Frequent Location Updates Research Articles

5G Network with Hexagonal SDN Control for Highly Secure Multimedia Communication

The 5G communication network is a promising technology that offers user-centric connectivity to customers, enabling quick, high-capacity, and latency-free access to many applications. Software Defined Networking Controller (SDNC) is an emerging technology that is used for increasing the security and maintaining the dynamic nature of mobile devices in latency and energy-assured 5G wireless communication. Different SDN topology open flow controllers are used in the literature for increasing the throughput and security of the network but they possess some drawbacks such as frequent location update (LU) overhead, high latency, and high energy consumption. This paper proposes a hexagonal software defined network (H-SDN) controller to overcome these challenges. The proposed H-SDN topology is used to preserve Intermediate Message Layer (IML) location during multimedia data transmission. A Core Switch (CS) updates an IML's location within clusters of cells, as long as it remains within the cluster. However, in the proposed method, there will be a location update on the server if the IML departs the cluster. Experiment results show that the proposed method can increase security, which in turn increases throughput, while reduces the location update costs, energy consumption, and transmission latency.

Dual Location Area Based Distributed Location Management for Hybrid LEO/MEO Mega Satellite Networks

Location management is the basis for ensuring service continuity in low earth orbit (LEO) satellite mobile communication systems. The dual mobility of LEO satellites and mobile users triggers frequent location update procedures, which will increase the network location management overhead and bring great challenges to network location management, especially in the mega satellite networks. In this paper, we propose a location management technology solution for mega satellite networks, including location management architecture, location area design, location update, and paging procedures. A medium earth orbit (MEO) satellite-assisted location management architecture is proposed to improve the efficiency of location management. It extends the location management control plane from the ground to space and adopts a distributed location management mechanism. A dual location area, including the satellite location area and user location area, is designed to balance the network location update and paging overhead. Based on the dual location area, we systematically design low-overhead location update and paging procedures. Simulation results have verified that the proposed location management technology solution can reduce the total location management overhead and delay by at least 45.8% and 20.8%, respectively.

An Improved Approach for Wireless Sensor Networks With Mobile Sink Using Dynamic Minimum Spanning Tree

In wireless sensor networks (WSNs), finding the best transmission route from each node to the mobile sink is not a simple task because of the dynamic characteristics of sink node and cluster transmission. In order to balance energy consumption and reduce collisions in wireless transmissions, this paper proposes a Dynamic Spanning Tree with Mobile Sink (DSTMS) routing algorithm. Firstly, based on the Low Energy Adaptive Clustering Hierarchy Protocol (LEACH), a multi-layer transmission framework with dynamic minimum spanning tree (MST) is constructed to optimize data transmission route. In this framework, the selected rendezvous points, according to the motion parameters of mobile sink, build the dynamic rendezvous layer to constraint the hierarchical transmission of DSTMS. In addition, considering some factors of transmission energy consumption and residual energy distribution,the weight factor based on energy efficient function is introduced to evaluate the cost of transmission path within the MST. Moreover, the proposed algorithm not only reduces network energy consumption caused by frequent location updates of mobile sink, but also reduces data transmission congestion by constructing dynamic hierarchical transmission strategy. The simulation results show that the DSTMS algorithm can effectively prolong the network life, balance the network load and reduce collisions in wireless transmissions.

Distributed Group Location Update Algorithm for Massive Machine Type Communication

Frequent location updates of individual Internet of Things (IoT) devices can cause several problems (e.g., signaling overhead in networks and energy depletion of IoT devices) in massive machine type communication (mMTC) systems. To alleviate these problems, we design a distributed group location update algorithm (DGLU) in which geographically proximate IoT devices determine whether to conduct the location update in a distributed manner. To maximize the accuracy of the locations of IoT devices while maintaining a sufficiently small energy outage probability, we formulate a constrained stochastic game model. We then introduce a best response dynamics-based algorithm to obtain a multi-policy constrained Nash equilibrium. From the evaluation results, it is demonstrated that DGLU can achieve an accuracy of location information that is comparable with that of the individual location update scheme, with a sufficiently small energy outage probability.

