An Open Service Architecture with Location Aware Calls and Services

1
An Open Service Architecture withLocation Aware
Calls and Services

• Lill Kristiansen, Prof. Dr. Scient
• Dept. of Telematics, NTNU, Norway
• www.item.ntnu.no/lillk
• www.pats.no (lab-information)
• lill_kristiansen_at_hotmail.com

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Outline of the talk

• Trends in evolution
• Layering, separation and towards all-IP
• Some mobility definitions
• User mobility, service mobility, terminal
  mobility,
• Virtual home environment
• Brief overview of UMTS IMS system (release 5,..)
• Brief overview of Parlay / UMTS OSA
• API for value added services
• A framework to discuss technical solutions to
  mobility
• Illustrations of GSM/Camel and IMS/OSA in this
  framework
• Illustrations of possible middleman
  arrangements using OSA, to decrease the operator
  centric view

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The scope of this talk

• We are mostly based on the current and upcoming
  ETSI/3GPP definitions (GSM, IMS and OSA)
• We look into combinations of telephony and
  location based services
• We consider that each operator
• Has some hardware and software controlled by
  himself
• Hence has control over the non-functional
  requirements in this way
• We do not consider mobile code in general
• But we may foresee upgrades of software from
  vendor to operator, or from operators management
  system to operators switches (call servers and
  service nodes

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Evolution

• Several activities going on
• From CS (Circuit switched) to PS (Packet
  switched)
• From monolitic systems (GSM and PSTN) to layered
  systems with one common core systemwith several
  access technologies
• QoS and realtime aspects
• GSM (2G CS)supports voice interactive
  conversation with 1 medium)
• UMTS (3G first releases)
• CS multimedia (H.324M) supports multimedia
  telephony

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System topology

• Today
• Separate Networks
• Separate Users
• Separate Services
• Tomorrow
• Separate Accesses
• Same Core network
• Same User on different accesses
• Same Services

Separate Services
Data/IP Networks
PLMN
PSTN/ISDN
CATV
Separate users
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UMTS from release 5 on IMS IP Multimedia
Subsystem

• Same Core network
• Same User on different accesses
• Same Services
• I can use WLAN, ADSL, LAN, UTRAN (GPRS) etc. as
  accesses in ONE system
• I can have several devices and move between them

Servers
Content
Content
Communication Control
Access Gateways
Access Gateways
Backbone Network
Access
Access
Access
Users
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General types of mobility

• Mobility between several technologies (e.g. with
  the same handheld device having several (radio)
  access modes).
• User mobility across different devices.
• Mobility in a network (i.e. inside one
  technology).
• Terminal mobility in GSM network
• Either inside one operator domain (/one country)
• Or roaming (to a foreign contry/operator domain)

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General mobility definitions

• Personal mobility enables users to use services
  that are personalized with their preferences and
  identity ubiquitously, independently of both
  physical location and specific equipment. (From
  TINA-C in the mid-90ties)
• Service mobility (of a particular service) is
  defined as the ability for a user to obtain that
  particular service independently of user and
  terminal mobility. (Ericsson contribution to ETSI
  Tiphon 1999)
• Virtual Home Environment (VHE) is defined as a
  concept for Personal Service Environment (PSE)
  portability across network boundaries and between
  terminals. The concept of VHE is such that users
  are consistently presented with the same
  personalized . (3GPP TS 23.127)

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Evolution (modified from Kanter)
WAPe.g. email
MMoIP(1) e.g. MMS
MMoIP(2) e.g. steaming (and H.324M)
Mobile
3G from rel.5 UTRAN
MMoIP(3) IMS/telephony
Internet
4-G WLAN
MMoIP(4) e.g. P2T
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QoS and realtime aspects

• The CS part
• GSM (2G CS)supports voice telephonyi.e.
  interactive conversation with one medium
• UMTS (3G first releases CS) (H.324M) supports
  multimedia telephonyi.e. interactive
  conversation with multi media
• The data part
• GSM supports CS-data not used for
  conversation (too much delay)
• GSM/GPRS (2G, 2,5G) supports SMS, and MMS
  MMoIP(1) QoS BE Best Effort (not requiring real
  time support)
• GPRS with streaming MMoIP(2)
• From realease 5 All-IP common voice/data
• Full QoS enabling MMoIP(3) (VoIP and MMoIP
  in)IMS Interactive Conversational Services over
  IP, using SIP
• Via WLAN P2T/PoC (Push to Talk /over Cellular)
  varying QoS(delays and walkie-talkie-like)

