Wu Shaochuan

AOHR: AODV and OLSR Hybrid Routing Protocol for Mobile Ad Hoc Networks

A hybrid routing protocol named AOHR (AODV and OLSR hybrid routing) for mobile ad hoc networks is proposed in this paper. In AOHR, each node maintains topology information of a zone with radius not larger than a set value. By the proactive property of OLSR, when a node wants to communicate with another node within its zone, packets can be transmitted directly. Otherwise, a routing request procedure will be invoked by the reactive property of AODV. In addition, AOHR utilizes MPRs (multipoint relays) to reduce overheads of route requests. This paper also proposes dynamic zone radius maintenance for AOHR to dynamically adapt to various scenarios. Analysis and simulation results show that AOHR combines the characters of high data delivery fraction, low overheads, and short delay in AODV with the characters of optimized routing length in OLSR, which means that AOHR is immune from topological structures

Grid-based autonomous geographic routing in wireless sensor networks

In this paper, a grid-base autonomous geographic routing is proposed to decrease end-to-end delay and improve network capability for wireless sensor networks. After numbering grids in sequence, every grid has a unique ID. In this ease, any node can utilize local decision to figure out which neighboring grid is closest to the center nodes. Since it is not needed to establish a routing in advance, this algorithm is very suitable for dynamic networks, real-time traffics and burst communications. By Matlab and Ns-2 simulation, the novel routing algorithm exhibits excellent performance in packet delivery fraction, end-to-end delay, protocol overhead, and path length.

Robust transmission of progressive images in the deep space communication

Signal to noise ratio in the deep space communication channel is so low that it is essential for deep space communication systems that information received is adequately used. Focused on the long delay and the high fading in the deep communication channel, a method of progressive robust image transmission is proposed based on the image compression algorithms using wavelet transform suggested by CCSDS. It divides Wavelet Coefficient of tree structure in CCSDS standard to different groups, which compensated the deficiency of the low efficiency in forward error correct and the long delay of automatic repeat-request if it is used to protect the image compression data in deep space communication. And with the help of a rate-distortion model for progressive wavelet coder and a way for voice quantization optimum bit assignment, the paper proposed a new method to allocate different compression rates to image groups in order to meet the minimum image data lost in the situation of constant channel rate. Simulation results have shown that the method is suited to implement error containment of the progressive image transmission in the deep space communication.

PVPSU: Publicly Verifiable and Parallel Share Updates for Mobile Ad Hoc Networks

Based on RSA algorithm, this paper provides a publicly verifiable and parallel share update algorithm for mobile ad hoc networks. According to Diffie-Hellman assumption and public verifiability, this new algorithm improves security and robustness. In addition, communication rounds have been decreased from three to two. This paper also proposes a new multiplicative shuffle scheme for share updates. Our simulation and implementation evaluate and confirm that the solution is effective