Advanced Paradigms for Building Convergent Next Generation Services. Service Composition and Service Brokerage in Multimedia Architectures

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12 Νοε 2013 (πριν από 3 χρόνια και 11 μήνες)

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Slide title

In CAPITALS

50 pt




Slide subtitle

32 pt



Advanced Paradigms for Building Convergent Next
Generation Services. Service Composition and
Service Brokerage in Multimedia Architectures

Dr. Sorin Georgescu

sorin.georgescu@ericsson.com

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

2

Agenda


NG Service Platform


Multimedia Services Ontology


Service Composition Patterns


Adding Semantics to Service
Composition


Enhancing the Business Model
through Service Brokerage

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

3

Next Generation Networks Evolution Drivers


Societal and Business trends



Internet is becoming a major enabler
of communications



Consumers are embracing
computing, mobile and digital
technology in their everyday life



Evolution of Business models require
increased levels of personal mobility


Access Technology Enhancements



HSPA (High Speed Packet Access)


evolved
WCDMA



OFDMA (Orthogonal Frequency Division
Multiple Access)


3GPP LTE, WiMAX, MBWA,
ADSL/VDSL, DVB
-
T/H etc.



Spatial Processing


multi
-
antennas Base
Stations supporting advanced spatial processing


Convergence



Converged devices (Mobile, WLAN,
Internet etc.)


Connectivity



Converged services


Ease of
use



Converged networks


Reliability,
Security, Reduced OPEX/CAPEX



Converged business models


Increased margins, Avoidance of
twin pitfalls risk


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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

4

The Evolution to Multimedia Applications

A Mobile View

Image

SMS

MMS

Presence

Active

phonebook

Push
-
To
-
Talk

Text

Voice

Voice

P2P Calls

Video

Person
-
to
-
Person

dominates traffic growth

Movies

Photos

Internet

Text/Pictures

SMS/MMS

HTTP

Streaming

Download

Video

Music

Ring tone

Person
-
to
-
Content

known usability patterns

Multimedia

Content

Social Networking

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

5

IMS


3GPP Architecture for Convergent Next
Generation Services



IMS is an open IP
-
based
architecture using the Client
-
Server
Network Computing model.



3GPP originally specified IMS to
enable real
-
time multimedia
services over the IP bearer, in GSM
and W
-
CDMA networks.



Later, 3GPP2 specified the MMD
architecture for CDMA2000
networks based on IMS. 3GPP2
requirements are part of Common
IMS in IMS release 8.



The xDSL access, specified by
TISPAN, is integrated into IMS.



The cable access, specified by
CableLabs in PacketCable 2.0, is
part of IMS release 8.



Interworking with WLAN was
specified in IMS release 6, while the
mobility with WiMAX has been
addressed in EPC specifications.

If IMS is not used:



Multimedia communication at best effort



Service roaming can be difficult to implement



Provisioning and charging are service specific



Compliance with LI requirements can be an issue

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

6

IMS Service Routing


the IFCs

P
-
CSCF

Visited A

P
-
CSCF

Visited B

S
-
CSCF

IMS AS

HSS

S
-
CSCF

IMS AS

HSS

I
-
CSCF

1

2

3

4

Home A

Home B

5

6

7

8

9

10

11



In comparison to IETF SIP Routing
where the originator of SIP request may
specify a preferred path in the Route
header, in IMS the P
-
CSCF removes
this path and ensures that IMS SIP
Routing is followed.



SIP requests in IMS architecture are
always routed to the Home S
-
CSCF, in
both the originating and terminating
network.



The S
-
CSCF uses subscriber’s
Service Profile (downloaded during
registration), to link
-
in the SIP AS’
which will process the SIP request.



The Initial Filter Criteria (IFC) within
the Subscriber Profile provide a simple
service logic to decide which AS shall
be linked
-
in. These rules are of static
nature i.e. they do not change
frequently.

IMS Service Routing =
Service Profile based Routing

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

7

Limitations of ISC Service Orchestration Model



The application server decides whether to remain
linked
-
in for the whole session by
adding its
address to the Record
-
Route SIP header.