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UMTS IMS architecture
HSS Home Subscriber Services HLR-like CSCF
Call Server Call/Session Control
Function P-CSCF Proxy- I-CSCF Interrogating- S-
CSCF Serving- xGSN GPRS-noder
Home B
Home A
HSS
HSS
S-CSCF
S-CSCF
I-CSCF
I-CSCF
Visited B
Visited A
P-CSCF
P-CSCF
GGSN
GGSN
SGSN
SGSN
Radio Access Network
Radio Access Network
B
A
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UMTS IMS basic call flow
Non-GPRS access Networks (e.g. WLAN)comes in
release 6
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Virtual Home Environment (3GPP)

• VHE enables end users to bring with them their
  personal service environment whilst roaming
  between networks, and also being independent of
  terminal used
• PSE Personal Service Environment
• describes how the user wishes to manage and
  interact with her communication services. It is a
  combination of a list of subscribed to services,
  service preferences and terminal interface
  preferences. PSE also encompasses the user
  management of multiple subscriptions, e.g.
  business and private, multiple terminal types and
  location preferences.
• The PSE is defined in terms of one or more User
  Profiles.

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3GPP OSA architecture

• Allows application to use underlying network
  resources
• Allows combinations
• Location capabilities (from GSM/UMTS and WLAN)
• Radionor Cordis Radioeye allows detailed
  location in WLAN
• SMS/MMS capabilities
• Call Control capabilities

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Parlay and UMTS Open Service AccessMigration
and Convergence
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Today (2000 and 2004) on PC type in your
location into web-pagemanuallyTomorrowfixed
LAN,and WLAN access into same core system
Parlay/OSA for data-services
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For data services (From Ericsson 2000) Avoid
typing, get location automatic e.g. into WAP
page (or into SMS content)
Today in Oslo, Norway(2004) Call taxi,
application fetches your locationnearest taxi
comes (combinations call, location,
applic.data!)Further issues mobility between
operators, countries and companies for this taxi
service
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A Framework to analyse the relations between home
and visited in 2G and 3G

• This figure assumes no mobile code
• i.e. more specifically
• Each box is hardware, software run by one
  operator
• (We may note that mobility in both 2G and planned
  versions of 3G all assumes no mobile code.)

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Framework applied to 2G with OSA

• NOTE There is a typo in the paper, this is the
  right version of Figure 3, showing Camel

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3G IMS system in this reference model

• This is previous IMS-slide, now slightly
  re-arranged

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OSA revisitedwith several service providers
involved
This may be the (national) regulator
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Advantages with this new solution

• Less operator centric
• Does not require the 3rd party service provider
  to have a business relation with the operator
• The regulator acts as neutral middleman
• assuring equal access for all service providers
• Single point of contact for the enduser
• Easier for the enduser to enforce a good privacy
  policy

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Network centric / operator centric

• AS3 is a network based solution, but totally
  independent from the network operator domain
• A personal web-page might also act as a network
  based solution
• See Jan Egil Kristiansen Our addresses and
  phones, http//heima.olivant.fo/styrheim/kontakt.
  en.html
• The enduser himself controls the user mobility,
  and (in non-realtime) informs his contacts about
  the current terminal/SIM card)
• Allows the enduser to buy local GSM-cards,
  instead of the often more expence network
  operator centric solution with roaming That is
  often very expensive, and subject to little
  competition

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Summing up the reference figure

• Allows us to discuss different business models
  between home and visited networks
• Fits in with 2G Camel OSA
• Shows some major drawback with Camel
• Due to call server (MSC in visited network)
• Also fits in with 3G (IMS) OSA
• Nice to use when discussing the advantages of
  having S-CSCF in home network vs. (the now gone
  option of S-SCSF in visited network)
• Useful when discussing the fully mobile case of
  call nearest taxi
• Fits in also with private initiatives not
  described in the 3GPP standards
• Further issues Mobile code is not covered