Due to the surge in the number of mobile phone users, the mobile phone communication network system is overloaded. This ultimate result will cause mobile phones that can easily appear like a drop, crossed, tangible, voice quality, difficult to go online, etc. . In order to solve the above fault phenomenon, there are now more and more mobile phone operators and manufacturers have begun to realize this, and constantly take relevant measures to further expand the mobile network system, improve the voice quality when mobile communication, so many mobile phones Producers have been on the mature GSM network, and launched mobile phones that support GSM networks and CDMA networks, although this dual-mode mobile phone has just been admitted, but due to its appearance, mobile phones based on GSM and CDMA are changed from dreams. reality. Use GSM / C
DMA dual-mode mobile phones, users can freely switch between GSM and CDMA, can effectively avoid problems such as polarity, interpolation and sound quality differences, which is more convenient than the calls that only use only GSM networks.
As the name suggests, the so-called "dual mode" is working in two network modes. These two working modes are GSM networks and CDMA networks. The so-called "GSM / CDMA dual-mode mobile phone" means that the mobile phone can support GSM and CDMA. Network communication technology, it can make a choice according to the environment or actual operation, which network technology can make a role, let mobile phone switch to, if in one mode, mobile communication quality Not high or other poor communication phenomena, can be transferred to another network mode, which actually expands the call frequency of the phone, and greatly improves the stability of communication. In some areas where some mobile phone users are more concentrated, especially inappropriate use of dual-mode phones, because dual-mode phones can be flexibly switching between GSM networks and CDMA networks, can always keep calls constant, and can receive signals at the same time, and then receive Signal synthesizes, filter noise signals, highlight voice signals, resulting in high quality voice enjoyment. In addition, dual-mode mobile phones use broadband technology, support call forwarding, call waiting, tripartite talks, call numbers display, short message, voice mail, and automatic roaming multiple functions.
Since the GSM / CDMA dual-mode mobile phone can work at both different technologies at the same time, the dual-mode mobile phone undoubtedly has the characteristics of these two network technologies. From a technical point of view, the GSM network has strong signal penetration capacity because of the high frequency band, so it can bring good call quality and communication over the complex environment of the high-rise forest; and the CDMA network, the system capacity is particularly large, the same frequency Resources, the system capacity of the CDMA network can be 8-10 times the simulation network, 3-4 times the GSM network. The GSM network has to cover the city, about more than 300 base stations, while CDMA can achieve this purpose, saving a limited frequency resource. CDMA-specific broadband transmission means with strong anti-interference capabilities and is suitable for high-speed data transmission services on your phone. In addition, the GSM network has strong confidentiality and anti-interference, clear sound quality, stable calls, and has high capacity, high frequency resource utilization, high interface open, powerful, and the CDMA network also has automatic tracking multipath signals and Soft switching technology greatly reduces the possibility of switching the drop, which will be very beneficial to call and data transmission during the mobile. The appearance of the double-mode mobile phone is undoubtedly the most deepest for the user. At the same time, it will be the most practical, because the use of dual-mode mobile phones, through the roaming of the GSM / CDMA network, the phenomenon will be greatly reduced, and it is playing Will be more free, and all the advantages of two network technologies can be obtained, so the dual-mode mobile phone ensures that mobile phone users are free to communicate in 160 countries in five continents.
Mobile users' greatest opinions on the network are often fallen, not only now people are deeply suffering during the call, but some people are worried that if the network supports the fax, they will turn the wireless fax to "water" . This is because the mobile handover is "hard switched", when entering another base station covering the area from a base station coverage, then the link to the original base station is then found, then find the base station of the newly entered coverage. This is what the "first break", of course, this break is only a few hundred milliseconds. Under normal circumstances, people can't feel, only once the mobile phone cannot contact the new base station due to entering the shield or channel busy, The drop will be generated; and now the dual-mode mobile phone uses "soft switching" technology. When handover, the dual-mode mobile phone does not break the contact with the original base station and simultaneously contact the new base station, when the phone is confirmed and new After the base station contacts, it will be broken with the original base station, which is "first after the first", the drop can be almost no. At the current China Mobile market, there are several mobile phone manufacturers to prepare for the CDMA network in China, to develop dual-mode mobile phones that can be applied to GSM and CDMA networks at the same time, and plan to see dual-mode mobile phone samples at the end of this year. . It is expected that the upcoming dual-mode mobile phone has a variety of advantages, high communication quality, high communication quality, stable row, switching mode flexible, and reasonable pricing, and use the phone to answer the phone, the phone is automatically in the voice channel state, once After the communication is over, the phone will return to the data channel status. If you are a user who often needs to travel around the world, the double-mode mobile phone will make you more unimpeded!
Of course, although the double-mode mobile phone is powerful, we should still believe that the GSM phone will still maintain considerable vitality. The first is the advantage of network coverage, and GSM mobile phones will have a significant advantage for international roaming and domestic roaming; followed by the advantages of maintenance level, a large number of experienced systematic training manufacturers and field technicians, effective Reduce the network operation cost and system risk; the third is brand advantage, GSM mobile phones have been widely known, but ordinary users do not understand the advantages of dual-mode mobile phones, which will increase the cost of dual-mode mobile phones in the initial advertising cost, marketing difficulty Big. Moreover, the technology of GSM mobile phones still has a large improvement, such as using EFR (enhanced full range of voice coding) instead of FR (full rate voice coding) to improve voice quality, make data faxes into applications as soon as possible, should say, GSM The attraction of the mobile phone is still very big.
