1. Field of the Invention
The invention is related to a method that can apply to different generation of mobile networks for testing the mobile networks, and more particularly to a method which utilizes the event logs data extracted from control plane with location information extracted from user plane in order to generate drive test like results with highly accurate geographical information and correspondent wireless signal measurements for mobile networks.
2. Description of the Prior Art
For wireless networks such as mobile networks and so on, drive test is the conventional method wireless network operators use to verify whether the wireless network operates as what they expect or not after any network deployment and modification, including adding and removing sites or adjusting sites' configuration. The traditional drive test equipment includes a cell phone, a laptop, and a GPS. During the conventional drive test trip, the drive test equipment usually collects information includes radio performance—such as signal strength and noise ratio—as well as some signaling information by making test phone calls. Meanwhile, the GPS unit in the drive test equipment collects location information associated to call activities. In this case, the engineers can learn how the mobile network performs with high geographical accuracy along the routes or locations drive test trips are conducted from the data traditional drive test equipments collected. One important advantage traditional drive test method provides is the highly accurate geographical information associated with call activities conducted by drive test equipment. However, the drawback of traditional drive test method is that it takes a huge amount of manpower and can only apply to certain routes or locations because of the manpower constraints. In recent years, a new kind of methods, called geolocation, is proposed to replace the drive test because this new kind of methods can monitor the whole mobile network instead of only certain routes or locations. This kind of methods utilize event logs or call trace logs, i.e. the logs of messages exchanged between devices and wireless network to maintain the connection and service, to locate where users (e.g., mobile devices) made calls, then associated call activities can be linked with those determined locations. However, the biggest challenge of this method is the accuracy of user positioning results, which usually falls into 100˜200 meter error ranges because that's the best this kind of methods can achieve due to the information constraint in event logs or call trace logs. This level of accuracy may not be sufficient for engineers to conduct detailed analysis of their mobile network, and thus leaves a room for further improvements.