A Web-Based Interface for a Digital Broadband Home Venu Dasigi (
[email protected]) Department of Computer Science, Southern Polytechnic State University, Marietta, GA 30060
Vijay Madisetti (
[email protected]) Department of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332
Abstract We envision the next generation set-top box to be a communications and control device that serves as the residential gateway between an external broadband communication channel and an internal home network. This broadband residential network, as a whole, represents various services (such as cable programming, or games or other software available on the Internet, or a broker of such services) and devices (such as a networked toaster or other appliance, or a home computer, etc.). Our goal is to provide a web-based remote control interface for such a Set-Top Box. The interface needs to be dynamically reconfigurable as new services and devices are added into the residential network. We have implemented prototypes of a web-based interface for a service and a device. The first prototype involves web-enabling of transcoders and making them available as a service for any user through Web. As an example we have used an existing MPEG converter to convert MPEG2 format into MPEG1/AVI format. The other prototype implemented a simple simulation of an Internet toaster through an Internet browser and web server. The user can check the status of toaster (available or not) and control it through an Internet browser. We are studying approaches to generalize the framework.
1.
comprising significant processing and storage capabilities. There are indications to believe that this “digital trend” is very likely to continue. With homes going digital in the above sense, there arises a need for a communications and control hub in every home. We envision such a hub to be a Set-Top Box (STB), somewhat like the signal unscrambler boxes provided by many cable companies that generally sit on the top of a TV set. The Set-Top Box acts as a residential gateway between an external network of services such as digital TV channels, the Internet, telephone signals, etc. and a home network consisting of digital TV, PC, telephone, etc. Further, on the residential side is a network of appliances or systems required to be controlled, such as, HVAC, home security, digital camera, microwave, toaster, etc. The STB includes processing capability to control access to the external services as well as devices in the residence, and also to perform content management. It also provides a potentially remotely accessible, dynamically upgradable user interface so new services or new devices can be added into the digital “broadband home.” This paper presents an overview of such a SetTop Box interface into a digital broadband home that is locally accessible, as well as acts as a web-based remote control. We present some background and related work, present an architectural framework, summarize the current state of the work, and describe research issues and future work.
Introduction 2.
Today, many communications intended for popular consumption are available in digital form with increasing frequency. Electronic information exchanged into a typical home through such communications includes cable and other types of television programming, telephone conversations, video conferencing, Internet access, etc. Some of these information exchanges are two-way. Exchanges of control information, such as those between a home security system and a central control room, are of interest, as well. Thus, information exchanges are either themselves represented in digital form, or controlled by digital signals. Further, many home appliances, such as digital TVs, CD and DVD players, home security systems, digital cameras, etc. incorporate digital controls in them,
Background
The Set-Top Box and its user interface are part of the Yamacraw Embedded Software (YES) project [2]. This brief overview summarizes Diaz-Herrera and Madisetti’s treatment. The YES project involves a model-based methodology to the development of embedded systems, and specific embedded system applications or “product lines”. Embedded systems involve application-specific software embedded into application-specific software. With increasing proportion of embedded system functionality being provided by software, embedded software requirements and specification methodologies and hardware/software co-design have been recognized as critical development activities. These modeling activities
are needed to ensure that close interaction between the hardware and software in an embedded system, real-time constraints, etc. are all met in addition to traditional software engineering concerns. The YES project has been divided into two broad areas (together comprising five more specific statements of work or SOWs), much along the lines of traditional engineering design and practice. Engineering design is concerned with application of first principles to create design patterns that can be applied in practice. Engineering practice, in contrast, does not start from first principles; instead it is concerned with fitting design patterns to specific user/product requirements. In the YES methodology, the first broad area concerns itself with the development of domain models (SOW 1.0) and solution models (SOW 2.0), while the second broad area deals with the development of specific applications or embedded software product lines to satisfy specific application requirements (SOWs 3.0, 4.0, and 5.0), based on the models. One of the application areas of interest, namely SOW 5.0, is home computing applications. The centerpiece of the home computing applications area is a home network along with the residential gateway called the Set-Top Box. As the communication and control hub of the digital broadband home, the STB provides access to Internet, Cable, DSL, wireless signals, etc. Home communications equipment such as the phone, digital TV, PCs, etc., audio and video entertainment devices, the home security system, the HVAC programming unit, home appliances such as toasters, microwaves, coffeemakers, etc. could be part of the residential network. The STB may be thought of as providing access to some services and allowing control of some devices (which include appliances, equipment, etc.). Examples of device control and service access include: • • • • • • • •
Manipulating and monitoring the HVAC settings, Turning the security system on/off, Viewing a selected area of the house through a camera Timing the lights in the house or otherwise controlling them Controlling the sprinkler system Programming the VCR Timing and/or tuning the TV Accessing the Internet
• • • •
Allowing utility company meters to be read, etc. Content management of TV programming Content management of Internet data, Communication between STBs, e.g., for game playing, etc.
