## 5 Discussion
### Cross-Platform Cooperation and Privacy Issues  
Currently, most advertising platforms on the market are based on traditional network advertising or mobile advertising. Each has its inherent mechanism for the operation of the advertising system. If you want to quickly integrate the time and location-based delivery mechanism mentioned in this study into the existing advertising platform on the market, it will also involve the issue of obtaining information and cooperation mechanism agreements with telecom operators. Hence, it's best not to reconstruct and develop the advertising platform on the existing market. Maybe it can try to use a cross-platform API connection method to cooperate with another advertising system that focuses on time and location-based delivery and quickly integrate the mechanism into the market for use (as depicted in Figure 6).  
If you want to cooperate across platforms, the first thing you have to deal with is user privacy. The processing of privacy rights is mainly to prevent any personal data of the user from being obtained. Therefore, the method used in the system to identify the user must be a set of codes that have nothing to do with the original personal data, and the user can be identified with such a set of user identification codes when advertising.  
There may be two modes to deliver advertisements to the audience. First, place it through a telecom operator, and second, place it through an advertising platform.  
Figure 6: System scope in the study.  
For telecom operators, the audience basically has no privacy at all. Even if the audience is replaced with a new mobile phone device, the telecom operators can still use the mobile phone number to identify the audience. Therefore, the best way to accumulate the audience's behavior data for user identification and advertising is through telecom operators. It will be the best solution among all feasible solutions, and the only possible problem is the degree of permission and tolerance of governments of various countries for this model.  
If you want to through the advertising platform to deliver, the first thing to solve is the identification of mobile devices. Telecom base stations only need to use the SIM card to distinguish mobile phone devices. Still, for advertising platform providers, if they want to identify mobile phone devices, they can only identify users through the standards provided by the mobile phone operating system. If there is no way to find a common form of identification and communication between these two mechanisms, the cooperation may only be with telecom operators.  
The main problem is that mobile phone operating system vendors are also based on the protection of user privacy, so there are many restrictions on the underlying mobile phone information that software developers can obtain. With the market changes of the times, various privacy policies or the user identification method provided are also constantly changing. Whether a feasible solution can be found or not can only be decided based on the actual market conditions.  
Since the core purpose of this research is not to discuss the above issues, we only present here the actual situation and the focus of the problem to organize and deal with the conceptual explanation. As for the real feasible solution, the relative necessary adjustments must be made under the system architecture.