The Missing Part of Seed Dispersal Networks: Structure and Robustness of Bat-Fruit Interactions

Mutualistic networks are crucial to the maintenance of ecosystem services. Unfortunately, what we know about seed dispersal networks is based only on bird-fruit interactions. Therefore, we aimed at filling part of this gap by investigating bat-fruit networks. It is known from population studies that: (i) some bat species depend more on fruits than others, and (ii) that some specialized frugivorous bats prefer particular plant genera. We tested whether those preferences affected the structure and robustness of the whole network and the functional roles of species. Nine bat-fruit datasets from the literature were analyzed and all networks showed lower complementary specialization (H2' = 0.37±0.10, mean ± SD) and similar nestedness (NODF = 0.56±0.12) than pollination networks. All networks were modular (M = 0.32±0.07), and had on average four cohesive subgroups (modules) of tightly connected bats and plants. The composition of those modules followed the genus-genus associations observed at population level (Artibeus-Ficus, Carollia-Piper, and Sturnira-Solanum), although a few of those plant genera were dispersed also by other bats. Bat-fruit networks showed high robustness to simulated cumulative removals of both bats (R = 0.55±0.10) and plants (R = 0.68±0.09). Primary frugivores interacted with a larger proportion of the plants available and also occupied more central positions; furthermore, their extinction caused larger changes in network structure. We conclude that bat-fruit networks are highly cohesive and robust mutualistic systems, in which redundancy is high within modules, although modules are complementary to each other. Dietary specialization seems to be an important structuring factor that affects the topology, the guild structure and functional roles in bat-fruit networks

Performance Analysis for Data Service in Mobile Telecommunication Networks

Wireless networks are becoming more and more popular and traffic over the networks is growing rapidly. Because the network infrastructure is expanding at a quick pace, especially the wireless Internet growth, both in size and in the types of applications, the performance issue and dimensioning issue of networks are becoming more critical. New wireless data applications are emerging over mobile telecommunication networks. These applications produce data that may have different characteristics from those of wired dada applications. In this case, a good evaluation of performance measures can help a system designer to make its strategic decisions concerning cell size and the number of channel frequencies allocated to each cell. In this paper we present a data services analysis in a mobile telecommunication networks based on simulation. In addition, we illustrate the need for a simulation in order to characterize the mix of several traffic types for capacity and quality of service (QoS) planning. We use the Pareto and heavy tailed Weibull distributions to simulate the data traffic and the resource occupation time for data service, respectively. Finally, we also comment some simulation results of third generation services where we analyze the QoS parameters of a mobile network, such as channel occupation time, handoff, new call blocking probabilities and traffic in Erlangs

5GinFIRE:An end-to-end open5G vertical network function ecosystem

Advanced communication networks, such as 5G and beyond, will be a complex ecosystem made of multiple physically interconnected elements, implying that the upcoming network will have to address capabilities such as flexibility, programmability and extensibility. This article, describes an Open and Extensible 5G Network Function Virtualization (NFV) based Reference ecosystem of experimental facilities, named 5GinFIRE, that integrates existing facilities with new vertical-specific ones but also lays down the foundations for instantiation fully softwarized architectures of vertical industries and experimenting with them. Additionally, we present 5GinFIRE as the forerunner experimental playground, together with three uses cases, wherein new components, architecture designs and APIs may be tried and proposed before they are ported to more industrially mainstream 5G networks that are expected to emerge in large scale