3G wireless network indoor coverage transfer direction

This year, 3G development has entered a blowout period. Operators are striving for data services. In particular, indoor networks need to ensure the ability to provide 3G services. Data service bandwidth and quality assurance have become the core of indoor network coverage and optimization.

Around this topic, more than one person in the industry mentioned that 3G indoor coverage must work hard on capacity. In addition to increasing the comprehensive coverage of multiple technologies and improving the coordination and networking capabilities of indoor and outdoor networks, it must also be effective in many ways. Control indoor and outdoor interference.

The application of new equipment such as Femtocell, in addition to gradually expanding the scope of the pilot, has not really stepped into the indoor coverage network of the operator.

Continued troubles with indoor coverage

Coverage, capacity, and quality have always been the most talked about topics in 2G / 3G indoor coverage. The expansion of the city, the construction and renovation of buildings, and the increase in smart terminals and data services have also brought obvious problems to the indoor coverage. .

A person from the Gansu Mobile Network Department said that in terms of coverage, the shielding and absorption of many buildings themselves have caused large radio wave transmission attenuation, forming weak field strength areas and even blind areas for mobile signals; in terms of capacity, Such as large shopping malls, conference centers, etc., due to the high density of mobile phones, local networks are prone to channel congestion; and in terms of quality, the number of high-rise buildings is increasing, and the high-rise space is prone to wireless frequency interference, which causes cell signals Unstable, with ping-pong switching effect, which impairs the user's mobile service experience.

Based on these problems, in order to improve the data service support capability of the indoor environment, engineers of the Huaxin Consulting Design Institute proposed that in addition to planning in advance high-quality and large-capacity indoor networks based on the user's business experience and business traffic forecast, operators should also choose from The frequency of the indoor network and the outdoor network is started. Priority is given to indoor and outdoor inter-frequency networking to ensure that indoor traffic is effectively absorbed by the indoor network and to ensure the user's indoor business experience; second, the main body of 3G indoor network optimization needs to have stronger In addition to engineering outsourcing, the capability of indoor and outdoor network integration should also be emphasized.

The key point of multi-network integration

Improving quality while increasing "capacity". In the post-3G period, this new focus on indoor coverage has prompted a plan to "use existing resources to achieve a unified indoor coverage design for multiple networks such as 2G / 3G / WLAN / LTE". It is widely used in engineering planning and design units and operator network departments.

For the key to the implementation of the multi-network integration system, engineers from Guangdong Telecom Planning and Design Institute proposed to use multiple networks to achieve indoor coverage. The output power of different systems is different, the transmission loss of different frequency band signals in the feeder is different, and different frequency bands The propagation loss of wireless signals in space is also different; at the same time, due to the different equipment and performance indicators of each system, the location of the access node of each system is inconsistent. Therefore, when building a multi-standard communication system into one, it is necessary to focus on solving inter-system interference (such as using combiner isolation, adding filters, using space isolation, etc.), system combining, power matching, and capacity requirements (multiple antennas, low power, etc.) Method).

The manufacturer's engineers emphasized that for the antenna sharing problem of multi-network integration, the lobe angle of a wideband antenna will change at different frequencies, which will cause the antenna coverage radius to be smaller in the 2100MHz band than 900MHz, so when performing antenna deployment The coverage of high-frequency signals needs to be dominated.

Increase industrial chain innovation

Indoor coverage has become one of the operators' long-term key investment projects, and naturally has also been valued by industry chain companies. Various solutions have emerged in an endless stream. However, after practical testing, the capacity of the micro base station is insufficient (the noise concentration on the trunk line reduces the signal-to-noise ratio and the system capacity decreases; the micro base station itself is the source, the baseband sharing, the traffic scheduling ability is weak, and more baseband resources are required). The limitations of the anti-interference ability of the radio equipment are highlighted, and BBU + RRU is widely used in 3G indoor coverage, especially the comprehensive indoor coverage of the TD network due to the multi-channel, space isolation, simple blind wiring and hot wiring.

Under the trend of 2G / 3G / WLAN / LTE multi-network co-construction, engineering design units and manufacturers have also successively released some innovative technologies and solutions for indoor coverage, such as the industry ’s first indoor dual polarization recently launched by China Mobile Design Institute TD-LTE antenna, in addition to the dual-polarization and dual-fluidization functions of the ceiling antenna, a major feature is that the indoor antenna generates dual-polarization gain, enhances the indoor coverage effect, and solves the problem of insufficient coverage of the TD-SCDMA antenna, and Covering frequency bands such as GSM, TD-SCDMA, WCDMA, cdma2000 and WLAN, it provides a great convenience for multi-system indoor coexistence.

A manufacturer's technical staff proposed a new indoor coverage scheme for WLAN buildings based on outdoor PHS base stations. Using the existing site resources of the PHS network, the outdoor WLAN signals are directly received in the building through the wireless network card. It is suitable for the building without a wiring system or Where additional WLAN wiring costs are required. However, people in the industry questioned that this solution requires a high-power AP of 1000mW. Such equipment is not common. At the same time, there are many users in the building and interference from multiple operators. This solution does not seem to be a good solution.

Pilot of TD-LTE and WLAN indoor shared network

Among the 29 stations built by the Guangzhou Asian Games in November last year, there were 6 indoor distribution points. According to a person from China Mobile Design Institute, the Asian Games TD-LTE experimental network uses a dual-stream construction scheme, with the two antennas separated by 10 times the wavelength, which is about 1 to 1.5m. For the adjacent frequency interference between TD-LTE and WLAN, the operator planned the isolation between TD-LTE and WLAN in advance, and made TD-LTE use the low-end frequency band of 2300 ～ 2400MHz indoors as much as possible to ensure the WLAN network quality.

Gansu mobile engineers said that TD-LTE and WLAN are used in indoor coverage, and the focus should be on the technical conditions of the TD system to determine the partition, and the technical conditions of the WLAN system to determine the clustering, so that the local adjustment of the distribution system should be clustered as much as possible. Or within a small area of ​​the partition. At the same time, according to the transmission power of each system base station and the trunk amplifier required to add a specific frequency band to the coverage, the signal of the specific system is amplified. By adding the trunk amplifier, the system coverage can be effectively enhanced and the difference in coverage between the various systems can be reduced.

KCC Certificate Extension Sockets

England Power Socket,Silver Wall Sockets,Wall Switches And Sockets,Wall Socket With Usb Charging Ports

Heikki Technology Co., Ltd. , https://www.heikkipower.com