Making Connected Cars Untraceable via DSRC Radios

This article shows potential of using DSRC radios for vehicle tracking protection. We focus on traffic data collection as our target application where vehicles send their locations to a server while driving. Such vehicles are easily trackable—revealing location history—as the application often requires frequent and accurate location updates. This article presents PathCloak, a method that enables vehicles to report their locations while preventing the server from properly tracking the vehicles. PathCloak leverages vehicles’ two network interfaces: in-car Internet (for accessing the server) and car-to-car DSRC (for creating path confusion). PathCloak-enabled vehicles exchange their kinematic information via DSRC radios, and use it to generate plausible path segments for each other, making their paths indistinguishable each other from the server’s viewpoint. We demonstrate its feasibility via field experiments on real roads using our DSRC testbeds. Our evaluation shows that PathCloak offers strong privacy (tracking success ratio< 1%), while maintaining high utility for various traffic statistics.

Heuristic data dissemination for mobile sink networks

Mobile sinks have advantages such as solving the hotspot problem which occurs because some sensor nodes deplete energy faster than others and enhancing energy balance among the sensor nodes. However, sink mobility raises two challenges, frequent location updates and packets delivery delay. To tackle these two problems, this work proposes a protocol that involves two mechanisms. First, to reduce the frequent location updates of the mobile sink to all sensor nodes, we proposed an accessible virtual structure (Double Ring) that acts as an intermediate structure between the sink and the sensor nodes when exchanging metadata and query packets. Second, to accelerate packets delivery, we proposed a heuristic data dissemination protocol, called HDD, in which the heuristic function is based on four values, direction, transmission distance, perpendicular distance, and residual energy. The experimental results showed that our proposed protocol outperforms the state of art protocols in terms of energy consumption, delivery rate, latency, and network lifetime.

Machine-to-Machine Content Retrieval in Wireless Networks

Machine-to-Machine (M2M) communication is a distinct capability that enables communications with anything. With the expected connection among several tens of billions of addressable mobile devices and the exchange of a huge amount of content, the Internet and mobile communication are entering a new era that inevitably faces several challenges, especially from a content dissemination perspective. It has been exposed to many limitations such as high control overhead, frequent location updates, and network congestion. To resolve such limitations, this paper proposes an efficient hierarchical routing and content retrieval mechanism, which is called Hierarchical Routing (H-Routing) for the wireless network based on Content-Centric Networking (CCN). The H-Routing is composed of a novel content discovery approach and a common service platform for generic communications and the integration of heterogeneous devices. The proposed mechanism uses CCN and Chord-like lookup in a hierarchical M2M system in the wireless mobile environment. The H-Routing mechanism reduces unnecessary flooding of content request messages, control overhead, and the waste of resources. We also implemented the proposed mechanism in the simulation environment and analyze the performance in terms of throughput, Interest packet overhead, and Interest error ratio.

Continuous monitoring of range spatial keyword query over moving objects

In this paper, we propose an efficient solution for processing continuous range spatial keyword queries over moving spatio-textual objects (namely, CRSK-mo queries). Major challenges in efficient processing of CRSK-mo queries are as follows: (i) the query range is determined based on both spatial proximity and textual similarity; thus a straightforward spatial proximity based pruning of the search space is not applicable as any object far from a query location with a high textual similarity score can still be the answer (and vice versa), (ii) frequent location updates may invalidate a query result, and thus require frequent re-computing of the result set for any object updates. To address these challenges, the key idea of our approach is to exploit the spatial and textual upper bounds between queries and objects to form safe zones (at the client-side) and buffer regions (at the server-side), and then use these bounds to quickly prune objects and queries through smart in-memory data structures. We conduct extensive experiments with a synthetic dataset that verify the effectiveness and efficiency of our proposed algorithm.

