Chamath Keppitiyagama

A public transport system based sensor network for road surface condition monitoring

A well maintained road network is a must for the economic development and the well being of people in any country. Unfortunately, most developing countries do not poses such road networks. While the lack of funds is mainly to blame for not building new road networks and maintaining the existing ones the lack of proper monitoring and reporting system is a major contributory factor for the dilapidated condition of road networks in third world countries. A case in point is the road network in Sri Lanka; Sri Lanka has an extensive road network that spans the country and new roads are being built every day, yet even the roads in the capital city are not maintained properly. The lack of a monitoring and reporting mechanism is apparent in this case. We propose a public transport system based sensor network to monitor road surface condition. We are currently building such a network called BusNet to monitor environmental pollution and that system can be extended for road surface condition monitoring by adding acceleration sensor boards to the system.

TempLab: a testbed infrastructure to study the impact of temperature on wireless sensor networks

Temperature has a strong impact on the operations of all electrical and electronic components. In wireless sensor nodes, temperature variations can lead to loss of synchronization, degradation of the link quality, or early battery depletion, and can therefore affect key network metrics such as throughput, delay, and lifetime. Considering that most outdoor deployments are exposed to strong temperature variations across time and space, a deep understanding of how temperature affects network protocols is fundamental to comprehend flaws in their design and to improve their performance. Existing testbed infrastructures, however, do not allow to systematically study the impact of temperature on wireless sensor networks. In this paper we present TempLab, an extension for wireless sensor network testbeds that allows to control the on-board temperature of sensor nodes and to study the effects of temperature variations on the network performance in a precise and repeatable fashion. TempLab can accurately reproduce traces recorded in outdoor environments with fine granularity, while minimizing the hardware costs and configuration overhead. We use TempLab to analyse the detrimental effects of temperature variations (i) on processing performance, (ii) on a tree routing protocol, and (iii) on CSMA-based MAC protocols, deriving insights that would have not been revealed using existing testbed installations.

Temperature hints for sensornet routing

Real-world experiments have shown that the transmission power and the received signal strength of low-power radio transceivers used in sensornets decrease when temperature increases. We analyze how this phenomenon affects the network layer, and find that temperature fluctuations may cause undesirable behavior by sensornet routing protocols such as CTP and RPL. Furthermore, we present an approach to make these protocols robust to temperature fluctuations by augmenting the ETX link metric with temperature hints.

ContextOS: A Context Aware Operating System for Mobile Devices

The Operating System (OS) manages the hardware resources of a computer. For an OS, the knowledge about context is valuable information in optimizing its tasks. Recent mobile devices, such as smart-phones and tablets, are providing new avenues in context aware computing, because of the wide variety of sensors integrated into them. This paper identifies the importance of integrating context awareness at the OS level. In particular, we propose ContextOS, a proof of concept implementation of a context aware OS for mobile devices. ContextOS leverages the context knowledge for process scheduling. We implemented ContextOS in Android. The results of our experiments confirm the feasibility and usability of our solution.

Sensor-based breakage detection for electric fences

The human-elephant conflict is one of the most severe natural problems in Sri Lanka. There are rich farmlands near the elephant habitats and elephants raid these farms in search of food. This has been the main cause for nearly 70 human deaths and over 200 elephant deaths that have been recorded each year in the recent past. To manage the problem, the government has initiated projects that secure the national wildlife parks with electric fences. However, maintaining the electric fence is a challenge, because of its large perimeter and the lack of available manpower. A particular concern is that of locating faults in electric fences since these typically span a few hundred miles. Currently, park rangers are required to travel on foot to locate the faults, which could take days to complete. In this paper, we propose a novel system architecture that considerably shortens the maintenance time for electric fences, at minimal and hence affordable cost. Our architecture benefits the park rangers of the national wildlife sanctuaries to detect and repair the breakages.

Wireless Sensing: What Simplicity Has to Offer?

We argue that, a wireless sensor does not have to implement a full networking stack in order to be a part of an energy efficient sensing application as long as it can deliver its sensed data to an Internet connected device over a single hop. Current hardware industry trends indicate the possibility of implementing wireless sensors for a low cost with simple capabilities. This poster highlights our preliminary work aligned with this trend and aims to open a discussion on this topic.

A Quadcopter Controller to Maintain Radio Link Quality

The excellent maneuverability and the availability of a large number of sensors including good quality video cameras make quadcopters attractive for surveillance systems. Most video surveillance systems need a real-time high quality video stream from the cameras on the quadcopter to the base station which requires a stable and reliable radio link. Moreover, to ensure a controlled flight, it is essential to maintain a good quality radio link from the base station to the quad- copter. The quality of this link depends on the distance between base station and quadcopter as well as the ambient noise. Towards this end, we present a controller to hover a quadcopter at the maximum distance from the base station while maintaining the link quality at a given value indicated by the Signal to Noise Ratio (SNR). There are existing solu- tions in the field of robotics that incorporate the concept of link aware mobility. However, to the best of our knowledge, this is the first link-quality aware mobility implementation on a quadcopter.

Listening to the Giants: Using Elephant Infra-Sound to Solve the Human-Elephant Conflict

The continuing human-elephant conflict in Sri Lanka has resulted in loss of human as well as elephant lives. Detecting and localizing elephants is an essential component of any viable solution to this problem. Currently, we conduct feasibility tests on using low cost sensors to detect elephants from a long distance, leveraging the infra-sounds emitted by them. In this paper we present the test environment that we have set up for this purpose and some preliminary, but promising results.

Towards a sensor system to tame the human elephant conflict

The human elephant conflict in Sri Lanka has been a cause of major concern over the past decade. Frequent clashes between wild elephants and villagers have resulted in severe damage to property, as well as loss of lives for both humans and elephants. Competition for space is the primary reason for conflict between humans and elephants. Elephants that escape from the wildlife national parks venture into villages creating destruction in their wake. To prevent such mishaps, a proper system is required to contain and monitor elephants in national parks. In this paper, we describe different approaches to detect elephants and possible ways of monitoring the national wildlife parks. We also elaborate on the advantages and limitations of each approach, and determine what sort of system is needed to tame the human elephant conflict.

Flight Simulator for Serious Gaming

Providing entertainment is the primary concern of the gaming. Once this primary objective alters to provide learning and training materials it calls simulators or the serious gaming. Learning through experiencing or facing the actual scenario is considered as an effective learning technique. The limitations of the experiential learning and how the simulations are going to address those limitations are also reviewed in this paper. Aviation field is one of the most critical and potentially high risk areas where one has to spend lots of money and resources in training scenario. Hence the serious gaming concepts have being playing as an effective cost cutting solution in aviation training. In this paper it is intended to discuss the seriousness of a selected flight simulator and how they adopted the teaching learning concepts. How the simulator can be used in the learning curve is also discussed separately