Application Servers are unaware of the existence
of other AS', and whether these will be linked
-
in.



No service or session state will be passed
between application servers unless they use
proprietary extensions i.e. are co
-
designed.



Response messages are routed to the AS’s in the
reverse order

S
-
CSCF

HSS

SIP
-
AS

SIP
-
AS

SIP
-
AS

I
-
CSCF

S
-
CSCF

HSS

SIP
-
AS

SIP
-
AS

SIP
-
AS

I
-
CSCF



If during call handling procedure an AS retargets
the SIP request by changing the Request URI,
subsequent filter analysis in the S
-
CSCF is stopped
and the S
-
CSCF forwards the request towards the
new target without linking
-
in the other AS’ specified
by IFC.

Req URI = A

Req URI = B

1

2

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

8

NG Service Platform

The IMS
-
based Design

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Multimedia Service Composition and Service Brokerage

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9

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

10

NG Service Platform

Functional Description

Service
Composition
Service
Brokerage
Service
Discovery
Service
Mediation
Web 2.0
RSS
REST
OpenSocial
AJAX
IT/Business
Partners
Semantic WS
WS
IMS & Non
-
IMS
Enablers
Native API
Parlay X WS
Service
Composition
Service
Composition
Service
Brokerage
Service
Brokerage
Service
Discovery
Service
Discovery
Service
Mediation
Service
Mediation
Web 2.0
RSS
REST
OpenSocial
AJAX
IT/Business
Partners
Semantic WS
WS
IMS & Non
-
IMS
Enablers
Native API
Parlay X WS
Service Composition:





Invokes the services published by external
Service Providers which are interconnected in a
Service Overlay Network.



Services can be linked in statically (BPEL
workflows) or dynamically, using their semantic
description (OWL
-
S)



Corresponds to the network
-
centric composition
model => lower complexity of client implementation.

Service Mediation:



Mediates service protocols, data format, identity,
security features, business processes


Service Brokerage:



Negotiates with other brokers in the Service
Overlay Network the services which the Service
Composition function will invoke.



Uses context information to bind services
based on dynamic conditions.

Service Discovery:





Publishes local services and performs service
searches in the Service Overlay Network.



Searches can be static (UDDI queries) or
dynamic (UDDI queries with constrains, SWS
Proxy queries).

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

11

Agenda


NG Service Platform


Multimedia Services Ontology


Service Composition Patterns


Adding Semantics to Service
Composition


Enhancing the Business Model
through Service Brokerage

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mark,
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partner logotypes.
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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

12

Service Modeling using Ontologies

Gruber, 1993:

“An Ontology is a formal, explicit specification
of a shared conceptualization of a domain.”



Formal = unambiguous, machine
understandable, described using a formal
language



Explicit = precise, clarifying the subject



Conceptualization = abstract representation
of the object of study



Ontologies consist of a set of axioms which
place constrains on classes of individuals, and
the types of relationships allowed between
them.



Can be described in graphical form (ex. RDF,
UML) or logical form (ex. Description Logic,
Rules).

Semantic Web Stack

User Interface and Applications

Trust

Encryption

Proof

RIF/ SWRL


OWL



Logic

RDFS



SPARQL



RDF

XML

URI

Unicode

RDF/S = Resource Description Framework / Schema

OWL = Ontology Web Language

SWRL = Semantic Web Rule Language

RIF = Rules Interchange Format

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

13

Multimedia Services Ontology



Multimedia Services Ontology is a
sub
-
ontology of
Multimedia Ontology

which is associated to Multimedia
Communication domain.



Multimedia Ontology makes
multimedia services provided by various
Service Providers (Telecom, IT, Web
2.0) interoperable.

