  The delay guarantee is a challenge in wireless sensor networks (WSNs), where
energy constraints must be considered. The coexistence of renewable energy and
electricity grid is expected as a promising energy supply manner for WSNs to
remain function for a potentially infinite lifetime. In this paper, we address
cross-layer control to guarantee worse case delay for Heterogeneous Powered
(HP) WSNs. We design a novel virtual delay queue structure, and apply the
Lyapunov optimization technique to develop cross-layer control algorithm only
requiring knowledge of the instantaneous system state, which provides efficient
throughput-utility, and guarantees bounded worst-case delay. We analyze the
performance of the proposed algorithm and verify the theoretic claims through
the simulation results. Compared to the existing work, the algorithm presented
in this paper achieves much higher optimal objective value with ultralow data
drop due to the proposed novel virtual queue structure.
