SHIFT-MAB: Fair and Mobility-Aware Handover Control for 6G Fully Decoupled RANs

Area of Science:

• Telecommunications Engineering
• Wireless Communication Systems
• Network Optimization

Background:

• Fully decoupled radio access networks (FD-RANs) offer spectral efficiency and coverage flexibility for 6G.
• Dynamic user mobility presents challenges in user association and resource allocation within FD-RANs.
• Existing methods suffer from network unfairness due to asymmetric interference and heterogeneous base station capacities, alongside inefficient mobility management causing excessive handovers.

Purpose of the Study:

• To propose a novel framework for FD-RANs that is mobility-resilient and guarantees fairness.
• To address the intertwined problems of network unfairness and inefficient mobility management in FD-RANs.
• To optimize joint user association and resource allocation under dynamic mobility conditions.

Main Methods:

• Developed a framework integrating short-term congestion pricing with the long-term Jain fairness index for equitable resource distribution.
• Introduced a composite handover penalty with a strict physical hysteresis margin to prevent invalid handovers.
• Formulated the optimization problem using a Sliding-Window Hysteresis-Integrated Fairness Two-Layer Multi-Armed Bandit (SHIFT-MAB) model with an EWMA sliding-window mechanism for real-time channel tracking.

Main Results:

• Theoretical analysis confirmed the SHIFT-MAB model's decoupling optimality, sublinear regret bound, and fairness convergence.
• Simulations demonstrated that SHIFT-MAB effectively suppresses invalid handovers and ensures high network fairness.
• The model optimizes system utility and achieves a superior handover-throughput trade-off.

Conclusions:

• The proposed SHIFT-MAB framework provides a robust solution for managing mobility and ensuring fairness in FD-RANs.
• SHIFT-MAB enhances overall network performance by balancing handover efficiency and throughput.
• This approach is crucial for realizing the full potential of 6G networks with dynamic user mobility.