Camel Application Part-By Abhinav Kumar & VAS

CAMELThe CAMEL Application Part (CAP) is a signalling protocol used in

the Intelligent Network (IN) architecture. CAP is a Remote Operations Service Element (ROSE) user protocol, and as such is

layered on top of the Transaction Capabilities Application Part (TCAP) of the SS#7 protocol suite. CAP is based on a subset

of the ETSI Core and allows for the implementation of carrier-grade, value added services such as unified messaging, prepaid, fraud control and Freephone in both the GSM voice and GPRS data

networks. CAMEL is a means of adding intelligent applications to mobile (rather than fixed) networks. It builds upon established

practices in the fixed line telephony business that are generally classed under the heading of (Intelligent Network Application Part)

or INAP CS-2 protocol.[1]

• 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.

• For operators that consider prepay a must-have, CAMEL (Customized Application for Mobile Enhanced network Logic) is becoming the prime method for putting the intelligence into intelligent networks. 

Protocol specificationThe CAMEL Application Part (CAP) portable software provides mechanisms to support operator services beyond the standard GSM services for subscribers roaming within or outside the Home PLMN (HPLMN). The CAP product extends the IN framework to GSM/3G networks for implementing IN-based services within GSM/3G networks.CAMEL is used when the subscriber is roaming between networks, allowing the home network to monitor and control calls made by the subscriber. CAMEL provides services such as prepaid roaming services, fraud control, special numbers (e.g., 123 for voicemail that works everywhere) and closed user groups (e.g., office extension numbers that work everywhere).As with CAMEL, CAP has been defined in 4 phases, each of which has an accompanying specification that builds upon the previous phase. Each CAP phase provides the message set and procedures needed to support the corresponding CAMEL phase requirements, as defined in 3GPP TS 22.078 (service aspects) and 3GPP TS 23.078 (technical realization).The definition of the protocol may be considered to be split into 3 sections:the definition of the Single Association Control Function (SACF)/Multiple Association Control Function (MACF) rules for the protocol, defined within the prose of the specification;the definition of the operations transferred between entities, defined using Abstract Syntax Notation One (ASN.1);the definition of the actions taken at each entity, defined by means of state transition diagrams.

• Initially designed for circuit-switched calls, CAMEL (phases I and II) triggered the intelligent network (IN) during a prepay call, so that companies could swiftly assess and respond to subscribers' status information regarding location, account balances and service characteristics. 

CAMEL phase III adds prepaid support for SMS and data services. By supporting SMS, phase III allows GSM operators to offer real-time charging for Mobile Originated Short Messages (MO-SMS) without the need for proprietary devices. By enabling real-time charging for data services, CAMEL III opens up options for prepay billing, with parameters based on the location of the sender, the destination of the message, as well as date and time. 

Networking for IN services on multiple networks

• CAMEL Phase III (now a part of the 3GPP GSM spec) will be germane to creating a foundation for service differentiation by enabling roaming. 

IN implementations, and subsequent roaming capabilities in large multi-vendor networks were difficult without CAMEL, because most vendors had developed proprietary IN standards around recommendations from CS1, the legacy standard from ETSI. 

• "Roaming is now being demanded by subscribers in Europe, South America and even North America. By giving end users access to operator-specific services when roaming outside their home network, there will be a perception of added value and an opportunity for carriers to charge accordingly and differentiate themselves," says Rogier Noldus, senior specialist, Intelligent Networks, Ericsson. Because CS1 has been open to many interpretations over the years, CAMEL is standardized to a "bit level," so that comments, questions and compatibility issues can be addressed in a standard manner, Noldus contends.

• Where multiple interpretations of previous standards inhibited intelligent networks, CAMEL will open the doors to inter-vendor compatibility. Ericsson, Nokia, Alcatel and Siemens work together regularly to improve CAMEL. "We work like friends, rather than competitors in the 3GPP environment, which has become a great breeding ground for building standards," says Noldus, claiming that engineers working on CAMEL want to ensure the industry gets the most out of GSM as a whole." 

"Any time operators can increase traffic on their networks, as well as the throughput and usage on those networks, it is an attractive proposition,"

CAMEL-Phase III 

• With CAMEL - Phase III - real-time charging moves from circuit switched to wireless with IN capabilities based on GPRS and UMTS. For operator that have implemented prepaid GPRS services, CAMEL phase III provides a standard interface between SMC and SCP within packet-based networks. Now, CAMEL enables the mobile station to request data from the SGSN (a serving GPRS support node) and GGSN (Gateway GPRS Support Node) so that the IN is involved during the data context creation. The SGSN triggers the SCP, which checks the user's account as in the circuit switched case. The SGSN updates the SCP in regular intervals with status information (time, volume, position) about the PDP context. The SCP performs hot-rating, decrements the account, and requests the SGSN to continue processing or to release the PDP context. Depending on the number, the duration and the traffic of the GPRS sessions, this can impose important performance requirements on the SGSN and SCP. 

CAMEL Phase IV (also known as "release 5" ) is slated for early 2005, is now being finalized. It is based on IMT-2000, the ITU's framework for global wireless access that links terrestrial and/or satellite networks. 

The Practical Side • Like any standard, carriers and operators cannot look through

rose-tinted glasses: For CAMEL III to really "work," there have to be many operators who implement it, as the whole point is to allow roaming in other places, says Steve Menear, associate VP within the IN division of Comverse. 

