Slashdot Mirror
USTR Critical Of Japanese TD-CDMA Licensing
News for nerds writes "Yahoo Asia reports that the Office of the U.S. Trade Representative (USTR) said in its annual report that the Japanese government has so far refused to issue experimental licenses to certain U.S. companies to test the new TD-CDMA technology. It attacks China and S. Korea along the line. The funny thing is, according to Impress Internet Watch, the Japanese government states that no U.S. companies had actually applied for the license so far. ITmedia also reports the Japanese government didn't deny foreign application, while criticizing the government for too narrow bandwidth of TD-CDMA that can be monopolized easily. Is this the precursor of another wave of pressure onto technology from Japan?"
That's it - this means war!
Ok.
Lawrence Lessig has quite a convincing argument for 'freeing' spectrum- in short (and not giving it the justice it deserves- he says it better in 'The Future of Ideas'), a lack of regulation (both legal and 'structural' regulation- i.e. the internet isn't structurally regulated whereas the phone system is, being centrally regulated) worked absolute wonders for the Internet. If the internet wasn't end-to-end and open, it'd be a shadow of what it is now.
So, basically, he believes that the spectrum is a medium which could be much like the internet, given protocols and standards that allowed things to connect using it.
As something somewhat like the internet would be much more useful than something like the phone system in the long run, I think the real news here, rather than there being a US-Japan spectrum spat, is that countries are squabbling over how to miserly regulate the spectrum in the first place.
RD
I seem to recall a similar debate over the U.S.'s attempt to push the use of CDMA at the expense of of GSM in Iraq.
The words pot and kettle come to mind
The preceding line was intentionally left blank.
No, CDMA is not on it's way out. CDMA is actually far superior to GSM (IMHO). Actually the commercial implementation of CDMA happened after GSM (CDMA was used by the US military before) which is probaby why most of Asia adopted GSM since that was the cutting-edge technology of that time. Now, both GSM and CDMA (IS-95) are 2G (second generation) technologies. Guess what's 3G? WCDMA (wideband-CDMA) and CDMA-2000. So CDMA is definitely not on its way out.
"When the only tool you own is a hammer, every problem begins to resemble a nail." - Abraham Maslow (1908-1970)
CDMA: Code Division Multiple Access. Here the entire allowed frequency spectrum is used (actually a band) by every user. The idea (in simple terms) is to send out signals that are coded with each user's individual (and unique) code so that only that user can decode it to get meaningful information, everyone else sees that information as noise. You don't need different frequencies in adjacent cells as in traditional cellphone technology (TDMA).
GSM: Global System for Mobile communications - an advanced technology based on TDMA (Time Division Multiple Access). Here you need different frequencies in adjacent cells. Usually a cluster of cells is used with each cell operating at a different frequency.
Some more info
"When the only tool you own is a hammer, every problem begins to resemble a nail." - Abraham Maslow (1908-1970)
As I understand it, CDMA costs about 10% of what GSM costs in terms of towers, switches and other related infrastructure. This is a major reason why the US is such a "fan" of CDMA (ignoring for a moment the obvious "MADE IN USA" aspect of US support). That said, the sound quality of CDMA, particularly with respect to transmission delays, is horrible when compared with GSM. Mobile telephones in GSM areas just sound much, much more like land-line telephones than CDMA ones.
CDMA may be a marvelous technology, but it has the unfortunate liability that the service that it delivers to the customer is ridiculously second-rate when compared with GSM. I have used cell phones in the US, and I must say that they are uniformly awful when compared with the GSM system in Europe, for example.
You are correct. However, it should be said that CMDA vs GSM is an apples and oranges comparison. CDMA is a radio protocol. GSM is a full mobile phone standard of which a radio protocol is just one component. GSM is based on TDMA radio technology, which is outdated by now. The positive point of GSM is that it defines the featureset, including voice (with all the trimmings), data/fax, and sms, as well as concepts like the SIM chip (keeps identity and phone separated), and even the audio codec! This ambitious featureset and level of compatibility is what allowed GSM to dominate most of the world. Of course, like most standards, GSM hasn't really changed in the last 10 years (although lately there have been some add-ons, like GPRS).
Even so, GSM has withstood the test of time. Some companies in the USA tried to build their own competing systems (using the same radio protocol, TDMA), but they paled in comparison to GSM. Even many CDMA implementations (ie, Sprint, Verizon) have lagged seriously behind GSM's featureset, despite being based on a better radio protocol. Today, CDMA implementations have surpassed GSM capabilities in many areas (wireless data throughput comes to mind), but until I see Verizon using SIM chips, it is safe to say that GSM isn't going anywhere.
The next generation of mobile technology will simply be improvements to GSM concepts. We'll hopefully continue the trend of network standardization with a solid featureset and a SIM-like identity mechanism, but with an upgraded (CDMA-based) radio protocol.
I forgot to complain about the parent posts claim regarding radiation level:
the radiation level is 10x less than AMPS and GSM. while as you say the amount we get is already very small, but this isn't just cutting it in half, it's several orders lower.
The main difference is that with CDMA2k you have continuous transmission, with GSM and GSM EDGE you have bursted transmission with a duty cycle of 12.5% for full rate and 6.25% for half-rate voice codecs.
For 2W peak power you would be down to 250mW or 125mW max power when you consider the duty cycle. What is important is the energy pr. bit, and that is not that different between the two systems.
Also you are not likely to transmit at full power neither in CDMA2k nor in GSM. The basestation will continuously monitor the signal strength from the mobile and command it to reduce transmitted power until the S/N at the basestation is just sufficient for decoding. This improves the spectrum efficiency by allowing faster frequency re-use and it improves your handsets battery life as well.
One problem in CDMA is that the basestation needs to transmit the same power level to all handsets, it can not reduce the transmitted power to handsets with good reception. One bozo with aluminium foil over the antenna will force the basestation to increase transmitted power to all handsets. In GSM the basestation would only need to boost power to the one bozo, not to all the other users. This can damage the spectrum efficiency of CDMA based systems in down-link.