03-08-2012, 12:27 PM
HAViTechnology
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ABSTRACT
Eight major consumer electronics manufacturers have come up with an open standard enabling home entertainment devices to communicate intelligently with each other. The HAVi (Home Audio Video Interoperability) standard promises to bring true platform independent interoperability to consumer devices using high bandwidth IEEE 1394 (FireWire) as the connecting medium. This paper studies the HAVi standard and what it has to offer to consumers.
1 INTRODUCTION
An average household nowadays contains many very complicated devices. Many of them are home entertainment devices related to handling different audio or video data. These devices are computers in essence, but just more specialized in their features than a home PC. Home networking has become very popular nowadays since a normal household might contain several PCs that need to use shared resources like printers or file shares. Home audio and video devices like VCR, TV, amplifier, tuner, DVD, CD player and set-top-box form a similar interconnected network (see Figure 1). Why couldn’t these miniature computers also make use of each other’s features and even control each other to make everything easier for the consumer?
Major consumer electronics, software, semiconductor and computer manufacturers think that this should be possible and have decided to make it happen. The manufactures, namely Grundig, Hitachi, Panasonic, Philips, Sharp, Sony, Thomson and Toshiba along with now over 230 other participants, have formed a non-profit organization called HAVi (Home Audio Video Interoperability) for promoting the development of interoperable consumer products. The goal of HAVi organization is to provide a standard open architecture for intelligent audio and video devices to interoperate with each other Regardless of manufacturer, operating system, CPU or programming language used for implementation (HAVi, Inc., 2001a). The first beta version of the HAVi standard version 1.0 was published in December 1998while the final 1.0 version was released in December 1999. The current version of the specification is 1.1 (HAVi, Inc., 2001b) and it was published in May 15th 2001.This paper presents the basic architecture and promises the HAVi standard offers. Various problems and questions still to be answered will also be discussed. Although HAVi is still to come into living rooms as a de facto standard, a brief look at the future of HAVi will be made. The paper is mainly based on the information offered by HAVi organization (HAVi, Inc., 2001a) and naturally the HAVi specification version 1.1 itself (HAVi, Inc., 2001b). Another main source of the paper is a HAVi introduction by Rodger Lea, Simon Gibbs, Alec Dara-Abrams and Edward Eytchison (Lea et al., 2000
2 PROMISES OF HAVI
The idea of an open standard sounds very promising, but how can a normal consumer benefit from it? How can it make lives easier and what kind of things, not possible before, can be achieved by using it?
The simplest example might be time synchronization between different devices. TV set might get the correct time from the broadcast stream and the other devices can query the TV and set their own clocks according to it. Setting the VCR to record a program is a familiar situation users usually have problems with. With HAVi enabled devices this task can be made very easy. User can select the program (s)he wishes to record with the Electronic Program Guide(EPG) residing on a digital TV set (or set-top-box). The task can be as simple as just browsing the program information, selecting the desired program and pressing one button to activate recording. The TV then locates an available recorder (e.g., a VCR or a recording DVD device) and commands it to record the program supplying it with the time, length and channel parameters taken from the EPG. Thus, the user doesn’t need to program or touch the recording device in any way.One of the more advanced scenarios might be automatic directing of an oncoming videophone call to the TV screen or part of it and muting all other sounds. Similarly, if a camera placed outside the door detects movement, the picture is automatically connected to the TV screen notifying the user about a possible visitor. All this could also be aided by giving voice commands to the devices. These are only some of the possible use cases. A lot more can be possible, especially when the HAVi devices are connected to other home appliances, PCs or even Internet. The possibilities HAVi offers seem endless and many of them might sound like science fiction or at least not likely in the near future, but that might not be the case. Many products have already been announced and several working demos have been presented at various consumer electronics fairs. HAVi (Home Audio Video interoperability) provides a home networking standard for seamless interoperability between digital audio and video consumer devices. In other words, all audio and video appliances within the network will interact with each other and allow functions on one or more appliances to be controlled from another appliance, regardless of the network configuration and appliance manufacturer. The spirit of HAVi is to extend the capabilities of consumer audio and video systems while decreasing the complexities
