Meeting the challenges of multi-network operation

At present, with the rise of 4G network construction around the world, multi-network operation has become the main theme of operator network development. The base station also develops in the direction of combining the macro station and the micro station with the network change. The antenna that is part of the base station will also change with the base station. Supporting multi-frequency and multi-mode, miniaturization is becoming the direction of antenna development.

Base station antennas face multi-network challenges

The antenna is an important part of the mobile communication system, which is directly related to the coverage and service quality of the mobile communication network. For example, call loss rate, call drop rate, handover success rate, etc. The selection and setting of antennas, as a basic means of controlling wireless network coverage, play a vital role in improving network performance.

Operators have been facing various challenges in the issue of base station antennas. First of all, the service life of the antenna will expire, and the operator will face the problem of degrading the quality of the old antenna. Secondly, the antenna is over-covered, the antenna size is too large to enter the property, and the shortage of antenna installation site resources and space is becoming a restriction of traditional antennas. At the same time, as users have more and more stringent requirements for network experience, antenna optimization, antenna failure concealment, and difficulty in online detection are the key issues for network optimization.

The emerging multi-network coexistence scenario also places higher requirements on the base station antenna. Taking China Mobile as an example, the pattern of coexistence of GSM, TD-SCDMA, TD-LTE, and WiFi networks has basically formed. The coexistence of multiple networks means that the construction of its own base station for each network will greatly increase the cost of network construction. With the rapid growth of land prices, the cost of new base stations has increased significantly. Relevant experts stated in an interview that due to the tight resources of the site, when operators select a site, a large number of base stations are built in the same area. If the planning omissions occur, it will cause interference between stations and affect network stability. .

Based on the above reasons, multi-network co-site, or even multi-operator co-site has become the main construction method for international operators. As the complexity of wireless communication systems increases, more frequency bands are used, and modes are increased. This requires that the frequency bands and modes supported by the antenna also increase accordingly, but the placement of the antenna on the base station is very limited. The dual requirements from the network and the base station location have become the inevitable choice for the same antenna supporting multiple frequencies and multiple modes.

Relevant experts from Huawei said that after the large-scale application of 4G, 2G, 3G, and 4G coexist in a relatively long period of time, which will bring great difficulties to the deployment of base station antennas, and many sites will face the situation where no new base station antennas can be added. . In the 4G era, it is necessary to accelerate the evolution of base station antennas to broadband, multi-frequency, and multi-channel, thereby simplifying site installation, making full use of site resources, and adapting to the development of multi-antenna technology.

Relevant experts of Shanghai Bell RFS also said that the biggest problem for operators in building base stations at present is the tightness of the antenna resources that can be installed with antennas. More multi-frequency antennas need to be used to replace the previous single-frequency antennas to allow more limited antenna resources. Frequency band.

Moving towards miniaturization

With the advent of the 4G era, higher requirements have been set for coverage efficiency and spectrum utilization. In the 3G era, the development of smart antenna technology has effectively supplemented the diversified antenna requirements of operators, effectively suppressed interference, improved spectrum utilization, and increased system capacity.

However, the smart antenna technology cannot change the current situation of the antenna sector of the base station being tight. Therefore, miniaturization has become the future development trend of the antenna. For the miniaturization of the antenna, the design of the antenna is developed toward a small size and a low parabolic surface, which effectively reduces the weight of the antenna and makes it easy to install and maintain. By reducing its wind load, it can reduce the impact of environmental factors on network coverage. Meet the operator's requirements for multi-system co-station and more systems for common antenna. At the same time, the integrated design of wireless base stations can effectively reduce feeder losses, increase system capacity, and improve system performance.

At present, the number of small base stations that have surpassed that of macro stations has a natural demand for miniaturization of antennas. With the construction of 4G networks, the network's demand for small base stations will further increase. Demand for small antennas will also grow further.

Small base stations need new antenna technology, that is, a new miniaturized antenna design, a miniaturized RF processing element, a baseband processing unit, and a cloud-like network that can provide centralized and virtualized. The miniaturization technology has better self-isolation characteristics and compact space characteristics of the antenna element, which can realize the layout of multiple arrays in a relatively limited space and efficiently radiate energy.

Dr. Cao Xi of the Institute of Wireless Research, China Mobile Research Institute, said that small base stations have strict antenna size requirements, and miniaturization is the primary choice for small base station antennas.

Baseband antenna quality

At present antenna quality has become a key factor affecting network quality. As an all-weather product, antennas need to be applied in outdoor environments for more than ten years, and many performances will gradually decrease with the occurrence of aging problems. At present, 3G and 4G are developing rapidly, and network service quality competition among operators is fierce. As the focus of network quality indicators and non-indicators, mobile communication networks have put forward higher requirements on the performance and quality reliability of base station antennas.

Shaanxi Unicom Zhou Shuangyang said in an interview with this reporter that at present, due to the construction of base stations without machine rooms, base station facilities such as antennas are facing worse living conditions and maintenance difficulties. The quality of the antenna will directly affect whether the base station can work normally and the life cycle. However, at present, the operator's centralized procurement price is too low, resulting in a significant reduction in antenna quality, which has hidden risks for future base station operation and maintenance. After years of antenna problems, operators will pay more attention to antenna quality.

Although the cost of the antenna in the entire base station equipment is relatively low, not more than 3%, it has a huge impact on network quality, and it is difficult to optimize and maintain. With the advent of the LTE era, operators need to consider multi-network antenna feed coordination and the application of advanced network equipment. Network self-optimization, self-organization, self-healing, and AAS will bring new changes to the base station antenna pattern.

However, the domestic production of base station antennas is very worrying. Although there are many domestic antenna manufacturers, the scale is generally small and it is difficult to produce enterprise scale effects. Most of them have low-level price competition at low cost. At the same time, operators' centralized procurement prices are low, resulting in severe price competition. This makes it difficult for domestic SMEs to have the funds to maintain normal R & D investment, and the technology and industry perspective are seriously lagging behind. The domestic antenna market has formed a low level of overall base station antenna quality, insufficient technology accumulation, limited technological front-end investment, and a superficial understanding of the entire industry. This will curb the development of China's antenna industry and further lead to shortcomings in China's wireless communications. At the same time, the test work to measure the excellent antenna performance can only be performed in a professional environment, which causes difficulties in assessing the antenna performance such as capital and site. For this reason, the antenna market urgently needs to establish a fair and effective judging mechanism to comprehensively consider factors such as performance and price to ensure the healthy and stable development of the antenna market.