Telecommunication Intelligent Networks (IN)
From the 1970s to the 1990s the move from Analog to Digital Switching Technology was picking up pace. Switching is associated with the Call processing, Rout(e)ing and charging capabilities of a Telephone Exchange.
Digital Switching coupled with a Digital Signalling System (SS7 / ISUP / TUP(+) / UK_NUP (BTNR_167), etc..) was the enabler for new Advanced Services. This allowed the move from Plain Old Telephony Services (POTS) to Pretty Amazing Network Services (PANS), basically POTS to PANS. A Digital Switch is another name for a traditional Telephone Exchange.
A traditional Time-Space-Time Digital Switch (Telephone Exchange) is based on Hardware and Software that is used to receive, process, route and charge (e.g. postpaid via Charging Data Records) for telephony traffic.
Key functions that a Digital Switch supports:-
- Switching Function
- Control Function, and
- Data Function
The traditional switch has a control and switching "fabric".
With the traditional approach New Features are designed and integrated with the Switch Software. The control logic will have to be updated and deployed. For a Network that has over sixty Switches this could take several months to complete. Time to Market (TTM) and innovation is totally reduced. Competitors can easily create and deploy a Service using IN capabilities. In the past IN was the innovation platform to deploy new Telecommunication Services. If we look at the situation today (2016) it is now fast to develop, test and deploy new Features.
Using, SaaS and Data Centre technologies several Application vendors can deploy over Two-Hundred features within a twelve month cycle. Time to Market is now an expectation with customers, it is not an add on requirement.
To help with innovation and a fast TTM it now makes sense to split the Switch so that we have a full separation of the Switching and Control Functions. To help with information exchange between the "switching" and "control" entities a new Data Communication Protocol is introduced. This is Capability Set 1 (CS1) and is based on a Non-Circuit Related SS7 (signalling) protocol. SS7 - Signalling Number 7 - is a well known Signalling protocol that is used with “Digital Switches” (pre Internet Store Programmed Telephone Exchanges).
The separation of nodes allows new Service Logic to be deployed on the "control" elements. This means that a few nodes can be updated with the new Service Logic.
The Functions:-
- Switching, known as IN SSF (Service Switching Function; physical SSP)
- Control, known as IN SCF (Service Control Function; physical SCP)
- Data, known as IN SDF (Service Data Function; physical SDP)
- Announcement Machines, known as IP (Intelligent Peripheral; physical: SRF)
- Service Creation Environment / Service Management System (SCE/SMS)
are key components of an IN - Intelligent Network - solution.
SCE/SMS is used to create, test and deploy IN Services to the SCF component. IN Services can also be deployed on a separate emulated SCF server. Note that SSP=Service Switching Point; SCP=Service Control Point; SDP=Service Data Point; SRF=Specialised Resource Function.
-SSF - This is controlled by the SCF entity. SSF equates to a a pure switch with a processor and a digital Time-Space-Time Switching plane
-SCF - This is the control entity. Service logic is created by a Service Creation Environment (SCE/SMS) and the "service flow" is deployed on the SCF entity
-SDF - Database entity. Hold customer information. As an example for PrePaid Services the SDF would support Account/Balance information and it will enable Rating / Charging using parameters extracted from the IN communication protocol. This could be CS-1, CS-2, CAP V2, CAP V3, Gy (Mobile Data Charging), etc..
-IP - Intelligent Peripheral or Announcement Machines. IVR / VXML-IVR capabilities.
-SCE/SMS - Service Creation and Management System was used a GUI to create "service logic" using lego building blocks that were known as (HL)SIBs (High Level Service Independent Building Blocks).
By having this layer split into Switching, Control and Data allows new Services to be deployed into a traditional Wireline Network. The same concept is used with the Mobile Networks (2G/3G/4G/etc..) and this is known as
CAMEL - Customised Application Mobile Enhanced Logic. Different versions exist: CAMEL Phase1 / 2 / 3 and 4. The following entities support CAMEL: gsmSSF, gsmSCF, gsmSRF, etc..
A very popular IN service is Prepaid and VPN / CUG (Virtual Private Network / Closed User Group) Services.
IN - Intelligent Network - started out as a way to connect two or more parties in a telephony call. During the 1990s, the take up of Mobile PrePaid started. IN techniques proved to be essential to build scaleable, fault tolerant PrePaid Real Time Charging solutions. At the same time other solutions were based on "hot-billing" which was based on fast processing of Charging Data Records or Service Nodes. Service Nodes had issues with scalability and redundancy.
IN - Intelligent Network - is always associated with Real-Time Charging Solutions for Telephony and Data.
Reference:
3GPP TS 23.078 V15.0.0 (2018-06)
BTNR - British Telecom Network Requirement
BTNR 167 - Network User Part Signalling (NUP)
CAMEL - Customised Application Mobile Enhanced Logic
CAP - CAMEL Application Part
CS-1, 2, 3 and 4 - Capability Set 1, 2, 3 and 4
CS1+ - Ericsson specific IN protocol
INAP - Intelligent Network Application Protocol
ISUP - ISDN User Part
IP - Intelligent Peripheral
IVR - Interactive Voice Recording
NUP - Network User Part
SaaS - Software as a Service
SS7 - Signalling System Number 7 (SS7)
SCE - Service Creation Environment
SCP - Service Control Point
SCF - Service Control Function
SDF - Service Data Function
SDP - Service Data Point
SME - Service Management Environment
SSF - Service Switching Function
SSP - Service Switching Point
SRF - Specialised Resource Function
TUP - Telephony User Part
VXML-IVR - Voice Extended Mark Up Language IVR
Note: gsmSSF, gsmSCF, gsmSRF, etc.. indicates a CAMEL functional entity
https://www.etsi.org/deliver/etsi_ts/101000_101099/101046/06.03.00_60/ts_101046v060300p.pdf
Customized Applications for Mobile networks Enhanced Logic - Wikipedia
3GPP TS 23.078 V15.0.0 (2018-06)
https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=766
