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15
Protocol design for dynamic Delaunay triangulation
, 2006
"... Delaunay triangulation (DT) is a useful geometric structure for networking applications. In this paper we investigate the design of join, leave, and maintenance protocols to construct and maintain a distributed DT dynamically. We define a distributed DT and present a necessary and sufficient conditi ..."
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Cited by 17 (9 self)
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Delaunay triangulation (DT) is a useful geometric structure for networking applications. In this paper we investigate the design of join, leave, and maintenance protocols to construct and maintain a distributed DT dynamically. We define a distributed DT and present a necessary and sufficient condition for a distributed DT to be correct. This condition is used as a guide for protocol design. We present join and leave protocols as well as correctness proofs for serial joins and leaves. In addition, to handle concurrent joins and leaves as well as node failures, we present a maintenance protocol. An accuracy metric is defined for a distributed DT. Experimental results show that our join, leave and maintenance protocols are scalable, and they achieve high accuracy for systems under churn and with node failures. We also present application protocols for greedy routing, clustering, broadcast, and multicast within a radius, and discuss and prove their correctness.
Geographic Routing in ddimensional Spaces with Guaranteed Delivery and Low Stretch ∗
, 2010
"... Almost all geographic routing protocols have been designed for 2D. We present a novel geographic routing protocol, MDT, for 2D, 3D, and higher dimensions with these properties: (i) guaranteed delivery for any connected graph of nodes and physical links, and (ii) low routing stretch from efficient fo ..."
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Cited by 16 (8 self)
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Almost all geographic routing protocols have been designed for 2D. We present a novel geographic routing protocol, MDT, for 2D, 3D, and higher dimensions with these properties: (i) guaranteed delivery for any connected graph of nodes and physical links, and (ii) low routing stretch from efficient forwarding of packets at local minima. MDT is the first geographic routing protocol that provides guaranteed delivery in 3D as well as 2D. (This property holds for node locations specified by accurate, inaccurate, or arbitrary coordinates.) The MDT protocol suite includes a packet forwarding protocol together with protocols for nodes to construct and maintain a distributed MDT graph for routing. We present performance comparisons of MDT and several geographic (and one nongeographic) routing protocols for nodes in 3D and 2D. Experimental results show that MDT provides the lowest routing stretch. MDT includes protocols for nodes to handle churn, i.e., dynamic topology changes due to addition and deletion of nodes and links. Experimental results show that the routing success rate of MDT is close to 100 % during churn and node states converge to a correct MDT graph after churn. 1.
Greedy Distance Vector Routing
, 2010
"... Abstract—Greedy Distance Vector (GDV) is the first geographic routing protocol designed to optimize endtoend path costs using any additive routing metric, such as: hop count, latency, ETX, ETT, etc. GDV requires no node location information. Instead, GDV uses estimated routing costs to destination ..."
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Cited by 14 (9 self)
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Abstract—Greedy Distance Vector (GDV) is the first geographic routing protocol designed to optimize endtoend path costs using any additive routing metric, such as: hop count, latency, ETX, ETT, etc. GDV requires no node location information. Instead, GDV uses estimated routing costs to destinations which are locally computed from node positions in a virtual space. GDV makes use of VPoD, a new virtual positioning protocol for wireless networks. Prior virtual positioning systems (e.g., Vivaldi and GNP) were designed for Internet hosts and require that each host measures latencies (routing costs) to distant hosts or landmarks. VPoD does not have this requirement and uses only routing costs between directly connected nodes. Experimental results show that the routing performance of GDV is better than prior geographic routing protocols when hop count is used as metric and much better when ETX is used as metric. As a geographic protocol, the storage cost of GDV per node remains low as network size increases. GDV provides guaranteed delivery for nodes placed in 2D, 3D, and higher dimensions. We also show that GDV and VPoD are highly resilient to dynamic topology changes. I.
