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SeeR: Simulated Annealing-based Routing in Opportunistic Mobile Networks

Opportunistic Mobile Networks (OMNs) are characterized by intermittent connectivity among nodes. In many scenarios, the nodes attempt at local decision making based on greedy approaches, which can result in getting trapped at local optimum. Moreover, for efficient routing, the nodes often collect and exchange lot of information about others. To alleviate such issues, we present SeeR, a simulated annealing-based routing protocol for OMNs. In SeeR, each message is associated with a cost function, which is evaluated by considering its current hop-count and the average aggregated inter-contact time of the node. A node replicates a message to another node, when the latter offers a lower cost. Otherwise, the message is replicated with decreasing probability. Moreover, SeeR works based solely upon local observations. In particular, a node does not track information about other nodes, and, therefore, reduces the risk of privacy leaks unlike many other protocols. We evaluated the…
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Text Highlighting in Latex

While preparing a manuscript with Latex, it is often useful to highlight the changes made in the current revision with a different color. This can be achieved using the\textcolor command provided by Latex. For example,\textcolor{red}{Hello World}would display the string "Hello World" in red color.

However, the final/published copy of the manuscript does not contain any highlighted text. Therefore, if a large volume of changes were made, it becomes tiresome at the end to find and remove all the individual portions of highlighted text.

This can be circumvented by defining a utility command to switch highlighting on and off as desired. In the following, we define a new Latex command, highlighttext, for this purpose. The command takes only a single argument -- the text that it should highlight.

    \usepackage{color}

% For highlighting changes in this version with red color
    \newcommand{\highlighttext}[1] {\textcolor{red}{#1}}
    % Remove all text highlighting
    % Useful to gener…

Welcome, 2017!

Dear Readers and Followers,

Wish you and your family a very happy and prosperous New Year! May this new year dawns with the promises of a brighter tomorrow. #HNY2017


Happy New Year

A very happy and prosperous new year to you all! Hope you had a great year in 2015, and wish you have a still better one in 2016! May you do excellent research in this year, and may your citations increase manifold :D

Book on Opportunistic Mobile Networks

Opportunistic Mobile Networks: Advances and Applications is our forthcoming book to be published by Springer in 2016. This book is a result of our years of experience in research and development in this domain. #TheOMNBook, if you may say, deals with fundamental challenges in OMNs as well as contemporary research issues. These include, but not limited to, routing, mobility, cooperation, heterogeneity, and emotions. An entire chapter is dedicated to protocol development and testing using the ONE simulator.

#TheOMNBook is shaped in a way to cater both beginning and advanced level readers. Contextual examples are provided to ensure better understanding of related topics. The chapters come with plenty of hands-on exercises. Several illustrations and other visual elements are used to make reading the book a pleasant experience. Whether you are a seasoned researcher looking for novel cross-dimensional ideas or a beginner to this field, give #TheOMNBook a try!

Learn more about our book at ou…

IllegalArgumentException in Simulations

At times, users have reported of runtime exceptions while running a simulation that uses PRoPHET. The error signature looks like the following.

Exception in thread "main" java.lang.IllegalArgumentException: Comparison method violates its general contract! at java.util.TimSort.mergeHi(Unknown Source) at java.util.TimSort.mergeAt(Unknown Source) at java.util.TimSort.mergeCollapse(Unknown Source) at java.util.TimSort.sort(Unknown Source) at java.util.Arrays.sort(Unknown Source) at java.util.ArrayList.sort(Unknown Source) at java.util.Collections.sort(Unknown Source)
It may be noted that the default sorting algorithm has changed since Java 7 — rather than Merge sort, Tim sort is now used by default. However, it seems like it is possible to override the default sorting algorithm in Java using the following argument to the JVM.
-Djava.util.Arrays.useLegacyMergeSort=true
The execution command in the one.sh (or one.bat) file should be updated with the above argument to something like this:

j…

Specifying Source and Destination of Messages

One of the frequently asked questions in the community is how to specify which particular nodes would act as source(s) and destination(s) of the messages created in the ONE simulator. The simulator, in fact, provides a pair of settings (shown below in bold face) aimed for this particular purpose.

Let us consider that there are $n + 1$ nodes in an OMN.  Further, let the nodes with addresses from $x$ to $y$, both inclusive, would create messages. The nodes in the range $w$ to $z$, both inclusive, would be the destinations of those messages, where $0 \le x \le y \le n$, and $0 \le w \le z \le n$. Then, the corresponding simulation scenario can be configured as follows.

## Message creation parameters # How many event generators Events.nrof = 1 # Class of the first event generator Events1.class = MessageEventGenerator # (Following settings are specific for the MessageEventGenerator class) # Creation interval in seconds (one new message every 25 to 35 seconds) Events1.interval = 25,35 # Me…