Routing Stretch Research Articles

An application of Next Generation Concrete Surface texture to an existing concrete pavement

Between 2011 and 2013, the California Department of Transportation (Caltrans) installed New Generation Concrete Surface (NGCS) along a stretch of State Route 113 (SR 113). In the fall of 2013, this pavement was evaluated using the on-board sound intensity (OBSI) testing method. NGCS is a flush ground and grooved surface developed at Purdue University's Herrick Laboratory in 2004. This innovative, low noise grinding texture has minimal positive texture with good microtexture, which was intended to reduce noise levels at low frequencies, and has great macrotexture, which was intended to reduce noise levels at high frequencies. To evaluate the acoustic longevity of the pavement, OBSI testing was again completed in early 2023, and the long-term results are discussed in this paper. Additionally, the acoustic longevity of the NGCS pavement is compared to the long-term OBSI results collected between 2003 and 2010 on a ground concrete surface installed along Mojave SR 58. In 2022, NGCS was applied on a section of the U.S. 101 Freeway in Carpinteria in Southern California. The results of these measurements and the noise reductions achieved are also presented.

Anchor-based void detouring routing protocol in three dimensional IoT networks

In recent years, several applications of Internet of Things (IoT) have been observed in various areas including environmental monitoring, healthcare systems, cognitive smart agriculture, industrial control, smart homes, intelligent transportation systems, and traffic management. For such applications, wireless sensor networks (WSNs) are generally deployed to gather the sensed data from the targeted application field. In order to transfer the sensor node data to the gateway (sink node), novel routing protocols need to be developed, leading to reduced data transmission delay, high data throughput, and improved energy efficiency across the network. In this context, geographical routing protocol has been considered as a promising approach for the path selection in WSNs. This approach is full of scalability and multi-hop routing is performed using local decisions. However, geographical routing protocols suffer from the void node problem (VNP) i.e., a region where active nodes are not available in the direction closer to the destination. Numerous protocols have been designed to get recovery from VNP in 2D networks which cannot be directly applied to 3D networks. The 3D routing includes the networks deployed in the hilly area, high buildings, airborne region, underground, underwater and so forth. On applying the 2D routing protocols on complex 3D topology, the network may face additional problems like packet looping, routing failure, ambiguity, or increased data latency due to longer path. Further, the majority of geographical routing protocols follow the boundary of void which leads to a longer path. In order to address the aforementioned challenges, this paper presents a novel anchor-based void detouring routing (AVDR) protocol where anchor node is treated as a sub-destination which provides the direct smaller path between source and gateway nodes. The proposed method bypasses the void boundaries and directly connects source to anchor, anchor to destination, or two successive anchors. Further, anchor information is distributed to the desired region to reduce the periodic anchor advertisement process. The effectiveness of the proposed method has been tested over both, real field data set and simulated testbed with OMNET++ simulator. The results obtained over real field data set claim that the proposed method takes only 29.09 ms (ms) for transferring the data on an average. However, this value is 32.37 ms, 34.32 ms, 33.61 ms, 37.20 ms, and 38.73 ms, respectively, using A3DR, EDGR, GPSR-3D, BSMH, and RPL methods. Moreover, it is also noted that the proposed method achieves an improvement of 8.2%, 7.54%, 7.66%, 8.49%, and 8.22%, in routing stretch when compared to aforementioned methods, respectively. This improvement with respect to network overhead is 30.25%, 57.45%, 51.05%, 75.56%, and 58.89% using the proposed method.

Performance of DIO Suppression attack in RPL based IoT networks

Wireless sensor networks are very important in many uses, but they can be attacked, which can make the network less secure and less effective. The Routing Protocol for Low-Power and Lossy “Networks (RPL) is the target of the DIO silencing attack. The goal of this study is to figure out how the DIO suppression attack affects RPL and how well the NLBGNDO algorithm stops the attack. To reach this goal, an accurate model of the RPL protocol and the DIO silence attack are built into a modelling code. The modelling code includes the NLBGNDO routing algorithm, which is a suggested safe and effective routing method for RPL. Key measures, like the number of packets delivered, the length of the path, and the amount of power used, are recorded and analysed both when the network is working normally and when it is under attack. The results of the study show how vulnerable RPL is to the DIO suppression attack and how well the NLBGNDO algorithm works to protect against its effects. The packet delivery ratio shows how the attack affects the network's ability to send data, and the route stretch measure shows how well the routing method works when under attack.

