BTS)
5) The data from that PDH link goes into a SONET network (SDH for us Europeans)
Then onto its destination where the reverse happens to a certain degree and we extract the original data.
So you have 5 layers at least, each of which has some overhead (Packet headers, framing, alignment, synchronisation, various network control data overheads).
Depending on what service you're using, your data may be taken out of the coms network at the PDH level and placed onto a seperate data network such as the Internet. However you may then find that the actual network your data is using is running TCP/IP over ATM over SONET anyway, so thats even more layers.
Telecoms networks are complicated things...