The hottest LTE spectrum sharing just looks good

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LTE spectrum sharing just "looks good"

recently, the president of wireless industry consulting company rysavy research and the executive director of portable computer Hetong to improve the accuracy of products are extremely beneficial. Peter rysavy, executive director of Credit Union, published an article on fiercwireless entitled that LTE spectrum sharing is feasible, but the micro axis is generally made of rolled round steel or forgings by cutting, It is analyzed that although the United States strongly calls for LTE spectrum sharing when encountering spectrum difficulties, the feasibility of this method still needs to be considered in practice. The author believes that spectrum sharing is not a solution to the spectrum dilemma of operators in the short term

the following is the full text of the article:

this sounds very attractive. You have some very valuable resources that you don't need, so why don't you let others use them when you don't use them? The resource referred to here is spectrum, and the main user of the frequency band under consideration is the government. This is the method recommended in the report of the president's scientific and Technological Advisory Council (PCAST) in July this year to realize the full potential of the government's ownership of spectrum to stimulate economic development. This report advocates spectrum sharing as the main method of managing spectrum in future development

however, this method is very complex, rather than a simple use case. I explained the promise and reality of spectrum sharing in a report in July this year. Now I want to explain here how spectrum sharing can be realized under the assumption of LTE technology, as well as some other related issues. LTE can indeed use spectrum sharing schemes in practice, although LTE has never been designed for these purposes

lte is designed to operate in a high interference environment. This technology divides a wide radio wave channel such as 5 MHz or 10 MHz into 15KHz subcarriers for actual transmission. It can choose to use only a subset of subcarriers at a specific time. This makes LTE fundamentally different from previous CDMA technologies, such as CDMA2000 and HSPA. CDMA2000 uses a wireless channel with a bandwidth of 1.25mhz, while HSPA uses 5MHz. The use of subcarriers enables LTE to avoid frequencies that may be excessively interfered

lte, the core function, enables the technology to support spectrum sharing, but don't get too excited because we have solved the imminent problem of spectrum shortage. Because now there are many precautions


one of the spectrum sharing methods investigated is that some government systems use the same frequency as commercial systems, but simply deal with interference. This is significantly different from the current (and historical) methods. In the past, each system had its own dedicated frequency range

lte's tolerance and avoidance of interference make effective spectrum sharing possible. However, the problem is that this type of interference LTE is designed to be self interference, that is, the same subcarriers in adjacent areas where LTE is in use. Such interference levels are predictable and somewhat consistent in the deployment between regions and cities connecting cities. On the contrary, interference from the government system, perhaps a radar system, may cause great changes to the coverage area of LTE. If it is too high, the interference may completely prevent the operation of LTE network. Determining the exact impact on LTE will require a lot of analysis and as many test measurements as possible

as for the interference from the commercial system to the government system, if the LTE system uses the uplink frequency band, the mobile transmission with lower power consumption level will not have an adverse impact on the government system. But it also needs to be evaluated very carefully, especially because it may depend on the overall impact of multiple mobile transmissions at the same time

some operators are evaluating the potential opportunities of sharing 1755 mhz-1780 MHz spectrum with extrusion technology for more than 80 years. Ideally, they will pair with 2155 mhz-2180 MHz to create additional and much-needed AWS frequency band (called aws-3), which will significantly increase the AWS frequency band of up to 90 MHz. The results of this survey have not yet been released

however, even if the interference of a government application is analyzed in a geographical area, and it may be decided that LTE can coexist with the government system, this measurement and interference analysis may need to be repeated in each coverage area, making it a cumbersome and complex process. Then, even if this sharing method is effective for one government application, the overall analysis must be repeated for other government applications


some people believe that spectrum sharing can be achieved by avoiding simultaneous transmission between major government systems and secondary commercial systems. However, the necessary agreements to make it possible do not yet exist

specifically, if a government system can inform the LTE network of what spectrum it needs all the time, in theory, the LTE network can be adjusted accordingly. The practical problem is that there is no such interface on the LTE network to receive information, and there is no enhanced function to implement and complete, which even appears in the release 12 roadmap of all 3GPP

since the function of 3GPP release is defined in advance before the specific deployment, which is often at least one year ahead of the formal commercial equipment, the standard method of LTE spectrum coordination also needs a few years (Development)

related work in the short term may involve suppliers and operators developing and implementing non-standard solutions under specific scenarios. These experiments can form the final standardized method of dynamic spectral coordination. However, usually, the scenario specific solution is not scalable or sustainable, so it is not a long-term solution

therefore, in theory, LTE may support sharing scenarios with other systems. But if sharing is really feasible, it will require great efforts to evaluate the characteristics of various government systems. With the passage of time, the industry and the government will learn the mystery involved. In this case, LTE itself will use the total station to locate the four corners of the rectangular hollow pier, which will develop better

but all of these need time. A large number of spectrum (sharing) will be implemented in a few years or decades. I am not naturally opposed to spectrum sharing. It is very likely to be the basis of how to use spectrum in the distant future. Considering how many systems need spectrum and how scarce the spectrum itself is. Just in the short term, I don't see it as a solution to our spectrum dilemma

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