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ENME: An ENriched MEdia application utilizing context for session mobility;
technical and human issues
Lill Kristiansen, Prof. Dr. ScientDept. of Telematics, NTNU, Norway
[email protected]/~lillk
Mainly based on Master Thesis of Egil C. Østhus
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Content
Scenarios
Background material From telecom and pervasive computing
Overview of the ENME service implementation
Discussion
Ideas and issues for the health care domain
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Scenario 1: Business trip
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Scenario 1: Business trip
Peter is on a business trip, and is currently at the airport express train station. Peter carries a laptop (packed away), as well as a mobile phone (ready for use).
His boss Carl tries to contact Peter to discuss a presentation and wants to use full multimedia for this discussion. I.e., he proposes: voice, (video) and shared data application.
At the train station there are some ’multimedia booths’.
When called, they start with voice telephony (due to capability limitations).
After 1 min. Peter finds and enters one of these booths.
The system realizes the new capabilities and propose to Peter to use the new screen for both video and shared application.
The session moves to the new device and new media flows are added. The old mediaflows are ended.
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Scenario 2: In a hospital
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Examples of possible terminals (devices / MDAs) in the hospital setting
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Scenario 2: In the hospital
Eve is a doctor and is discussing a patient with a nurse who got worried about the situation. They use voice, as well as video showing the patients hearthbeat (ECG)
The multimedia conversation goes to an MDA (variant of PDA: Medical Digital Assistant)
Eve enters a multimedia booth
The system propose to move the video to a bigger screen
Variant: Eve passes a public bigger screen. Shall the video be moved?
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Focus in this paper
The border between human and technical issues NOT: The details of context gathering NOT: The details of the SIP protocol extensions NOT: The GUI details
BUT: How human issues add requirements to the technical
solution How technical possibilities may fit or not fit in with human
and organizational requirements
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Content
Scenarioes
Background material From telecom and pervasive computing
Overview of the ENME service implementation
Discussion
Ideas and issues for the health care domain
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SIP: Session Initiation Protocol
From IETF (Internet Engineering Task Force)
Also used by traditional telecom standardization bodies 3GPP (with ETSI for UMTS) for use in IMS
IPMultimedia Subsystem in UMTS
3GPP2 the US variant
Baseline SIP handles call set up SIP Refer handles ’call transfer’ (used by us) SIP allows for extensions (used by us)
SIP for presence SIMPLE (not used here, but relevant for pervasive comp.)
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Telecom and computer science
’Computing’ has less focus on realtime than telecom
Computing has more focus on rich information sources But only recently was the PDA capable of acting as a
phone
In the telecom domain one (always) assumes the possibility to call another person in another operator domain, and using another terminal vendor Without the need for installing common special software This is the reason why we wanted to experiment with
common SIP This assumption is not always present in computer
science / pervasive computing
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Recent changes in telecom
Servers
Users
Backbone Network
AccessAccess
Communication Control
Content Content
Access
Dat
a/IP
Net
wo
rks
Dat
a/IP
Net
wo
rks
PL
MN
PL
MN
PS
TN
/ISD
NP
ST
N/IS
DN
CA
TV
CA
TV
Separate Services
Separate users
To open layered system components (see e.g. IMS)
From several monolithic systems (PSTN, GSM, IP,..)
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Advantages of a layered approach
Using the same infrastructure for many applications and many services
Same core infrastructure for data (’chat’/IM) and phone, namely IMS (SIP Proxies etc.)
Same application may be used for non-real-time media and real-time media This may however not always be wanted (more later)
Typical example: Location and other context informaton may be used by
many applications
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Relevant work from pervasive computing
Some issues in pervasive computing [1]: Effective use of smart spaces Localized Scalability Invisibility
Weiser’s ideal that the computer disappears from the user’s consiousness
Masking Uneven Conditioning The deployment of pervasive computing into the environment
is depended on non-technical factors such as organizational structure, business models and economics.
Our focus here is on the last two bullets
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Definition of context
The definition proposed by Dey [2]:
“Context is any information that can be used to characterize the situation of an entity. An entity is a person, or object that is considered relevant to the interaction between a user and an application, including the user and application themselves.”
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Managing context information
Context stack proposed by Li[4]:
We base our work on such a model as this allows for the following the same context info may be used in many applications The same sensors may be used in many applications Many sensors may be used in the same application as well Basically the same advantages as for the layeres approach
shown before
Fusion
Conversion
Measurements
Sensor
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Context model
Henricksen et al [5] introduce an object-oriented approach. They suggest dividing the context information into persons, devices and channels.
Person Device
Channel
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Content
Scenarioes
Background material From telecom and pervasive computing
Overview of the ENME service implementation
Discussion
Ideas and issues for the health care domain
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Requirements of ENME
We base our implementation on SIP
We separate between the ENME subscriber and other users (i.e., the communicating partner(s))
Users shall be able to communicate with the subscriber of the ENME service using his normal SIP client and well established extensions of SIP
The ENME subscriber shall use plain SIP or well established SIP extensions to the extent possible
The service shall be meaningfull to the subscribers and other users, and make sense in their daily life/work
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The service logic
More formalized here1. Assume there is an ongoing communication session between
two or more users, the service maintain knowledge about users preferences when it comes to service description, e.g. voice only or video.
