Transcript S-38.118 Tietoliikennetekniikan perusteet Service Creation

S-38.118 Teletekniikan perusteet
Service Creation
• Services, without any additional particulars, like bearer
services, teleservices, QoS services etc. refer to value
added and supplementary services.
• What are these services and why the creation of services is
an issue?
• There are various supplementary and value added services
that one can obtain from a telephone or a mobile phone by
pressing a sequence of buttons. Basically, few people
remember them and use them and it would seem like these
services are rather unnecessary decorations.
• This is actually not so. There are services which are of
great economic value to an operator or service provider.
Service Creation, summary
• Examples of successful services include:
– Intelligent Network (IN) Freephone in US, about 60% of long
distance calls are 800-numbers
– Camel Prepaid service for mobile phones in many countries, it
reduces operator’s costs considerably
– In Finland information on telephone and mobile numbers, payable
Premium rate number
– In some countries entertainment services
– Televoting, other mass call services
– Emergency calls, Malicious user identification not commercially
succesful but very useful services
– Call forwarding, answerers, Virtual Private Network etc.
– These are voice services, but there are data services:
– email, Web, file transfer are value added services
– transaction processing, web searching, advertisement services
Service Creation, summary
• Combined voice and data services should have a large potential in the
future:
• Karaoke-on-demand in Japan is a success
• Other on-demand services (video, news etc. on demand) could work
• WAP-services
• Electronic payment
• Videotelephony, (video)conference calls
• Networked games
• Net location service (nearest taxi etc.)
• Virtual home environment
• The problem is, that we do not really know what services will succeed, but
there should be possibilities to invent new services which become as
popular as the Web. Only to invent what.
• That is why the goal is to make platforms and methods for service creation.
Service Creation, summary
• Some claims on services:
• There are new good services to be invented, probably everybody believes
this.
• The services can be end-system services, network is needed only as a
transmission media. This view is held by some but not by most:
• You need network resources if you try to offer in an efficient way services
which do any of the following things:
– Change routing in the network, like number translation services in IN
(Freephone, PremiumRate etc.)
– Change charging of the connection (like Freephone, PremiumRate)
– Can affect the dimensioning of the network (like Televoting)
– Use network for location of users or network elements (net location)
– Provide connections in a way anonymously (like PremiumRate)
– Limit access by network mechanisms (VPN)
– In some cases, handle multiparty calls effectively
• Many services can gain from accessing network resources, so the endsystem view is not so popular.
Service Creation, summary
• Services must be introduced very fast in a competitive environment. A
view generally accepted to be true.
• Network should be opened for external service providers. A disputed
view, some operators support it as it should speed up creation of
services, not all operators support it as management will be more
difficult.
• Service creation is a new business area - generally believed to be true.
• There will also be many free services. Probably.
• Electronic commerce will be very important. Probably.
• Security problems can be overcome. Probably/maybe.
• Services pop up spontaneously from the Internet and there is no need for
any special service creation platforms. The view is probably partially
correct but mostly wrong. It is fine for web pages, but more complicated
services need solutions for charging, use of network resources,
management etc.
• Technology for service creation is not clear. There are many
possibilities.
Service Creation, summary
• Service then is an application which is offered as a service by some
party, so somebody wants to earn money by offering the service.
• A service platform is a system which facilitates service creation,
provisioning and management.
• End-system applications like email and file transfer were developed
originally in the Internet and proprietary data networks (like SNA,
DNA)
• They, and other data application protocols, were considered as Value
Added Services to be offered by an operator in the OSI model, but this
did not succeed at that time. Now the data applications (largely using
TCP/IP protocols) are offered as Value Added Services and there is
much work done in order that operators and service providers can offer
data, voice and video applications as services.
• Voice services were created first in the PSTN and the Intelligent
Network architecture was made to speed up service creation. Most of the
early IN services were invented before IN as services on a voice only
network are of rather limited character.
Service Creation, summary
• The Intelligent Network deployment is made in phases, called the
capability sets. IN CS1 is deployed and is voice only, IN CS2 and IN
CS3 are specified and offer a larger range of services, but the role of IN
is unclear in the future network architecture. It is quite possible that IN
technology will be used and certainly some ideas will be reused.
• Camel (Customized Applications of Mobile Enhanced Logic) is of
current interest as it offers GSM Phase 2+ users IN services. It is quite
likely that Camel services, like prepaid, will exist for a long time.
• TINA (Telecommunication Information Networking Architecture) was
an effort to put service creation and management on distributed
processing platform using the ideas of ODP (Open Distributed
Processing). There were several good ideas in TINA, notably use of
middleware and TCP/IP under the middleware (CORBA) platform.
• From ODP TINA inherited OOD (Object Oriented Design) pronciples
for service development. One can say that while TINA as such is dead,
TINA ideas are reused in many modern approaches.
• There are solutions which simply build on CORBA (Common Object
Request Broker Platform) and provide e.g. interworking of IP and SS7.
Service Creation, summary
• IP phone may get IN services using an agent which connects to an IN SCP
(Service Control Point). This approach is called PINT. It is of limited use.
