Centralized and Distributed Self-x Features in heterogeneous 5G Networks.

The continuous evolution of mobile network technology is leading to the 5th Generation (5G) of cellular networks, a level of development that exhibits unprecedented network features, capability, and intelligence. New technological cost–efficient solutions are, therefore, required to boost the network capacity and advance its capabilities in order to support the Quality of Service (QoS) requirements. Network densification is known to be as one of the promising approaches aiming to increase the network capacity and reduce latency. For example, Heterogeneous Wireless Networks (HWN) can provide flexible and diverse network access to the users by integration of different wireless technologies. By introducing dense and diverse networks, the importance of network coordination and automated controllability has never been higher. Despite the advantages of network densifications, there are challenges that have to be addressed properly in order to use the best performance of heterogeneous networks. An example of HWN is the 5 GHz unlicensed band which is open to different wireless systems such as WiFi or Unlicensed LTE. The presence of the two mentioned OFDM-based systems in the same band rise the importance of studying their performance when sharing the same band with the other technologies and introduce new models and methods to reach the friendly coexistence. Another example of dense networks is roaming, especially in the 5G systems, with ever-increasing heterogeneous users. In the small cells and densified networks, Mobile Network Operators (MNOs) need to share their mobile networks with other operators more often to reduce the operator investment costs on infrastructure. Thus, the mobile networks are transferring from uniquely own single authorities to complex interactions among heterogeneous participants which rise the need for a new level of controllability.