A study on the optimal placement of the decision-making entity in LTE mobile networks

Μάργαρης, Αριστοτέλης Γ.

Master Thesis

Author

Μάργαρης, Αριστοτέλης Γ.

Date

2014-06-17

Abstract

The technological improvements of the advanced cellular radio networks and the ever- increasing functionalities provided to the end users by the smartphones, lead to more strict requirements in the performance of algorithms and procedures that are executed by them. One very important parameter of these networks is the placement of the logical entity that executes the intelligent functionalities of a 4th Generation heterogeneous cellular radio network. The placement of the intelligence can either be in the LTE User Equipment, right next to the source of the change in the traffic demands of the user, or it can be placed in the underlying network (i.e. the eNodeB) with access to contextual information about the network composition and load. A very important decision that needs to be taken in these networks is the handover decision of a connected UE’s active data call as it crosses the complex network of the provider. This network consists of Macro-cells, pico-cells, WiFi Access Points owned by the provider and other Radio Access Technologies. To evaluate the optimal selection of the wireless node, a fitness function has been developed that uses as input data from the mobile terminal, from the registries of the provider’s network and also from the ANDSF template, an xml-based file that contains the provider’s preferences for the decision-making functionalities. Based on the results of this fitness function, all the possible handover targets are compared in order to discover the optimal and perform the handover procedure to change its serving node. For the comparison of the two different decision-making paradigms, a special simulation software has been developed with the capabilities of entering a plethora of input variables to form multiple sets of simulation scenarios, projection of the simulation during runtime with detailed and potent graphical elements and a powerful central processing core that is based on the architecture of micro simulation based on deterministic Event Queue. The extracted output data from the simulation of key-scenarios for the selected research is then utilized and correlated with the respective attributes that concern different stakeholders (End Users, Network Providers, Technology vendors) in order to synthesize an adequate list of arguments to proceed to recommendations. After that a detailed appendix section follows that contains the summary of the developed source code and the development principles that were used for its implementation.