Barun Saha's blog on AI and Networks

Given a network (a set of nodes) and a set of traffic flows, a network flow allocation assigns network paths to these flows, so that data (for example, packets) can be sent from the respective source nodes to the corresponding destination nodes. In case of optimal network flow allocation, certain criteria, such as latency and utilization, need to be optimized. Moreover, in case of integral network flow allocation, all packets from a source node to a given destination node must travel via a single path or none at all. In other words, such a flow cannot be “split” across multiple paths. Optimal network flow allocation is a computationally hard problem, which not only requires a long time to solve, but also high level of skills. The problem becomes further challenging when unique business and industrial requirements are considered. In our recent work, we investigated this problem in the context of power grid networks, where the flows often require delay-symmetric upstream and ...

The 1 st ACM International Workshop on Future Industrial Communication Networks  (FICN) will be held in conjunction with ACM MobiCom 2018 at New Delhi, India. The tentative date of the workshop is either 29 October or 02 November, 2018 (to be confirmed very soon) . ACM FICN seeks original, novel, and previously unpublished (and currently not under consideration anywhere else) papers that address the challenges faced by modern industrial networks. Submitted papers will be peer-reviewed by the members of the Technical Program Committee where technical merit, novelty, timeliness, and relevance to the workshop shall be taken into consideration. Topics of interest to ACM FICN include, but are not limited to: Autonomous and intelligent intent-based networks Critical communication network and systems Industry 4.0 communication systems and related standards Green communication and battery-saving systems Large-scale sensor networks and industrial IoT (IIoT) applications...

Conceptual architecture of SeeR 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 m...

Opportunistic Mobile Networks: Advances and Applications is our forthcoming textbook 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...

In this post, we look at how buffer size affects, if at all, the performance of the routing protocols in DTNs. For this purpose, we will consider the following five routing protocols: Epidemic PROPHET Spray-and-Wait (SnW) First Contact (FC) Direct Delivery (DD)  Detailed discussion of these protocols is scoped out here. We just note that in case of Epidemic, there is unlimited replication of the messages. In PROPHET, however, the replication is usually less than that of Epidemic. On the other hand, SnW has a fixed limit ( L ) on possible number of replications of a message. Finally, FC and DD involve message forwarding -- not replication. So, in the latter cases, there is always a single copy of any message in the DTN. We will consider the buffer sizes from 20 MB to 180 MB, both inclusive, in steps of 20 MB so that we have total 9 different buffer sizes. We will use the real-life connection traces from Infocom'06. Therefore, we will need to simulate 5 * 9 = 45 scenarios...

A new post on parametrized simulations with the ONE in batch mode is available now: http://delay-tolerant-networks.blogspot.com/p/parametrized-simulations.html This explains how to run multiple scenarios in batch mode considering different parameters.

Today, we will play around a bit with the ONE simulator, specifically with the Epidemic routing protocol. We will simulate two scenarios and look at the results. Detailed analysis of the results are left out for the time being. Parameters Here are few common parameters for the simulations. Group.movementModel = RandomWaypoint Group.msgTtl = 300 (5 hours) MovementModel.worldSize = 450, 340 Scenario.endTime = 14400 (4 hours) Stats are collected from MessageStatsReport from a single run.

A key difference that can be observed between Internet and DTN routing is that Internet routing is based on packet forwarding. Whereas in DTN, routing mostly involves message replication. A node in DTN, which wants to transfer a message to the other node in contact, creates a copy of that message and forwards that * copy * to the other node. This process is repeated at every (or limited # of) node(s) until the message reach its destination. In Internet it is only the sender who buffers the message until an acknowledgement is received from the other end of the connection. Epidemic and Spray-and-Wait are two popular DTN routing protocols using such principle. Epidemic protocol replicates the message at every node it comes in contact with. Spray-and-Wait imposes certain limit on the # of replications to be done.