Ringing in transparency

The introduction of Calling Name Presentation (CNAP) aims to empower telecommunications users by displaying the caller's name on the recipient's phone

At present, through the CLIP (Calling Line Identification Presentation) feature, the calling number is displayed on the mobile phone of the called customer. If he/she has stored the calling number against a particular name in SIM/mobile phone storage, that name also will be displayed on the mobile phone. If somebody has downloaded the Truecaller app, the caller name provided by the Truecaller app will be displayed on the mobile phone. In addition to CLIP service, there is DND (Do Not Disturb) service launched by TRAI (Telecom Regulatory Authority of India) to prevent unsolicited calls to the customers from unregistered telemarketers.

The Department of Telecommunications (DoT) had suggested the introduction of CNAP to empower customers to make informed decisions while receiving an incoming call and to protect them from spam/ unwanted calls. It wanted to facilitate CNAP feature to smart phone as well as feature phone customers. DOT desired to evaluate the readiness and feasibility of implementing CNAP in multi technology networks across the TSPs. It requested TRAI to give its recommendations on this subject.

TRAI recommendations

After wider consultations, recently TRAI has recommended that all the Telecom Service Providers (TSPs) should display the calling customers names on the called customer mobile phones and all smartphone makers should be mandated to enable this feature within a stipulated time, say six months. CNAP feature will be provided as additional service on the request of the customer. In the case of calls originating from 140 number series, allocated to businesses or telemarketers for making calls to subscribers, the name of the calling entity should be displayed on the mobile phone of the called customer.

The pan-India implementation of CNAP shall be done after trials in one LSA (Licensed Service Area) where all the TSPs shall participate. TRAI has recommended that the customers having bulk connections and business connections should be given the facility of presenting their preferred name (trademark name registered with the corporate affairs ministry or the trade name registered with the GST council or any other such unique name registered with the government) instead of the name given in the CAF (Customer Application Form). It has recommended that DOT specify the documents that should be provided by such customers for registering their preferred name with the TSPs. It has also suggested that DOT stipulate rules for preventing any misuse of this facility.

The TSP on whose network call is terminated will make a query to the CAF database of TSP from which the call originated, obtains the name of the calling customer and displays it on the mobile phone of the called customer. For the customer whose legal name has changed after the submission of the CAF, the TSP will amend the CNAM (Calling Name) of the customer, based on the request of the customer which should be supported by verifiable documents. DOT will issue guidelines to TSPs to avoid any misuse in this regard.

Implementation of CNAP

At present the large part of the mobile network is based on Circuit-Switched core. For implementing the CNAP, at the time of receiving a call, based on the telephone number of the calling customer, the terminating network queries its Local Number Portability Database (LNPD) to determine the call originating TSP. In case call originating TSP and call terminating TSP are the same, the call terminating TSP queries its own CAF database and presents the CNAM to the called customer. In case call originating TSPand call terminating TSP are different, the call terminating TSP queries the CAF database of call originating TSP, gets the CNAM and presents it to the called customer.

When Circuit-Switched core networks are phased out, for implementing the CNAP, the call originating TSP sends the CNAM data over the signalling path to the call terminating TSP. The intermediate networks relay the CNAM data as received. The call terminating TSP receives the CNAM data and presents it to the called customer.

CLIR (Calling Line Identification Restriction) facility

TRAI has suggested that the CNAM of those callers who are provided with CLIR facility will not be presented to the called customers. CLIR facility will be given only to VVIP status persons such as President, PM and Ministers. Officers of central Intelligence agencies and top government officers can also apply. If any other person wants to get this facility, he should apply for it stating the reason and with recommendation from the DGP/ IGP of the state police intelligence wing. After verification of the details, the CLIR facility will be provided for one year by the TSP which can be renewed. Police personnel can override CLIR and can get the caller's name displayed on the called person's phone.

Way forward

Telecom customers are seeking the CNAP feature for protecting them from spam calls, fraud calls, CLI spoofing and Unsolicited Commercial Calls (UCC). CNAP feature promises to usher in a new era of transparency and user convenience in telecommunication service. However the TSPs should ensure that the provision of CNAP feature should not increase signalling load, should not increase the call set up time unduly and should not introduce latency/ interconnectivity issues in the network.

This feature will force the customer to convert the SIM he/she is using, on his/her name (if it is not already) thus preventing the frauds. Such conversion will lead to tallying of the name of the SIM user with the name in the CAF, thus cleansing the CAF records of TSP.

Though Sweden based Truecaller app provides calling customer names, the information may not always be accurate as it is collected through Crowdsourcing, unless the name is registered in the Truecaller app through OTP. For example if many close relatives and friends store somebody's name as his/ her nickname and if that person makes a call, the True Caller app of the called customer will display the calling customer name as nickname only and not the actual name.

CNAP overrides the name stored in the SIM/ mobile phone of the called customer as well as that provided by Truecaller app in the called customer mobile phone.

Though there is concern about the risks to user confidentiality, especially in the case of women callers, in any case the Truecaller app displays the caller name now also.

In the CNAP regime, the Call Completion Ratio (CCR) of the terminating network decreases as all the calls are not picked up by the called customers.

(The author is a former Advisor, Department of Telecommunications (DoT), Government of India)