Okan Turkes

BLESSED with Opportunistic Beacons: A Lightweight Data Dissemination Model for Smart Mobile Ad-Hoc Networks

This paper introduces BLESSED, a universal opportunistic ad hoc networking model intended for smart mobile devices. It enables fast and lightweight data dissemination in wireless community networks through the complementary utilization of the IEEE 802.11 and Bluetooth Low Energy standards. As a ubiquitous alternative to the publicly-limited ad hoc networking interfaces, it resolves many of the peer-to-peer data forwarding issues with smart beacon advertisements. Opportunistic beacons of BLESSED require neither association nor connection for data sharing, instead exploit the network identifiers as message carriers. Our applicability tests on a real-life setup indicate the soundness of the model. Providing a high data dissemination performance, BLESSED can be applied to numerous daily application scenarios.

A smartphone based method to enhance road pavement anomaly detection by analyzing the driver behavior

This paper introduces a method to detect road anomalies by analyzing driver behaviours. The analysis is based on the data and the features extracted from smartphone inertial sensors to calculate the angle of swerving and also based on distinctive states of a driver behaviour event. A novel approach is introduced to deal with the gyroscope drift, reducing the average angle estimation error for curves up to 2° and the overall average angle error up to 5°. Using a simple machine learning approach and a clustering algorithm, the method can detect 70% of the swerves and 95% of the turns on the road.

Opportunistic beacon networks: Information dissemination via wireless network identifiers

This paper presents OBN, a universal opportunistic ad hoc networking model particularly intended for smart mobile devices. It enables fast and lightweight data dissemination in wireless community networks through the utilization of universally-available wireless network identifiers. As a ubiquitous alternative to the publicly-limited ad hoc networking interfaces, it resolves many of the peer-to-peer data forwarding issues with smart beacon advertisements. Opportunistic beacons of the model require neither association nor connection for data sharing, instead exploit wireless network identifiers as message carriers. Our applicability tests on both real-world setups and simulations indicate the soundness of the model. Providing a high data dissemination performance in highly dense and highly mobile environments, OBN can be readily integrated to numerous mobile participatory sensing applications without requiring any specialized setup.

RoRo-LT: Social Routing with Next-Place Prediction from Self-Assessment of Spatiotemporal Routines

Current trend in store-carry-forward fashioned opportunistic networks is towards utilizing social ties in communities. However, keeping social knowledge/network information up-to-date is a non-trivial task due to ever-changing dynamics such as mobility and other human behavior. Therefore, social-based message forwarding proposals in which network information are initially provided to mobile nodes are subject to lose actuality within time. Motivated with this shortcoming, this study presents a social unicast routing scheme, called RoRo-LT, which is based on self-assessment of peoples daily routines. Without requiring any network information, RoRo-LT provides an up-to-date social awareness with long-term spatiotemporal observations. In RoRo-LT, nodes in contact estimate their own future trajectories and decide on forwarding according to their social similarities. In comparison to well-known forwarding schemes, RoRo-LTs performance results indicate a high socio-spatial awareness as well as a reasonable effectiveness for opportunistic routing.

Voice quality analysis in wireless multimedia sensor networks: An experimental study

Audio data processing and transmission in Wireless Sensor Networks (WSNs) require systems which satisfy the equilibrium between heavy data traffic and limited resources. In the lossy nature of the network, transmission techniques matter to sustain a certain content validity to be preserved. Besides, data handling is a worth-stressing issue to sustain a decreased computation and traffic overhead. An admissible quality of the voice signals being gathered at the sink node is to be directly maintained with network transmission assessments. To this respect, basic characteristics of a voice signal must be compromised with network properties. In this study, we investigate the quality of voice signals sent through the homogeneously constructed multi-hop network in which recorded signal segments in the source node are touched with the counterparts expected to be collected in each hop with a transmission rating factor. The basic characteristics of the voice samples used in the testbed are essayed with different in-network qualifications that can directly affect the quality; so that a reasonable trade-off between voice quality and sensor network capabilities is tried to be proposed.