The last three are examples of specialized services. Content management involves flexible, easy, and customizable access to available services, programming or Internet content for a variety of users with different preferences and tastes. One way to allow for customized content management is to allow each user to create, update, and retrieve profiles, either manually or automatically. Once created, a user profile could help with selecting a program or Internet content, or recording a program. It may be noted that for most, if not all, of the device control examples in the above list, the specified functionality is not new, but is part of the device, e.g., security system activation, VCR programming, etc. What is needed is an appropriate interface through the STB. As a matter of fact, the STB has to provide an interface to any of the networked devices, as well as external services. Thus, not only should the STB interface allow access to any of the devices and services, it should be dynamically upgradable, as well. In other words, as new devices or services are added into the network, right from the beginning, the STB interface should be upgraded to access the new addition into the network. Further, the interface should be accessible through the worldwide web, in effect providing a web-based remote control.
3.
Architectural Framework
Figure 1 shows a residential network, with the STB forming the bridge between an external network of services such as cable, digital TV, Internet, etc., and a home network. The home network may comprise multiple physical networks with a wireless network and other networks of varying bandwidths, such as an IEEE1394 (also known as Firewire) and a Universal Serial Bus (USB). The IEEE 1394 bus supports high data rates into the Gbps range, whereas the USB network supports low to medium speed devices.
External Network
Digital Subscriber Line
Hybrid Fiber Coax
Wireles s RF
RF
DSL
ATU-R
Transverter
CABLE MODEM
Wireless Modem Server
RESIDENTIAL Gateway (YESSetTopBox)
DISK Storage
IEEE 1394 FireWireTM
Telephone Video VCR
Answering machine
Scanner
Copy machine Mouse Keyboard
Wireless
Wireless Network
Digital TV / Video On Demand
Laser printer
USB Network for Medium to Low Speed Peripherals
DVD
USB Network for Medium to Low Speed Peripherals
Laptop computer
IEEE 1394 Network for High Speed Peripherals
Multimedia PC
Universal Serial Bus-USB
Video Cell. Phone
Television VCR
Telephone Fax
FIGURE 1: A Digital Broadband Home Network with a Set-Top Box The figure indicates that many devices and services could be managed by the STB. As pointed out in the previous section, the STB must support device-specific interfaces. In the general case, it is proposed that the STB start with a high level, generic interface, and as new service or device is added to the network, this high level interface be upgraded. Such upgrades can be performed by either locally installing a new interface corresponding to the new service or device or automatically downloading from the Internet and installing it. As new devices or services are added, a hierarchical interface develops, wherein at the highest level would be options which, when chosen, would allow users to zoom into a new level. At this new level would be a highly customized servicespecific or device-specific interface. This notion of downloading and installing service-specific or devicespecific controls is very similar to what can be found in emerging standards such as HAVi (Home Audio/Video Interoperability) [4] and OSGi (Open Services Gateway Initiative) [www.osgi.org]; we will return to this topic in Section 5. Such dynamic installation of interfaces
allows product manufacturers to upgrade their products in a “future-proof” way, simply by means of software upgrades, much like today’s computer software upgrades.
4.
Current Implementation and Issues
As a part of our effort toward providing preliminary proofs of concept in a situation where competing standards are only slowly emerging, with a lot of development work conforming to the standards yet to be done, we set out to provide three somewhat related demonstrations. The three implementations demonstrate different categories of STB functionality that are of interest: • • •
STB-to-STB communication via an external service An STB used with a service An STB controlling a home-networked device
Although these applications have demonstrated the principles and been very useful, they have not
incorporated the generality of dynamic upgrading of interfaces yet.