Constructs of the ontology:



Syntactic/semantic description
of offered services (WSDL/OWL)



Description of mediation
functions that can be linked
-
in at
run
-
time



Description of data published



Specification of communication
protocols



Description of Service
Composition framework. Should
include, if applicable, the
description of the language used
to specify the semantic
composition

Multimedia

Ontology

Services

Sub
-
ontology

Identity

Sub
-
ontology

Presence

Sub
-
ontology

Content

Sub
-
ontology

Security

Sub
-
ontology

Context

Sub
-
ontology

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Multimedia Service Composition and Service Brokerage

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14

Agenda


NG Service Platform


Multimedia Services Ontology


Service Composition Patterns


Adding Semantics to Service
Composition


Enhancing the Business Model
through Service Brokerage

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partner logotypes.
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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

15

Service Oriented Computing (SOC)

Service composition types:




Service Orchestration

= centralized engine which
coordinates composed services according to a set of rules
(workflow specification)

Service Choreography

= multiple actors/agents participate
at the implementation of service composition
(orchestration between every pair of choreographers)

Distributed Computing Evolution


Message Driven
(MOM)

Components
(Corba, EJB)

Client/Server

Service Oriented
(SOA, Web 3.0)



In SOC, applications are statically/dynamically composed using
services deployed in the network. The collaboration model can be
t
ransactional (synchronous), or workflow
-
based (asynchronous)



SOA is one possible realization framework of SOC. The
communication paradigm typically used in SOA is Web Services



Web
Services are:



Published (WSDL, OWL, SWSF)



Deployed



Discovered (UDDI, WSMO)



Invoked (SOAP)

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Multimedia Service Composition and Service Brokerage

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16

Service Oriented Computing (cont.)

Static Service Composition

Developer

Studio

End User

Studio

Service
Creation
Environment

Publish

UDDI

Composition

Engine

Discover

User / Service
Profile

User context

BPEL

Rules

Ambient
context

Service Discovery

and Publication

Temporal
context

Broker

Context

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

17

Web 2.0 in SOC landscape

Tim O’Reilly Web 2.0 definition:



The Web as a platform



Leverages customer data management (mash
-
ups) and user interaction model. Hence the
challenge is to own core data (presence, location,
identity, namespaces)



Promotes service evolution through user
contributions.





The API’s exposed are simple enough so
anybody can innovate.



No more software release cycles. Services are
permanently in beta release.



Syndication of data instead of control. The data
owner is actually paid by the advertisers.



Multi
-
device client (ex. Google/Open Handset
Alliance Android mobile platform)



Rich user experience

Podcast
Wiki
Weblog
Folksonomy
Mashup
Share & Consume
Share & Consume
News
Web 2.0
Podcast
Podcast
Wiki
Wiki
Weblog
Weblog
Folksonomy
Folksonomy
Mashup
Mashup
Share & Consume
Share & Consume
News
News
Web 2.0
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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

18

Web 2.0 Design Elements

Devices

Transport / Control Layer

Service Enablers

Application

Social APIs

Social Applications



Blogs, Wikis, IM & Chat



Buddy List, Mashups



Publishing, Content Sharing




Open APIs: REST, RSS, JSON,
SOAP, XML



Widgets: OpenSocial, Web Widgets,
Gadgets, Badges



Syndication: RSS, ATOM

OpenSocial highlights:



Based on open standards
(XML, HTML, Javascript,
ATOM and REST). Uses
Google Gadgets FW.



Can be combined with
OpenID (common identity
framework).



Personal data moves from
site to site.



Each API addresses one
area: People & Friends,
Activities, Persistence,
General API.

Mashup highlights:



Aggregation of data centric network services using asynchronous interactions (AJAX)



Implemented with client/server or three
-
tier architectures:



Content/API provider: shares mashable data objects typically retrieved using
RSS, ATOM, SOAP, REST interfaces or “
Screen Scraping”



Mashup hosting site (in three
-
tier architecture): server which aggregates data
using Java Servlets, CGI, PHP or ASP.