2. If a user moves to a new location, check for available devices. If there are devices that are better than the ones in use, and match user’s preferences, proceed to Step 3 . Otherwise goto to Step 1.
3. Request the user if he wants to move the session to a new device. Proceed to Step 4 if positive answer, goto to Step 1 otherwise.
4. Move (parts of) the session to new device. Then goto step 1
Still this description allows for much flexibility in the design
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Design of EMNE
We use the following entities in addition to the familiar SIP entities: Context handler
Receiving info from the sensors Talking SIP to the SIP-system (via SIP-proxies)
Context data Data repository
Our implementation uses RFID readers as location sensors
Our implementation: the user and his PDA is located on a model railroad
system RFID registeres 2 zones (The context model is more general)
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SIP and our context model
We base our work partly on [5], as well as on terminology from SIP
Session User
CapabilitiesDevice
Zone
has
takes part in
is used in
is located in
is located in
Rough comparision with[5]:
User - Person Session – Channel
Device - Device
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Our context model
User: A person with access to use the offered application
Zone: A geographical area, e.g. a room or inside a booth.
Device A terminal, both public and nonpublic available. A device is
described by its capabilities (ability to support video and voice, screen resolution, speakers, related codecs, etc). Sub-entities: High/low capability device. (In the implementation only available codecs are looked at.)
Session A session is a communication between two or more parties. A
session may consist of zero or more dialogs. A dialog will comprise media transfer.
A zero-dialog session consists of only signaling, but no media transfer. This is according to SIP [7],
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Design continued
Voice
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Design continued
VoiceVideo
Voice
!
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Content
Scenarioes
Background material From telecom and pervasive computing
Overview of the ENME service implementation
Discussion
Ideas and issues for the health care domain
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Video
VoiceVoiceVoice
Discussion of simple alternative
By sending the SIP REFER message to the A terminal the technical solution would be much simpler But: This is meaningless, since A may never have heard of
ENME, the question should go to B (the subscriber)
?
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Virtual terminal
An other type of solution could use some type of virtual terminal
The new media flows goes via the handheld device Terminal must forward it, (though not display it) Timing/synchronization issues?
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Human factors
What about the user –terminal relation? Good to get a bigger screen? Or confusing to relate to different layouts on different
screens? Medium size for less confusion? Does one size fit all?
In our implementation the control part of the session follows the media flows to the new terminal. Maybe instead the control part should at all times stay on
the handheld device Needs to look into details in SIP to see if this is possible
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Media types (media richness theory)
User choose (wanted) media types when starting the service, Sometimes quite consious choice at initiation
….but may only get a subset Continue at all if less media?
Probably yes, if wanted media can be established ’soon’
It might be disturbing in the middle of the conversation to change media types Different media types have different properties, and one might
think that the ’communication strategy’ migh have changed due to less media. However this change in communication strategy in not explicit,
we cannot assume that the system can detect this easily/automatically.
Hence if the context handler keeps the wanted media types, it is not in accordance with the new communication strategy of the user. Adding media later is of no (good) use.
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Content
Scenarioes
Background material From telecom and pervasive computing
Overview of the ENME service implementation
Discussion
Ideas and issues for the health care domain
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Issues in a hospital setting
Security: many issues in general, even more in hospital setting(not
looked into)
Organizational issues! Shall the patient be able to call the nurse? (replacing the
current ’button’ near the bed) Shall a nurse be able to call a doctor? Shall healthcare workers be able to see each other’s
locations and status information? Call eachother, or write messages in the patient’s journal? Call a ’function’ /arbitrarily member in a group or call an
individual human?
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Related work in hospital setting
Mexico: IM (Instant Messaging) and message box in hospital setting but not for real time voice communication
Others: A lot for PDA/MDA and patient journal research Less with real time communication (’telephony’)
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Questions?
Contact:
Lill Kristiansen, Prof. Dr. ScientDept. of Telematics, NTNU, Norway
[email protected]/~lillk
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M. Forthuns work H2004
Using ServiceFrame for user context has been done by Forthun,
Using ServiceFrame also in this case combined with SIP might be looked into
Group communication in health care, implemented in ServiceFrame Full information and report can be found at:
http://www.item.ntnu.no/lab/nettint1/activities/prosjekter/host2003/ForthunPresentasjon.pdf
2 next foils are based on this student’s presentation
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Interface on the terminals
Location: Room 333Presence: Busy with patientGroupSession: 1
Mary Dan
Location: Room 337Presence: FreeGroupSession: 0
Primary group - G1
Help Patient
Stroke Unit
Primary group - G1
Stroke Unit
Able to help with patient
in Room 333?
Yes No
SCENARIO 1 FROM ST.OLAV – HELP WITH PATIENT
Keeping track of Context inform-ation
Automatic handling /redirecting of the message,based on type and context
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Location: Room 333Presence: EmergencyGroupSession: 1
Emergency team
The patient’s doctor
Dan
Primary group - G1
Emergency
Stroke Unit
Primary group - G1
Stroke Unit
EMERGENCY IN ROOM 333
Interface on the terminals
SCENARIO 2 FROM ST. OLAV – EMERGENCY
Location: Room 310Presence: EmergencyGroupSession: 1
Eve
Location: Room 310Presence: EmergencyGroupSession: 1
Benny
Location: Room 310Presence: EmergencyGroupSession: 1
Anna
