We study the problem of enhancing the fault tolerance of a data gathering tree by adding additional links so that failure of a sensor or a pair of adjacent sensors would not disconnect the tree.
In the third paper, "Determining localized tree construction schemes based on sensor network lifetime," Lee et al. study the network lifetime of different localized data gathering tree formation algorithms by considering the communication overhead due to imperfect link quality.
This structure of incentives, as it turns out, is quite common in nature examples include food gathering, tree height, the expansion of plant roots, body size, and even the replication of virus populations (see Easley and Kleinberg 2010, Chap. 7).
Referred to as the LET-DG tree, the data gathering tree has been observed to be more stable in the presence of node mobility, as well as incur a significantly lower delay per round of data gathering (due to the shorter height of the tree with more leaf nodes) and larger throughput per tree.
As an alternative, we propose an algorithm to determine a minimum-distance spanning tree (MST) based data gathering tree that is more energy-efficient and prolongs the node and network lifetimes as well as inflicts a lower coverage loss on the underlying network at any time instant, all of these at the cost frequent tree reconfigurations.
The selected k data reporters for a round form a data gathering tree to get rid of wait-and-forward delay which may result from the random sensor scheduling and are scheduled to remain active (with transceiver on) during that round only, thus saving energy.
The selected papers may be classified into five categories: (1) coverage and localization in wireless sensor networks; (2) energy efficiency in wireless sensor networks; (3) link layer and physical layer issues; (4) performance optimization; (5) tracking, data gathering tree, and transport layer in wireless sensor networks.
Optimal data-gathering trees are analyzed and the effects of several sensor capabilities and constraints are discussed, e.g., radio power constraints, energy consumption model, and data aggregation functionalities.
The data-gathering trees for the lowest ETX parent selection and the minimum hop routing schemes are illustrated in Figure 1. Figure 1 The illustration of the data-gathering tree with the lowest ETX parent selection and the minimum hop routing schemes.
As it took shape in the 19th century, it was always an occasion focused on family gatherings, tree trimmings and the exchange of gifts.
