Sachin Bhardwaj

Smart lighting using LED luminaries

The target of a smart lighting system is to control light sources in an environment (e.g. home, office) adaptively according to user contexts and preferences. Literature work in this area focuses on traditional light sources such as incandescent and fluorescent lights, whereas this paper takes a step towards adopting LED luminaries. A novel illumination model for distributed LED luminary control is presented. A prototype system is designed and implemented using several LED luminaries and light sensors. Experiments carried out on the reading space use case show that the desired illumination can be achieved based on user preferences, irrespective of the existence of external light sources.

Smart indoor solid state lighting based on a novel illumination model and implementation

Smart lighting research traditionally focuses on conventional incandescent and fluorescent luminaries. However, in addition to its higher energy efficiency and longer lifetime, Solid State Lighting (SSL) offers better control of spectral, spatial, temporal polarization, and color properties of light. Combined with the recent developments in smart environments research, SSL utilizing Light Emitting Diodes (LED) creates a new playground for user-light interaction. We present a novel illumination model for SSL and implement this model on a wireless sensor network (WSN). The light sensors and actuators in the WSN provide services for sensing illumination changes and dynamically adjusting luminary brightness according to user preferences. Experiments conducted two key scenarios, i.e. reading and watching TV, show that the preferred illumination levels in an activity space can be achieved and maintained, irrespective of external light variations.

Resource and service management architecture of a Low Capacity Network for smart spaces

A smart space is typically composed of heterogeneous networks of communicating and collaborating nodes with varying capacities of resources such as processing power, memory and energy. Recent developments in wireless communication technology and miniaturization of Consumer Electronics (CE) hardware have made Low Capacity Networks (LCN) such as Wireless Sensor and Actuator Networks (WSAN) an important element of smart spaces. However, resource and service management in LCNs that interoperate with resource-rich nodes of a smart space is still a challenge. We propose and implement an architecture for lightweight resource and service management in LCNs. Furthermore, we present a validation of the proposed architecture through performance analysis in comparison to an existing interoperability architecture.

Power-managed smart lighting using a semantic interoperability architecture

We present a power-managed smart lighting system that allows collaboration of Consumer Electronics (CE) lighting-devices and corresponding system architectures provided by different CE suppliers. In the example scenario, the rooms of a building are categorized as low- and high-priority, each category utilizing a different system architecture. The rooms collaborate through a semantic interoperability platform. The overall smart lighting system conforms to a power quota regime and maintains a target power consumption level by automatically adjusting power consumed by luminaries in the building. Experiments with CE devices of different suppliers operating on different networks show that the semantic interoperability architecture allows device collaboration that can lead to lower power cost.

Performance evaluation of a semantic smart space deployment

A smart space is a physical space with heterogeneous smart objects that collaborate and share information to perform tasks desired by users. Interoperability among smart objects is the key challenge in smart spaces. In this paper, we discuss a semantic interoperability approach for smart spaces introduced by the SOFIA (Smart Objects for Intelligent Applications) project. A semantic interoperability architecture is introduced and implemented for a use case scenario deployment. This deployment consists of many heterogeneous smart objects, designed and manufactured by different companies and institutions, that exchange information through the interoperability architecture. The architecture, realized as a smart home pilot, is evaluated based on a performance analysis. The results indicate acceptable response times for a networked user interface.

Increasing reliability and availability in smart spaces: A novel architecture for resource and service management

Smart spaces are physical spaces where services provided by Consumer Electronics (CE) devices with varying resource availabilities work together to realize user-specific automated scenarios. These scenarios may be interrupted in case one of the services making up the scenario stops working, e.g. due to lack of resources, node failure or leave. Therefore, the user experience is highly dependent on the availability and reliability of smart space resources and services. This paper proposes an architecture for resource and service management in smart spaces. We present mechanisms for automatic node entry and exit, service discovery and matching, failure detection and recovery, and resource monitoring. The proposed architecture is evaluated in the context of a simple use case scenario.

Semantic Interoperability Architecture for Smart Spaces

The advancements in the smart space research bring us closer and closer to a future, in which the living standards of people are greatly enhanced. Smart spaces are composed of heterogeneous networks of embedded devices that communicate, perform computations and actuate. From a system point of view, a smart space is a specific type of ubiquitous system. Like any ubiquitous system, a smart space is usually heterogeneous, i.e. it is made up of embedded devices with various hardware, software and communication platforms. There is need for information exchange and interoperability between these embedded devices and their services. However, embedded devices in a smart space vary in terms of their sensing, actuation and control capabilities, as well as their resources of processing, storage, and networking. For an interoperability solution, this paper proposes a semantic interoperability architecture for smart spaces. The description details of an ontology model and interoperability interactions between smart objects are explained. An example implementation of a heterogeneous smart lighting system as a smart space using the proposed semantic interoperability architecture is discussed.