Mashup client: uses client scripts (JavaScript) or applets to allow support of
Rich Internet Applications (RIA)



Data may be cached in the client device (SQLite)

Social Network Diagram

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

19

Service Composition in Web 2.0



Compared to BPEL/WSCI

developer
-
centric composition,
Web 2.0 uses
ad
-
hoc composition
. The user builds the
composite service “on
-
the
-
fly” from data retrieved from the
network. Mobile devices (Smartphones) now have 128MB of
RAM and 620 Mhz CPU, so Web 2.0 clients can now be
mobile.



Web 2.0 application design is performed by the end user who
in essence, has low programming skills. The service
composition is defined through interaction with a GUI.


Client controlled composition



Development: client components use APIs to access server
data



Execution: components run on the client and pre
-
fetch data
from the server


Server controlled composition

(early stage)



Development: the server uses public APIs to link services into
new services



Execution: the client invokes the server which acts as an
orchestrator

Photo Storage

Data Base

Node Service

Application Logic

Page Logic

API

Templates

Endpoints

Email

Flickr.com

3PP Appl.

Flickr Appl

Flicker Architecture

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

20

SOA Reference Model


Service
Description

Visibility

Reachability

Functionality

Service

Service
Interface

Interaction

Information
model

Contract &
Policy

Behavior
model

Real world
effect

SOA Service Description Model

What is SOA:


A paradigm which defines concepts
and general techniques for the
design, encapsulation and
instantiation of reusable business
functions using loosely coupled
service interactions

SOA Reference Model:



Service



Service description



Interaction



Contract & Policy



Visibility



Execution Context



Real world effect

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Multimedia Service Composition and Service Brokerage

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21

SOA Service Composition

SOA Characteristics



Services have well defined Service Contracts



Services are encapsulated



Services share a message bus and messages
exchanged are well documented



Services can be discovered dynamically



Services are loosely coupled



Systems of services are assembled at runtime

Routing based on service
identity (equivalent to PSI
routing in IMS)

Service bus functions:



Supports an asynchronous message
based communication protocol that
uses a common format encoding
scheme (SOAP/XML)



Routes, Translates and can Store
and Forward exchanged messages



Supports a Discovery mechanism

Application 1
Enabling
Service 1
AS1
Enabling
Service 2
AS2
Enabling
Service 3
Application 2
AS3
Enabling
Service 4
Appl
1
Terminal
Application 1
Enabling
Service 1
AS1
Enabling
Service 2
AS2
Enabling
Service 3
Application 2
AS3
Enabling
Service 4
Appl
1
Terminal
Client

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Multimedia Service Composition and Service Brokerage

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22

IMS
-
SOA Architecture

Service Enablers:



Provide functionality which can be used by other
end
-
user applications (ex. Location Service)



Unaware of the context in which they are used. Only
the consumer service is aware.

Service Bus



Handles the communication between IMS
Application Servers and the Service Enablers and the
communication with SOA Application Servers.



Optimized for Server
-
to
-
Server communication



Besides providing support for standard open
protocols (ex. SOAP), may provide support for Native
Interface protocols (ex. MLP, MM7, SIP etc.)

Service Orchestration



The consumer AS that invokes the Service Enabler
implements the SCIM function. An external Service
Broker may be used as well.



IMS Service Enablers are invoked from SOA
domain through the GW AS.

CSCF

IMS AS

GW AS

Service Bus

SOA AS

UDDI

SOA

IMS

Orig. network

SOAP/XML

SB API

SB API

Schema

Service
Contract

JSR 281

Enabler

SB API

SIP

MLP

MM7

Heterogeneous Service Bus
IMS
-
SOA Architecture

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

23

AS
HSS
CSCF
Media
resources
Sh
ISC
H.248
IMS Core Network
Trusted Domain
Trusted Domain
AS
Parlay
-
X WS GW
WS Security,
WS
-
Addressing
Customized
Compound
WS
IMS Service
IMS Service
Enablers
Enablers
AS
AS
Parlay
-
X, Customized interfaces
Parlay X Web Services

WS
-
I Basic Profile:

WSDL + SOAP

WS
-
I Secure Profile:

WSDL + SOAP + WS
-
Security



Parlay X Web Services is an
abstraction of Parlay WS



Parlay X WS GW acts as a
Service Broker SCIM



Enablers which only support
WS
-
I Basic Profile are
enhanced with additional WS
functionality such as WS
-
Security, WS
-
Policy, WS
-
Addressing



Services defined so far (17)
cover: call control, messaging
(SMS, MMS), payment,
location, geocoding and
mapping, presence etc.



