5G network come into being

In the early stage of 5G, 5G base station will form a 4/5G cooperative network with the 4G base station as anchor station, which is also called the 5G network in the non-Standalone stage. Obviously, in order to make 5G mobile phone experience well, we need this 4/5G collaborative network with good quality.

Fig. 5G and 4G base stations in NSA network

First, the dependence of the new and old systems in the 5G era is much higher than that of the new and old systems in the 4G era. On the one hand, in NSA scenario, 4G as anchor needs to carry 5G signaling, and the poor performance of 4G directly affects 5G rate; on the other hand, there are a large number of dual-mode base stations, while the current dual-mode base station devices simultaneously turn on 5G and 4G Masive MIMO functions, both of which need to take into account in the configuration of frequency, power, azimuth and dip angle. The coverage quality of 4G network should be guaranteed, and 5G performance should be guaranteed to be competitive.

Figure. There is a strong dependence between the old and new systems under NSA networking in 5G Era

4/5G integrates a network to optimize double lifting. While guaranteeing the stable quality of the stock network, predicting the capacity requirement of 4G network based on large data, and accurately formulating 4/5G collaborative power and parameter scheme based on the test and validation data of the existing network, finally realizing 4/5G network collaborative optimization and achieving double performance experience improvement.

The second level: Frequency shift will face the double challenges of capacity and interference while acquiring more available bandwidth of 5G spectrum. As large bandwidth is the main factor of 5G capacity, in order to maintain competitiveness in 5G era, it is recommended that 5G spectrum should be opened when the available bandwidth is 100 MHz or more. But at present, the available spectrum of 5G of some operators is less than 100MHz. It is imperative to achieve 100MHz by frequency shift under the condition of complementing bandwidth. For example, if the bandwidth of 5G spectrum available to an operator is to reach 100MHz, it is necessary to use the part of spectrum bandwidth currently occupied by the frequency-shifted 4G. While the bandwidth problem has been solved, it will also bring challenges to 4/5G cooperative network. There are still many growing services in the 4G network. Frequency shift may have an impact on the current network's 4G capacity, as well as interference between 5G NR and 4G LTE systems.

Fig. 5G NR/4G LTE Spectrum Frequency Shift Scenario

For a smooth transition of the 4G user experience, the most important thing is to fully evaluate the network performance such as capacity and interference before frequency shift. In terms of capacity, since new bands are introduced into capacity planning, it is necessary to evaluate terminal support for new bands and existing network 4G hardware support to consider expansion schemes to ensure the quality of 4G network. In terms of interference, NR-LTE interference test and evaluation is carried out under the overlapping frequency of the current network to find out whether NR interferes more with LTE or LTE interferes more with NR, and the impact is different at different stages. For example, at the beginning of 5G, the traffic is still growing on the 4G network, so the interference of NR to LTE needs special attention, thus implementing a differentiated scheme.

The third level: The capacity and optimization difficulty of Massive MIMO in 5G era are both improved. Massive MIMO, as the core technology in 5G era, makes the capacity and experience rate of 5G network dozens of times higher than that of 4G network, but at the same time, the difficulty it brings to 5G network optimization is also greatly increased compared with that of 4G network optimization. For example, parameter combinations have increased from 100 combinations in the 4G era to 10,000 combinations in the 5G era. If we need to match the optimal parameter combinations, we need more efficient and intelligent algorithms.

Fig. 5G Massive MIMO New Technologies Increase the Difficulty of Network Optimization

Faced with the 5G challenge, Huawei first introduced AI capability into the tool platform, and formed the model of "expert + tool platform" to optimize the 5G network intelligently. In the early stage of construction, Huawei Network Optimizer Tool Platform can be deployed to predict 5G network coverage based on large data of 4G stock, and identify potential problems of 5G network as early as possible. According to the parameter characteristics of Massive MIMO, the multi-parameter combination is optimized iteratively through the network optimization tool platform, in which the experts participate in the artificial correction simultaneously.

The fourth level: 5G can support the rapid growth of business types, different business differentiation experience requirements are higher. Compared with 4G, 5G has extended its business application to a wide range of industrial applications, and requires unprecedented stringency in the speed and delay of data services. For example, the current 5G applications in eMBB (enhanced mobile broadband) services such as VR live broadcasting, VR games and so on, different services have put forward high requirements for the stability of network speed and delay. Compared with 4G, 5G network brings great challenges to 5G network optimization due to its unique experience modeling and delay-based network optimization requirements.

Fig. 4K VR (left) needs to guarantee 100Mbps rate and 8K VR (right) needs to guarantee 500Mbps rate.

For differentiated experience, network optimization formulates different management schemes. In the initial stage of 5G construction, eMBB (enhanced mobile broadband) service is focused, matching the development strategy of 5G VR service of operators, establishing experience standards and networking standards for VR service, optimizing VR service experience, and constructing end-to-end experience management scheme. For example, for services such as VR video, many use cases and scenarios are studied, and key network performance metrics such as SINR and RSRP are mapped to different rates and delays to establish 5G network standards. Improve user experience through VR video experience optimization scheme.

With the growth of different kinds of 5G applications, the challenges to 5G network will become more and more serious, so the difficulty of network optimization is also increasing.

Faced with the rapid global development momentum of 5G network in 2019, Hua5G Network Optimizer and operators together in the earliest and fastest to provide 5G services to users at the same time, has been insisting on continuing to bring high-quality 5G network to users. As of World Telecom Day on May 17 this year, Hua5G Network Excellent "Expert+Tool Platform" program has been implemented in the global 20+operator network. The results show that network capacity and user rate have been significantly improved, which really enables operators to develop users under the condition of guaranteed network quality, and create a high-quality 5G network to continuously provide users with high-quality 5G services.