Dec 10
2
Measured Chinese 3G standard TD-SCDMA network
April 1, China Mobile in Beijing, Tianjin, Shanghai, Qingdao, Qinhuangdao, Shenyang, Shenzhen and Guangzhou cities in eight official launch of China-made 3G (ie TD-SCDMA) socialization of testing and trial commercial operations, allowing the public free number to purchase 3G and the 3G network terminal equipment. For a time, the whole country, without exception, and to talk about 3G, laid to rest, TD.
However, looking forward to the hot sales of the scene only focus on a few days to start, and then sank into a complete silence. According to survey data show that, as of April 10, eight cities in TD total sales volume of just more than 2,000 terminals, of which only the TD mobile phone 1800, TD data card to more than 200, much lower than expected sales. Sale terminals mainly concentrated in the lowest prices of several models, such as Lenovo’s TD800, LG and Samsung, and several other foreign-branded products, there are many users choice, and expectations of ZTE’s most high-end smart phones are seriously unmarketable TD.
What is 3G
The so-called 3G, in fact it’s full name 3rdGeneration, the Chinese meaning refers to the third generation of digital communication, which is opposite to the former two generations of mobile communications technology for the purposes of.
Since the advent of mobile phones has gone through a first-generation analogue phones (1G) and second-generation GSM, TDMA and other digital mobile phones (2G) and other two times, and then there data services technologies, such as GPRS, CDMA2001X, EDGE, there are one of these later known as 2.5G and 2.75G technologies.
Relative first-generation analogue phones (1G) and second-generation GSM, TDMA and other digital mobile phones (2G), 3G standard name for a wide range, such as the ITU defined as “IMT-2000″ (International Mobile Telephone 2000) Standard , Europe’s telecom giants claimed it as “UMTS” Universal Mobile Telecommunications System. However, their standards are unified to provide mobile terminals in order to speed the move of its data transmission rate of 144kbps, outdoor static or walking rate 384kbps, while the indoor 2Mbps.
We have said before, 3G standard is not the only, while the number of options. According to the International Telecommunication Union (ITU) to determine the three major wireless 3G communication interface standards are W-CDMA (Broadband Code Division Multiple Access), CDMA2000 (multi-wavelength division multiplexing spread spectrum modulation is contained), and TD-SCDMA (Time Division Synchronous Code Division Multiple Access). WCDMA standard which originated in Europe and Japan, early third-generation wireless research activities, the system in the existing GSM networks to use, for system providers can be a lesser ex-situ transition, the main supporters of the standard in Europe, Japan, South Korea, and America’s AT & T Mobile Business Group has selected for its WCDMA third-generation business platform.
CDMA2000 system is mainly dominated by Qualcomm Inc. made in North America, its construction cost is relatively low, the main backers include Japan, South Korea and North America and other regions and countries, China Unicom’s new space is the primary criteria used in this program.
TD-SCDMA standard in China with independent intellectual property rights of communication protocol standards, on June 30, 1998 a formal application to the ITU organization. In the November 1999 Helsinki, ITU-RTG8 / 1 and on the 18th meeting in Istanbul in May 2000 the ITU-R plenary session, TD-SCDMA standard was officially accepted as one of the options CDMATDD become the standard one CDMATDD , this is a pioneering mobile communications sector, but also China’s third generation mobile communication contribution to development.
hinese 3G standard in the end is how the real situation like? TD-SCDMA mobile phone just as it did in the legend amazing power? We have organized this field test.
Lenovo TD800
The parameters measured the terminal, we got a cell phone provided by Lenovo TD800 and Cool 6260, which is the most selling two TD mobile phone market share is high.
Lenovo TD800 phone is equipped with a 1050mAh lithium-ion batteries, because of instability in the network, making the use of aircraft in the daily course of frequent search network, power-hungry. Under normal use, this piece of the battery is only Nengcheng day and a half, but in a bit after use, fever, more severe.