Friend-to-friend short message service with opportunistic Wi-Fi beacons

This study introduces Oppline, an ad hoc opportunistic short message service that can be collaboratively used by everyone who has a smart mobile device. The data exchange method of Oppline is built on top of the universal Wi-Fi standard, thus expedites platform-independent integration of related mobile applications for delay-tolerant communications in public space. Even in highly-dense mobile networks of smart portable devices, Oppline gains performance from peoples participation according to our experimental analysis validated with a real-life deployment. Without creating any network overhead, Oppline performs multi-hop message transmissions via short messages encoded in and decoded from Wi-Fis service set identifier field. As a ubiquitous alternative to the situated communication systems, Oppline provides high versatility and usability for mobile ad hoc applications based on friend-to-friend messaging and data dissemination.

Cocoon: A lightweight opportunistic networking middleware for community-oriented smart mobile applications

Modern society is surrounded by an ample spectrum of smart mobile devices. This ubiquity forms a high potential for community-oriented opportunistic ad hoc networking applications. Nevertheless, today’s smart mobile devices such as smartphones, tablets, and wristbands are still onerous to automatically establish mobile ad hoc connections with our physical circle of friends and between occasional contact opportunities. Motivated by this, this study presents Cocoon as a lightweight middleware proposed for smart mobile platforms to support mobile opportunistic communications for general public use. Cocoon employs an adaptive context-aware service that can fairly coordinate a multitude of concurrently-running networking applications. Along with this service, the opportunistic networking service of Cocoon facilitates fast and reliable information sharing between participating devices according to our real-world applicability and validation experiments presented in this work. The routing protocols of Cocoon are designed above the universally-accepted Wi-Fi and Bluetooth standards. Without requiring any configuration or modification on top of the affiliated wireless interfaces, Cocoon is therefore suitable for direct use on any kind of smart mobile platform.

An Ad-Hoc Opportunistic Dissemination Protocol for Smartphone-Based Participatory Traffic Monitoring

This study introduces an ad-hoc opportunistic data dissemination protocol, called VADISS, that facilitates participatory traffic monitoring applications with smartphones. As a ubiquitous alternative to existing vehicular networking methods, VADISS uses the default WiFi interfaces universally adopted by todays mobile devices. The routing is enabled with intermittent service advertisements and discoveries, and the data exchange is provided via built-in IEEE 802.11 beacon frames. VADISS orients neither association nor connection between devices, is not based on any road-side unit, and thus is readily available for vehicular end-use applications. Together with a smartphone-based online road monitoring application, VADISS has been tested in a real- traffic setup to assess the data dissemination performance. With the increasing coverage, quite promising efficiency has been reached, especially for routing of critical traffic information.

Introspection-based Periodicity Awareness Model for Intermittently Connected Mobile Networks

Recently, context awareness in Intermittently Connected Mobile Networks (ICMNs) has gained popularity in order to discover social similarities among mobile entities. Nevertheless, most of the contextual methods depend on network knowledge obtained with unrealistic scenarios. Mobile entities should have a self-knowledge determination in order to estimate their activity routines in a group of communities. This paper presents a periodicity awareness model which relies on introspective spatiotemporal observations. In this model, hourly, daily, and weekly locations of mobile entities are being tracked to predict future trajectories and periodicities within a targeted time period. Realistic simulations are utilized to analyze the predictions in weekly observation sets. The results show that a reasonable accuracy with an increasing level of determination can be obtained which does not require global network knowledge. In this regard, the presented model can give insights for any type of ICMN objectives.

Voice quality improvement with error concealment in audio sensor networks

Multi-dimensional properties of audio data and resource-poor nodes make voice processing and transmission a challenging task for Wireless Sensor Networks (WSN). This study analyzes voice quality distortions caused by packet losses occurring over a multi-hop WSN testbed: A comprehensive analysis of transmitted voice quality is given in a real setup. In the experiments, recorded signals are partitioned into data segments and delivered efficiently at the source. Throughout the network, two reconstruction scenarios are considered for the lost segments: In the first one, a raw projection is applied on voice with no error concealment (V-NC) whereas the latter encodes a simple error concealment (V-EC). It is shown that with an affordable reconstruction, a comprehensible voice can be gathered even when packet error rate is as high as 30%.