Making the phone not ring

1
Making the phone not ring

• Henning Schulzrinne
• Department of Computer Science
• Columbia University
• hgs_at_cs.columbia.edu
• Internet2 spring meeting
• May 3, 2005 (Arlington, VA)

2
Overview

• Ring-and-hope ? presence-mediated communications
• Uses for presence
• Old Im on-line
• Location-based services
• Presence-derived call handling
• Presence-derived trust
• Presence and privacy

3
Context-aware communication

• context the interrelated conditions in which
  something exists or occurs
• anything known about the participants in the
  (potential) communication relationship
• both at caller and callee

4
Evolution of VoIP
how can I make it stop ringing?
does it do call transfer?
long-distance calling, ca. 1930
going beyond the black phone
amazing the phone rings
catching up with the digital PBX
1996-2000
2000-2003
2004-
5
The role of presence

• Guess-and-ring
• high probability of failure
• telephone tag
• inappropriate time (call during meeting)
• inappropriate media (audio in public place)
• current solutions
• voice mail ? tedious, doesnt scale, hard to
  search and catalogue, no indication of when call
  might be returned
• automated call back ? rarely used, too inflexible
• ? most successful calls are now scheduled by email

• Presence-based
• facilitates unscheduled communications
• provide recipient-specific information
• only contact in real-time if destination is
  willing and able
• appropriately use synchronous vs. asynchronous
  communication
• guide media use (text vs. audio)
• predict availability in the near future (timed
  presence)

Prediction almost all (professional)
communication will be presence-initiated or
pre-scheduled
6
Basic presence

• Role of presence
• initially can I send an instant message and
  expect a response?
• now should I use voice or IM? is my call going
  to interrupt a meeting? is the callee awake?
• Yahoo, MSN, Skype presence services
• on-line off-line
• useful in modem days but many people are
  (technically) on-line 24x7
• thus, need to provide more context
• simple status (not at my desk)
• entered manually ? rarely correct
• does not provide enough context for directing
  interactive communications

7
Rich presence

• More information
• automatically derived from
• sensors physical presence, movement
• electronic activity calendars
• Rich information
• multiple contacts per presentity
• device (cell, PDA, phone, )
• service (audio)
• activities, current and planned
• surroundings (noise, privacy, vehicle, )
• contact information
• composing (typing, recording audio/video IM, )

8
Presence data model
calendar
cell
manual
person (presentity) (views)
alice_at_example.com audio, video, text
r42_at_example.com video
services
devices
9
RPID rich presence

• Provide watchers with better information about
  the what, where, how of presentities
• facilitate appropriate communications
• wait until end of meeting
• use text messaging instead of phone call
• make quick call before flight takes off
• designed to be derivable from calendar
  information
• or provided by sensors in the environment
• allow filtering by sphere the parts of our
  life
• dont show recreation details to colleagues

10
The role of presence for call routing
PUBLISH

• Two modes
• watcher uses presence information to select
  suitable contacts
• advisory caller may not adhere to suggestions
  and still call when youre in a meeting
• user call routing policy informed by presence
• likely less flexible machine intelligence
• if activities indicate meeting, route to tuple
  indicating assistant
• try most-recently-active contact first (seq.
  forking)

PA
NOTIFY
translate RPID
LESS
CPL
INVITE
11
Presence and privacy

• All presence data, particularly location, is
  highly sensitive
• Basic location object (PIDF-LO) describes
• distribution (binary)
• retention duration
• Policy rules for more detailed access control
• who can subscribe to my presence
• who can see what when

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12
Location-based services

• Finding services based on location
• physical services (stores, restaurants, ATMs, )
• electronic services (media I/O, printer, display,
  )
• not covered here
• Using location to improve (network) services
• communication
• incoming communications changes based on where I
  am
• configuration
• devices in room adapt to their current users
• awareness
• others are (selectively) made aware of my
  location
• security
• proximity grants temporary access to local
  resources

13
Program location-based services
14
Presence for spam prevention

• VoIP spam (spit) and IM spam (spim) likely to
  be more annoying than email spam
• Subscription to another person is indication of
  mutual trust
• other person allows me to see their status ?
  trusts me
• Thus, use watcher list (who is watching me) as
  trust vector

15
Conclusion

• Media delivery ? controlled interaction
• Binary presence ? rich presence
• Presence as enabler of loosely-coupled advanced
  services
• location-based services
• serve as service script inputs
• trust indicator for spit/spim prevention

16
Backup slides
17
Presence data architecture
presence sources
PUBLISH
raw presence document
privacy filtering
create view (compose)
depends on watcher
XCAP
XCAP
select best source resolve contradictions
composition policy
privacy policy
(not defined yet)
draft-ietf-simple-presence-data-model
18
Presence data architecture
candidate presence document
raw presence document
post-processing composition (merging)
watcher filter
SUBSCRIBE
remove data not of interest
difference to previous notification
final presence document
watcher
NOTIFY
19
RPID rich presence