of their operation. It is expected that HAVi will become the de facto standard for high quality A/V networks HAVi will provide for a home network, which is optimized for audio and video devices .The main reason for having a dedicated HAVi network for the audio and video devices is that for the exchange of high quality digital video and high fidelity audio signals, a much higher bandwidth is necessary than can be provided by other home networks that are optimized e.g. to control home devices such as lighting, heating, air-conditioning, cooking appliances, etc. The possibility to integrate other home networks such as existing analog links, telephone lines or new wireless technologies into the HAVi network, was built into the HAVi architecture from the beginning and bridges to these networks are likely to be developed in the future.HAVi is an initiative from eight major Consumer Electronics companies. The eight CE companies are Grundig AG,Hitachi, Ltd., Matsushita Electrical Industrial Co., Ltd. (Panasonic), Royal Philips Electronics, Sharp Corp., Sony Corp., Thomson Multimedia and Toshiba Corp.HAVi provides an environment for audio and video devices to interoperate with each other, irrespective of the actual brands or their HAVi implementation. The HAVi architecture is open, scaleable in implementation complexity, platform-independent and language neutral, i.e. HAVi can be implemented in any programming language and on any CPU or real-time operating system. It provides CE manufacturers the freedom to develop interoperable devices while additionally, application developers can write Java applications for these devices using the open Interoperability API that HAVi provides. Current CE devices, such as Digital STBs and DV camcorders, contain sophisticated digital processing and storage systems. Future devices will contain even more sophisticated resources. By connecting these devices into the HAVi network it is possible to share their resources and use these to build up more sophisticated applications, such as
having two VCRs connected to two tuners with either VCR able to record the signal from either tuner. Under the HAVi system there is no single master controlling device: any device in the HAVi network that has been designed to do so can control other devices. Both the controlling devices and the controlled devices can be located anywhere within the HAVi network. HAVi also allows a device to be a controlling device and a controlled device atthe same time. The benefit of a network of interoperable devices is that the whole is greater than the sum of all the components.
For example, the time and program channels of a video recorder could be set by the information received by the television tuner. The user can now program a recording on a VCR following a menu generated by the TV on the TV screen. Even one step further, HAVi allows the TV to generate a complete menu structure to interact with any HAVi device or a combination of devices in the network, using ONLY the TV’s remote control, and present the system in a consistent way to the user. This will significantly improve the user-friendliness of the system. In the sameExample, if the VCR is also a controlling device, it could detect at recording time that the original tuner is not available e.g. because it is already in use by someone else. It could try to resolve this situation by trying to find another
2.1 HAVi and Home Networking
HAVi, Home Audio Video Interoperability The interoperability of HAVi devices seems pretty extensive and complex. Will the installation and configuration of the network be as complicated as in computer networks? Fortunately no, since devices are hot-pluggable and they are supposed to automatically announce their presence and capabilities to other devices and configure themselves when connected to the network saving the user from reading installation instructions and configuring network addresses and drivers. Finally, HAVi standard promises to be future proof by maintaining current functionality while making it easy to upgrade and add new capabilities. Non-HAVi devices can also be connected to the network if at least one of the HAVi devices supports the interface the legacy device provides. Here are some examples of how a HAVi system might work:
You are watching a show on television, and a phone call comes in. You have programmed the television set to automatically mute, so you can carry on the phone conversation without distraction. If you wish, you can carry on the conversation in video-phone mode, and use the television screen as the display.
Someone rings the buzzer at your front door. You walk over to a wall-based video intercom unit that is playing the five o'clock television news. The screen is switched to a video camera located over the front door so you can see who is there. The audio switches from the television show to a two-way link with the front door.
You are watching an educational television show, and a scientist uses a word that you do not recognize. You speak the word into a microphone, and an Internet-based dictionary, complete with speech recognition, looks the word up and displays the meaning(s) in the corner of the screen or announces the definition(s) in a synthesized voice.
The HAVi specification will be easy to upgrade. As is the case with popular Web browsers today, updates will be available for downloading from the Internet. You might even program the system to automatically download the updates as they become available. HAVi will be operational across devices from all participating manufacturers. Users will be able to choose their own favorite hardware brands. The video disk recorder (VDR), television set, telephone, home video intercom system, computer (if wanted), and telephone set (with or without video) might all be manufactured by different companies, but they will function seamlessly in the HAVi-based network. When a new device, such as a printer/scanner/fax machine, is installed, the system will configure itself to accommodate it. Somewhat similar standards for interconnecting devices include Home API (HAPI), Open Services Gateway Initiative (OSGi), Universal PlugnPlay, and Vesa Home Network. HAVi and Vesa are specifically aimed at the home entertainment environment. The other standards are aimed at remote interconnection and make use of Internet protocols