Load sharing methods in a WCDMA macro multi-carrier scenario

The evolution of a WCDMA network is characterized by a variety of scenarios. At the beginning, macro cells may be provided with one carrier to achieve continuous coverage. In order to cope with increasing voice and data traffic demand, different deployment strategies may be adopted, such as the addition of carriers to existing macro-sites. The paper proposes load sharing methods for efficiently distributing the offered traffic load among available radio resources in a macro multi-carrier scenario. Different services, i.e. speech, video conversational and Web, have been considered separately and the following methods have been evaluated: cell reselection for mobiles in idle mode or on a common channel; redirection at switch to dedicated channel; inter-frequency handover (IFHO); network triggered channel down-switch for mobiles having a dedicated channel. Radio network simulation results demonstrate that the use of more advanced load sharing methods ensure a more effective sharing and a more efficient usage of the available radio resources, compared to the basic method, i.e. the cell reselection.