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Energy-Aware Routing Protocol for Delay Tolerant Networks
Published in Athanasios Vasilakos, Yan Zhang, Thrasyvoulos V. Spyropoulos, Delay Tolerant Networks: Protocols and Applications, 2016
Seung-Keun Yoon, Zygmunt J. Haas
As mobile nodes are typically limited in their energy capacity, one of the main considerations in the design of wireless mobile networks is energy consumption, with the goal of extending the lifetime of the network. One approach which reduces energy consumption is to limit the transmission power, and consequently the transmission range, of the network nodes. However, unavoidably, this approach leads to sparse network topologies, in which the average number of neighbors of a network node is less than one. In sparse networks, nodes remain often disconnected from the rest of the network nodes. Routing in such network becomes a challenge, as frequently an end-to-end path does not exist when a packet is to be routed in the network. A possible approach to routing in such networks is for packets to be carried by network nodes until such time as the mobile node is able to create a forwarding link to another node in the network. This new networking paradigm is referred to as store-carry-forward, to distinguish it from the traditional store-and-forward paradigm. Store-carry-forward routing increases, often quite significantly, the delay and the delay jitter relative to the store-and-forward routing protocols. Consequently not all applications are capable of using the store-carry-forward networking paradigm. Rather, only those applications that can tolerate the increased delay are good candidates for this type of network. Networks which support such delay-insensitive applications are referred to as Delay Tolerant Networks (DTN).
A context-aware improved POR protocol for Delay Tolerant networks
Published in Automatika, 2023
Allam Balaram, T. Sakthivel, Radha Raman Chandan
The sparse network disconnections and limited node capacity make the DTN routing a complex task. The geographic opportunistic routing protocols are introduced in the DTN environment to handle the intermittent connectivity and reachability issues. Best progressive set selection is a key issue of POR protocols, as the routing efficiency mainly depends on the relays. The context information like mobility, connectivity, and contact duration creates a high influence on the performance of POR. Also, the practical application of DTN is uncertain owing to the environmental diversity. The context-aware methods are appropriate solutions to maximize DTN-POR efficiency. However, they lack to incorporate more application-specific context parameters, resulting in poor POR performance. Also, the multiple copy maintenance at different locations leads to a high duplication rate. Hence, effective cache management is essential. This work proposes a context-aware POR routing with appropriate catching management for highly partitioned DTN. The diagrammatic form of the problem statement is provided in Figure 1.
Exponential random graph modeling of a faculty hiring network: The IEOR case
Published in IISE Transactions, 2020
Enrique del Castillo, Adam Meyers, Peng Chen
Other descriptive statistics in the IEOR network shown in Table 1 are also somewhere between those of the CS and the Business networks. The density or connectance of the IEOR network, defined as the number of non-zero entries in the adjacency matrix divided by the maximum number of possible edges, is between CS (which has a very sparse network) and Business (which is densest). As it will be shown below, the IEOR faculty hiring network is actually quite sparse except for a group of departments, those at the top of a hiring hierarchy, which connect more often among them. The proportion of female faculty in IEOR is 19.5%, higher than in CS (16.8%) but lower than in Business schools (25.6%), an inequality that calls for further analysis that is beyond the present study. Also shown in Table 1 is the reciprocity, the proportion of departments with exchanges of mutual hires. The reciprocity of the IEOR network is also between that of CS and Business.