Cool 6260
Lenovo TD800 relative to the lower end of positioning, this Coupe is even more high-end 6260 number, which uses dual sim dual standby, for TD-SCDMA and GSM network standard for backward compatibility support, has also adopted WINCE5.0 Smart the operating system kernel. We have been given Coupe 6260 with the 1,700 mAh lithium-ion battery of thicker, supposedly at the expense of body size piece of the battery should be able to bring about the corresponding extension of standby time, but we found in the evaluation process Cool 6260 less than 2 days of standby time, probably in search TD-SCDMA network signal to waste too much power, we hope that the formal listing of models have been improved.
TD-SCDMA measurement 
The first: Network Speed
Many users reflect the TD-SCDMA network is too slow to find, here we had a look at testing, in particular with the GSM signals were compared to see how slow TD’s network in the end. Test, the first turn off the phone’s wireless phone functions, and then opened mobile phone signal is displayed as the termination of the test cell phone use is Cool 6260, in determining the final seconds of network time of 50’54. The same with GSM networks, the Nokia 5700, let’s shut down its wireless signal, and then re-opens, showing the network signal time 4’24 seconds, the gap is quite obvious. So, everyone complained about long TD network network is based.
The second: TD signal area measured
Measured on the TD signal region, we are mainly from the signal coverage and stability testing. Beijing Mobile announced TD-SCDMA networks in five-ring can be covered within the scope. As we measured, we have to the north of the airport highway exit north road Gao, 3 kilometers away from the North Fifth Ring, testing, and found the signal, you can easily make video calls and calls.
The second point on the external test sites are selected in the east, Tongzhou Bali Qiao toll station port, 12 kilometers away from the Fifth Ring Road, no TD signal.
Selected in the third locations in the south of Beijing-Shijiazhuang high-speed long-xiangyangzhen from the Fifth Ring Road 10 km, no TD signal.
Next to City-signal test, first office, the computer world, newspapers, Ring to Ring, the signals under grid. The second point on the South Second Ring Guang’anmen, the signal full. Third Department, Suzhou Qiao, Beijing Polytechnic University, the signal full. Fourth Department, the Zhongguancun area, the signal full.
In addition, when we tested and found considerable instability in TD signal, drift serious, frequent loss of the signal the whole, the consequences is that the call can not be, always remind you of the dial-up number is not in service area. That was rather frequent, has seriously affected the normal phone, not just a model, parameter measurements such problems have a variety of models.
third: Download speed measured
For the actual download speed, we have installed in a notebook Coupe 6260 PCModem procedures and to set Modem in the Cool 6260 under the guidance of the document set-up process was very complex, and a far cry from CDMA. Then, in the phone’s “PC Connection” and enter “modem” to open the modem feature, the data cable to connect to the notebook, TD-SCDMA dial is * 98 * 1 #. Also in IDG office environment with TD-SCDMA wireless Internet access, download a size 3MByte the MP3, with around 128 seconds when the average speed of about 25KByte / s.
Fourth: Video calls measured
TD-SCDMA is the most widely used features that a video call, this is also a feature is highly desired. From our testing situation, the video call is basically achieved the expected, although there are also quality smear screen rigid, there is stress, and so flawed, but other areas were able to meet user demand.
fifth: Standby Time
This parameter measured from several models, most of the battery easier to 1700 milliamperes, the smallest, when there are 1050 milliamperes can be described as a big easy. However, TD’s normal mobile phone use, the use of time, no more than two days and kept the search signals, coupled with video calls, will soon deplete the battery, so life is a very thought-provoking questions .
Summary:
TD-SCDMA commercial trial had been almost two months, from our latest available information, China Mobile has stopped the issuance of TD-SCDMA numbers. In other words, even if now you get the TD-SCDMA mobile phones, China Mobile can not go to the previous number, thus can only be used when an ordinary cell phone.
From this evaluation of the actual situation, the first reference measurement models less, and only a few models. The second parameter measured is the mobile phone is still functional in terms of appearance, the products can not be comparable with GSM. Third, is the TD-SCDMA is indeed less than perfect in performance, standby time is short, power-hungry, and imagined a far cry from 3G mobile phones.
Currently, telecom restructuring has already started, the emergency brake on China Mobile’s TD-SCDMA is not affected is also hard to say. However, TD-SCDMA as China’s 3G standard, the Chinese market is fully capable of prop up one of China’s standards. But I want to ask is: China Mobile, you really do in the TD-SCDMA on it?
