Salutation in the Home

Consider the home of the future. Visionaries are designing home networks which will interconnect the information, entertainment, security and environment control appliances found in your home. These interconnections will provide you with a higher degree of control over the information and entertainment that comes into your home, allowing you to decide when, where, and how they will be used. Home networks will allow you to access your home from the Internet, allowing you to change the settings of your heating, sprinkler, lighting, and security systems. You will be able to perform power consumption monitoring. Your devices will run self checks and call for repair service without your intervention. Pretty cool, huh!

There's lots of neat stuff behind the scenes to coordinate this activity, and the Salutation Architecture (www.salutation.org) will be in there to help. Salutation's Capability Exchange and Service/Availability Requests provide just what's needed to coordinate interoperability within a home network.

Let's examine a home configuration, beginning with a component home entertainment system and growing it to a sophisticated online home of the future, and see how Salutation plays a role in each stage.

The Digital Entertainment Center

The Digital Entertainment Center of the future will be similar to those purchased today -- modular units which interconnect via easy to install wiring. This enables a user to assemble various components to meet desired price/performance objectives. Let's assume that the entertainment center consists of :

As is the case today, the functionality of these components varies by manufacturer and price. For example, a sound amplifier may or may not have Dolby, Surround Sound, graphic equalizer, balance and fade controls, etc. The HDTV monitor may or may not have multiple inputs such as computer generated RGB, analog NTSC/PAL, SVHS, or MPEG, with support for various compression and encryption algorithms.

Once these pieces of equipment are interconnected, the owner expects that they will function together with the highest capable levels of visual and audio performance with a minimum amount of technical knowledge on the owner's part. The owner expects to plug it in and begin to play.

Salutation's value-add provides each piece of equipment knowledge of the capabilities of other equipment in the configuration. For example, each time the DSS receiver/tuner is turned on, it has a Salutation dialog with the HDTV monitor to determine its capabilities. With this information, it selects the monitor's input stream that has the highest picture quality. Likewise, the DSS receiver/tuner has a Salutation dialog with the sound amplifier and sends audio data in the correct form and format to provide the optimum audio quality. Similar scenarios can be constructed for use of the FM tuner and CD player -- Salutation dialog is used each time a unit is activated to determine what's there and how to use it. If the owner adds a new piece of equipment to the entertainment center, or upgrades an existing piece, the Salutation dialog allows the original equipment to sense the capabilities of the new stuff and make appropriate changes -- without the knowledge or intervention of the owner.

In the scenario above, there is no central directory. Each piece of equipment performs its own search of the local environment, finding only the information it needs to match its functionality. For example, the DSS receiver/tuner would not interrogate the CD player and visa versa. Since the Salutation dialog is performed each time the equipment is activated, there is no need for persistent storage in any unit.

The Wireless Remote

Salutation will enable a true universal wireless remote control. With a Salutation enablement, the remote can sense the capabilities of the equipment in the local environment and adjust the form and format of device interactions and user interface accordingly. For the entertainment center described above, using Salutation dialogs, the remote would sense all components. The remote would then configure the user interface to provide control of the devices in the entertainment center, then initiate the appropriate wireless commands when the user interface is activated. The Salutation Service Personality is a good choice for this interaction, as it provides a technique for binding between the remote and a specific Functional Unit, and passing information through that binding.

In essence, Salutation provides a technique to program the remote device on the fly. Therefore, as the user caries the remote to another room, it will immediately discover the devices in that new environment and adjust its user interface and device interactions accordingly.

The sophistication and price/performance point of the remote will determine if it contains persistent storage. With persistent storage, the remote may contain User Functional Unit descriptions with attributes for users' favorite audio and video settings as well as the favorite content channels. When a user identifies him/herself to the remote, the associated User Functional Unit is interrogated and the remote can cause the preassigned attributes to be set in the associated devices.