Sink-oriented tree based data dissemination protocol for mobile sinks wireless sensor networks

Data dissemination toward static sinks causes the nearby nodes to deplete their energy quicker than the other nodes in the field (i.e., this is referred to as the hotspot problem). Accordingly, topology disruptions will occur and no data will be delivered to the sink. Mobile sinks are proposed to solve the hotspot problem in wireless sensor networks; they provide a load balancing and an energy consumption balancing for the whole network. However, sink mobility introduces new challenges (e.g., frequent location updates and packets delay). In this paper, we proposed a distributed sink-oriented dissemination protocol called Sink-oriented Tree based Data Dissemination (STDD). STDD constructs just one main dissemination tree for each mobile sink. When the access node is changed, the main tree will be updated and maintained to guarantee the shortest path to the mobile sinks. The updated and maintained tree is not a new tree; however, it is just a new version with only a few changes in a few levels of the main tree itself. Simulations show that STDD achieves a significant performance in terms of latency, network lifetime, delivery rate, and energy consumption compared with the state-of-the-art approaches.

Preallocated Duplicate Name Prefix Detection Mechanism Using Naming Pool in CCN Based Mobile IoT Networks

As the number of mobile devices and IoT (internet of things) devices has explosively increased, various contents are created anytime and anywhere. To meet such trend, current internet architecture has exposed many limitations such as high control overhead due to multistaged address resolution, frequent location updates, and network congestion. Recently, information centric networking (ICN) is considered as new networking architecture to redesign current internet’s content exchange paradigm. In current ICN architecture, whenever a mobile node moves to a new domain, it needs long latency to configure and confirm the temporary name prefix. So, this paper presents an efficient name prefix configuration mechanism in mobile CCN to reduce the latency needed for the name prefix configuration during MCS’s handover. From the performance analysis, the proposed mechanism is shown to provide lower control overhead and lower resource consumption.

A privacy-aware monitoring algorithm for moving $$k$$ k -nearest neighbor queries in road networks

Location privacy is a major obstacle in the ubiquitous deployment of mobile and pervasive computing services. In this study, we present a new approach for preserving the trajectory privacy of moving $$k$$k-nearest neighbor (M$$k$$kNN) queries in road networks. Several location anonymization algorithms have been proposed for providing location privacy to users traveling on a road network. These algorithms focus primarily on the location anonymization of snapshot queries. Indeed, users move freely and arbitrarily, and thus query results provided to them soon become invalid as their locations change. To refresh the query result, each user must therefore periodically contact the location-based service, enabling attackers to identify and track the user easily. In addition, frequent location updates for the user may incur severe computational and communication costs. We address these issues by proposing a privacy-aware monitoring algorithm, called PAMA, for preserving the trajectory privacy of M$$k$$kNN queries in road networks. Our simulation results show that PAMA significantly outperforms conventional algorithms in terms of both security and performance.

Nearest surrounder searching in mobile computing environments

SUMMARYThe key issue in mobile computing environments (MCEs) is how to relieve communication congestion and provide accurate information through location‐based services (LBSs). The nearest surrounder (NS) query, used to find all visible objects around a given location, is a type of spatial query that suggests broad application base in LBS domain. However, because existing works for NS query only take into account static query points, the application of the NS query is limited to various LBSs in MCEs requiring frequent location updates. Motivated by this limitation, this paper introduces the continuous nearest surrounder (CNS) query, which uses a decentralized system framework to continuously maintain updated query results in MCEs. In this framework, the LBS server executes an initial NS query to prepare a region, termed non‐provoked polygon (NPP), defines a set of visible objects that cannot be changed. Conversely, a client caches the NPP and does not update request unless it leaves its NPP. We performed extensive experiments using synthetic and real datasets with various data cardinality, and query mobility to validate the accurate performance of the proposed strategy. The results show that the CNS algorithm outperforms NS, in terms of computation and communication costs as well as scalability.Copyright © 2012 John Wiley &amp; Sons, Ltd.

MMM: multi-channel TDMA with MPR capabilities for MANETs

Many Ad-hoc networks for military and public safety environments are characterized by: large number of nodes in the same area (that means that frequency spatial reuse is less applicable), crucial situation awareness (which implies periodically frequent location updates, mission status, etc.), or high propagation delay (for example, acoustic or airborne networks). In order to support such networks, an efficient medium access control broadcast protocol is essential. Obviously, using one shared channel with only one packet reception at a time is not scalable and therefore multi-packet reception techniques are more suitable. Recent technological developments (patent pending) enable nodes to receive messages simultaneously in many, even hundreds of channels. In this paper we study the impact of the new multi packet reception capabilities. In order to compute close upper and lower bounds on the maximum delay, we consider the best scenario that is, the simple case of full mesh. We then propose algorithms that achieve a close to the best possible maximum delay between updates over all pairs of nodes. This is done by providing close upper and lower bounds on the maximum delay and giving simple algorithms that meet the upper bound. For theoretical completeness we study bounds for all possible relations between the number of nodes and the number of channels.

