Types Of Cellular Networks Research Articles

Measurement and modeling of paging channel overloads on a cellular network

IP and cellular networks used to be isolated from each other. In recent decade however, the two networks have started to overlap with the emergence of devices that access the Internet using cellular infrastructures. One important question then is whether actions or threats on the Internet side can impact the telecom or cellular side. We address this problem in the paper and specifically consider the paging channel, which is a key conduit shared by both Internet and cellular traffic. Our contributions are as follows: we illustrate through experiments on a CDMA2000 cellular network that attacks launched from the Internet can significantly increase the paging load and increase the delay of paging messages including cellular call setup requests; we derive a simple but accurate queuing model for the paging system in a CDMA2000 network and use this model to demonstrate that the paging channel exhibits sharp rather than graceful degradation under load; and through this model, we identify critical parameters that impact paging performance. Although our study is focused on CDMA2000 networks, similar problems exist in other types of cellular networks that employ a single control channel with limited bandwidth for both synchronous and asynchronous control messages.

Interfacing cellular networks of S. cerevisiae and E. coli: Connecting dynamic and genetic information

BackgroundIn recent years, various types of cellular networks have penetrated biology and are nowadays used omnipresently for studying eukaryote and prokaryote organisms. Still, the relation and the biological overlap among phenomenological and inferential gene networks, e.g., between the protein interaction network and the gene regulatory network inferred from large-scale transcriptomic data, is largely unexplored.ResultsWe provide in this study an in-depth analysis of the structural, functional and chromosomal relationship between a protein-protein network, a transcriptional regulatory network and an inferred gene regulatory network, for S. cerevisiae and E. coli. Further, we study global and local aspects of these networks and their biological information overlap by comparing, e.g., the functional co-occurrence of Gene Ontology terms by exploiting the available interaction structure among the genes.ConclusionsAlthough the individual networks represent different levels of cellular interactions with global structural and functional dissimilarities, we observe crucial functions of their network interfaces for the assembly of protein complexes, proteolysis, transcription, translation, metabolic and regulatory interactions. Overall, our results shed light on the integrability of these networks and their interfacing biological processes.

Base Station for Monitoring of Unmanned Aerial Vehicle Flight

A configuration of universal base station designed to use mobile networks for long-range transmission of telemetry data is described in the paper. Types of cellular networks and modes of their operation are presented. Next, GPRS system is shown as a possible method of data transmission between UAV and Base Station. Communication modes of the station can be augmented by additional close-range communication system based on Xbee modules. The configuration and integration of test stand for telemetric signals monitoring are shown. Finally, the modes of possible operations based on the conditions of mobile networks are described.

Stress induces remodelling of yeast interaction and co-expression networks

Network analysis provides a powerful framework for the interpretation of genome-wide data. While static network approaches have proved fruitful, there is increasing interest in the insights gained from the analysis of cellular networks under different conditions. In this work, we study the effect of stress on cellular networks in fission yeast. Stress elicits a sophisticated and large scale cellular response, involving a shift of resources from cell growth and metabolism towards protection and maintenance. Previous work has suggested that these changes can be appreciated at the network level. In this paper, we study two types of cellular networks: gene co-regulation networks and weighted protein interaction networks. We show that in response to oxidative stress, the co-regulation networks re-organize towards a more modularised structure: while sets of genes become more tightly co-regulated, co-regulation between these modules is decreased. This shift translates into longer average shortest path length, increased transitivity, and decreased modular overlap in these networks. We also find a similar change in structure in the weighted protein interaction network in response to both oxidative stress and nitrogen starvation, confirming and extending previous findings. These changes in network structure could represent an increase in network robustness and/or the emergence of more specialised functional modules. Additionally, we find stress induces tighter co-regulation of non-coding RNAs, decreased functional importance of splicing factors, as well as changes in the centrality of genes involved in chromatin organization, cytoskeleton organization, cell division, and protein turnover.

Mapping and measuring molecular networks in cells

At a molecular level biological systems such as cell signaling or metabolism can be represented as dynamic networks of interacting molecules. In the living cell multiple such networks are concurrently present and active. These include the gene regulatory (transcriptional) networks, protein interaction networks, networks of enzymes and their substrates (e.g. protein kinase substrate networks), networks of microRNA and their substrates etc. Notably, most of these types of networks consist of or involve proteins. Therefore, the systematic analysis or the proteins that constitute a biological system, their interactions and the networks they constitute is a central theme of the emerging field of systems biology.Mass spectrometry is the most widely used method for the analysis of proteins and proteomes. In this presentation we will discuss new mass spectrometry based technologies for the analysis of different types of cellular networks and their dynamic change as a function of cellular state.

Using Bandwidth-Space Partitioning to Improve Cell Coverage and Near-Far Unfair Access Problem in a Noise-Limited CDMA Cellular Network

This paper concerns CDMA cellular networks equipped with conventional matched filter receivers. For this type of cellular networks, two problems exist. One is the inverse relationship between the c...