Home Sweet Digital Home

Digital technologies penetration into home is growing rapidly. The digital home era is here and slowly morphing from legacy systems towards fully unified digital entity. While each digital home service provides unique features and capabilities, they all require the use of Internet and sharing of data, voice and video among home appliances. Several value-added services in digital homes are enabled with the arrival of high speed Internet access. Taking cost into consideration, an ideal home would deploy single access point to the Internet; therefore there is need for a solution that will be essential for application providers to deploy multiple services using Internet. This solution or standardized procedure is known as middleware.

In digital home scenario, middleware technology refers to a layer of software that lies on top of a home devices or appliances operating system. Middleware provide the opportunities in facilitating rapid development, increasing scalability of a systems and integration of services in digital homes. It bundles hardware and software into a single solution and provides transparent interaction between home systems and databases, enables unified user interfaces, reduce infrastructure requirements and allows multiple services become easier to manage. In a typical digital home, there could be number of home devices and appliances, which allow the physical interconnection of multiple systems and services. Home systems and services are inevitably supplied by different manufacturers and use a wide range of different protocols and standards for communication. The home systems and services must be interconnected seamlessly in a consistent platform. This is one of the main functions of middleware technology. Figure 1 below shows the integration of middleware with various digital home services.

Middleware Standards

Middleware consists of various networked services in home that are shared by home appliances, applications and users. It also provides a number of tools that reduces the complexities out of application and home device integration. The tools are considered to be an important part of middleware deliverable which allows a system integrator to configure and construct a level of integration needed for usable middleware system. Growth of middleware and its core functionalities has caused the need for universality in interfaces, protocols and usability so that even though different services providers in digital homes provide different solutions, they should still be able to interoperate. Analysts are forecasting that market for digital home middleware will be worth several billion dollars in a couple of years. To capitalize the opportunities of middleware technologies in digital homes, a number of consortium have been established to deliver home products into this evolving business niche. Current initiatives includes as follows:

OSGI Alliance – The OSGI Alliance founded in March 1999 to standardize efforts in connecting various consumer electronics to the residential gateway. The OSGI middleware specification delineates Application Programming Interface (API) standards for the Services Platform execution environment. Digital home devices and services must support these API standards to conform to the OSGI specification. This will help system developers, software vendors and equipment manufacturer to easily develop and deploy multiple home services in a coordinated manner.

Universal Plug and Play (UPnP) – Initially was known as UPnP version 1, announced in 1999 which is based on standard Internet protocols; XML, TCP, HTTP, UDP and IP. UPnP version 2 was announced in 2003 and targeted for enterprise wide architecture. This version of middleware developed towards adherence on Web Services standards, reliable in terms of security and using a SOAP-based eventing model which allow appliances from different companies perform interoperation.
Jini – Jini is a middleware solution developed by Sun Microsystems comprising layer of Java software that allows home appliances plug in directly into digital home without need for installing device drivers and operating system configuration. Jini is designed to suit home appliances that are simple that they may have small amount or even no computational intelligence.

.NET Framework – .NET Framework developed by Microsoft is a standardize platform which is compliant to ECMA-335 Common Language Infrastructure (CLI) standard. It is a software component bundled with Microsoft Windows operating systems. The CLI maximizes the code reusability in single or multiple operating system platforms. The framework provides native support to XML and SOAP. It includes Just-in-Time (JIT) compiler to enhance the efficiency of intermediate language execution. .NET Framework is expected to become an ideal middleware solution for home technologies due to its language and platform independence feature for application development.

Web Services – Web Services functions as ‘protocol glue’ for various services and technologies offered in digital home. Web Services consist of three entities, Service Provider, Service Registry and Service Requester. These entities are founded upon three major standards called Simple Object Access Protocol (SOAP), Web Services Description Language (WSDL) and Universal Description, Discovery and Integration (UDDI). Web Services seems to be the ideal solution that combines TCP/IP networking, browser-based multimedia interface and control instructions for digital home. Using XML to tag the information, Web Services are expected to be dominant middleware solution for home applications.

HAVi (Home Audio-Video Interoperability) – HAVi started by Sony and Philips in year 1996 and was then included with Thomson, Grundig, Toshiba, Hitachi, Sharp and Matsushita. The Home Audio-Video Interoperability middleware architecture is an open and platform-independent specification that allows developers to write their customized application for audio and video appliances. It ensures interoperability between digital audio and video devices from various manufacturers that are connected via a network in the digital home. This HAVi middleware focuses on transferring digital contents retrieved from audio and video appliances as well as processing (playback and recording).
Advantages of Middleware in Digital Home

Primary advantage of deploying middleware in digital home scenario will be standardization of communication mechanism between different entities and services. Home developers also could make some cost justification by making investment in middleware for digital homes. This is particularly true as middleware bring several benefits as follows:

Standard Platform – Middleware brings different home systems and services into a standard platform. It allows a single application to interoperate among multiple devices and services in home. Home application developers are not required to create application for each digital home component as they could utilize the middleware which provides connectivity and middle layer between each digital home component and services.

Home Databases – Middleware consist of standardized databases that can provide data inputs to third party service providers like billing utility for electricity and other sort of energy management aspect. With this middleware feature, home dwellers will have the access for home management information like billing tariffs, usage rate, automated reporting and service cost. Home databases extend utility service providers towards enterprise level in home scenario.

Appliances Interoperability – It is common to have multiple home appliances and devices doing dedicated tasks pertaining to security, audio and video distribution and more. These various appliances are expensive to install and maintain as well as lack of functionality required in justifying home dwellers investment. Middleware technology solves this by providing appliances interoperability between various manufacturers regardless of firmware and operating systems used.

User Interfaces – One of the important criteria in digital home requirement is flexible user interfaces for all services offered in the home. With middleware, a standard user interface could cater the requirement for all services provided in digital home. As middleware combines multiple services and appliances, it provides an efficient base to deploy interfaces based on web environment. This eventually promotes more development and use of functional services in home.

Hybrid Solution – Home owners have been making investments in their home services with dedicated controllers, appliances and user interfaces. Unfortunately these systems are slowly becoming obsolete as they contain little integration to other systems and outdated interfaces. Middleware can provide hybrid solution by supporting legacy systems with extending new applications and advanced features. This will extend the life cycle of existing devices and reduce capital expenses for home dwellers.


Home application developers depend on middleware to develop solutions that can be implemented across multiple systems, amortizing the implementation cost of different systems integration. Home technology companies and vendors benefit by having functionality to install advanced appliances, knowing that those appliances will be seamlessly connected with middleware. Finally, middleware brings digital home to greater heights towards faster deployment, high scalability, realize interoperation among systems and provide multiple alternatives than relying on single proprietary technology.


1. OSGI Alliance , http://www.osgi.org/Main/HomePage
2. HAVi, http://www.havi.org/
3. Open Building Information Xchange(OBiX), http://www.obix.org
4. Continental Automated Buildings Association(CABA), http://www.caba.org
5. UPnP Forum, http://www.upnp.org/
6. Jini, http://java.sun.com/products/jini/

About the Author:
Thinagaran Perumal is pursuing his PhD in Smart Technology and Robotics and attached with Institute of Advanced Technology, University Putra Malaysia. He has been involved in research areas of middleware technologies and interoperability for smart home environment. He can be reached at thinagaran@hotmail.com