14 papers
Deadline-Bound Finite-Object Delivery over Intermittent LEO Satellite Contact Plans under Residual-Service Accounting
Houtianfu Wang, O. Tansel Baydas, Hanlin Cai +2
Low-Earth-orbit (LEO) relay networks deliver finite objects -- sensing tiles, telemetry blocks, model updates, and checkpoints -- over intermittent inter-satellite and space-to-gro…
A reversed solar illumination dependence of unintended emission from Starlink Direct-to-Cell satellites at 72-234 MHz with the EDA2
Haofan Dong, Houtianfu Wang, Hanlin Cai +1
Second-generation Starlink Direct-to-Cell (DTC) satellites carry an additional payload for direct cellular phone connectivity whose unintended electromagnetic radiation (UEMR) at s…
Graph Representation Learning Augmented Model Manipulation on Federated Fine-Tuning of LLMs
Hanlin Cai, Kai Li, Houtianfu Wang +4
Federated fine-tuning (FFT) has emerged as a privacy-preserving paradigm for collaboratively adapting large language models (LLMs). Built upon federated learning, FFT enables distr…
Rain Rate Estimation Bounds and Weather-Adaptive Pilot Allocation for LEO Satellite ISAC
Haofan Dong, Houtianfu Wang, Hanlin Cai +2
Rain attenuates Ku-band satellite signals by up to 20~dB, encoding precipitation information along the Earth-space slant path. This paper derives the Bayesian Cramér-Rao bound (BCR…
Performance Bounds and Robust Filtering for LEO Inter-Satellite Synchronization under Cross-Epoch Doppler Coupling
Haofan Dong, Houtianfu Wang, Hanlin Cai +1
Low Earth orbit (LEO) inter-satellite links (ISLs) must achieve joint synchronization and ranging under severe hardware impairments, namely oscillator phase noise, clock drift, and…
Edge-Side Fingerprints of Service Tiering and Quota Throttling in Starlink
Houtianfu Wang, Hanlin Cai, Haofan Dong +1
We design and evaluate an edge-side measurement procedure for auditing service tiering and quota-based throttling in Starlink. Using a 232.8-hour plan-hopping campaign on a UK resi…
RIS-Aided E2E Multi-Path Uplink Transmission Optimization for 6G Time-Sensitive Services
Liu Cao, Zisheng Gong, Ziyue Xiao +3
The Access Traffic Steering, Switching, and Splitting (ATSSS) defined in the latest 3GPP Release 19 enables traffic flow over the multiple access paths to achieve the lower-latency…
Environment-to-Link ISAC with Space-Weather Sensing for Ka-Band LEO Downlinks
Houtianfu Wang, Haofan Dong, Hanlin Cai +1
Ka-band low-Earth-orbit (LEO) downlinks can suffer second-scale reliability collapses during flare-driven ionospheric disturbances, where fixed fade margins and reactive adaptive c…
AFDM for LEO Inter-Satellite Links: Path-Level CSI Prediction and CRLB-Guided Pre-Equalization
Houtianfu Wang, Ozgur Akan
Low-Earth-orbit (LEO) inter-satellite links must cope with strongly doubly selective channels and aged channel state information (CSI). In this paper, the term ``sensing'' refers t…
Graph Representation-based Model Poisoning on the Heterogeneous Internet of Agents
Hanlin Cai, Houtianfu Wang, Haofan Dong +3
Internet of Agents (IoA) envisions a unified, agent-centric paradigm where heterogeneous large language model (LLM) agents can interconnect and collaborate at scale. Within this pa…
Fundamental Limits of Cooperative Integrated Sensing and Communications over Low-Earth Orbit THz Satellite Channels
Haofan Dong, Houtianfu Wang, Hanlin Cai +1
Terahertz inter-satellite links enable unprecedented sensing precision for Low Earth Orbit (LEO) constellations, yet face fundamental bounds from hardware impairments, pointing err…
Graph Representation-based Model Poisoning on Federated Large Language Models
Hanlin Cai, Haofan Dong, Houtianfu Wang +2
Federated large language models (FedLLMs) enable powerful generative capabilities within wireless networks while preserving data privacy. Nonetheless, FedLLMs remain vulnerable to…
Semantic Communication for the Internet of Space: New Architecture, Challenges, and Future Vision
Hanlin Cai, Houtianfu Wang, Haofan Dong +1
The expansion of sixth-generation (6G) wireless networks into space introduces technical challenges that conventional bit-oriented communication approaches cannot efficiently addre…
Gravitational Communication: Fundamentals, State-of-the-Art and Future Vision
Houtianfu Wang, Ozgur B. Akan
This paper provides a comprehensive overview of fundamentals and the latest research progress in gravitational communication, with a detailed historical review of gravitational wav…