Reactive local algorithms are distributed algorithms which suit the needs of battery-powered, large-scale wireless ad hoc and sensor networks particularly well. By avoiding both unnecessary wireless transmissions and proactive maintenance of neighborhood tables (i.e., beaconing), such algorithms minimize communication load and overhead, and scale well with increasing network size. This way, resources such as bandwidth and energy are saved, and the probability of message collisions is reduced, which leads to an increase in the packet reception ratio and a decrease of latencies. 
Currently, the two main application areas of this algorithm type are geographic routing and topology control, in particular the construction of a node's adjacency in a connected, planar representation of the network graph. Geographic routing enables wireless multi-hop communication in the absence of any network infrastructure, based on geographic node positions. The construction of planar topologies is a requirement for efficient, local solutions for a variety of algorithmic problems.
This thesis contributes to reactive algorithm research in two ways, on an abstract level, as well as by the introduction of novel algorithms:
For the very first time, reactive algorithms are considered as a whole and as an individual research area. A comprehensive survey of the literature is given which lists and classifies known algorithms, techniques, and application domains. Moreover, the mathematical concept of O- and Omega-reactive local topology control is introduced. This concept unambiguously distinguishes reactive from conventional, beacon-based, topology control algorithms, serves as a taxonomy for existing and prospective algorithms of this kind, and facilitates in-depth investigations of the principal power of the reactive approach, beyond analysis of concrete algorithms.
Novel reactive local topology control and geographic routing algorithms are introduced under both the unit disk and quasi unit disk graph model. These algorithms compute a node's local view on connected, planar, constant stretch Euclidean and topological spanners of the underlying network graph and route messages reactively on these spanners while guaranteeing the messages' delivery. All previously known algorithms are either not reactive, or do not provide constant Euclidean and topological stretch properties. A particularly important partial result of this work is that the partial Delaunay triangulation (PDT) is a constant stretch Euclidean spanner for the unit disk graph. 
To conclude, this thesis provides a basis for structured and substantial research in this field and shows the reactive approach to be a powerful tool for algorithm design in wireless ad hoc and sensor networking.

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Silence is golden: reactive local topology control and geographic routing in wireless ad hoc and sensor networks

With the advance of wireless communication technologies and the increasing popularization of wireless devices, mobile ad hoc networks have attracted substantial interest in recent years. Due to the frequent changes in the network topology and the constrained power supply, routing in Mobile Ad Hoc Networks (MANETs) is difficult compared with the traditional routing protocols. Presently existing routing schemes are not well adapted to the mobile environment in terms of energy efficiency and routing robustness. In this thesis, we present schemes for energy-efficient routing and for robust routing. For energy-efficiency, a localized topology control scheme is proposed to achieve energy-efficient routing on mobile ad hoc networks. The distributed algorithm is simple yet efficient, and hence suitable for mobile ad hoc networks. With this algorithm, nodes can dynamically adjust their transmission power to construct an energy-efficient topology on the underlying ad hoc network. The power control approach not only reduces the power consumption in transmission, but also maintains the overall network connectivity so that the communication routes between nodes will not be disconnected. For routing robustness, we present a geographic routing protocol inspired by the fisheye technique. A node maintains accurate location information of nearby nodes and approximate location information of faraway nodes. The further away a node x is with respect to a given node y, the less information about x will be maintained on y. The routing protocol is based on the approximate location information and greedy forwarding. Packet forwarding decisions can be made independently for each node. This protocol is adaptive and robust for the mobile environments without high update messages overhead. This master thesis documents the project, the issues involved, our approach toward routing as well as the results obtained. We believe that the experience and results gained in this research could be useful for further work. ix ATTENTION: The Singapore Copyright Act applies to the use of this document. Nanyang Technological University Library

https://dr.ntu.edu.sg/bitstream/10356/2643/1/SCE-THESES_69.pdf

Efficient and robust routing on mobile ad hoc networks

Energy-Aware geographic routing in wireless ad hoc networks(hereinafter referred to as ad hoc networks) has a significant effect on network performance. It is of great importance for reducing energy consumption, prolonging network lifetime, among other things, thus receiving more and more attentions. This paper provides a comprehensive introduction to the research development on energy-aware geographic routing protocols in ad hoc networks. First, the geographic routing in ad hoc networks is introduced. Next, the formation background, the metrics, the rule of node selection, the research significance and the classifications of energy-aware geographic routing protocols are discussed in detail. Then, some classical energy-aware geographic routing protocols are presented along with multi-angle comparisons and summaries. After that, existing problems are analyzed and open research issues are highlighted. Finally, a summary of this paper is given.

Overview of Energy-Aware Geographic Routing Protocols in Wireless Ad Hoc Networks

The geographical routing protocol employs position information from the localization system for multi-hop data communication. However, the location inaccuracy due to the unpredictable node mobility and the power consumption of localization system reduces the performance of geographical routing protocol. Several geographical routing protocols have been proposed in Mobile Ad Hoc Network (MANET). The well-known geographical routing among them is Greedy Perimeter Stateless Routing (GPSR). In GPSR, the dead end node selection for data communication easily handles the network scalability. However, the highly dynamic network topology makes frequent changes in the neighbor’s location. Hence, the inaccurate location information degrades GPSR performance. This paper proposed a Modified GPSR (MGPSR) protocol to improve the performance under a large scale and a high mobility network. Moreover, the MGPSR consists of Neighbor List Learning (NNL), Node Mobility Prediction (NMP), and Periodic Position Update (PPU) schemes to balance the data delay and packet delivery ratio. The NNL along with NMP scheme provides the accurate neighbor list under a high mobility network. Furthermore, the PPU supports the guarantee for accurate neighbor location. In addition, the proposed schemes reduce the usage of localization systems to provide accurate location information with low power consumption which improve the routing performance in MGPSR. This work simulates and compares the performance of an enhanced MGPSR in the aspects of packet delivery ratio and throughput with the existing GPSR. Thus, it proves the MGPSR outperforms the GPSR under a large scale with a high mobility network.

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Effective Geographical Routing in the Presence of Unpredictable Node Mobility

We present a location-aware routing protocol called MGPSR (Modified Greedy Perimeter Stateless Routing) for Mobile Ad Hoc Networks. MGPSR offers the crucial correctness guarantee of the well known Greedy Perimeter Stateless Routing (GPSR) protocol; moreover, it possesses two additional attractive properties: (1) the modified Greedy forwarding scheme balances between the transmission power consumption and the transmission latency, and (2) the modified perimeter forwarding makes use of the localized delaunay graph which offers higher connectivity and provides a path with fewer hops. In contrast to pure topology-based protocols, MGPSR does not drain the network bandwidth by imposing large amount of protocol traffic. Extensive simulations have demonstrated that the MGPSR outperforms the GPSR protocol in terms of planar graph connectivity and energy consumption.

Wen-Jing Hsu

Papers

Power-Efficient Geographic Routing for MANETs *