An Index Structure for Frequently Updated Network-Constrained Moving Object Trajectories

Index is a key technology to improve the query processing performance of moving objects databases.However,current index methods for moving object trajectories,such as STR-Tree,TB-Tree,FNR-Tree,and MON-Tree,take trajectory units as the basic index records,and therefore,frequent insertions are needed when location updates occur in order to keep the consistency between the index and the trajectories in database,which greatly affects the overall performance of moving objects databases.To solve this problem,we propose a new index method,Dynamic Sketched-Trajectory R-Tree for Network-constrained Moving Objects(DSTR-Tree) in this paper.The DSTR-Tree divides the spatial-temporal space into equal-sized grid cells,transforms every trajectory into a sketched trajectory with each unit connecting two centers of the grid cells that the moving object travels through,and indices the sketched trajectory units as an R-Tree.Since the sketched trajectory has much coarser granularity than the original trajectory,the index updating cost can be greatly reduced-when a location update occurs,even though the original trajectory needs to be changed,the sketched trajectory may remain unchanged so that the DSTR-Tree does not need to be changed either.The experimental results show that the DSTR-Tree outperforms the previously proposed trajectory index methods in running moving objects databases with frequent location updates.

Power-aware data dissemination protocol for grid-based wireless sensor networks with mobile sinks

In wireless sensor networks (WSNs), sink mobility has been drawing more and more attention in recent years. Some approaches suggest that mobile sinks repeatedly propagate packets to notify the potential sources of their latest location information. As a result, frequent location updates from multiple sinks introduce both increased transmission traffic and rapid power expenditure. In order to reduce power consumption and minimise the overhead of frequently propagating packets, the authors propose a power-aware data dissemination (PADD) protocol for grid-based WSNs with mobile sinks. Rather than propagate the query messages from each sink to all sensor nodes to establish data forwarding information, a source constructs a grid structure beforehand so that only the dissemination nodes located at grid points need to acquire forwarding information. A properly grid cell size is determined to ensure that a dissemination node can directly communicate each other with its eight neighbouring dissemination nodes. As a result, a message can traverse not only vertically or horizontally but diagonally as well. Besides, dissemination nodes with the most residual energy are selected for forwarding query and disseminating data to evenly distribute energy load in the sensor field. Simulation results demonstrate the effectiveness of PADD in reducing the energy consumption and prolonging the network lifetime.

An Adaptive Location Updates and Propagation Scheme for Mobile Sinks

Mobile sink can be used to balance energy consumption of sensor nodes in Wireless Sensor Networks (WSNs). Sink is required to inform sensors about its new location information whenever necessary. However, frequent location updates of mobile sink can lead to both rapid energy consumption of sensor nodes and increased collisions in wireless transmissions. We propose ALUPS (A New Solution with Adaptive Location Update and Propagation Scheme) for mobile sinks to resolve this problem. When a sink moves, it only needs to broadcast its location information within a local adaptive area other than among the entire network. The overhearing feature of wireless transmission is employed when the adaptive location information is transferred. Compared with LURP (Local update-based routing protocol in wireless sensor networks with mobile sinks) and SLPS (Simple Location Propagation Scheme for Mobile Sink in Wireless Sensor Networks), ALUPS performs better both in low energy consumption and success delivery ratio.

