The Family Intercom

Vision

Over the last two years, we have been working on software infrastructure with our minds bent toward building an effective software intercom that might be deployed using ubiquitous computing paradigms in a house or small office. This intercom system would facillitate conversations across traditional house or office boundaries. Conversations might be initiated to connect any people as they move throughout the environment while one-way audio connections might allow a person to listen to a sleeping baby as he or she moved throughout the house. In our current implementation of the Family Intercom, we leverage existing locationing infrastructure in Georgia Tech's Aware Home. While we have been building the software behind such an intercom, colleagues here at Georgia Tech have been exploring the social semantics of such interaction. Figure 1 is an example screen from the current GUI implementation. People and intercom audio nodes (icombos) are displayed in the home based on where they are logically (master bedroom). The user can then actuate the GUI to create one or two-way connections between people and rooms. In this way, a person might listen or announce to a room/person/people, or rooms of people might communicate across the house's boundaries.


Figure 1, The current GUI for the Family Intercom allows simple visualization of where in the home users are. The users can then be connected via audio channels provided by nearby Microphone/ Speaker media nodes.

Research

Over the course of three implementations of the Family Intercom, we have learned some significant lessons about the deployment and development of ubiquitous computing infrastructure. Early in the process, we decided to use simple microphone/speaker combination nodes that would provide feedback-free full-duplex audio by using a specialized proprietary audio card. Our initial implementation was a very ad hoc deployment of singular programs allowing the connection of audio inputs to audio outputs through the MediaBroker. This implementation relied on a single control interface and required the direct specification of the network locations for all nodes. As the MediaBroker evolved our Family Intercom evolved into a second implementation. This second implementation still lacked the scalability and autonomic tendencies we wished for. Our third implementation again leveraged the MediaBroker to do what the MediaBroker was very good at; transfering media from sources to sinks while transcoding the media to suit all parties. This time, we have added UPnP to the implementation in order to allow autonomic creation of connections to other audio nodes as well as the now distributed control nodes. UPnP interaction has also allowed interaction with the new Aware Home location system based on transient UPnP People devices. The current audio node architecture and the current control node architecture can be seen in Figure 2.


Figure 2

After each iteratively more successful implementation of the Family Intercom we have examined our success and where we have still fallen short. Our experience with the Family Intercom has led us to look to what current academic and industry infrastructures exist and how they might be leveraged in the deployment of future applications. This examination has roughly emerged as the search for a standard ubiquitous infrastructure.