Zhenzhen Jiao

NBP: An efficient network-coding based backpressure algorithm

In this paper, we propose an efficient network coding based back-pressure algorithm (NBP). NBP introduces the interflow network coding to improve the performance of the backpressure algorithm (a famous throughput-optimal cross-layer scheduling algorithm) for scheduling the transmissions of packets and also higher transmission efficiency. We theoretically prove that NBP can stabilize such networks. Simulation results demonstrate that NBP significantly outperforms traditional back-pressure algorithm in terms of packet delivery delay and average forwarding queue length.

Backpressure-based routing and scheduling protocols for wireless multihop networks: A survey

Backpressure-based routing and scheduling has been considered as a promising strategy for efficient resource allocation in wireless multihop networks. It has many attractive features such as throughput optimality, achievable adaptive resource allocation, support for agile load-aware routing, and simplicity. In this article, we first categorize existing backpressure-based protocols based on different design criteria and then summarize several key issues faced in the design of efficient backpressure-based protocols. We present a comprehensive survey of state-of-theart backpressure-based protocols for wireless multihop networks. We illustrate how each of the protocols works, and discuss their merits and deficiencies. Finally, we point out some future directions for supporting efficient backpressure- based routing and scheduling.

Efficient location-based topology control algorithms for wireless ad hoc and sensor networks

Topology control is an efficient strategy for improving the performance of wireless ad hoc and sensor networks by building network topologies with desirable features. In this process, location information of nodes can be used to improve the performance of a topology control algorithm and also ease its operations. Many location-based topology control algorithms have been proposed. In this paper, we propose two location-assisted grid-based topology control GBP algorithms. The design objective of our algorithm is to effectively reduce the number of active nodes required to keep global network connectivity. In grid-based topology control, a network is divided into equally spaced squares called grids. We accordingly design cross-sectional topology control algorithm and diagonal topology control algorithm based on different network parameter settings. The key idea is to build near-minimal connected dominating set for the network at the grid level. Analytical and simulation results demonstrate that our designed algorithms outperform existing work. Furthermore, the diagonal algorithm outperforms the cross-sectional algorithm. Copyright

A distributed gradient-assisted anycast-based backpressure framework for wireless sensor networks

Recently, much effort has been made for implementation of back-pressure scheduling in wireless networks. In this paper, we explore the implementation of back-pressure-based forwarding in wireless sensor networks. For this purpose, we propose Gradient-pressure, a practical Gradient-assisted anycast-based back-pressure framework for wireless sensor networks. Gradient-pressure introduces gradient information to assist transmission scheduling and realizes distributed anycast-based back-pressure scheduling on top of IEEE 802.11. Simulation results demonstrate that Gradient-pressure has high performance in terms of energy-use efficiency and goodput.

DTN routing with back-pressure based replica distribution

Replication routing can greatly improve the data delivery performance by enabling multiple replicas of the same packet to be transmitted towards its destination simultaneously. It has been studied extensively recently and is now a widely accepted routing paradigm in delay tolerant networks (DTNs). However, in this field, the issue of how to maximize the utilization efficiency of limited replication quota in a resource-saving manner and therefore making replication routing to be more efficient in networks with limited resources has not received enough attention. In this paper, we propose a DTN routing protocol with back-pressure based replica distribution. Our protocol models the replica distribution problem from a resource allocation perspective and it utilizes the idea of back-pressure algorithm, which can be used for providing efficient network resource allocation for replication quota assignment among encountered nodes. Simulation results demonstrate that the proposed protocol significantly outperforms existing replication routing protocols in terms of packet delay and delivery ratio.