• Parley is a new technology which offers an API (Application
Programming Interface), in reality several APIs, for accessing network
resources. One can create many IN services using Parley.
• Net location based on Parley is likely to appear in near future, as well as
many other Parley services. Parley adds authentication of the service
provider to the Parley Framework owned by the operator. Using Parley
network resources are opened to untrusted service providers.
• OSA (Open Service Architecture) is very similar to Parley, currently OSA
is a subset of Parley. OSA is standardized by 3GPP.
• JAIN is a larger effort to put Java APIs everywhere, connected with Java
telephony (JTAPI). JAIN is based on the assumption that there will be
several network technologies, so there are APIs to many common
networks (IN, PSTN, GSM, IP) and they are unified on a Java platform.
For service creation JAIN offers two solutions: either you directly write
Java services, or you use JAIN Parley interface and the services are
offered by untrusted service providers.
Service Creation, summary
• MExE (Mobile station Execution Environment) is a way of creating
services where service logic is downloaded from the network partially to
a mobile station, partially to a SIM card.
• SIM, USIM. In this technology service logic is placed on the SIM card
of GSM or USIM card of UMTS phone.
• Mobile agents are a technology from the late 90-ies where on top of a
mobile agent platform you write applications (mobile agents) which can
move in the network. Mobile agents have been proposed as a way to
distribute Intelligent Network service logic. This technology does not
offer special methods for service creation but agents are easy to write.
• VHE (Virtual Home Environment) is an effort which is standardized by
3GPP, but there are also many ex TINA people working on similar ideas.
The intention is to provide the user everywhere with home environment,
I.e., everything looks like at the home network. VHE is currently a
combination of all possible technologies to create services. The VHE
additions will be service, user, network and terminal profiles which are
needed to give the user the home look and feel.
Service Creation, IN
• In the Intelligent Network, if we follow the approach of the standard which may not be the case in practice - service creation proceeds as
follows:
• IN CM (IN Conceptual Model) defines 4 planes. These are design
planes for creating services:
• In the Service Plane the service is described in words and a service is
composed of service features. It is better to use existing service features
as on a capability set of IN the defined service features can be
implemented, other would require creation of new building blocks.
• For instance to create a Portable Number service we might use Local
Number Portability and Universal Call Transfer, to create Caller-ID
based services we might use service features for screening, routing and
authentication. In general, definition of services is up to the operator,
but services should normally be composed of existing service features.
• In the Global Functional Plane the services are realized as a chain of
SIBs (Service Independent Building blocks). Some vendors offer an
graphical interface SCE (Service Creation Environment) which has
Service Creation, IN
• Graphical objects from which the SIB chain is made. These objects
may be standard SIBs as in the IN standard, or something more or less
similar, like logic diagrams. Anyway, in GFP the service is a chain of
SIBs starting from the BCP (Basic Call Process) - describing in a
logical way processing of a call - from some POI (Point of
Initialization) and ending to one or more POR (Point of Return).
• In the Distributed Functional Plane the BCP is described as two
automatons BCSM (Basic Call State Machine),originating and
terminating. (In each switch there are the two automatons and the call
establishment is jumping from one switch to another, but we need to
worry only about that switch which executes the IN part of call
processing.) The SIB chain is mapped in not one-to-one way to FEAs
(Functional Entity Actions) and IF (Information Flows). There are
many ways this mapping can be made. The FEAs are basic
functionalities of Functional Entities (FE). There are a small number of
functional entities in IN. They are SSF (Service Switching Function),
SCF (Service Control Function), SDF (Service Data Function) and
SRF (Specialized Resource Function).
Service Creation, IN
• SSF is an extension of the functionality of a telephone switch so, that it
can communicate with SCF.
• SCF is capable of running service logic programs (SLP), also called
scripts.The SLPs contain the actions the service should do,like translate
an 800-number to another number, check credit card number in a credit
card call etc.
• SCF needs some data. This data,like the valid credit card number, is
stored into a database realizing SDF.
• SRF is a set of functionalities for giving the caller voice responses,
collecting digits from the caller’s phone, recognizing voice etc.
• A main problem in the DFP is to map the SIB chain into detection
points in the BCSM. The POI and POR points map either to the states
of the state automaton BCSM or to places before the states called
detection points. There are two types of detection points TDPs (Trigger
Detection Points) and EDPs (Event Detection Points). To TDPs it is
possible to set some trigger rules in order to start a dialog between SSF
and SCF. The EDPs are used for instance when a call returns to POR
continue call processing.
Service Creation, IN
• In the Physical Plane (PL) the information flows are realized as
protocols and the Functional Entities are placed into physical network
elements. The IN CS1 contains the following physical entities: SSP
(Service Switching Point), it is a telephone switch with SSF
functionality; SCP (Service Control Point), it is a computer running
service logic programs, SCP contains the functionality of SCF, but
often it also contains SDF. There may be a stand-alone database SDP
(Service Data Point). There is a faster version of SCP called Adjunct
(AD), it is like SCP but connected to SSP via a fast link. SCP is
connected to SSP via SS7 network. SRF can be placed in a special
devise IP (Intelligent Periferial), but it can also be placed in SSP. It is
also possible to place SCF to SSP, then the SSP is called SSCP, joint
SSP and SCP. There are more functionalities in IN CS2 and CS3.