Modelling Approach to Develop a Multimodal Transportation Network

Multimodal transportation (MMT) refers to a system that utilizes various means of transportation to transfer people & goods from one place to another. Transit operations are measured as the maximum number of passengers that can be carried past a fixed route, in a given period. Investing in and using multiple modes of transportation does not only bring efficiencies but also goes a long way to reduce time & delay, as well as the overall cost of transportation. This paper presents the efficient mode of transportation system at selected routes in the Bengaluru city, the route stretch selected is 12.2 km in length and it has 8 major intersections. The type of pavement surface consists of both bituminous and Reinforced cement concrete (R.C.C). The complete study stretch is a 2-way 4-lane road. This study provides walkability-index, traffic volume studies in terms of passenger car unit (PCU), time and delay study, and Cost & time analysis. Four modes of transportation are used in this study to find the effective multimodal-transportation system namely, 2-wheeler, 4-wheeler, para-transit [15], and buses/metro. The outcome of this paper is to arrive at the shortest distance for reducing delay & time, and cost-effective travel using multi-mode transport. While focusing on the present condition of the para-transit transport facilities. The time, delay & cost during MMT and to provide a safe, cost-effective & convenient way to travel or transport. The result shows the reduction in time, cost & delay of transportation by using the MMT model. This MMT system could be adopted as an efficient mode of transportation on this route. Similar rural-urban junction routes around the world could use this approach for effective transit by making a modal study.

A Novel Data Placement and Retrieval Service for Cooperative Edge Clouds

Mobile edge computing is a new paradigm in which the computing and storage resources are placed at the edge of the Internet. Data placement and retrieval are fundamental services of mobile edge computing when a network of edge clouds collaboratively provide data services. However existing methods such as distributed hash tables (DHTs) are not enough to achieve efficient data placement and retrieval services for cooperative edge clouds. This paper presents GRED, a novel data placement and retrieval service for mobile edge computing, which is efficient in not only the load balance but also routing path lengths and forwarding table sizes. GRED utilizes the programmable switches to support a virtual-space based DHT with only one overlay hop. Data location can be easily implemented on top of the GRED. We implement GRED in a P4 prototype, which provides a simple and efficient solution. Results from theoretical analysis, simulations, and experiments show that GRED can efficiently balance the load of edge clouds, and can fast answer data queries due to its low routing stretch.

3D geographical routing protocols in wireless ad hoc and sensor networks: an overview

Geographical routing is a prominent area of research in wireless networks where route establishment is based on known locations of wireless nodes. The location may be an exact physical location or virtual location. Many geographical routing protocols based on greedy and face routing approach have been designed for 2D networks, but these protocols may not be suitable in 3D environment like hill area, airborne networks, underground networks, underwater networks and so forth. The objective of this paper is to provide the research issues and challenges of geographical routing in the three-dimensional surface. These routing techniques suffer from many problems like energy efficiency, localization, mobility, load balancing, routing stretch, void node problems, etc. These issues have been addressed in the literature survey. In this paper, the recent research papers related to geographical routing have been discussed, but the main focus is on 3D geographic routing techniques, issues and challenges.

An energy efficient and load balanced distributed routing scheme for wireless sensor networks with holes

Abstract In this paper we present a new approach to route packets in the presence of routing holes. In our proposal, nodes cooperate to determine the approximate polygon of a specific hole and then exchange information about the approximate polygon. Based on the hole covering parallelogram and the hole view angle of a specific node, packets can be forwarded along an escape route that bends around the hole. We rigorously prove that the Euclidean stretch of an escape route is bounded. Simulation results show that the proposed scheme can save more than 16% of the energy consumption and 7% of the network lifetime in the comparison with existing routing algorithms. The average length of routing paths in our approach is less than 60% of other routing schemes.

