ESTA: An Efficient Spatial-Temporal Range Aggregation Query Processing Algorithm for UAV Networks
Liang Liu, Wenbin Zhai, Xin Li, Youwei Ding, Wanying Lu, Ran Wang
TL;DR
ESTA addresses the challenge of in-network spatial-temporal range aggregation in energy-constrained, highly mobile UAV networks. It leverages pre-planned UAV trajectories to construct a topology-change graph and compute the minimum query response delay via a shortest-path-like algorithm on temporal edges, then transforms aggregation into a recursive set-cover problem to build a Spatial-Temporal Aggregation Tree (STAT) for energy-efficient data delivery. The approach yields substantial energy savings (often over 50% compared to baselines) while satisfying user-defined query delays, and can accommodate relaxed delay requirements with a slack parameter to further optimize performance. These results demonstrate the practical value of combining trajectory-aware topology modeling with in-network aggregation for scalable UAV-based data queries in dynamic environments.
Abstract
Unmanned Aerial Vehicle (UAV) networks are increasingly deployed in military and civilian applications, serving as critical platforms for data collection. Users frequently require aggregated statistical information derived from historical sensory data within specific spatial and temporal boundaries. To address this, users submit aggregation query requests with spatial-temporal constraints to target UAVs that store the relevant data. These UAVs process and return the query results, which can be aggregated within the network during transmission to conserve energy and bandwidth-resources that are inherently limited in UAV networks. However,the dynamic topology caused by UAV mobility, coupled with these resource constraints, makes efficient in-network aggregation challenging without compromising user query delay. To the best of our knowledge, existing research has yet to adequately explore spatial-temporal range aggregation queries in the context of UAV networks. In this paper, we propose ESTA, an Efficient Spatial-Temporal range Aggregation query processing algorithm tailored for UAV networks. ESTA leverages pre-planned UAV trajectories to construct a topology change graph that models the network's evolving connectivity. It then employs an efficient shortest path algorithm to determine the minimum query response delay. Subsequently, while adhering to user-specified delay constraints, ESTA transforms the in-network aggregation process into a series of set cover problems, which are solved recursively to build a Spatial-Temporal Aggregation Tree (STAT). This tree enables the identification of an energy-efficient routing path for aggregating and delivering query results. Extensive simulations demonstrate that ESTA reduces energy consumption by more than 50% compared to a baseline algorithm, all while satisfying the required query delay.