Aerial base stations with opportunistic links for next generation emergency communications

Rapidly deployable and reliable mission-critical communication networks are fundamental requirements to guarantee the successful operations of public safety officers during disaster recovery and crisis management preparedness. The ABSOLUTE project focused on designing, prototyping, and demonstrating a high-capacity IP mobile data network with low latency and large coverage suitable for many forms of multimedia delivery including public safety scenarios. The ABSOLUTE project combines aerial, terrestrial, and satellites communication networks for providing a robust standalone system able to deliver resilience communication systems. This article focuses on describing the main outcomes of the ABSOLUTE project in terms of network and system architecture, regulations, and implementation of aerial base stations, portable land mobile units, satellite backhauling, S-MIM satellite messaging, and multimode user equipments

Group Handover for Drone-Mounted Base Stations

The widespread use of new technologies such as the Internet of things (IoT) and machine type communication(MTC) forces an increase on the number of user equipments(UEs) and MTC devices that are connecting to mobile networks. Inherently, as the number of UEs inside a base station's (BS) coverage area surges, the quality of service (QoS) tends to decline. The use of drone-mounted BS (UxNB) is a solution in places where UEs are densely populated, such as stadiums. UxNB emerges as a promising technology that can be used for capacity injection purposes in the future due to its fast deployment. However, this emerging technology introduces a new security issue. Mutual authentication, creating a communication channel between terrestrial BS and UxNB, and fast handover operations may cause security issues in the use of UxNB for capacity injection. This new protocol also suggests performing UE handover from terrestrial to UxNB as a group. To the best of the authors' knowledge, there is no authentication solution between BSs according to LTE and 5G standards. The proposed scheme provides a solution for the authentication of UxNB by the terrestrial BS. Additionally, a credential sharing phase for each UE in handover is not required in the proposed method. The absence of a credential sharing step saves resources by reducing the number of communications between BSs. Moreover, many UE handover operations are completed in concise time within the proposed group handover method

On the Feasibility of Handover over WiFi Backhaul in LTE-based Aerial-Terrestrial Networks

In this paper, we investigate scenarios where 4G LTE base stations are mounted on balloons raised in the sky for the provision of cellular connectivity and coverage within an area of few kilometers (e.g., scenarios for emergency communications). In this context, the link between the base stations need to be completed using wireless technologies, thus impacting the performance of the X2 logical interface. We propose the adoption of a wireless backhaul link based on WiFi technology. The main contributions of this paper consist in i) modeling the LTE handover over a WiFi link, ii) analyzing the binary exponential backoff with a hands-on one-dimensional Markov Chain including a finite number of packet retries as well as accounting for packets corruption due to Rice fading and iii) showing the average handover latency and handover preparation failure probability, thus proving that WiFi can meet LTE handover constraints in the majority of the investigated cases