The image can make us understand what kind of SFP problem

Andrew Liu Bin: high iron environment is due to the Doppler effect is mainly along the high-speed mobile users between base stations and the relative velocity changes caused by the up and down the wireless signal at the receiving end of the frequency offset, which may cause the signal frequency offset receiver bit error rate when improvement of communication quality. In general, the faster speed, the resulting frequency shift greater, especially in the base station location, the mobile users almost immediately after the high-speed and high-speed away, resulting in maximum frequency offset. This is like we stand along the railway, high-speed train whistle when passing, heard the siren tone change is the same principle.


Different communication systems because of their technical maturity and technical characteristics of their different sensitivity for different levels of the Doppler effect. 2G 3G business, the business is relatively less affected by the Doppler effect. In the 3G business, TDD mode TD-SCDMA system by more than doppler effect larger.Switched cellular mobile communication system is the technical features for mobile users with continuous uninterrupted communications services. However, the switch is take some time to complete, otherwise it would cause dropped calls or data service interruption. Therefore, high-speed railway environment,in the region to meet the long-distance switching signal overlapping coverage to meet the requirements of switching time. On the other hand, also used in the network deployment RRU or SFP repeater to extend the logic of the base station as far as possible to reduce the switching frequency and quantity and improving the stability of communication Sex.


"Communications World Weekly": Prior to the Bank of Andrew is too high in iron and other cases provided coverage and capacity systems. High-speed rail is more recent upward trend, Andrew wireless coverage in high-iron on, what good experience and the latest technology in place to publish? Liu Bin, Andrew: Andrew Corporation has years of experience in high-speed railway wireless coverage, and ongoing product upgrades and updated to meet the modern needs of wireless coverage with high iron. Andrew's high-speed railway wireless coverage products, including feeder cables, leakage,Cable, antenna, SFP repeater, Repeater, and passive components such as automotive products in Europe, North America and mainland China has a high-speed rail project for many years successfully.


We believe that the quality of wireless coverage to improve the one hand, high-speed rail along the railway station needs to optimize the system configuration. SFP stable and reliable high-performance repeater system with the base station wireless coverage in Europe, North America and other regions of the high-speed railway successful application.At the same time, mature and stable vehicle wireless signal distribution system is to improve the quality of high-speed railway wireless coverage necessary choice. Andrew's car repeater systems and products in the world, including China's Beijing-Tianjin high-speed railway has been successfully applied. andrew has successfully launched in 2010 a new generation of car repeater product line NodeAM, small volume, high degree of integration, all-digital, performance and stability characteristics, can support multi-carrier independent, multi-technology system, the system simultaneously , Head before the start of high-speed trains in Europe, install and use. Mainland China is very suitable for the existing multi-technology multi-system operators and system operation mode, small size, small changes in body installation, reliable performance, easy maintenance, user friendly interface."Communications World Weekly": network operators, optimization should be more attention to what the new technology?


Andrew Liu Bin: We believe that high-speed railway to enhance and improve the application of wireless coverage requires a combination of high-speed rail cover characteristics adapted to new technologies and new products. Along the railway network in the end, need to be considered mature and stable product RRU or SFP repeater, leakage,Cable products, taking into account the special network coverage by network planning. The train terminal, rail and locomotive actively communicate with manufacturers to consider the application of vehicle repeater system to a full range of wireless coverage to improve performance of high-speed railway


High-speed rail in particular 3G wireless coverage coverage, along with the base station in the matching set, such as antennas, cables, etc., which raised more than conventional rail more demanding requirements?Andrew Liu Bin: The wireless coverage is a high-speed railway running trains for high speed wireless coverage, with the traditional ground and indoor wireless coverage is very different. On the one hand, the wireless signal the body to cope with the decline of the insertion loss caused by the other party hand, to cope with the rapid movement of mobile users switching requirements. And 3G data services business, mostly on the wireless network coverage with higher quality and stability requirements. Therefore, the characteristics of high-speed railway for wireless coverage consideration.


In general, solving high-speed trains running on the wireless coverage issues to consider from two aspects, one is high-speed mobile users for the characteristics of the railway station along the way to optimize the setup and configuration, on the other hand, high-speed train wireless information,the introduction of number to meet the full range of high-speed communications needs of mobile users.


As a high-speed rail along the train radio base station equipment covering the information source, it is necessary to meet the quality of radio signals along the railway but also to minimize the high-speed mobile user's cell switch. Therefore, the base station to set the base station when it is necessary to shorten the distance between the transmitter unit to meet the base station firing units within range of the signal quality, but also try to extend the logic to reduce the distance between the base station switching. Therefore, usually with high quality and reliability of the RRU and the SFP to match the base station repeater system common wireless coverage.

XFP/Transceiver/SFP Transceivers