Because it is relatively expensive to upgrade switches, many carriers are "sitting on their hands" waiting for others to do it first. "It will be the operators who need support for charging for short messages and GPRS services that will be the first too implement CAMEL III," says Menear. "It was the same with CAMEL II; though it seemed obvious everyone should want it, it was a matter of the biggest operators in Western Europe to go ahead before others thought the value outweighed the cost." Because CAMEL does not support all data services, the decision to implement CAMEL III or IV will be a business decision. "Whether you spend the money to upgrade switches to support roamers depends on your bu siness plan," adds Menear.

• CAMEL is not a • service, but a feature to create services.

• Participation:

Value added services(VAS)• A value-added service (VAS) is popular as a telecommunications industry

term for non-core services or, in short, all services beyond standard voice calls and fax transmissions but, it can be used in any service industry for the services providers provide for no cost to promote their main service business. In telecommunication industry on a conceptual level, value-added services add value to the standard service offering, spurring the subscriber to use their phone more and allowing the operator to drive up their ARPU. For mobile phones, while technologies like SMS, MMS and GPRS are usually considered value-added services, a distinction may also be made between standard (peer-to-peer) content and premium-charged content.

• Value-added services are supplied either in-house by the mobile network operator themselves or by a third-party value-added service provider (VASP), also known as a content provider (CP). VASPs typically connect to the operator using protocols like Short message peer-to-peer protocol (SMPP), connecting either directly to the short message service centre (SMSC) or, increasingly, to a messaging gateway that allows the operator to control and charge of the content better.

 Value-added Service Characteristics

• All VAS share the same characteristics:• Not a form of basic service but rather adds value total service offering• Stands alone in terms of profitability and/or stimulates incremental demand

for core service(s)• Can sometimes stand alone operationally• Does not cannibalize basic service unless clearly favorable• Can be an add-on to basic service, and as such, may be sold at a premium

price• May provide operational and/or administrative synergy between or among

other services – not merely for diversification• Every VAS will demonstrate one or more of the above characteristics.

Furthermore, a value-added service will never stand in stark contrast to any of the above characteristics.

• VAS also have a certain time dimension associated with them. Subjectively speaking, a value-added service today becomes a basic service when it becomes sufficiently common place and widely deployed to no longer provide substantive differentiation on a relative basis.

Relationship to other Services

• There are two types of VAS. The first service type are those value-added services that stand alone from an operational perspective. These types of services need not be coupled with other services, but they can be. Many non-voice services fall into this category. They are often provided as an optional service along with voice services, but they could be offered and used by themselves without the voice service. For example, SMS could be offered and used as a service without voice calling.

• The second, and arguably more numerous and important type of VAS, are those services that do not stand-alone. Instead, this category adds value to existing services. While it seems implicit in the definition of value-added, this is an important principle that makes value-added services stand apart from other services.

Value-added Services Examples

• There are many services that could be considered "value-added". For discussion purposes, we will a few of these services below.

Push-to-Talk

Push-to-Talk (PTT) is a VAS because it:• Drives additional revenue to the wireless carrier, but doe not cannibalize existing revenues• Provides differentiated service offerings• May be packaged with various other VAS such as MIM to provide even greater value• Call Management Services• This type of service can not stand alone as a service. Instead, it adds value to a core service by

allowing the subscriber to manage incoming and/or outgoing calls. For example, value-added service interactions occur when the subscriber receives a call. Many call management services allow the subscriber to establish when, where, and under what circumstances they may be reached by calling parties. This provides value to the core service - voice communications - by way of increased control and flexibility.

• Depending on the specific commercial situation, this value-added service could be offered as either a premium service (at a premium price) or be bundled with other the core service offering. The benefit of bundling would be to provide a differentiated core service and/or to increase the use of the core service.

Location Sensitive Billing• This is another example of a service that can not stand-alone. Instead, location

sensitive billing (LSB) adds value to the core service by location enabling the core service. Location sensitive billing can be used in conjunction with post-paid, prepaid, and/or VPN based mobile communications services to establish zones for which differentiated billing treatment may be applied. For example, a "home zone", "work zone", and "premium price zone" could be established to allow an operator to offer differentiated service to its customers.

• This is viewed as a value-added service to both the customer and the mobile operator. The customer benefits from LSB through his ability to use the mobile phone at preferred rates based on location. The wireless carrier benefits from incremental revenues derived from additional usage and from premium charge zones where there is already high demand and perhaps overly taxed system capacity. While the issue of potential cannibalization of existing service arises, customer behavior and studies indicate a net benefit derived from overall increased usage and revenues.

• Taken together, call management services and LSB also depict characteristic number six, operational synergy. Call management services add value in terms of providing the user options depending on location. For example, the user may want to receive certain calls at the home zone, but not at work, and perhaps receive only urgent calls when traveling or on vacation. LSB provides the additional synergistic benefit of location based billing when the user is in those various locations

Mobile Data Services• This is an example of a value-added service that does stand-alone. Mobile data

services are considered value-added because they depict many of the characteristics discussed earlier.

• Does not cannibalize existing services• Can be offered at a premium price• Provides differentiation• Can provide synergy with basic service• Largely due to the current state of mobile communications evolution, many non-voice

services can be considered to be value-added. However, the extent to which additional value-added services can be layered on top of mobile data services will determine the limit of their value. For example, many non-voice services will have even greater value through personalization. Two of the most significant ways to personalize wireless services are through location enabling them and making them personal profile driven.

• Mobile data services are utilized to obtain information, content, and to perform transactions. All of these activities are more meaningful if they are tailored to the individual. Location based services add value by way of putting the data into a location context for the user. Personal profiles further enhance the value through Personalization