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STiMi is a mobile multimedia broadcasting trade standard that was released by the Chinese State Administration of Radio Film and Television in 2006. This paper details the algorithm research and development work on the acquisition for STiMi. First, the STiMi physical layer is briefly reviewed. secondly, individual algorithms, including time slot detection, fractional frequency offset estimation, integer frequency offset estimation and fine timing synchronization are discussed with simulation results presented. An implemented STiMi receiver prototype is also introduced with a focus on the acquisition algorithms implementation. Finally, the whole acquisition procedure is summarized. Acquisition algorithms and structures presented in this paper are adopted for prototyping and perform well. [ABSTRACT FROM AUTHOR]

Broadcasting has been widely used in mobile Ad hoc networks as a communication means to disseminate information to all reachable nodes. Because radio signals are likely to overlap with others in a geographical area, straightforward broadcasting by flooding becomes very costly and results in serious redundancy, contention and collision, to which we refer as the broadcast storm problem. In this paper we propose the Relative Degree Adaptive flooding Broadcast (RDAB) algorithm for Ad hoc networks to efficiently reduce the broadcast overhead in the network. Based on the current situation of the network and the degree of the nodes, RDAB calculates the relative degree of the nodes, decides which nodes need to re-transmit and which nodes only need to receive. The higher the neighbor node's relative degree, the more uncovered nodes it can cover, hence these nodes can be selected to re-transmit broadcasting packets in the networks. We analyze the reliability and the validity of the RDAB algorithm to prove that the RDAB algorithm is a valid flooding broadcast algorithm. Simulation results show that the RDAB strategy outperforms the Ordinary Flooding Broadcast Method (OBM) and the Multipoint Relaying (MPR) protocol for Ad hoc networks. [ABSTRACT FROM AUTHOR]

Recently, the use of a virtual backbone in various applications in mobile ad hoc networks (MANETs) has become popular. These applications include topology management, point and area coverage, and routing protocol design. In a MANET, one challenging issue is to construct a virtual backbone in a distributed and localized way while balancing several conflicting objectives: small approximation ratio, fast convergence, and low computation cost. Many existing distributed and localized algorithms select a virtual backbone without resorting to global or geographical information. However, these algorithms incur a high computation cost in a dense network. In this paper, we propose a distributed solution based on reducing the density of the network using two mechanisms: clustering and adjustable transmission range. By using adjustable transmission range, we also achieve another objective, energy-efficient design, as a by-product. As an application, we show an efficient broadcast scheme where nodes (and only nodes) in a virtual backbone are used to forward the broadcast message. The virtual backbone is constructed using Wu and Li's marking process [37] and the proposed density reduction process. The application of the density reduction process to other localized algorithms is also discussed. The efficiency of our approach is confirmed through both analytical and simulation study. [ABSTRACT FROM AUTHOR]