1. Why did HAVi adopt IEEE-1394 for the HAVi network?
   
   
2. Is HAVi IEEE-1394 specific?

HAVi adopted the IEEE-1394 bus (also referred to as i.LINK™ or FireWire™) as the underlying network technology for the HAVi protocols as well as for the transport of the real-time AV streams. Today this means that HAVi devices are IEEE Std 1394-1995 and also IEC 61883 compliant for the transport of real-time AV streams like DV and MPEG2. More precise compliance requirements can be found in section 1.5 of the HAVi specification.

IEEE-1394 was adopted because of the following features:

• Support for isochronous streams to transfer real-time AV streams.
• Sufficient speed (400 Mb/s) at acceptable cost.
• Hot plugging, self configuration.
• Transfer of asynchronous commands for the HAVi protocols and isochronous streams over the same interface.
• Wide acceptance in the CE and IT industry.

In IEEE, additional standardizations are ongoing such as P1394.a, P1394.b and P1394.1. These standards enhance the functionality of IEEE Std 1394-1995 to allows for higher speeds, longer distances and larger configurations. When these standards are completed, HAVi will evaluate these new technologies. However for the next 2 to 3 years, IEEE Std 1394-1995 will allow users to build clusters of HAVi devices of sufficient size and complexity to prove valuable for users.

Yes. IEEE-1394 is the only mandatory interface for a HAVi device, as well as for a BAV device. This guarantees that all HAVi and BAV devices can be physically connected (they have the same type of plug) and it also prevents the need for internetworking as a general mechanism in the HAVi protocol stack on each HAVi device. This greatly simplifies issues for the user as well as for HAVi devices in these ways:

• Adding new devices remains a matter of plug-and-play for the user.
• No need for special and possibly expensive devices like routers or gateways that may need to be configured by the user.
• No need for additional protocols in the HAVi protocol stack. However, this does not prevent individual vendors from offering multiple interfaces on their HAVi devices, such as wireless links, analog, etc., to be able to connect more devices. It is up to the manufacturer of such a HAVi device to provide a DCM and, if necessary, transcoding of real-time AV streams to allow other HAVi devices to control these devices and send or receive real-time AV streams from it.