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 CARRIER SELECTION for National and International Long Distance calls.

             TRAI (Telecom Regulatory Authority of India) has issued directions on Carrier Selection Procedure vide their Press Release dated 24^th July 2002. The key points mentioned in the Press Release and the implementation difficulties and the new requirements in our Switches are briefed in this article.

 Directions issued by TRAI:

            Consequent to the opening up of the National & International long distance service markets, the customer has multiple choices to route his long distance calls through carriers chosen by him. As per provisions in the License Agreement & the policy directive of the government, this has to be done by dialing four extra digits called Carrier Access Code (CAC) after '0' (for NLD calls) & '00' (for ILD calls), which will enable the switching system of the Access Providers (BSOs / CMSOs) to identify the long distance carrier selected by the subscriber, and route the call accordingly.

             Alternatively, the subscriber can intimate his choice to the Access Providers (APs) in advance in a process called 'polling', so that the four extra digits i.e. CAC could be embedded in the exchange subscriber data base in advance and with that the subscriber is not required to dial them.

             The latter mode of Carrier Selection called Carrier Pre-selection (CPS) is implemented in telecommunication networks to provide ease to customers in dialing their long distance calls. Both the modes of Carrier Selection i.e., 'Call by Call' in which four extra digits are required to be dialed for routing of each call, and Carrier Pre-selection (CPS), are required to be implemented in a time bound manner in the Indian telecommunication network.

            This direction has been formulated based upon the principle that the choice of carrier must be with the subscriber. The subscriber would be able to exercise this choice in respect of both domestic long distance as well as the International long distance carrier.

            However, the facility may not be available at all places simultaneously, as it would depend upon the type of the switching system and the feasibility of their up-gradation to meet the requirement of Carrier Selection. However, the question of exercising a choice would arise only if more than one NLDO or ILDO is in a position to pick up calls for long distance carriage by interconnecting his network to that of the Access Providers' networks.

 The new Terminologies used in this scenario:

 1. Carrier Selection: Who is carrying my Long Distance Call?

·         Pre Select Carrier

·         Dynamic call selection or Call by Call selection

·         Default selection

2. National Long Distance Operator (NLDO)

3. International Long Distance Operator (ILDO)

4. Basic Service Operator (BSO)

5. Cellular Mobile Service Operator (CMSO)

6. Carrier Selection Code (CSC)

7. Carrier Access Code (CAC)

8. Carrier Identification Code (CIC)

9. Point of Presence (POP) ( At LDCA and SDCA level)

 Dialing sequence by the Subscriber:

 The subscriber has to dial for his Long Distance Call as below:

Trunk Prefix + CSC + NSN ( ‘0’ is the Trunk Prefix and CSC = CAC + CIC)

For dialing Delhi Number using BSNL as NLDO the sequence will be like this:

            0 10 20 11 25740725

• ‘0’ is the Trunk Prefix
• ‘10’ is the Carrier Access Code (‘CAC’ to identify the call by the switching system for routing purpose)
• ‘20’ is the Carrier Identification Code (‘CIC’ allotted to BSNL) Note: the CIC will vary from one operator to other. DOT had already issued Carrier Selection Code as ‘10’ and Carrier Identification Code as ‘20’ for BSNL, ‘30’ for Reliance Infocomm, ‘40’ for VSNL and ‘50’ for BTSOL;

 Why – the necessity of “CAC”: 

• To identify the call as a NLDO call
• ‘10’ is decided for CAC. This ‘10’ should not be a area code in our country. Now this is free only.
• Single CIC will be allotted to every Operator.
• Different CIC will be allowed for Toll Quality and Non Toll Quality calls. ( Circuit Switched calls and Voice over IP Calls)

 Some Basic rules of Carrier Selection Régime: 

• NLDO’s can carry only inter-circle traffic.
• NLDO’s can not terminate a call in same circle from where it was taken.
• BSO’s are not allowed to route the calls to ‘Default Carriers’;
  • Thereafter, in all cases of long distance (i.e. prefix '0') calling, in which the subscriber has not pre-selected his carrier and has also failed to dial the four-digit pre-fix i.e. Carrier access code (CAC), the calls will be routed by the Access Providers (BSOs /CMSOs) to a recorded announcement. Through the announcement, the subscriber shall be requested to select his long distance carrier either on the basis of Call by Call or Pre-selection. If he does not make the choice, the announcement will request him to do so.
  • If there is congestion in the network of the NLDO at the POI, the calls are to be failed by giving proper Announcements.
• Mandatory CLI ( Since CLI based charging to be effected).

 Impact on the existing network: 

• Additional resources like ‘DTMF, Sender/Receiver’ are needed due to increase in holding time of the calls.
• Storage of more digits (21 Digits in case of ISD calls); CDOT supports 20 Digit storage at present.
• Out pulsing of more digits ( upto 21 digits).
• Additional routing data to be created.
• Additional Processing Power of the Switching System.

 Billing issues: 

• Revenue sharing between BSO and NLDO / between NLDO’s
• Generation of Bill by BSO for Local call + NLDO calls.
• Generation of Bill by BSO for Local calls only and separate Bill by NLDO’s.
• CDR based billing to be implemented very soon.

 Implementation of Carrier Selection feature in CDOT Switches: 

1. CDR based billing software is to be retrofitted.
2. New software version “2_3_1_6” for NLDO implementation is to be done where ever required.
3. Provision has been made to define by the subscribers for Carrier Selection in the new software.
4. Augmentation of additional resources like “DTMF” and “Announcements” is to be done by change of hardware in “Time Switch Unit”. (Present TSU complex is to changed by new one)
5. To meet the increased traffic handling capacity and Processor capacity, the “BPU” complex is to be changed by new one.

 Polling and Subscriber Education: 

• Polling is a process undertaken by the Access Providers to ascertain the choice of each subscriber, in regard to his pre-selected long distance carrier in a fair and objective manner. Thus polling is an essential pre-requisite for the introduction of Pre-selection facility in an exchange. The operators concerned shall therefore take urgent steps for customer education and also give adequate publicity to the polling, so that the customers are fully aware about the choice of long distance carrier available to them.
• The publicity and customer education should also give details about the new dialing procedure particularly relating to the Call by Call selection. The subscriber should be made fully aware that after the expiry of the stipulated time periods in this direction, if he does not either pre-select his long distance carrier (NLD /ILD) or dials his long distance call without prefixing the Carrier Access Codes for each call, his call will be routed to a recorded announcement and that there will be no default carrier for such calls. The operators are directed to publish Carrier Selection consumer guidelines giving full details of the dialing procedure applicable to various types of calls and the benefits that the consumers will derive from the newly introduced Carrier Selection procedure.

 Conclusion: 

• Similar study is to be done in other Technology Switches available in BSNL Network for the capability of additional processing power and resources.
• Publicity and customer education is to be done in phased manner before implementation of this carrier selection for his long distance calls.
• CDR based billing to be introduced in advance and should be stabilized.
• Any how, after the introduction of ONE INDIA Plan, this NLDO will loose its charm in the business is my feeling.

Prepared by: M.Pandian, Divisional Engineer, CDOT Installation, Salem 636 001.

 E-Mail: [email protected]

15-02-2006

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