A Delaunay triangulation architecture supporting churn and user mobility in MMVEs
 IN PROC. NOSSDAV
, 2009
"... This article proposes a new distributed architecture for update message exchange in massively multiuser virtual environments (MMVE). MMVE applications require delivery of updates among various locations in the virtual environment. The proposed architecture here exploits the location addressing of g ..."
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Cited by 6 (2 self)
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This article proposes a new distributed architecture for update message exchange in massively multiuser virtual environments (MMVE). MMVE applications require delivery of updates among various locations in the virtual environment. The proposed architecture here exploits the location addressing of geometrical routing in order to alleviate the need for IPspecific queries. However, the use of geometrical routing requires careful choice of overlay to achieve high performance in terms of minimizing the delay. At the same time, the MMVE is dynamic, in sense that users are constantly moving in the 3D virtual space. As such, our architecture uses a distributed topology control scheme that aims at maintaining the requires QoS to best support the greedy geometrical routing, despite user mobility or churn. We will further prove the functionality and performance of the proposed scheme through both theory and simulations.
P2P Network for Storage and Query of a SpatioTemporal Flow of Events
"... We develop a novel approach to store and query realtime (contextual) information from/to a population of wireless/wired devices generating a stream of spatiotemporal events corresponding to sensors/applications and/or humans. The approach is based on a novel peertopeer overlay network architectur ..."
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Cited by 5 (1 self)
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We develop a novel approach to store and query realtime (contextual) information from/to a population of wireless/wired devices generating a stream of spatiotemporal events corresponding to sensors/applications and/or humans. The approach is based on a novel peertopeer overlay network architecture which exploits the spatial relevance of events and the locality of queries to store and query events close to where they are likely to be consumed. This paper focuses on the development of the basic protocols necessary to operate such a system. We propose a simple model for such systems and explore the sensitivity of performance (query delay) to node density and overlay connectivity. I.
M.: Aoicast by compass routing in delaunay based dve overlays
 In: High Performance Computing and Simulation (HPCS), 2011 International Conference on, IEEE (2011) 135–142
"... This paper presents a AOI cast strategy for P2P Distributed Environments which is exploited to notify the position updates of a peer P, i.e. its heartbeats, to all the peers located in its Area of Interest. An algorithm for the construction of a spanning tree covering all the peers is presented. Th ..."
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Cited by 5 (5 self)
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This paper presents a AOI cast strategy for P2P Distributed Environments which is exploited to notify the position updates of a peer P, i.e. its heartbeats, to all the peers located in its Area of Interest. An algorithm for the construction of a spanning tree covering all the peers is presented. The algorithm exploits the properties of Delaunay Triangulations to reduce the traffic load on the P2P overlay. The paper presents a set of formal results which hold when the AOI is a circular area and the root of the tree is at the center of the area. The algorithm is then refined to take into account possible inconsistencies among the local views of the peers due to the latency of the underlying network. A set of experimental results are presented.
InNetwork Analytics for Ubiquitous Sensing ∗
"... Abstract. We address the problem of innetwork analytics for data that is generated by sensors at the edge of the network. Specifically, we consider the problem of summarizing a continuous physical phenomenon, such as temperature or pollution, over a geographic region like a road network. Samples ar ..."
