3 research outputs found
Delay-Guaranteed Cross-Layer Scheduling in Multi-Hop Wireless Networks
In this paper, we propose a cross-layer scheduling algorithm that achieves a
throughput "epsilon-close" to the optimal throughput in multi-hop wireless
networks with a tradeoff of O(1/epsilon) in delay guarantees. The algorithm
aims to solve a joint congestion control, routing, and scheduling problem in a
multi-hop wireless network while satisfying per-flow average end-to-end delay
guarantees and minimum data rate requirements. This problem has been solved for
both backlogged as well as arbitrary arrival rate systems. Moreover, we discuss
the design of a class of low-complexity suboptimal algorithms, the effects of
delayed feedback on the optimal algorithm, and the extensions of the proposed
algorithm to different interference models with arbitrary link capacities
Cross-Layer Control for Worse Case Delay Guarantees in Heterogeneous Powered Wireless Sensor Network via Lyapunov Optimization
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
Cross-Layer Scheduling for OFDMA-based Cognitive Radio Systems with Delay and Security Constraints
This paper considers the resource allocation problem in an Orthogonal
Frequency Division Multiple Access (OFDMA) based cognitive radio (CR) network,
where the CR base station adopts full overlay scheme to transmit both private
and open information to multiple users with average delay and power
constraints. A stochastic optimization problem is formulated to develop flow
control and radio resource allocation in order to maximize the long-term system
throughput of open and private information in CR system and ensure the
stability of primary system. The corresponding optimal condition for employing
full overlay is derived in the context of concurrent transmission of open and
private information. An online resource allocation scheme is designed to adapt
the transmission of open and private information based on monitoring the status
of primary system as well as the channel and queue states in the CR network.
The scheme is proven to be asymptotically optimal in solving the stochastic
optimization problem without knowing any statistical information. Simulations
are provided to verify the analytical results and efficiency of the scheme