On Hierarchical Routing in Doubling Metrics

We study the problem of routing in doubling metrics and show how to perform hierarchical routing in such metrics with small stretch and compact routing tables (i.e., with a small amount of routing information stored at each vertex). We say that a metric ( X , d ) has doubling dimension dim(<i<X</i<) at most α if every ball can be covered by 2 α balls of half its radius. (A doubling metric is one whose doubling dimension dim(<i<X</i<) is a constant.) We consider the metric space induced by the shortest-path distance in an underlying undirected graph G . We show how to perform (1 + τ)-stretch routing on such a metric for any 0 < τ ≤ 1 with routing tables of size at most (α/τ) O (α) log Δlog δ bits with only (α/τ) O (α) log Δ entries , where Δ is the diameter of the graph, and δ is the maximum degree of the graph G ; hence, the number of routing table entries is just τ − O (1) log Δ for doubling metrics. These results extend and improve on those of Talwar (2004). We also give better constructions of sparse spanners for doubling metrics than those obtained from the routing tables earlier; for τ > 0, we give algorithms to construct (1 + τ)-stretch spanners for a metric ( X , d ) with maximum degree at most (2 + 1/τ) O(dim(X)) , matching the results of Das et al. for Euclidean metrics.

SLICE: Enabling Greedy Routing in High Genus 3-D WSNs With General Topologies

In this paper, we propose a highly efficient scheme, SLICE (a scalable and low stretch routing scheme), enabling greedy routing for wireless sensor networks (WSNs) deployed in complex-connected 3-D settings, whose topologies are often theoretically modeled as high genus 3-D WSNs. Compared to previous 3-D greedy embedding techniques, SLICE improves both the robustness and applicability. 1) It achieves a smaller distance distortion and a lower routing stretch with guaranteed delivery. While it follows the basic idea to embed the surface network to a planar topology to enable greedy routing, the embedding method proposed in SLICE is novel. We first slice the surface network to a genus-0 open surface with exactly one boundary. Then, to achieve a lower distance distortion, we purposely propose a variation of the Ricci flow algorithm, by which this open surface is flattened not to a planar annulus, but to a planar convex polygon, resulting in a lower routing stretch. 2) This is the first work, to the best of our knowledge, that enables greedy routing in high genus 3-D WSNs with general topologies. SLICE not only works for high genus 3-D surface WSNs, but also can be easily adapted to more general cases: high genus 3-D surface networks with holes, and high genus 3-D volume networks. For a high genus 3-D surface network with holes, SLICE embeds it to a planar convex polygon with circular holes, where our proposed greedy routing variation can be applied. For a high genus 3-D volume network, SLICE embeds the inner nodes to a height structure attached to the convex polygon, and a variation of greedy routing scheme with guaranteed delivery is proposed in this structure. The effectiveness of SLICE is validated by extensive simulations.

Moving to Map and Mapping to Move: The East Africa Colonial Itineraries of the IGMI Archives and Library as a Special Genre in Cartography

Colonial Itineraries represent an informative product that has its origins in the innovative military organization of Revolutionary and Napoleonic France. Italian Colonial Itineraries were the outcome of exploration and intelligence activities carried out by selected military units in unknown lands. The knowledge of the places was an essential precondition of conquest and its stabilization. The major feature of the itineraries is the juxtaposition of a reconnaissance map to a list of detailed information concerning every short stretch of route covered: running times, road conditions, climate, landforms, land-use, water resources, culture, economy, monuments, etc. The Archives and the Library of the IGMI (Istituto Geografico Militare Italiano), set in Florence, preserve a great deal of such documents and they are probably the richest Italian stock. Itineraries represent a valuable source of geographical knowledge about Ethiopia and Eritrea during the period between the late nineteeth and the thirties of the twentieth century. These pages are the result of an attempt at census and interpretation.