Described in WSDL. Service
discovery is based on UDDI.

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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

24

Agenda


NG Service Platform


Multimedia Services Ontology


Service Composition Patterns


Adding Semantics to Service
Composition


Enhancing the Business Model
through Service Brokerage

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mark,
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partner logotypes.
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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

25


The Semantic Web

Tim Berners
-
Lee, 2001:

“The Semantic Web looks at applications that enable
transformations, by being able to take large amounts of data and be
able to run models on the fly
-

whether these are financial models for
oil futures, discovering the synergies between biology and chemistry
researchers in the Life Sciences, or getting the best price and
service on a new pair of hiking boots.”

Highlights:




Information on the Web is machine
understandable => automatic service
discovery, invocation and composition.



Modeled as a graph where nodes have
semantic descriptions. In Web 1.0 and 2.0
node descriptions are only syntactic.



Uses ontologies to represent elements of a
domain and their relationships (OWL
-
S,
SWSF, IRS
-
III, WSMO)

Non
-
semantic web tag:


<item>cat</item>

Semantic web tag:


<item rdf:about=“http://dbpedia.org/resource/cat”>cat</item>

Semantic Web Stack
User Interface and Applications
Trust
Encryption
Proof
RIF/
SWRL
OWL
Logic
RDFS
SPARQL
RDF
XML
URI
Unicode
Semantic Web Stack
User Interface and Applications
Trust
Encryption
Proof
Proof
RIF/
SWRL
OWL
Logic
RDFS
SPARQL
RDF
XML
URI
Unicode
SWS

Service Profile

Semantic Modeling using OWL
-
S

Service Grounding

Service Model

SWS = Semantic Web Service

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Multimedia Service Composition and Service Brokerage

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SWS Execution Engine

Semantic Execution Environment



Performs semantic information
processing and ontology reasoning in
order to:



discover and select the
matching service



mediate the data, the protocol
or the business process
associated to service invoked.



invoke the service



Supports both the orchestration and
choreography paradigms



Data exchanged by SWS is described
as an ontology.



Can be looked at as a SOA
implementation which allows to
add/remove components at run
-
time.

Web Service

Discovery

Composition

Engine

Communication

Handler

Matchmaker

Service

Mediation

Semantic/Ontology

Reasoning

Resource DB

Top right
corner for
field
-
mark,
customer or
partner logotypes.
See Best practice
for example.


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Multimedia Service Composition and Service Brokerage

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Semantic Service Composition

Semantic Composition Paradigms:



Action Based
: the Reasoner uses the semantic
description of discovered services to match
requester goal at each composition step (run
-
time). Execution takes place directly through the
grounding of the services.



AI Planning
: a task list is generated to achieve
the composition objectives i.e. service selection
and flow management. Compensation in case of
failure and replanning is a challenge. Examples of
AI Planning: Conditional Planning, Conformant
Planning, Hierarchical Task Planning (HTP)



Hybrid (Xplan)
: Combines guided local search
with graph planning and a light form of HTP to
produce a plan sequence of actions.

There is not yet a unifying framework to allow
interoperability between intelligent agents /
reasoning engines.

Y

Z

X

Z

X

Y

Planning

-

Set of actions

-

Pos./neg. effects

-

Initial state description

-

User’s goal

Sequence

PDDXML Parser
Topology Handler

Connectivity
Graph

Goal
Determination

Xplan
-
based Composition

Enforced Hill
Climbing Engine

PDDXML plan

description

Planning Graph
Generation

PDDXML problem,

domain description

Top right
corner for
field
-
mark,
customer or
partner logotypes.
See Best practice
for example.


