FDD and TDD will unify the core network
"The 4G network construction plan of Telecom and Unicom should be the same. Create a clean 4G core network and adopt the FDD-LTE / TD-LTE convergence solution. This is the first step, and then carry out the 3G core network and the 4G network. Integration and convergence. "Xu Ming (pseudonym), a person close to the operator, said.
Earlier, the chairman of China Telecom stated that he wanted to lease China Mobile's TD-LTE network. At that time, some people questioned how to seamlessly switch between self-built FDD-LTE network and leased TD-LTE network. Xu Ming made it clear to reporters that the scheme adopted by telecommunications is that two 4G systems share a core network, which also indirectly denies the possibility of renting a mobile network.
Xu Ming did not disclose the investment expected by Telecom this year on the hybrid trial network, but Wang Xiaochu said at the performance briefing at the beginning of the year that once the 4G license is issued, the company will not hesitate to increase capital expenditure. The data given by China Mobile is that in 2013, it invested more than 40 billion yuan in 4G. Even if the investment peak of China Unicom and Telecom was delayed until 2014, the investment in the entire 4G industry chain exceeded 100 billion yuan.
30% higher cost of converged network construction
Under the signal from the country that "it must go to TD-LTE", both telecommunications and China Unicom adopt a convergent network construction method, which is really helpless. Telecom and Unicom originally intended FDD-LTE for a simple reason. FDD-LTE is more widely used internationally and the industry chain is more complete. The network investment cost is less than TD-LTE, and the cost of converged networking will be higher.
Xu Ming admits that the cost of converged network construction is higher, but the good news is that the two 4G systems, except for the front-end radio frequency equipment, can be shared by most of the equipment. "There are technologies that can also share antennas."
"For a CDMA network, the construction costs of a purely new FDD-LTE network and a TD-LTE network are almost the same, but from the perspective of network effect comparison, the FDD-LTE system is superior to the TD-LTE system." A network optimization engineer believes The cost difference may be reflected in the network solution. At present, from FDD-LTE to CDMA to 2G voice seamless switching, there are already mature and feasible solutions abroad, but there is no mature solution in the similar way of TD-LTE .
In addition, after FDD-LTE and TD-LTE converged networking, the possibility of interference between each other cannot be denied. ZTO wireless product CTO Xiang Jiying clearly stated that there will be four interference channels: FDD-LTE base station Interference between TD-LTE mobile phones, mutual interference between mobile phones, FDD-LTE mobile phone interference TD-LTE base stations, FDD-LTE and TD-LTE base stations interfere with each other.
Two major operators may be clearly required for TDD construction
According to Wang Xiaochu's speech at the Internet Summit Forum at the end of June, the 4G network with large coverage and wide coverage uses FDD-LTE, while the densely populated areas in the urban area use TD-LTE to absorb excess traffic. What can be affirmed is that in a super city such as Beishangguang, convergent networking should be the inevitable choice, but in suburban areas, third- and fourth-tier cities, and even rural areas, the speed and mode of 4G network construction are unclear.
The question is, how does Telecom and Unicom allocate their energy? How much effort will it take to promote TD-LTE? Will it "repair the path along the road and darken the warehouse", thus making TD-LTE a guise?
"There is such a practice abroad. After an operator obtains a license, the government requires it. For example, within a certain period, it is necessary to complete the coverage of the population, etc., and if it is not completed, the operator will be restricted." Deutsche Telekom Consulting Tan Yanming, a senior consultant in China, said that Hutchison Whampoa in Hong Kong had been withdrawn its CDMA license by the Hong Kong government a few years ago because it failed to complete the request.
New possibilities for spectrum allocation
Another mystery is how to divide the spectrum? On the one hand, in addition to the clear spectrum, can TD-LTE and FDD-LTE obtain spectrum resources again? On the other hand, for every operator, spectrum is an extremely precious resource. How will spectrum be allocated among operators?
Last year, the Ministry of Industry and Information Technology allocated a total of 190MHz in the 2.6GHz band (2500-2690MHz) to TD-LTE, and allocated two unallocated 60MHz in the 1800MHz and 2100MHz bands, that is, 2 & TImes; 60MHz, for a total of 120MHz for FDD-LTE frequencies.
Are only these frequency bands used for TD-LTE and FDD-LTE? This is not the case. "The 700M frequency band of radio and television can not be taken down, there are other lower frequency bands, this possibility is there." Fu Liang said. If there is a lower frequency spectrum, operators can use it for wide area coverage, saving network construction costs.
Another change is whether Telecom and China Unicom can get more FDD-LTE frequency bands. Cheng Dejie believes that one of the reasons for supporting FDD-LTE / TD-LTE converged networking in China Telecom and China Unicom is that the spectrum currently allocated to FDD-LTE in China is much less than that of TD-LTE, which is not enough to support the two adopting FDD-LTE Mobile operators' network construction must adopt FDD-LTE / TD-LTE dual-mode fusion networking to improve spectrum utilization efficiency. However, carefully analyze the distribution of FDD-LTE spectrum. On the left side of the 1755-1785 / 1850-1880 spectrum, it is the GSM1800 spectrum allocated to Unicom; on the left side of the 1935-1940 / 2125-2130 spectrum, it is Telecom CDMA2000 3G supplementary spectrum.
If this is really the case, then there will be no worries about the small FDD-LTE network capacity of telecommunications and China Unicom. This is undoubtedly a good thing for the two. Naturally, the enthusiasm for promoting the development of TD-LTE is even less, and because of this, the situation becomes uncertain.
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