Return on Investment (roi) for Multi-Technology son juan Ramiro, Mark Austin and Khalid Hamied

B.2. X-Map Estimation Approach

An overview of the X-map estimation approach is given in Figure B.1. The UE Location and Measurement Unit (LMU) gathers measurement data such as the Reference Signal Received Power (RSRP) or the Reference Signal Received Quality (RSRQ), location data, and the corresponding time from the UEs in the network. In order to manage the positioning of UEs in LTE, the Evolved Serving Mobile Location Center (E-SMLC) is introduced [2]. Depending on the conditions in the network and on the UE/enhanced NodeB (eNodeB) positioning capabilities, this entity decides which positioning method should be used and combines all the received results to determine one single position estimate for the UE. Furthermore, it can provide additional information such as the accuracy of the position estimate or the velocity of the UE. Thus, the E-SMLC provides all important positioning features that have to be fulfilled by the LMU and may be utilized for providing the necessary data for an X-map estimation function. In addition to the LMU, a RAN Measurement Unit (RMU) is introduced which collects the measurement data from the RAN, e.g. the interference and load, and utilizes this data in order to better estimate the network state. The measurement data of both measurement units together with the positions of the UEs are then delivered to the X-map estimation function, which uses this data directly for updating the corresponding bins in the X-map (approach 1) or for updating a propagation model (approach 2).
If new measurement data together with a UE position estimate become available, approach 1 uses this information for updating the corresponding bin in the X-map where the UE is located, similar to the approaches in [5, 6]. Various update mechanisms are possible, e.g. the latest measurement value can replace the current value in the bin or it can be combined with the current value in the bin, such as by applying a filter approach. In the presented simulations, the average of the value in the X-map and the UE reports gathered over a time interval is
Appendix B: X-Map Estimation for LTE 275