22 papers
Reliability Limits and Decoding for Partial Nanopore Protein Rereads With Persistent State
Hongbin Ni, Haofan Dong, Ozgur B. Akan
Repeated observations of one physical object need not constitute independent channel uses. We model partial nanopore protein rereads as a finite-alphabet channel with canonical con…
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…
CisLunarSense: Opportunistic ISAC for Debris Detection at the Lunar Gateway
Haofan Dong, Ozgur B. Akan
We propose CisLunarSense, an opportunistic integrated sensing and communication (ISAC) framework that exploits the Lunar Gateway's Ka-band relay for monostatic debris detection, ad…
Fisher Information Limits of Satellite RF Fingerprint Identifiability for Authentication
Haofan Dong, Ozgur B. Akan
RF fingerprinting authenticates satellite transmitters by exploiting hardware-specific signal impairments, yet existing methods operate without theoretical performance guarantees.…
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…
Distortion Is Not Noise: On the Limits of the Kappa Model for Monostatic ISAC
Haofan Dong, Ozgur B. Akan
Monostatic ISAC sensing differs from communication because the transmitter can monitor its distorted transmit waveform. Thus, the aggregate distortion model, which treats impai…
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…
Cramer--Rao Bounds for Magneto-Inductive Integrated Sensing and Communications
Haofan Dong, Ozgur B. Akan
Magnetic induction (MI) enables communication in RF-denied environments (underground, underwater, in-body), where the medium conductivity imprints a deterministic signature on the…
MI-ISAC: Magneto-Inductive Integrated Sensing and Communication in the Reactive Near-Field for RF-Denied Environments
Haofan Dong, Ozgur B. Akan
Radio-frequency integrated sensing and communication (RF-ISAC) is ineffective inunderground, underwater, and in-body environments where conductive media attenuate electromagnetic w…
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…
Performance Limits of Hardware-Constrained THz Inter-Satellite MIMO-ISAC Systems
Haofan Dong, Ozgur B. Akan
Terahertz inter-satellite links (THz-ISL) offer unprecedented bandwidth for future space networks but face fundamental constraints from onboard power and thermal budgets. This pape…
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…
Fundamental Limits of THz Inter-Satellite ISAC Under Hardware Impairments
Haofan Dong, Ozgur B. Akan
This paper establishes a theoretical framework for analyzing the fundamental performance limits of terahertz (THz) Low Earth Orbit (LEO) inter-satellite link (ISL) Integrated Sensi…
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…
MASC: Integrated Sensing and Communications for the Martian Internet of Space
Haofan Dong, Ozgur B. Akan
Mars exploration missions increasingly demand reliable communication systems, yet harsh environmental conditions -- particularly frequent dust storms, extreme Doppler effects, and…
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…
Martian Dust Storm Detection with THz Opportunistic Integrated Sensing and Communication in the Internet of Space (IoS)
Haofan Dong, Ozgur B. Akan
This paper presents the Mars Dust Storm Detector (MDSD), a system that leverages the THz Opportunistic Integrated Sensing and Communications (OISAC) signals between Mars surface as…
DebriSense: Terahertz-based Integrated Sensing and Communications (ISAC) for Debris Detection and Classification in the Internet of Space (IoS)
Haofan Dong, Ozgur B. Akan
The proliferation of Low Earth Orbit (LEO) satellite constellations has intensified the challenge of space debris management. This paper introduces DebriSense-THz, a novel Terahert…