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Multimedia Service Composition and Service Brokerage

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Agenda


NG Service Platform


Multimedia Services Ontology


Service Composition Patterns


Adding Semantics to Service
Composition


Enhancing the Business Model
through Service Brokerage

Top right
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field
-
mark,
customer or
partner logotypes.
See Best practice
for example.


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Multimedia Service Composition and Service Brokerage

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Service Brokerage in SOC

Service

Consumer

Service

Description

Service

Provider


invoke ( )


bindTo ( )

Service

Broker


find ( )


negotiate ( )

use

offer

described in


contains
description


Why we need Service Brokers:



Users are interested to customize service
interaction model and run
-
time features based on
context conditions (Ambient Intelligence,
Location, Privacy Preferences etc.)



Control of the payment model. Users who do
not want adds and are rather looking into QoS
and Security/Privacy, need a Service Broker
function in the network which can negotiate the
service characteristics with multiple service
providers based on user profile.

User /
Service
Profile

User
context

Ambient
context

Temporal
context

Broker

Context
decisions

Google business model:

Users accept advertising and profiling in return to free

services. AsSense, AdWorks
-

advertisers/publishers

or youTube
-

content providers/users, perform

brokerage at business level.

Service Broker functions:



Ranks services offered by the Service Providers
based on service characteristics. It may do this
autonomously (rules based negotiation), or by
interacting with the user



Matches the service interaction model with
context conditions



Performs identity and trust brokering



Performs payment brokering



Handles synchronization between fine
-
grained
services

Top right
corner for
field
-
mark,
customer or
partner logotypes.
See Best practice
for example.


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Multimedia Service Composition and Service Brokerage

Sorin Georgescu

30

IMS Payment Brokerage



Goods/Se
rvice selection and negotiation

User

Broker

(Acquirer)

ASP

(Merchant)

Issuer

Transaction Details

Transaction Credentials
1

Transaction Credentials
2

Authorize
Transaction

Payment

Credentials

Funds
2

Bill

Funds
1

Delivery

Transaction Record

Service Delivery
Validation

The roles in Payment Model are similar to
those in Credit Card industry:



Consumer



Merchant = Content Provider who
publishes, supplies and sells content.



Broker/Acquirer



Issuer = Mobile Operator. The
Operator uses its existing billing
relationship with the consumer to
charge for content.



IMS services standardized so far
(MMtel, PoC, Image/Video Share) have
been deployed in the operator domain
as their target are the telecom
communities (mass deployments).



Separate from these basic services, it
is expected that many new community
specific services (niche services) will
be provided in the near future by
Service Providers. These services use
open communication protocols (instead
of SIP) and do not handle charging of
the user directly. Instead, they use their
business and trust relationship with the
operator, to delegate payment service.



The Payment Brokerage function
facilitates the establishment of the
business relation between 3rd Party
Content/Service Providers and mobile
operators.

Payment Model

Top right
corner for
field
-
mark,
customer or
partner logotypes.
See Best practice
for example.


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Multimedia Service Composition and Service Brokerage

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Conclusions


Recent deployments of Multimedia and VoIP services in the Telcom and the
Internet domain, have determined a blurring of roles in the value chain while at the
same time enabling new business models.


Next Generation Services Convergence requires:


Implementation of converged devices (multi
-
access devices)


Support of a multi
-
access edge network


Unified roaming and session management framework


Development of service enablers


Interoperability between the native Service Platform (SP) and external Service
Overlay Networks


The SP Interoperability Middleware has to provide support for:


Service Composition and Brokerage


Service Mediation


Service Discovery


Service Platform features like Multimodal Interaction, Interaction Management
based on Ambient Intelligence, Content Management, Brokerage and Management
of Semantic Information are desirable due to their significant impact on service
usability.

Top right
corner for
field
-
mark,
customer or
partner logotypes.
See Best practice
for example.


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Multimedia Service Composition and Service Brokerage

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Thank you for your attention!

sorin.georgescu@ericsson.com