Through the Telco Lens: A Countrywide Empirical Study of Cellular Handovers

TL;DR

This paper provides the first comprehensive countrywide analysis of cellular handovers, examining their performance, causes of failures, and the influence of device types and radio technologies using large-scale operator data.

Contribution

It presents a novel large-scale empirical study of handovers across an entire country, analyzing geo-temporal dynamics and device heterogeneity from real operator data.

Findings

Heterogeneity in handover performance across regions and device types

Identification of key causes and patterns of handover failures

Insights into the impact of radio technologies on mobility management

Abstract

Cellular networks rely on handovers (HOs) as a fundamental element to enable seamless connectivity for mobile users. A comprehensive analysis of HOs can be achieved through data from Mobile Network Operators (MNOs); however, the vast majority of studies employ data from measurement campaigns within confined areas and with limited end-user devices, thereby providing only a partial view of HOs. This paper presents the first countrywide analysis of HO performance, from the perspective of a top-tier MNO in a European country. We collect traffic from approximately 40M users for 4 weeks and study the impact of the radio access technologies (RATs), device types, and manufacturers on HOs across the country. We characterize the geo-temporal dynamics of horizontal (intra-RAT) and vertical (inter-RATs) HOs, at the district level and at millisecond granularity, and leverage open datasets from the country's official census office to associate our findings with the population. We further delve into the frequency, duration, and causes of HO failures, and model them using statistical tools. Our study offers unique insights into mobility management, highlighting the heterogeneity of the network and devices, and their effect on HOs.