The remarkable growth of the digital AV market in recent years has made it apparent that the time will come when users will find it necessary to be able to connect their digital AV appliances to create home entertainment networks. For different brands of AV electronics appliances to be interconnected and interoperated, each appliance must incorporate middleware that contains certain software elements common to all appliances on the network. The core open home network specification defines these elements, their roles, and their functions. In addition, it ensures that the software elements of different appliances will work together.

Home networks comprised of AV appliances which incorporate the core open home network specification will provide users with the convenience of the following:

A) Plug-and-Play Connectivity

Users will be able to create a home network simply by connecting various electronics appliances through their digital interfaces, such as the IEEE1394. If a user wants to add a new appliance to or remove an appliance from the network, he or she can do so without adjusting any settings because the appliances would be able to communicate, recognize changes in the network configuration, and automatically make adjustments to the network settings without interrupting the functioning of the network.

B) Appliance Interoperability

Not only would users be able to interconnect and interoperate AV electronics appliances based on this specification, but in the future it will also be possible for appliances on the network to share functionality. This means that any one appliance could make use of the functions and capabilities of the many different appliances connected to the network.

C) Future-proof Appliances

Once appropriate applications software is developed, electronics appliances incorporating these specifications will be able to share functionality. This means that consumers will be able to import functions from newly purchased appliances into appliances purchased earlier as long as both appliances incorporate the HAVi specification.

1)	1394 Communications Media Manager (CMM) - acts as an interface between the other software elements and the IEEE1394.
2)	Event Manager (EM) - informs the various software elements of events in the network such as the changes in the network configuration that occur when appliances are added or removed from the network.
3)	Registry - maintains information about the appliances connected to the network and the functions they offer. Applications can obtain this information from the registry.
4)	Messaging System (MS) - serves as an API (Application Programming Interface) that facilitates communication between the software elements of the various appliances on the network.
5)	Device Control Module (DCM) - represents an appliance on the network. Applications programs can interact directly with a DCM. This shields them from the idiosyncrasies of each individual appliance.
6)	DCM Manager - Installs the DCMs. It automatically reacts to changes in the network by installing new DCMs for new appliances
7)	Data Driven Interaction (DDI) Controller - renders a GUI (Graphical User Interface) on a appliance's display on behalf of a HAVi software element. It supports a wide range of displays, varying from graphical to text-only.
8)	Stream Manager (SMGR) - creates connections and routes real-time AV streams between two or more appliances on the network.

Grundig, Hitachi, Matsushita, Philips, Sharp, Sony, Thomson and Toshiba plan to promote the HAVi core specification broadly as an open standard not only for the AV electronics industry, but for the entire multimedia industry as well.

The HAVi core specification is available at the following web-sites for evaluation purposes only.