4.1.
STB-to-STB Communication - a Doom Game Demonstration
In this application, we showed how a home network broker service that may be available on the Internet can broker a “Doom” game to be set up to be played between two digital broadband homes. A home network broker can provide the service of making any general application server available to digital broadband homes. The broker can communicate with the application server, as well as to the STBs in the homes. The STBs can in turn communicate with application clients sitting somewhere in the home networks and thus establish communication between the application server and the individual clients, in an application-specific manner. This application involves a flexible scenario in that the STBs and the application clients could be running on physically different machines of the same machine; also, the home network broker could be running either as a service on the Internet, or within the home network associated with some known STB.
4.2.
STB used with a Service – Webenabled Transcoding
controls the time according to the user instruction. When it times out, the timer sets the control bit to “available” to indicate that the toaster is available to other users, and then stops. The new status of toaster is written in XML format, which allows user to get the status at any time. Details may be found elsewhere [3].
5.
Results and Future Work
We have only scratched the surface, but have laid the foundation for further work. An important next step is to evaluate competing standards such as HAVi and OSGi for intrinsic merit and for its suitableness to fit into our general framework. These standards provide fairly general APIs that can be implemented. HAVi is languageindependent yet supports content management, but only for audio/video/home entertainment domain. In contrast OSGi is oriented toward Java and some preliminary implementations are becoming available. OSGi is also broader in scope, and does not limit itself to the home entertainment arena as HAVi does. But unlike HAVi, it does not address issues of content support directly! Thus, if OSGi is chosen, content management issues may be considered either as part of the STB design, or as a separate service. Issues of content processing are addressed in a separate paper [1].
In this application, an existing MPEG transcoder has been web-enabled to make it available as a service for any user through the Internet. As an example we have used a transcoder named FlaskMPEG to convert MPEG2 format into MPEG1/AVI format, and provide access to it through our STB. A separate paper describes the architecture used to implement this concept [5]. The transcoder has been installed on a machine running a web server. The API is stored on the public area of the web server through which user at home network / STB can make request for transcoding and also can upload and download the input and output files.
In summary, we envision digital broadband homes of the future in stark contrast to current homes. Current homes are a loose collection of appliances (e.g., TV and telephone) and systems (e.g., HVAC and home security) with inflexible control. The digital broadband home of the future integrates various services and home appliances and systems into the home network, through the residential gateway device known as the Set-Top Box. Services are accessible and devices are controllable either locally or remotely over the network. New services and devices can be added into the network very conveniently, and the STB interface is automatically upgraded. This approach is vendor-independent through the adoption of a standard framework.
4.3.
Acknowledgements
STB controlling a Networked Device – A Networked Toaster
In this application, we have implemented a simple simulation of an Internet toaster through a web server. The user can check the status of toaster (available or not) through an Internet browser (the STB interface). If the toaster is busy, a message is sent to the user. If the toaster is available (not in use), new settings are allowed and sent to the web server on the toaster. The web server gets the settings and set the control bit to “unavailable”. At the same time the web server starts a timer, which
The authors would like to express appreciation to Prof. Mani Subramanian whose involvement in the first phase of this project made the home network architecture what it is now. Other members of the team have been Gaurav Agarwal, Fatima Ahmad, Xiuqi Chen, Subrato De, Bobby DeVos, Jim Dooley, Yan Jiao, Keyur Naik, Pranit Shah, and Bliss Thevakadadcham.
References [1] [2]
[3]
[4]
[5]
Dasigi, V., Broadband Content Processing, Yamacraw IAB Workshop, October, 2000. Diaz-Herrera, J., and Madisetti, V., The Yamacraw Embedded Software (YES) Methodology: A Technical Analysis, Yamacraw (YES) Technical Report CSIP-TR-00-01, 2000. Jiao, Y., Ahmad, F., Web-Enabled Information Appliances, Yamacraw IA B Workshop, October, 2000. Lea, R., Gibbs, S., Dara -Abrams, A., and Eytchison, E., Networking Home Entertainment Devices with HAVi, IEEE Computer, 33(9), September, 2000, pp. 3543. Naik, K., and Rahim, M., Web-Enabled Transcoding for Broadband Residential Networks, Yamacraw IAB Workshop, October, 2000.
