The phenomenon of T-network users backflowing to GSM networks seriously affects the network perception of TD and 2G users. ZTE has effectively improved the utilization of TD network resources and ensured user perception from three aspects.

Based on the analysis of factors such as current network coverage and user behavior, the main reasons for severe backflow are as follows:

1. 2/3G interoperability parameter setting issue: Due to the conservative 2/3G interoperability parameter setting, frequent 2/3G reselection and switching occur, resulting in a shortened residence time for G3 end users in the TD network. At the same time, excessive 2/3G interoperability can easily lead to unreachable user calls and low data service rates, seriously affecting user perception, making users tend to prefer the GSM network when making network choices, further leading to more G3 end users residing in the GSM network, exacerbating T/G service backflow.

2. TD network coverage issue: Based on the analysis of user behavior and traffic models in the current TD network, IS420YDOAS1B indoor scene user distribution and traffic volume distribution account for 64% and 69%, respectively. Residential areas are the main area for G3 end users to conduct business, and deep coverage of indoor scenes such as residential areas has always been a weakness of the TD network. Insufficient depth coverage capability is also an important factor causing high backflow ratio.

3. Network selection and setting issues for terminals: Through terminal analysis, it is found that just over half of G3 terminals have used the T network, and nearly half of the users have been residing on the GSM network, which is one of the main reasons for business backflow. This requires the terminal manufacturer to set the network selection to automatic network selection mode when leaving the factory, and cannot set it to only TD or GSM. At the same time, sales personnel need to guide users correctly in network selection.

ZTE and China Mobile have collaborated to propose a GT diversion technology solution to solve the problem of TD network business backflow in GSM network through actual analysis and testing of the existing network. The solution mainly includes three aspects: 2/3G interoperability parameter optimization, PCCPCH transmission power improvement, and the application of TD new technology. Through the joint action of these three aspects, the utilization rate of TD network can be greatly improved.

2/3G parameter optimization: Reasonably adjust the 2/3G interoperability parameters, while not affecting the current network KPI level, to allow more TD end users to stay in the TD network for a long time to carry out business, and enjoy the high-quality voice and high-speed data services provided by the TD network;

PCCPCH power improvement: On the basis of the existing network, try to increase the hard coverage range of the TD network as much as possible. IS420YDOAS1B improves the deep coverage ability of the TD network, allowing more users to stay in the TD network for a long time; The application of TD new technology mainly includes two aspects. Firstly, the 2/3G parameter customization strategy based on IMEI divides terminals into different types through their IMEI numbers. For different types of terminals, different 2/3G switching thresholds are used. For example, data cards are mainly used for data services, and the threshold is set to be difficult to switch to GSM networks, making it easier for them to reside in TD networks and enjoy high-speed TD networks, ensuring user perception of data services; Secondly, in order to prevent the implementation of the above series of strategies from having negative effects on the current network performance indicators, a strategy based on uplink and downlink quality is adopted. Through the implementation of uplink and downlink quality monitoring algorithms, the network dropout rate and dropout rate are improved, and user perception is improved.

This scheme was implemented in an RNC of TD’s current network, and compared with before and after the use of the scheme, the phenomenon of TD network backflow to GSM network has been significantly improved. After the implementation of the GT diversion plan, the TD network’s all day voice service in Ireland increased by 65%. During the implementation of the GT diversion strategy, the backflow ratio of voice services has been consistently decreasing, decreasing from 64.60% to 49.31%, with an overall decrease of 24%. The effect is very significant.

Similarly, the backflow phenomenon of data services has also been significantly improved. After the implementation of the GT diversion scheme, the overall data traffic of TD network has increased by 72%, undertaking more data services. After the implementation of the strategy, the proportion of data business backflow decreased from 23.77% to 10.80%, an improvement of 55%, and the effect was very significant.

Through the actual deployment of the GT diversion scheme on the current network, ZTE and China Mobile have collaborated to explore an effective GT diversion strategy.

Optimizing the 2/3G interoperability parameters can reduce the frequency of 2/3G interoperability for TD users, improve the soft coverage capability of TD networks, and enable more users to reside in TD networks for a long time; The increase in PCCPCH power has enhanced the deep coverage capability of TD networks, expanded the hard coverage range of TD networks, and enabled more users to reside in TD networks for business operations; Based on the 2/3G strategy of IMEI, personalized 2/3G interoperability parameters were set for specific types of terminals, fully leveraging the performance characteristics of various types of terminals under current network coverage conditions and maximizing the utilization of TD network resources; Based on the quality link monitoring algorithm for uplink and downlink, it can effectively improve the performance indicators of the network and ensure user experience.

Therefore, this plan is worth gradually promoting in the existing TD network, which has significant effects on improving TD network utilization, reducing GSM network load, and developing TD network 3G services.