LINK CONVERGENCE IMPROVEMENT IN RADIO-AWARE ROUTING

Techniques are described herein to reduce link flapping scenarios in existing Radio-Aware Routing (RAR) technology, on both the server side and the client side. Existing techniques provide no mechanism to prioritize vendor-based or reliable/preferred clients. In particular, Open Shortest Path First (OSPF) protocol and/or Enhanced Interior Gateway Routing Protocol (EIGRP) often initiate a call based on link quality and other metrics at that moment in time, which may lead to constant link/session flapping. This is due to the limited set of link characteristics relied upon by existing techniques for computing session establishment to a Dynamic Link Exchange Routing (DLEP) client. The techniques described herein introduce added parameters for better convergence to enable prioritization of reliable clients, thereby enhancing existing RAR protocols (e.g., DLEP). Thus, latency and performance with wireless clients may be enhanced in the industrial Internet of Things (IoT) routing space

Performance evaluation of Wireless Mesh Network routing protocol for smart grid networks

Recent Advances in Wireless Mesh Networks (WMN) makes it one of the candidate communication technologies for Smart Grid Automatic Metering Infrastructure (AMI) because of its scalability and low cost of deployment. However, its capacity and multi-hoping performance in dynamic environment may not guarantee resilience and packet delivery reliability requirements of AMI. Theoretical and practical studies have shown that the multi-hoping capacity of a mesh network is constrained by increase in the number of nodes and number of hops in the network. In addition traffic requirements for smart meters will further compound WMN multi-hopping issues. In this paper, the performance of WMN when deployed for AMI is carried out using two wireless routing protocols; Hybrid Wireless Mesh Protocol (HWMP) and Optimised Link State Rout protocol (OLSR) in NS-3. Simulation results show that compared to the reliability requirement of AMI, there is need for improving the routing metric for both protocols. Furthermore, The Dynamic Link Exchange Protocol (DLEP) which allows layer 2 link estimation was proposed to enhance the route decision

A testbed based performance evaluation of smart grid wireless neighborhood area networks routing protocols

Smart Grid networks have a data communication network associated with the electrical energy distribution infrastructure. This network connects all the sub- scribers’ homes with the data control centers of the supplying companies, which in turn have access to the global Internet network. They are in charge of transporting the needed information between the elements that comprise the electricity network and the control centers. A part of these networks is the so-called Neighborhood Area Networks (NANs), which transports the data from the subscriber’s home to some data concentrators. This article presents a comparison of the performance of different routing protocols that can be used in this part of the data network, when a wireless technology is selected. For this comparison, a hardware testbed has been implemented, with a simple initial configuration, which allows the comparison of the OLSR v1, OLSR v2 and HWMP protocols. The numerical results are presented in terms of network throughput, protocol overhead, number of retransmissions, net- work transit and packet transfer times.This work was supported by the Spanish Research Council under project MAGOS (TEC2017-84197-C4-3-R), and Juan Pablo Astudillo León is the recipient of a full scholarship from the Secretaría de Educación Superior, Ciencia, Tecnología e Innovación (SENESCYT), Ecuador.Peer ReviewedPostprint (published version

Self-stabilizing leader election in dynamic networks

The leader election problem is one of the fundamental problems in distributed computing. It has applications in almost every domain. In dynamic networks, topology is expected to change frequently. An algorithm A is self-stabilizing if, starting from a completely arbitrary configuration, the network will eventually reach a legitimate configuration. Note that any self-stabilizing algorithm for the leader election problem is also an algorithm for the dynamic leader election problem, since when the topology of the network changes, we can consider that the algorithm is starting over again from an arbitrary state. There are a number of such algorithms in the literature which require large memory in each process, or which take O(n) time to converge, where n is size of the network. Given the need to conserve time, and possibly space, these algorithms may not be practical for the dynamic leader election problem. In this thesis, three silent self-stabilizing asynchronous distributed algorithms are given for the leader election problem in a dynamic network with unique IDs, using the composite model of computation. If topological changes to the network pause, a leader is elected for each component. A BFS tree is also constructed in each component, rooted at the leader. When another topological change occurs, leaders are then elected for the new components. This election takes O (Diam) rounds, where Diam is the maximum diameter of any component. The three algorithms differ in their leadership stability. The first algorithm, which is the fastest in the worst case, chooses an arbitrary process as the leader. The second algorithm chooses the process of highest priority in each component, where priority can be defined in a variety of ways. The third algorithm has the strictest leadership stability; if a component contains processes that were leaders before the topological change, one of those must be elected to be the new leader. Formal algorithms and their correctness proofs will be given

