Saturday, 15 December 2007


CAMEL (Customized Application for the Mobile network Enhanced Logic) is a standard for Intelligent Networks for mobile communications networks. It is currently deployed in all regions of the world, enabling mobile network operators to offer fast and efficient services to their subscribers.

Standard Releases

The ETSI GSM Releases
European standardisation activities

CAMEL Phase 1 standardised by ETSI in 1996, as part of the GSM R96

CAMEL Phase 2 standardised by ETSI in 1997, as part of the GSM R97

In 1998, enhancements to CAMEL Phase 2 released by ETSI, as part of GSM R98

The 3GPP 3G Core Network Releases…
Global standardisation activities

CAMEL Phase 3 specified by 3GPP in 1999, as part of the 3G Core Network R99.

3GPP Rel-4 does not contain new functionality for CAMEL.

3GPP Rel-5 contains CAMEL Phase 4.

CAMEL Application Part (CAP)

CAP is a derivative of ETSI CS1

ITU-T CS; Q.1210 series (Core INAP CS1)

ETSI EN 300 374 series (ETSI CS1)

ETSI EN TS 101 046 - GSM TS 09.78 (CAMEL Application Part, CAP V1, V2)

3GPP TS 29.078 (CAMEL Application Part, CAP V3, V4)

Camel Phase 1

Number Translation, Call redirection

Camel Phase 2

Charging Control, User Interaction

Camel Phase 3

GPRS Control, SMS-MO, Mobility Trigger, SS interaction, Dialed service

Camel Phase 4

Mid-Call trigger, Call-party handling, SCP initiate, SMS-MT

CAMEL Phase 1 Architecture

Basic control of MO-, MT- and MF-calls

- No announcements

- No prepaid charging


Network Overview

Basic Call State Machine Principle

- Call handling is specified in GSM TS 03.18 ("Basic Call Handling"). Interaction between the BCSM and the gsmSSF is specified in GSM TS 03.78 ("CAMEL stage 2").

- BCSMs have Detection Points (DPs) and Call States. The SCP may be contacted at DPs for Service Logic invocation or for instructions.

- For every MO Call or MF Call, O-BCSM invoked in MSC or GMSC.

- For every MT Call, T-BCSM invoked in GMSC.

- CAMEL Phase 1, Phase 2, Phase 3 and Phase 4 have different BCSMs (more TDPs/EDPs).

- Three types of DPs exist:

Trigger Detection Point (TDP)

- TDP may be statically armed (in O-CSI or T-CSI).

- CAMEL Service may be invoked from a TDP, provided that trigger conditions, if available, are fulfilled.

Event Detection Point – Notify (EDP-N):

- EDP-N may be dynamically armed within a Service Logic.

- When an EDP-N is met, the SCP is notified. Call processing continues.

Event Detection Point – Interrupt (EDP-R):

- EDP-R may be dynamically armed within a Service Logic.

- When an EDP-R is met, the SCP is notified. Call processing is suspended. The SSF waits for instructions from the SCP.