CRAM: Cooperative Resource Allocation With Spotlighting for Zero-Interruption ISAC Networks

Abstract

The emergence of sixth-generation (6G) communication systems promotes an integrated sensing and communications (ISAC) framework to address growing demands for seamless connectivity. This paper proposes a cooperative resource allocation method (CRAM) that enables uninterrupted service for mobile terminals (MTs) moving across heterogeneous base stations (BSs) without resource handovers—inspired by a spotlight tracking a moving actor. Specifically, we tackle the challenge of dynamically managing resources in macro–micro heterogeneous ISAC networks by exploiting real-time MT speed and location information. CRAM achieves a spotlight effect for MTs through two core strategies: a resource pre-allocation mechanism driven by network topology sensing, and a resource sharing strategy that mitigates ping-pong effects in micro-BS overlapping regions. For high-velocity MTs, spectrum resources are assigned at macro-BSs to enhance service quality and minimize handovers. Furthermore, we incorporate the Cramer–Rao lower bound to derive optimized resource allocation policies adapted to diverse MT speeds and locations. Simulation results demonstrate that CRAM tailors resource distribution to MT characteristics, guaranteeing zero-interruption connectivity while maximizing system performance. In comparison with existing benchmarks, CRAM improves system throughput by 24.5% and 20.9%, reduces the total number of handovers by 29.1% and 16.5%, and increases the average signal-to-interference-plus-noise ratio (SINR) for all MTs by 41.3% and 30.3%. These outcomes highlight CRAM’s potential to redefine 6G network management by substantially boosting network efficiency and user experience.