A self-organized backpressure routing scheme for dynamic small cell deployments

The increase of demand for mobile data services requires a massive network densification. A cost-effective solution to this problem is to reduce cell size by deploying a low-cost all-wireless Network of Small Cells (NoS). These hyper-dense deployments create a wireless mesh backhaul among Small Cells (SCs) to transport control and data plane traffic. The semi-planned nature of SCs can often lead to dynamic wireless mesh backhaul topologies.This paper presents a self-organized backpressure routing scheme for dynamic SC deployments (BS) that combines queue backlog and geographic information to route traffic in dynamic NoS deployments. BS aims at relieving network congestion, while having a low routing stretch (i.e., the ratio of the hop count of the selected paths to that of the shortest path). Evaluation results show that, under uncongested conditions, BS shows similar performance to that of an Idealized Shortest PAth routing protocol (ISPA), while outperforming Greedy Perimeter Stateless Routing (GPSR), a state of the art geographic routing scheme. Under more severe traffic conditions, BS outperforms both GPSR and ISPA in terms of average latency by up to a 85% and 70%, respectively. We conducted ns-3 simulations in a wide range of sparse NoS deployments and workloads to support these performance claims.

THE GROWTH IN ENERGY ACTIVITIES IN THE SOUTH CHINA SEA – ARE WE TRULY PREPARED?

ABSTRACT Stretching from Singapore and the Strait of Malacca chokepoint in the southwest to the Strait of Taiwan in the northeast, the South China Sea is one of the most important energy trade routes in the world. Almost a third of global crude oil and over half of global liquefied natural gas (LNG) passes through the South China Sea each year. Coupled with the significant economy growth from China, that is the world's largest oil importer, protecting the flow of oil becomes a prime consideration of the South East and East Asia governments. All of these factors make the South China Sea to hold one of the highest potential for oil spill, be it by quantity of oil or frequency of energy activities. In the region, our industry faces increasing political challenge due to the disputed territorial waters and hence if an incident affecting multiple countries such as an oil spill occurs, the response may be chaotic if not adequately prepared for. The duty is on industry to work with regional governmental groups to promote joined-up response that is sufficiently robust and flexible to deal with both marine and well-control incidents. Other factors that could pose a major challenge are the understanding of response tool kits and prioritization given to national environmental laws and regulations which will vary amongst the affected administrations. Has there been sufficient investigation into the range of national laws which could help/hinder inter-regional approach? What about each of the area contingency plan along the South China Sea? Is there sufficient data on the crude oil characteristics in this region and the availability of Stockpile of equipment along this stretch of the trade route? This paper provides an overview of the oil industry's response to the growing energy activities in the South China Sea using case studies to illustrate the situations that are still occurring in practice.

Building on Shaky Ground

The southern 1 mi stretch of Route 99 in Seattle has been rebuilt as two adjacent viaducts that cross active rail lines, roadways, and utilities. But what challenged the design team most wasn’t the built environment but the extreme seismic vulnerability of the site.

Distributed and compact routing using spatial distributions in wireless sensor networks

In traditional routing, the routing tables store shortest paths to all other destinations and have size linear in the size of the network, which is not scalable for resource-constrained networks such as wireless sensor networks. In this article we show that by storing selectively a much smaller set of routing paths in the routing tables one can get low-stretch, compact routing schemes. Our routing scheme includes an approximate distance oracle with which one can obtain approximate shortest path length estimates to destinations. This distance oracle can be obtained, for example, by a landmark-based scheme, or in case of sensor networks, from the geographic distance between node locations. With an approximate distance oracle one can attempt greedy routing by forwarding to the neighbor whose estimate is closer to the destination. But there is no guarantee of delivery nor of the routing path length. We augment the distance oracle by storing, for each node u , routing paths to O (log 2 n ) strategically selected nodes that serve as intermediate destinations. These nodes are selected with probability proportional to 1/ r ρ , where r is the distance to u and ρ is a suitable constant for the network. Then we derive a set of sufficient conditions to select the next step at each stage of routing, such that these conditions can be verified locally and guarantee 1+ε stretch routing on any metric. These conditions serve as the “greedy routing” or local decision rule. On graphs of bounded growth, our scheme guarantees 1+ε stretch routing with high probability, with an average routing table size of O (√n log 2 n ). This scheme is favorable for its simplicity, generality, and blindness to any global state. It demonstrates that global routing properties could emerge from purely distributed and uncoordinated routing table design.

