The current trend in the cellular networks to reduce the amount of spectrum dedicated to GSM networks put a burden on the radio access part to keep the promised quality of service. In addition to the focus of operators on other radio access technologies and data networks have raised the need to direct most of the effort towards other activities.
Subsequently new techniques are needed to compensate for the lack of time and resources to keep GSM networks as optimized as possible.
The handover functionality is in the heart of any cellular system. It is more important when delay is not tolerated. Therefore, the choice of its parameters is important. These parameters are chosen based on network performance and traffic load patterns among other criteria. It is a time consuming task, and investigating in a way to automatically choose appropriate settings for its parameters is desired.
This work investigates the possibility of such an automated procedure. A simulation environment is developed in order to run simulations. An automated function that utilizes the principles of control theory, optimization, and live networks statistics is developed and used to build an algorithm to regulate the settings of the handover procedure.
By regulating four parameters from the handover procedure, and by introducing different traffic loads, frequency reuse and mobility patterns, while testing the results against a set of performance metrics in the simulator. The results show better network performance in terms of performance metrics when the regulating algorithm is applied than when manually choosing values of these four parameters.
However, further investigation shows that the algorithm under an aggressive mobility pattern imitating a high speed moving users, might need a stopping rule. The algorithm tries to find a better network performance even if the current metrics are acceptable. This appears to be invalid approach under some aggressive models.
Source: KTH
Author: Bazzari, Ahmad