An efficient network‐coding based back‐pressure scheduling algorithm for wireless multi‐hop networks

Summary Back-pressure scheduling has been considered as a promising strategy for resource allocation in wireless multi-hop networks. However, there still exist some problems preventing its wide deployment in practice. One of the problems is its poor end-to-end (E2E) delay performance. In this paper, we study how to effectively use inter-flow network coding to improve E2E delay and also throughput performance of back-pressure scheduling. For this purpose, we propose an efficient network coding based back-pressure algorithm (NBP), and accordingly design detailed procedure regarding how to consider coding gain in back-pressure based weight calculation and how to integrate it into next hop decision making in the NBP algorithm. We theoretically prove that NBP can stabilize the networks. Simulation results demonstrate that NBP can not only improve the delay performance of back-pressure algorithm, but also achieve higher network throughput. Copyright

Predictive Big Data Collection in Vehicular Networks: A Software Defined Networking Based Approach

Data collection is key issue in vehicular networks since it is vital for supporting many applications in vehicular environments. With the explosive growth of sensing data in urban area, however, strategies for efficient collection of big data in vehicular networks are still far from being well studied. In this paper, we focus on studying this issue and accordingly propose a Software Defined Vehicular Networks (SDVN) architecture. On this architecture, a predictive data collection algorithm is proposed. In this algorithm, packet delivery is fulfilled by cooperative cellular and ad hoc network interfaces, in which collections of big data always adopts ad hoc based multi-hop relaying whenever applicable to forward packets to Road Side Units (RSUs). Cellular networks are used for data uploading only when no multi-hop relaying opportunity is available. Our proposed SDVN architecture enables such efficient cooperative communications, in which predictive routing decisions are made based on real-time network status other than empirical knowledge. Simulation results demonstrate that our algorithm outperforms existing algorithms in terms of packet delivery ratio and transmit efficiency.

Virtual gradient based back-pressure scheduling in wireless multi-hop networks

In this paper, we study how to effectively reduce the average end-to-end (E2E) packet delay in backpressure based scheduling in wireless multi-hop networks. We accordingly propose a virtual gradient based back-pressure scheduling algorithm, referred to as VBR. In VBR, intentional virtual queue, whose length (called virtual gradient) depends on the distance to destination, is first built at nodes in a network in the network configuration phase. In this way, virtual gradient is established at nodes in the network. In the network operation phase, the scheduling decision at each node needs to jointly consider both real queue length and virtual queue length. Simulation results show that VBR can obtain significant performance improvement on back-pressure based routing and scheduling, in terms of packet delivery ratio and average E2E delay.

A gradient-assisted energy-efficient backpressure scheduling algorithm for wireless sensor networks

Backpressure based scheduling has revealed remarkable performance in wireless multihop networks as reported in a lot of previous work. However, its lack of consideration on energy use efficiency is still an obstacle for backpressure based algorithms to be deployed in resource-constrained wireless sensor networks (WSNs). In this paper, we focus on studying the design of energy efficient backpressure based algorithm. For this purpose, we propose a gradient-assisted energy-efficient backpressure scheduling algorithm (GRAPE) for WSNs. GRAPE introduces a new link-weight calculation method, based on which gradient information and nodal residual energy are taken into account when making decisions on backpressure based transmission scheduling. According to the decisions made by this new method, packets are encouraged to be forwarded to nodes with more residual energy. We theoretically prove the throughput-optimality of GRAPE. Simulation results demonstrate that GRAPE can achieve significant performance improvements in terms of energy use efficiency, network throughput, and packet delivery ratio as compared with existing work.

Visible Light Communication Based Indoor Positioning Techniques

Positioning technique has become an indispensable part of our daily lives. Compared with the well-solved positioning issue in outdoor areas, indoor positioning is still far from being well explored, and existing techniques in this area are still far from being sufficiently mature to be widely used in practice. Recently, visible light communication based indoor positioning, also referred to as visible light based positioning, has attracted great attention and much work has been carried out, which reveals remarkable positioning accuracy. In this article, we provide a comprehensive survey of visible light based positioning. We first introduce some fundamental issues in visible light based positioning and further categorize existing systems in this field according to different design criteria. We then give a comprehensive survey of state-of-the-art systems, and introduce how each of the systems works and discuss their merits and deficiencies. Finally, we discuss challenging issues in this area and also point out future directions.