Advances in wireless community networks with the community-lab testbed

Beyond traditional telecom providers, citizens and organizations pool their own resources and coordinate in order to build local network infrastructures to address the digital divide in many parts of the world. These crowdsourced network infrastructures can be self-organized and shared by a community for the collective benefit of its members. Several of these networks have developed open, free, and neutral agreements, and are governed as a common-pool resource: community networks. These are built using a variety of commodity wireless hardware (e.g., Wi-Fi long-range point-to-point links, Wi-Fi and GSM access points, and mesh networks), sometimes optical fiber links, heterogeneous nodes, routing protocols, and applications. A group of researchers, developers, and community networks developed the Community-Lab testbed, and for the last five years have worked together to overcome obstacles, improve the technologies, tools, and operational models being used, as well as model best practices for more effective and sustainable community networks. This article presents the challenges for experimentation, the testbeds built, results, lessons learned, and the impact of that work to place wireless community networks as one sustainable way toward an Internet accessible to all.Peer ReviewedPostprint (author's final draft

QoS Provisioning in Converged Satellite and Terrestrial Networks: A Survey of the State-of-the-Art

It has been widely acknowledged that future networks will need to provide significantly more capacity than current ones in order to deal with the increasing traffic demands of the users. Particularly in regions where optical fibers are unlikely to be deployed due to economical constraints, this is a major challenge. One option to address this issue is to complement existing narrow-band terrestrial networks with additional satellite connections. Satellites cover huge areas, and recent developments have considerably increased the available capacity while decreasing the cost. However, geostationary satellite links have significantly different link characteristics than most terrestrial links, mainly due to the higher signal propagation time, which often renders them not suitable for delay intolerant traffic. This paper surveys the current state-of-the-art of satellite and terrestrial network convergence. We mainly focus on scenarios in which satellite networks complement existing terrestrial infrastructures, i.e., parallel satellite and terrestrial links exist, in order to provide high bandwidth connections while ideally achieving a similar end user quality-of-experience as in high bandwidth terrestrial networks. Thus, we identify the technical challenges associated with the convergence of satellite and terrestrial networks and analyze the related work. Based on this, we identify four key functional building blocks, which are essential to distribute traffic optimally between the terrestrial and the satellite networks. These are the traffic requirement identification function, the link characteristics identification function, as well as the traffic engineering function and the execution function. Afterwards, we survey current network architectures with respect to these key functional building blocks and perform a gap analysis, which shows that all analyzed network architectures require adaptations to effectively support converged satellite and terrestrial networks. Hence, we conclude by formulating several open research questions with respect to satellite and terrestrial network convergence.This work was supported by the BATS Research Project through the European Union Seventh Framework Programme under Contract 317533

DIFFERENTIATED RETRANSMISSION IN WIRELESS MESH NETWORKS

Techniques are described herein for enabling diverse retries at a lower layer based on possibilities provided by routing operations. An anycast model is used to indicate a set of next hops and forwarding interfaces that enable indicating raw constraints such as bounded latency to perform a transmission

Adaptive header compression techniques for mobile multimedia networks

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Cognitive Networking With Regards to NASA's Space Communication and Navigation Program

This report describes cognitive networking (CN) and its application to NASA's Space Communication and Networking (SCaN) Program. This report clarifies the terminology and framework of CN and provides some examples of cognitive systems. It then provides a methodology for developing and deploying CN techniques and technologies. Finally, the report attempts to answer specific questions regarding how CN could benefit SCaN. It also describes SCaN's current and target networks and proposes places where cognition could be deployed