In an environment where spectrum resources are becoming increasingly competitive, the US government and operators have begun to promote spectrum sharing technology, which will gradually replace the TVWS band that was vacated by analog TV after digital TV, and used mainly by the US military in the past. The 3.5GHz CBRS spectrum relieves the pressure on spectrum resources that are scarce and increasingly congested.
In April 2015, the Federal Communications Commission (FCC) announced the release of the CiTizens Broadband Radio Service (CBRS) band at 3,550∼3,700MHz with a bandwidth of 150MHz. It is worth noting that the FCC uses a three-layer spectrum access architecture to release the right to use the band, which means that anyone has the opportunity to use the band. According to Google estimates, commercial services using this band are expected to appear in 2017.
Spectrum management dynamic congestion problemAccording to Feng Minghui, director of the Zhitong Institute, the 5G and the new business opportunities of the Internet of Things have a common point, that is, they must borrow heavy spectrum. In the past, individual spectrum was mainly licensed for use by a single vendor, but now there is a dynamic spectrum, so that everyone can share the cost and accelerate the development of the network economy.
Figure 1 Google wireless system engineer Xuan Yi said that sharing can reduce the waste of spectrum resources.
Google Wireless Systems Engineer Xuan Yi (Figure 1) said that in general, operators are bidding on only the spectrum that they can use. However, some operators do not use so many users because of the fact that the spectrum is idle. In some cases, the number of users is too large, resulting in overcrowded spectrum. In addition, there are some smaller companies that do not have much capital or have not obtained a spectrum license because they are not competitive.
Xuan Yi pointed out that if the spectrum sharing method can effectively reduce the waste of resources, other users can use it without using it, and it can also reduce the congestion problem.
In the FCC's 3.5 GHz CBRS band release plan, a three-layer spectrum access architecture was introduced (Figure 2). Under this architecture, when the high-level user (the first-tier user who is the license holder of the band and the second-tier user who has paid the license fee) does not use the band, the third-tier user (anyone) can use. When there are many third-tier users in the same place, use the available frequency according to the principle of fairness. However, the management of the third layer requires strict control regulations. Therefore, the FCC will implement spectrum sharing between different users and applications using the Spectrum Access System (SAS).
Figure 2 SAS is a dynamic spectrum sharing solution.
At the same time, considering the key role played by the SAS mechanism in managing CBRS access and operation and ensuring the continuity of spectrum assignments, the FCC will design a certification process to review applications from SAS managers.
Xuan Yi further analyzed that the concept of spectrum sharing has been introduced for a long time, but the main key to success is the government. Because when the spectrum has been auctioned, how to redistribute and share it must be rigorously prescribed by law. Second, the industry also needs heavyweight operators to support such practices. Not only that, but also whether the spectrum itself is easy to use. When a spectrum is easy to use, it will be supported by operators. If the frequency of the spectrum is too high or too low, it will reduce the operator's support. Willingness.
Qualcomm, Nokia, Intel, Google's Access Technologies, Federated Wireless and Ruckus Wireless announced the establishment of the CBRS Alliance in early 2016. The alliance is currently promoting the commercialization of LTE solutions for the CBRS band, including LTE-TDD, Licensed Assisted Access (LAA) and MulteFire, all of which are technologies that can co-exist in the CBRS band.
High availability of TVWS bands with high coverage and other characteristicsIn addition, another focus of recent spectrum sharing is the TVWS (TV White Space) band. With the popularity of digital TV, the traditional analog TV has gradually withdrawn, and this TVWS band has also been vacated. At present, many countries use this idle frequency band to provide free Internet service--Super Wi-Fi. This White Space frequency band has the characteristics of large coverage and excellent penetration rate, and it is of great help in improving transmission quality and reducing the digital difference between urban and rural areas.
Figure 3 Liu Junjing, deputy general manager of Yaxu Computer Intelligence Integration Headquarters, said that the characteristics of White Space have to meet some special spectrum needs.
Liu Junjing (Fig. 3), deputy general manager of Yaxu Computer Intelligence Integration Headquarters, said that Askey's Super Wi-Fi system can build 10-15 TVWS base stations under the conditions of a location, which will be 5.8. The GHz MulTI-radio Wi-Fi-Mesh Backhaul network has a maximum range of 1,000 square kilometers. It will use the 470∼790MHz TVWS system band, the base station total data transmission rate will reach 150Mb / s, while the number of Internet users can reach 250.
Liu Junjing pointed out that TVWS is cheap to build and easy to set up, and can be applied to smart grids, last glimpse, 3G, 4G traffic removal. At present, the application of TVWS by international operators or governments is like the wireless broadband access infrastructure construction, the vast and sparse communication construction, and the hot spot coverage of public areas in rural areas, fishing villages, mountainous areas, etc. in developing countries. , M2M IoT communication applications, disaster relief communication and public safety, maritime wireless broadband communication, special network construction for specific businesses.
Opzs Series 2V100Ah Battery,Opzs Series Solar Power Battery,Lead-Acid Opzs Batteries,Opzs Solar Tubular Batteries
Shaoxing Honyo International Trading Co., Ltd , https://www.honyopower.com