Salutation is implemented above the transport layer. Therefore, the Salutation dialogs between the entertainment center components and the remote are the same dialogs used among the various entertainment center components in the earlier discussion. A single Salutation implementation may be accessed over wired and/or wireless transports. In order to provide both 'plug and play' and 'remote' functionality, a manufacturer need only provide a single Salutation implementation and the appropriate transports.

The Home Controller

A more sophisticated home may have a central controller. This device monitors the home's systems, routes information from content provider entry ports (cable, DSS, phone, etc.) to viewing station (PC, TV, etc.), and manages connectivity requests, content filters and service requests. To perform its functions, the central controller must understand the configuration and capabilities of the components of the home. Salutation provides the mechanism for retrieving this information and maintaining a central directory.

Because of its scalability (refer to section on Scalability of Salutation Architecture at the end of this paper), the Salutation Registry may be used to store information about local Functional Units, information about local and selective remote Functional Units, or about all Functional Units, regardless of location. This latter usage provides a 'whole house' directory mechanism. Another positive aspect of Salutation's registry is its implementation dependency. That is, the Salutation Architecture requires a registry for storing Functional Unit attributes, but does not specify its structure (the architecture specifies only the form and format of this information in the Salutation Protocols and APIs -- not the directory format). The internal format is an implementor's choice. Therefore, the Salutation Manager Registry could be built as a flat file or on a popular directory base such as Novell Directory Service (NDS).

As noted in the discussion of remote controllers, support for a Salutation central directory does not require additional functionality in the device. Therefore, with one Salutation implementation, a device may support a local interconnect, remote control and central directory configurations.

Legacy Product

Home networking is not a new concept. Technologies such as X10 and CEBus have provided limited interconnectivity in the home environment for many years. A home networking solution must include these legacy products to assure growth into existing installations.

Salutation embraces a Port-of-Entry model to support legacy environments. The Port-of-Entry provides a bridging technique between the legacy environment and the Salutation environment. A Port-of-Entry is created by enabling one node in the legacy environment with Salutation. All nodes in the legacy environment are registered as Functional Units with the Salutation Manager in this Port-of-Entry node. Registration may be automated if the legacy environment supports device discovery processes. Otherwise it is manually described through the user interface of the Port-of-Entry or the central home controller.

Commands, controls and data within the legacy environment are not changed and function as usual. The legacy environment is represented to the rest of the home network through the exchange of Functional Unit Attributes via the Salutation Capability Exchange. One of these Functional Units will be defined for the Port-of-Entry, detailing the type of legacy network supported.

The Salutation Emulated Personality provides a mechanism for a devices, applications or services located outside of the legacy domain to interact with the legacy devices using legacy commands, controls and data formats. The Salutation Emulated Personality delivers legacy formatted information to a specific legacy Functional Unit through the Port-of-Entry via a Salutation Service Request. The Port-of-Entry strips off the Salutation wrappers and delivers the remaining information to the legacy network.

Home Office

Office equipment manufacturers have begun to roll out Salutation-enabled devices. These manufacturers will resist supporting additional discovery and service control protocols if Salutation already meets the needs of the home environment. With Salutation available in the home office desktop (via the IBM SLM), using the PC to discover other non-office devices in the home make it (the desktop) a candidate for a central home control station and/or home/Internet gateway.

With the scalability of Salutation, the home PC could function as a central directory for the home network. This is logical use of the PC as it contains persistent storage needed for directory-like functionality. Existing directory models/implementation exist in the PC space, providing for short time-to-market implementations.

Fault Tolerance

A major concern for designers of home networks is keeping the system operating if a portion of the network is down. As noted above, the scalability of Salutation provides for interoperation of equipment clusters within the home network without the necessity of a central controller. For example, the entertainment center may function as an independent cluster even when the central controller is not operating. And the remote may reconfigure itself by interactions with local devices rather than depending on a centralized directory.


A single implementation of Salutation in a device enables

A device manufacturer implementing Salutation can operate in all three of these environments without retrofitting or upgrading.