Voice Project Review
December 18, 1986

CSL Voice Project

· Background and rationale
· Current goals
· Who has done what

· System overview (video), summary of overall architecture
· Recent applications
· Summary of overall architecture

· Conversation control (switching)

· Recorded voice support, databases 
· System issues

· Directions
Background, Rationale
· Taming the telephone
critical component in office
user interface still crude
not well integrated into other office tools
· Voice as data
recorded voice messages
synthesized text-to-speech messages
speech recognition (not yet)
voice-annotated documents
integration with other interactive applications
· Earlier PARC attempts to incorporate voice fell short of critical mass
Danray system in POLOS
Alto voice boards
. . .
Overall Goal: A Voice Systems Architecture
· User-programmable
language-level interfaces
simple things are simple
complicated things make sense
acceptable impact on reliability
· Supports interoperability
multiple workstations and environments
multiple networks and protocols
multiple telephone transmission and switching choices
· Extensible
admits new applications
admits new services
admits new workstations, networks, . . .
Voice Architecture Layering
<<Interpress Artwork: []<>Users>Terry.pa>Talks>IntervoiceLayers.IP!2 topMargin: 50.8mm, height: 152.4mm, width: 190.5mm>>
Cast of Characters
· Project management
D. Swinehart, S. Ornstein
· Hardware design and implementation, Etherphone software
L. Stewart, D. Swinehart, S. Ornstein
· Telephone control, switching, overall software architecture
D. Swinehart, S. Owicki
· Voice file server
J. Ousterhout, S. Ades (Cambridge student)
· Voice synthesizer integration
P. Zellweger
· Databases, recorded-voice support ("voice ropes"), telephone directories
D. Terry, L. Adams (Stanford student, 1983)
· Workstation Applications
P. Zellweger, S. Ades, D. Swinehart, S. Owicki
Voice Control Server
· manages connections
· monitors and controls state of each Etherphone
· coordinates workstation user interfaces
· stores voice objects
· maintains databases
Etherphone-workstation assignments
directory assistance (white/yellow pages)
ring tunes
Conversation Management
· one or more parties per conversation
sources and sinks of voice
non-voice participants, e.g. workstations
· conversation establishment
state machine (idle, notified, ringing, ringback, active, ...)
parties act autonomously
notifications of state changes
· authenticated or presumed identities
· active parties use Voice Transmission Protocol
· broadcast reports during active conversation
encryption key distribution
recording started, playback finished, etc.
Conversation Management -- Challenges
· Novel conversation models
background calls, lectures, "watercooler" simulators
unsymmetric participation in (multiple) conversations
under workstation program control
· Workstation/telephone partnership
workstation decisions override telephone decisions
workstation tracks telephone-initiated activities
default behavior when workstation fails or drops out
· Reliability in the face of:
simultaneous actions by all parties
possibly-unreliable client code in workstation
distributed control, failures
real-time nature of the activity
Directions
· Left to do
Intervoice for Etherphone system released to programmers
Provocative telephone applications
Receptionist's assistant
Group background calls (SCL flavor)
Locator
Call filtering
Publication, technology transfer
· Current plans
after 1-1-87, as time permits (some aspects become part of other projects, e. g. document frameworks)
provocative telephone applications "unfunded"

· Possible customers
Corp. strategy -- Intervoice becoming feasible
"ISD?" -- never had stable customer
ISL -- myriad voice interests
SCL -- related interests, but possibly disjoint approaches; low-level technical communications problems