Geographic Routing in $d$-Dimensional Spaces With Guaranteed Delivery and Low Stretch

Almost all geographic routing protocols have been designed for 2-D. We present a novel geographic routing protocol, named Multihop Delaunay Triangulation (MDT), for 2-D, 3-D, and higher dimensions with these properties: 1) guaranteed delivery for any connected graph of nodes and physical links, and 2) low routing stretch from efficient forwarding of packets out of local minima. The guaranteed delivery 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 for routing. We present the performance of MDT protocols in 3-D and 4-D as well as performance comparisons of MDT routing versus representative geographic routing protocols for nodes in 2-D and 3-D. Experimental results show that MDT provides the lowest routing stretch in the comparisons. Furthermore, MDT protocols are specially designed to handle churn, i.e., dynamic topology changes due to addition and deletion of nodes and links. Experimental results show that MDT's routing success rate is close to 100% during churn, and node states converge quickly to a correct MDT after churn.

A case for hierarchical routing in low-power wireless embedded networks

Hierarchical routing has often been mentioned as an appealing point-to-point routing technique for wireless sensor networks (sensornets). While there is a volume of analytical and high-level simulation results demonstrating its merits, there has been little work evaluating it in actual sensornet settings. This article bridges the gap between theory and practice. Having analyzed a number of proposed hierarchical routing protocols, we have developed a framework that captures the common characteristics of the protocols and identifies design points at which the protocols differ. We use a sensornet implementation of the framework in TOSSIM and on a 60-node testbed to study various trade-offs that hierarchical routing introduces, as well as to compare the performance of hierarchical routing with the performance of other routing techniques, namely shortest-path routing, compact routing, and beacon vector routing. The results show that hierarchical routing is a compelling routing technique also in practice. In particular, despite only logarithmic routing state, it can offer small routing stretch: an average of ∼ 1.25 and a 99th percentile of 2. It can also be robust, minimizing the maintenance traffic or the latency of reacting to changes in the network. Moreover, the trade-offs offered by hierarchical routing are attractive for many sensornet applications when compared to the other routing techniques. For example, in terms of routing state, hierarchical routing can offer scalability at least an order of magnitude better than compact routing, and at the same time, in terms of routing stretch, its performance is within 10--15% of that of compact routing; in addition, this performance can further be tuned to a particular application. Finally, we also identify a number of practical issues and limitations of which we believe sensornet developers adopting hierarchical routing should be aware.

Greedy Geographic Routing in Large-Scale Sensor Networks: A Minimum Network Decomposition Approach

In geographic (or geometric) routing, messages are by default routed in a greedy manner: The current node always forwards a message to its neighbor node that is closest to the destination. Despite its simplicity and general efficiency, this strategy alone does not guarantee delivery due to the existence of local minima (or dead ends). Overcoming local minima requires nodes to maintain extra nonlocal state or to use auxiliary mechanisms. We study how to facilitate greedy forwarding by using a minimum amount of such nonlocal states in topologically complex networks. Specifically, we investigate the problem of decomposing a given network into a minimum number of greedily routable components (GRCs), where greedy routing is guaranteed to work. We approach it by considering an approximate version of the problem in a continuous domain, with a central concept called the greedily routable region (GRR). A full characterization of GRR is given concerning its geometric properties and routing capability. We then develop simple approximate algorithms for the problem. These results lead to a practical routing protocol that has a routing stretch below 7 in a continuous domain, and close to 1 in several realistic network settings.