Modeling the Energy Performance of Event-Driven Wireless Sensor Network by Using Static Sink and Mobile Sink

Wireless Sensor Networks (WSNs) designed for mission-critical applications suffer from limited sensing capacities, particularly fast energy depletion. Regarding this, mobile sinks can be used to balance the energy consumption in WSNs, but the frequent location updates of the mobile sinks can lead to data collisions and rapid energy consumption for some specific sensors. This paper explores an optimal barrier coverage based sensor deployment for event driven WSNs where a dual-sink model was designed to evaluate the energy performance of not only static sensors, but Static Sink (SS) and Mobile Sinks (MSs) simultaneously, based on parameters such as sensor transmission range r and the velocity of the mobile sink v, etc. Moreover, a MS mobility model was developed to enable SS and MSs to effectively collaborate, while achieving spatiotemporal energy performance efficiency by using the knowledge of the cumulative density function (cdf), Poisson process and M/G/1 queue. The simulation results verified that the improved energy performance of the whole network was demonstrated clearly and our eDSA algorithm is more efficient than the static-sink model, reducing energy consumption approximately in half. Moreover, we demonstrate that our results are robust to realistic sensing models and also validate the correctness of our results through extensive simulations.

An intelligent agent-based routing structure for mobile sinks in WSNs

Mobile sink brings new challenges to densely deployed and large wireless sensor networks (WSNs). When the sink moves, frequent location updates from the sink can generate excessive power consumption of sensors. In this paper, we propose IAR, an Intelligent Agent-based Routing protocol that provides efficient data delivery to mobile sink. Proposed algorithm reduces signal overhead and improve degraded route called triangular routing problem. We have evaluated IAR performance through both mathematical analysis and simulation experiments. The results show that our scheme effectively supports sink mobility with low overhead and the improvement of triangular routing problem.

A holistic sensor network design for energy conservation and efficient data dissemination

One important application of wireless sensor networks is to track mobile elements in the field, where the sensor network generally consists of a large number of sensor nodes deployed in an unattended environment and the sensor nodes are unlikely to be recharged. Redundant sensor nodes are often deployed to increase network robustness and extend network lifetime. There is a big challenge to distribute information and conserve energy in resource-constrained, densely populated sensor networks. Target and inquirer mobility brings further challenges to large-scale sensor networks. Frequent location updates for multiple inquirers and targets can drain the limited on-board energy excessively. We propose a holistic system design across media access control, network and application layers to optimize the performance of large-scale sensor networks by taking into account the interactions and tradeoffs between different design objectives. Our system includes a two-level node activity scheduling scheme for energy conservation and a scenario-aware data dissemination scheme to efficiently distribute query and event data and handle inquirer and target mobility. Furthermore, we analyze the system delay and introduce an adaptive scheduling scheme to reduce the initial sensing delay. The simulation results show that our system can save more than six times of the energy with reduced transmission delay and increased data delivery ratio.

Efficient Location Updates for Continuous Queries over Moving Objects

The significant overhead related to frequent location updates from moving objects often results in poor performance. As most of the location updates do not affect the query results, the network bandwidth and the battery life of moving objects are wasted. Existing solutions propose lazy updates, but such techniques generally avoid only a small fraction of all unnecessary location updates because of their basic approach (e.g., safe regions, time or distance thresholds). Furthermore, most prior work focuses on a simplified scenario where queries are either static or rarely change their positions. In this study, two novel efficient location update strategies are proposed in a trajectory movement model and an arbitrary movement model, respectively. The first strategy for a trajectory movement environment is the Adaptive Safe Region (ASR) technique that retrieves an adjustable safe region which is continuously reconciled with the surrounding dynamic queries. The communication overhead is reduced in a highly dynamic environment where both queries and data objects change their positions frequently. In addition, we design a framework that supports multiple query types (e.g., range and c-kNN queries). In this framework, our query re-evaluation algorithms take advantage of ASRs and issue location probes only to the affected data objects, without flooding the system with many unnecessary location update requests. The second proposed strategy for an arbitrary movement environment is the Partition-based Lazy Update (PLU, for short) algorithm that elevates this idea further by adopting Location Information Tables (LITs) which (a) allow each moving object to estimate possible query movements and issue a location update only when it may affect any query results and (b) enable smart server probing that results in fewer messages. We first define the data structure of an LIT which is essentially packed with a set of surrounding query locations across the terrain and discuss the mobile-side and server-side processes in correspondence to the utilization of LITs. Simulation results confirm that both the ASR and PLU concepts improve scalability and efficiency over existing methods.