Multipath and Doppler Characterization of an Electromagnetic Environment by Massive MDT Measurements From 3G and 4G Mobile Terminals

Abstract

This paper describes an innovative approach to radio channel characterization in UMTS and LTE mobile networks. In place of traditional drive tests (DT), which employ a single test mobile, a massive collection of georeferenced radio measurements is made from a wide population of user equipment (UE). This is possible with new 3GPP features, called ''minimization of DTs'' (MDT), which are implemented in the last generation UEs and enable the reporting of additional periodical measurements, including GPS position and estimated UE distance (i.e. delay) over the radio path. This opens to new fields of investigation in the mobile radio channel, unreachable with the legacy DT approach, such as multipath and Doppler analysis. The UE MDT data of UMTS and LTE RAN of Telecom Italia Mobile, in the Italian midsized city of Bologna, have been statistically analyzed. The big data elaboration has been performed with the Nokia proprietary system ''GeoSynthesis.'' The results give a high-resolution geographical view of the abovementioned channel phenomena affecting the quality and user experience. They are in good accordance with network performance indicators: the higher the multipath time, the worse the decoding performance of radio blocks (block error rate). The estimated Doppler shift also fits the known mobility patterns in the urban environment.

Enhanced MDT-Based Performance Estimation for AI Driven Optimization in Future Cellular Networks

“…However, this study does not consider MDT-based performance estimation nor does it consider the impact of bin width or sparse measurements. By using MDT reports, authors in [23] focus on characterizing multipath time, coherence bandwidth and doppler shift of propagation channels in mobile networks. In this study, the GPS position of UE is considered reliable if its uncertainty shape has a radius below 39 m. The bin size is taken to be 10 ⇥ 10 meters, because it was the highest resolution currently available with the visualization tool authors used.…”

“…In summary, though positioning error is well investigated in literature as represented by the aforementioned studies i.e., [4], [17]- [23], ], none of these existing studies take into account the errors resulting from quantization or scarcity of user measurements. This study aims to fill this gap by proposing enhanced MDT-based performance estimation methods while taking into account other errors such as sparse user measurements and quantization errors that were not taken into account by [4], [17]- [23].…”

Cellular Network Capacity and Coverage Enhancement with MDT Data and Deep Reinforcement Learning

“…Minimization of Drive Tests (MDT) is a feature introduced in 3GPP Release 10 [7] that enables operators to utilize users' equipment (UE) to collect radio measurements and associated location information [8] (e.g., via GPS or WLAN localization (Release 16)). Collected MDT measurement reports can be aggregated into datasets with user location information (ULI) as well as statistical channel state information, providing a realistic description of the network state and allowing network troubleshooting and inference of human behavior-related statistics [9][10][11]. With this contribution, the authors aim to shed light on the potential of MDT data-driven algorithms for network automation.…”

Rain Effect on 4G LTE In-Car Electromagnetic Propagation Analyzed Through MDT Radio Data Measurement Reported by Mobile Phones

“…7) because of cycles of rainy and dry moments in Trentino Alto Adige, so creating useful experimental environment to detect if, and how, RSRP in-car measurements are influenced by rain, despite propagation of the 4G LTE frequencies (below 3 GHz) results very weakly affected by air humidity level as reported by the ITU recommendations [7][8][9][10]. The presence of multiple radio signals paths [11] affects the cellular electromagnetic propagation and wet environment changes, at least, the surface dielectric characteristics of the soil, building walls, building roofs, foliage, cars, glass windows and so on. Some authors reported interesting considerations on the effect of rain on electromagnetic propagation.…”