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Abstract. We address the problem of innetwork analytics for data that is generated by sensors at the edge of the network. Specifically, we consider the problem of summarizing a continuous physical phenomenon, such as temperature or pollution, over a geographic region like a road network. Samples are collected by sensors placed alongside roads as well as in cars driving along them. We divide the region into sectors and find a summary for each sector, so that their union is a continuous function that minimizes some global error function. We designate a node (either virtual or physical) that is responsible for estimating the function in each sector. Each node computes its estimate based on the samples taken in its sector and information from adjacent nodes. The algorithm works in networks with bounded, yet unknown, latencies. It accommodates the addition and removal of samples and the arrival and departure of nodes, and it converges to a globally optimal solution using only pairwise message exchanges between neighbors. The algorithm relies on a weaklyfair scheduler to implement these pairwise exchanges, and we present an implementation of such a scheduler. Our scheduler, which may be of independent interest, is locally quiescent, meaning that it only sends messages when required by the algorithm. It achieves quiescence on every link where the algorithm ceases to schedule pairwise exchanges; in particular, if the algorithm converges, it globally quiesces. 1
GoDel: Delaunay Overlays in P2P Networks via Gossip
, 2012
"... P2P overlays based on Delaunay triangulations have been recently exploited to implement systems providing efficient routing and data broadcast solutions. Several applications such as Distributed Virtual Environments and geographical nearest neighbours selection benefit from this approach. This pape ..."
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Cited by 1 (0 self)
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P2P overlays based on Delaunay triangulations have been recently exploited to implement systems providing efficient routing and data broadcast solutions. Several applications such as Distributed Virtual Environments and geographical nearest neighbours selection benefit from this approach. This paper presents a novel distributed algorithm for the incremental construction of a Delaunay overlay in a P2P network. The algorithm employs a distributed version of the classical Edge Flipping procedure. Each peer builds the Delaunay links incrementally by exploiting a random peer sample returned by the underlying gossip level. The algorithm is then optimized by considering the Euclidean distance between peers to speed up the overlay convergence. We present theoretical results that prove the correctness of our approach along with a set of experiments that assess the convergence rate of the distributed algorithm.
Global Estimation with Local Communication ∗
"... We present a distributed optimization algorithm for estimating a continuous function such as temperature or pollution over a geographic region, e.g., a road network. The estimate is generated from samples taken by sensors placed alongside roads or in cars driving along them. We employ piecewise esti ..."
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We present a distributed optimization algorithm for estimating a continuous function such as temperature or pollution over a geographic region, e.g., a road network. The estimate is generated from samples taken by sensors placed alongside roads or in cars driving along them. We employ piecewise estimation, that is, we divide the region into sectors and find an estimate for each sector, e.g., a polynomial or a line, so that their union is a continuous function that minimizes some global error function. The computation is distributed by designating a node (either virtual or physical) that is responsible for estimating the function in each sector. The estimate is then computed based on the samples taken in the sector and information from adjacent nodes. The algorithm works in networks with bounded, yet unknown, latencies. It accommodates dynamic inputs (samples) and node arrivals and departures. Our algorithm converges to the global optimum with only local communication, using a novel, distributed implementation of coordinate ascent optimization. 1
AOIcast in distributed virtual environments: An approach based on delay tolerant reverse compass routing,’’ inConcurrency and Computation: Practice and Experience
, 2012
"... This paper presents a novel AOIcast algorithm for Distributed Virtual Environments targeted to Delaunaybased P2P overlays. The algorithm exploits the mathematical properties of the Delaunay Triangulations to build a spanning tree supporting the notification of the events generated by a peer to the ..."
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This paper presents a novel AOIcast algorithm for Distributed Virtual Environments targeted to Delaunaybased P2P overlays. The algorithm exploits the mathematical properties of the Delaunay Triangulations to build a spanning tree supporting the notification of the events generated by a peer to the other ones located in its Area of Interest (AOI). The spanning tree is computed by reversing compass routing, a routing algorithm proposed for geometric networks. Our approach presents a set of novel features. First of all, it requires only the knowledge of the neighbours of a peer, so that the amount of traffic load on the P2P overlay is minimized. Furthermore, we prove that, for circular shaped AOI, the algorithm builds a spanning tree covering all and only the peers of the AOI. Finally, our approach takes into account the possible inconsistencies among the local views of the peers due to the network latency by introducing a tolerance threshold in the reverse compass routing. We present a set of simulations considering both synthetic data and real data traces taken from the HoN multiplayer game which show the effectiveness of our proposal.