• The information flows are realized by the INAP protocol (IN
Appilication Part). INAP runs on top of TCAP, which is on SCCP and
SCCP is on MTP3. TCAP, SCCP and MTP3-1 are the parts of SS7.
• There is usually no need to change INAP when making a new service,
though operators have their modified versions of INAP.
Service Creation, Camel
• Service creation in Camel (Customized applications for mobile enhanced
logic) is quite similar to service creation in IN.
• Camel enables interworking of IN and GSM so, that roaming GSM users
can use their home services via IN. Camel introduces Camel SCF, called
gsmSCF, and a new functionality to MSC (Mobile Switching Center)
called gsmSSF. Camel services are provided as in IN: when a Camel call
comes to MSC with gsmSSF, the gsmSSF starts a dialog with gsmSCF
using a simplified version of INAP called CAP (Camel Application Part).
• As GSM users are mobile, there is needed an additional operation, which
is added to MAP (Mobile Application Part): gsmSCF can at any time make
the AnyTimeInterrogation from gsmSCF to HLR (Home Location
Register) in order to ask HLR for some information it needs.
• Often creation of Camel services is made with a Service Creation
Environment with SIBs. There are the same problems of deciding where to
put trigger tables to Trigger Detection Points in the BCSM, but the Camel
BCSM is at least more simple than the IN BCSM.
• Camel is now at phase 3. The standards can be downloaded from ETSI,
but a warning, there are many standards in Camel.
Service Creation, TINA
• Service creation using TINA is relevant even though TINA is stopped
as the OOD ideas have not disappeared.
• One is supposed to follow the ODP four viewpoints and define first (in
the Enterprise viewpoint) the business model with the roles of the
players. The next viewpoint (Information viewpoint) is to draw class
diagrams with OMT (Object Modeling Technique), or UML, and
sequence diagrams.
• In the Computational viewpoint one is describing computational
objects and their interfaces. These interfaces are described in IDL,
CORBA’s interface definition language. Then the service is coded with
some programming language. The difference to IN is that there is no
separation between application development and service creation. In
IN creation of a service usually will not require coding. In TINA it is
coding a new application.
• TINA approach to service creation is inherently complicated and the
architecture is so large that it cannot be seen to support fast service
creation. Still, there can be useful concepts in TINA, like the service
session interface, Dolmen mobility solution etc.
Service Creation, CORBA and mobile agents
• TINA being so complicated, there have been attempts to create services
using CORBA middleware platform but no TINA.
• With CORBA there are services and facilities that can be used for
service creation. Also in this approach service creation is application
development along ODP and OOD methodology.
• Some of the services, like ODP Trader can be interesting, however, one
should notice, that CORBA does not support mobility very well.
• CORBA may be used to interface PSTN to IP, access databases etc.
• Mobile agent technology is one possibility. Then services are created in
a suitable language, often Java, as objects on top of a mobile agent
platform. The mobile agents move with simple instructions,like move
to target system. Mobile agents have agent languages facilitating agent
communication. There are no special guidelines for implementing
services using mobile agents. Consider it one form of writing an
application in Java with the difference that the object is capable of
moving and agents can be forming an agent society.
Service Creation, Parley, OSA, Jain
• In all these approaches service creation is made more easy by providing
a Parley API, by which network resources can be used. Therefore the
approach concentrates on services which need network resources.
• In order to create an application, the creator is describing his service
with a sequence chart with Parley messages/method calls, like
authenticate, discover, sign etc.
• Parley defines in addition to the Framework also Service Components,
it can be compared to capability sets of IN in this respect. One can use
the service components as service features and create desired services
by describing the service as a message sequence chart.
• OSA is quite similar to Parley and service creation according to OSA
will be even more similar in the future, at the moment OSA has adopted
a subset of Parley APIs.
• OSA is originally strongly connected with the VHE (Virtual Home
Environment) concept, but currently there are also other approaches to
VHE than 3GPP VHE, for instance VHE by the Vesper EU-project.
Service Creation, Parley
Domains:
user
service provider
SP’s WWW-server
(Value Added
Services)
operator
Operator’s
WWW portal
Parlay Framework
Parlay Service
(call control)
User A
Retrieve www-page and select service (call forwarding)
The user gets url to server
provide call forwarding to B
User authenticated
Authenticate application
Discover service
Sign agreement
Notify when someone calls to user A
user A called
route to A
route to number B
Parlay interface
A doesn’t answer
Service Creation, Conclusions
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There are other possibilities for service creation including
WAP
MExE
USIM
TSAS (OMGs Telecommunication Service Access and Subscription
specification)
• It is not possible to go into the details of these technologies in the
scope of this lecture. It suffices to say that service creation is an area
which is fast developing. There is need for service creation methods by
which more services can be fast introduced.
• There is an equally problematic area of service management. It is
connected with network management as service management is
logically a part of network management. However, a large number of
services, which are fast introduced may add special problems. In
general, there is always the problem that a new service interacts in an
unexpected way with existing services,