Speaker
Umberto Spagnolini, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy
Topic
LTE-handover on high speed trains
Abstract
High speed (≥ 350km/h) train (HST) is revitalizing the train as the preferred mid-range transportation system. Seamless on-board Internet-to-passengers is one of the key services in the competition among train-operators. Spectral efficiency and data rates (up to 100Mbps for high mobility) of the UMTS LongTerm Evolution (LTE) are expected to offer the solution for high quality on-board Internet in HSTs. High speed makes impairments such as Doppler and link instability particularly severe as one train packs 600-1000 users that all make handover (HO) almost simultaneously (in less than 2sec) upon cell-border crossing. Frequent HOs for a large number of users increase the service interruption time due to signaling overhead, and this in turn degrades intolerably the quality of experience (QoE) for on-board Internet-like services. After the introduction to the subject, this talk shows that the impairments caused by frequent HOs in HST can be mitigated by employing multi-cell processing that diversifies the number of cells the HST can be simultaneously connected to. The deployment of fixed directional antennas on board of HST for train-to-ground connectivity provides a simple but effective countermeasure that greatly relief service discontinuities due to frequent HOs. Results are from preliminary experimental load-stress tests carried out on commercial LTE equipment’s.
Speaker's biography
Umberto Spagnolini is Professor of Politecnico di Milano, and his interests are in statistical signal processing for communication systems and remote sensing. He is author of 250+ peer-reviewed papers and some patents, his areas of experience include channel estimation and space–time processing for wireless communication systems, cooperative and distributed systems, parameter estimation/tracking and wavefield interpolation for UWB radar, oil exploration and remote sensing. He is consultant on IPR. Latest projects are on distributed estimation, interference mitigation in NG-DSL, LTE for high-speed trains.
Invited by Professor Pin-Han Ho