How so difficult,Quad Band Phones popular

In recent years, the mobile communication network in China have developed rapidly. According to estimation, 2000, mobile phone users (not including Hong Kong, Macao and Taiwan) will be more than 40 million. By 2005, more than 1 million will reach or, GSM users will be more than 80 million. Because GSM900 network by frequency resource constraints, the largest number of subscribers can carry around in 40 million, cannot satisfy the GSM network development needs, thus developing GSM1800 system will become the necessity of the development of GSM network. Facing the huge pressure of network development, although at present in Beijing, Shanghai, guangzhou, fujian province, jiangsu, has successively started construction and application GSM1800 system, but compared with foreign GSM900/1800, double-frequency network in China's far to achieve epidemic levels. Facing the accelerated development in the period of mobile communication services, Quad Band Phones network development lags behind gradually become the focus of attention.
Due to the different frequencies of radio waves propagation path is different, GSM900/1800, double-frequency network is network capacity and network covers two aspects of the fusion needs one of the most effective methods. They use the same source code, channel coding, modulation, multi-access technologies such as spacing, the bandwidth channel, system structure, such as the theory of functional performance, the difference is only in full-duplex interval and the working band: GSM900 full-duplex interval and the working frequency 45MHz respectively, and the corresponding 900MHz GSM1800 for 95MHz and 1800MHz. Therefore, GSM900 and GSM1800 together constitute, double-frequency nets from engineering point of view to economy, many GSM1800 becomes the first GSM900 insufficient capacity after system.
The waves 1800MHz 900MHz is half of, hence its multipath fading and shadow effect will be more apparent. Therefore, GSM1800 system covering area of more than 40-58 GSM900 small. From the investment costs and equipment utilization, some frequency resource more nervous in the provinces should mix network development GSM1800 nets. In this sense, we now discuss the Quad Band Phones wireless network is essentially GSM network based on 9 GSM1800 network covering area of double network structure. GSM1800 to solve the problem of high traffic capacity, at the same time, using GSM network seamless coverage 900 GSM900 countries, is the basic model of network / 1800, GSM network development also won't exception.
Although the development prospect was double-frequency network in China, but agree the GSM system is still on the stage, 900MHz GSM1800 in many users heart or a strange nouns. Undoubtedly, the development of GSM1800 net will be funding constraints, but China, double-frequency GSM network development speed slow the deep reason lies in the development of the network, double-frequency timing is not good, the direct cause the insiders and mobile phone users to GSM900/1800, Quad Band Phones network development lack of confidence.
According to the expert's point of view, in high traffic density, single base load switch to the maximum capacity of the two-thirds, traffic demand density high, still should be timely, double-frequency network development. Otherwise GSM900 exhausted when the full capacity, could SM1800, will lead to GSM900 network cannot support still increasing single-rate mobile phones. Other than GSM1800 due to imperfect, early network GSM1800 access network tend to after GSM900 insufficient capacity is too, therefore, Quad Band Phones network access GSM1800 also become very difficult. Therefore, the development of GSM1800 network traffic density demand, according to actual situation and the frequency of local network resources construction, double-frequency net timely.
Although China mobile population, but mostly concentrated in the rapid economic development of the city. That is to say, only density capacity of tension will actively developing cities, double-frequency users around the city because density capacity is not nervous at the recent GSM1800 network, not natural also won't positive development, double-frequency users. Therefore, in the development of the network GSM900/1800 when the game's thought is not reality. GSM900 network capacity in the region, such as saturated with close to Beijing, Shanghai, shenzhen, vigorously develop GSM900/1800, Quad Band Phones network is imperative.
GSM900 restricts the development of Quad Band Phones / 1800 network another major factors in the development of mobile phone number, double-frequency problem. It is not difficult to imagine that if our most users are 900MHz single-rate mobile, construction GSM1800 network is meaningless. If a user, double-frequency development in GSM1800 if they all valid area, due to the net GSM1800 and GSM900 nets exists, covering area is busy, threshold set idle disadvantages such differences, there would still be a considerable number of users to access GSM1800 nets, call and GSM900 access. Say so, only double-frequency mobile phone users reached considerable proportion, GSM1800 network can lessen the pressure GSM900 network.
The point is, need is not in GSM1800 no user network under the condition of the purchase of mobile phones, double-frequency because no consumer spending would not use function. Therefore GSM1800 network of the actual development opportunity than theory, some more time in developing some users. Only GSM1800 network to a certain scale, double-frequency mobile phone users choose the enthusiasm will increase, and bi-frequency excited phone would promote increased utilization of GSM1800 network construction. If GSM900 network capacity in saturated situations to GSM1800 development, will cause the waste of money, the user will also meet GSM1800 expand business more resistance.
Anyhow, the construction GSM900/1800, Quad Band Phones network is an inevitable trend in the development of mobile communication, in our absolute impossible is dispensable emergency. To the end of this year, GSM900 network users in theory will reach saturated. Although all users access network at the situation in China, but not because of the distribution of mobile phone users in big cities, the imbalance will appear on already-stretched network will is undisputable fact. If not, they will give mobile users to bring immeasurable losses. Of course, also is the imbalance of the consideration of the network construction in China, double-frequency also can never watch, blind, and should be pursued trend in the basic situation of local basis. Only clear to GSM900/1800 network advantage and deficiency, to find the optimal point, Quad Band Phones network development, can let consumer truly realize the fast and convenient mobile communication.

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Tri band Phones

"Tri band Phones" is contained 3 working frequency, the three working frequency is GSM900Mhz, DCS1800Mhz and PCS1900Mhz, repeating the process, the so-called "Tri band Phones" means to receive GSM900M, DCS1800Mhz and PCS1900Mhz these three PinLvDuan signal, choose a band, the choice of signal intensity, the base of the signal, if one party can free disconnected, turn to another frequency signal. It is actually expanded phone connection. In some mobile phone users were concentrated regions, especially suitable for mobile phone use Tri band Phones, three frequency cell phones can flexibly in GSM900, DCS1800 and PCS1900 switching between to always keep call quality unceasingly and calls. PCS1900 trillion nets, is North America (the United States, Canada and European countries communication network field commonly used nets.Due to the mobile phone can also work in the frequency of three different frequencies segment, so the phone has Tri band Phones characteristics of three kinds of network. From technical Angle, GSM1800 because of high frequency signals penetrate, strong ability in high-rise, therefore the complex environment of good quality and communication covered call, And PCS1900 channel, in North America (the United States, Canada and Europe have good communication ability, this is for those who went from intercontinental between people they need, provides the service.For operator speaking, Tri band Phones of constructing Internet, thoroughly GSM900 alleviates the existing problem of the frequency and the capacity of the network, and further optimization of hotspots, effectively relieve, peak traffic volume, and thus more connection.

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