Using novel distributed heuristics on hexagonal connected dominating sets to model routing dissemination

Network-centric Future Force must support a large and diverse group of communication nodes. Despite the fact that there is ample scope for network design in networks such as Future Combat Systems (FCS) and Warfighter Information Network-Tactical (WIN-T), there are important performance limits when network conditions become more extreme (highly mobile or dense). In previous work, we modeled and analyzed the expected user performance of a number of novel approaches to flooding link state routing information in wireless ad hoc networks for routing update. We compared routing dissemination schemes such as this of Flat Flooding and Multi-Point Relays (MPRs), with our own variations on Connected Dominating Sets (CDSs), assuming other parts of the routing protocol were taken from standard Link State Routing protocol (OLSR) or Open Shortest Path First protocol (OSPF), widely used in the Internet and WIN-T. Although the existing literature provides a variety of models for Flat Flooding and MPRs, it lacks similar analytical work for relays placement under a CDS approach. Towards the latter, we selected one representative from our novel CDS-based models--the CDS Hexagon, as it provides the lowest routing overhead among other properties. Our analysis demonstrates the difference in the impact of conditions on key performance metrics, such as this of network density on routing overhead as well as a tradeoff between routing overhead and routing stretch. We then advance CDS-HEX dissemination from the limited-scope centralized scenarios with strictly symmetrical relay placement to dynamic scenarios with totally random relay placement. We use novel heuristics to adapt the analytical CDS-HEX to dynamic environments. We show that: (a) although the distributed scheme naturally operates sub-optimally compared to its centralized ancestor, it is still superior to MPRs over certain metrics of interest, (b) the set-up overhead of CDS-HEX is not significantly higher than this of MPRs, while at the same time, the steady state overhead of CDS-HEX appears adequately lower than this of MPR, and (c) all the closed analytical formulae and asymptotic results derived in our previous analysis are verified by our simulations which also provide additional insight on metrics that cannot be analytically measured. Our scheme on one hand is not overly expensive to set up despite the more complex generation process, and on the other hand has a superior performance for the majority of network conditions, and close to the optimal one anticipated by the corresponding centralized model.

S4: Small State and Small Stretch Compact Routing Protocol for Large Static Wireless Networks

Routing protocols for large wireless networks must address the challenges of reliable packet delivery at increasingly large scales and with highly limited resources. Attempts to reduce routing state can result in undesirable worst-case routing performance, as measured by stretch, which is the ratio of the hop count of the selected path to that of the optimal path. We present a new routing protocol, Small State and Small Stretch (S4), which jointly minimizes the state and stretch. S4 uses a combination of beacon distance-vector-based global routing state and scoped distance-vector-based local routing state to achieve a worst-case stretch of 3 using <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> (√( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N)</i> ) routing state per node in an <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> -node network. Its average routing stretch is close to 1. S4 further incorporates local failure recovery to achieve resilience to dynamic topology changes. We use multiple simulation environments to assess performance claims at scale and use experiments in a 42-node wireless sensor network testbed to evaluate performance under realistic RF and failure dynamics. The results show that S4 achieves scalability, efficiency, and resilience in a wide range of scenarios.

Impact of routing parameters on route diversity and path inflation

Years after the initial development of the current routing protocols we still lack an understanding of the impact of various parameters on the routes chosen in today’s Internet. Network operators are struggling to optimize their routing, but the effectiveness of those efforts is limited. In this article, we study sensitivity of routing stretch and diversity metrics to factors such as policies, topology, IGP weights, etc. using statistical techniques. We confirm previous findings that routing policies and AS size (in number of routers) are the dominating factors. Surprisingly, we find that intra-domain factors only have marginal impact on global path properties. Moreover, we study path inflation by comparing against the paths that are shortest in terms of AS-level/router-level hops or geographic distances. Overall, the majority of routes incur reasonable stretch. From the experience with our Internet-scale simulations, we find it hard to globally optimize path selection with respect to the geographic length of the routes, as long as inter-domain routing protocols do not include an explicit notion of geographic distance in the routing information.