In the telecom services domain, delivering a service to each customer requires an often-overlooked resource, the numbering system to uniquely identify and differentiate end users. Currently, the Department of Telecommunications (DoT) administers numbers for fixed and mobile networks based on the International Telecommunication Union’s (ITU) Telecommunication Standardisation Sector (ITU-T) Recommendations. Further, the management of numbering resources is governed by the National Numbering Plan (NNP).

In India, a major review of the numbering plan was carried out in 1993, with the introduction of a large number of new telecommunication services and the opening up of the entire telecom sector for private participation. It was considered necessary to rationalise and review this plan to make it flexible so that it could cater to the numbering needs for the next 30 years. Subsequently, due to a rapid growth in the number of subscribers, a major review of the numbering plan was again carried out in 2003, with the formulation of the National Numbering Plan, 2003 (NNP, 2003).

The NNP, 2003 was designed to take care of the numbering requirements for about 30 years. However, the situation has changed rapidly since 2003. While fixed line connections have shown a declining trend, the mobile segment exhibited an unprecedented growth. The anticipated 450 million cellular mobile connections by 2030 in the NNP, 2003 had already been achieved in 2009. Further, the overall subscriber base stood at 1,177.02 million as on January 31, 2020. Therefore, 17 years into the NNP 2003, adequate availability of numbering resources is threatened due to a massive growth in the number of connections, especially in the mobile segment. As a result, the industry needs to review the utilisation of numbering resources and make some policy decisions to ensure that adequate resources are available for a sustainable growth.

TRAI issued a consultation paper on “Developing a Unified Numbering Plan for Fixed Line and Mobile Services” in September 2019. The consultation paper elicited many responses from stakeholders. Further, an open house discussion was also conducted on January 16, 2020. Based on inputs received from stakeholders and its own internal analysis, TRAI has now finalised its recommendations on ensuring adequate numbering resources for fixed-line and mobile services.

A look at TRAI’s key recommendations…

Current scenario

In India, the national telecom network has been divided into short distance charging area (SDCA), also called local area, and long distance charging area, which comprises one or several SDCAs. For public switched telephone network, the National Destination Code is the trunk (area) code assigned to each SDCA. Each SDCA is allotted a unique trunk code. Further, both fixed line numbers and mobile numbers consist of 10 digits, excluding the country code. The telephone number for basic/ fixed services has three components – country code, SDCA code and subscriber number (SN). The SDCA codes consist of 2/3/4 digits while the SN is of 8/7/6 digits respectively.

Capacity in the existing numbering scheme

Currently, we have about 1.2 billion telephone subscribers. These subscribers have multiple telephone connections. Due to technological developments and other means of communication like over-the-top services, the multiplicity of telephone connections is expected to decrease. Further, a large-scale increase in the requirement of numbers for mobile network-based devices catering to machine-to-machine (M2M) and internet of things applications is likely. However, a 13-digit numbering series has already been earmarked for these applications. Keeping in view the declining fixed line connections and adequate availability of numbering resources for fixed line, the main focus should be on the numbering resources for mobile services.

Even if we assume a highly optimistic 200 per cent mobile teledensity in India, the total number of mobile phones working in this country is likely to be nearly 3.278 billion by 2050. Assuming 70 per cent utilisation of the numbering resources, 4.683 billion numbers will be enough to cater to the requirement of mobile telephones working in the country by 2050.

During the consultation process, options such as creating a unified numbering plan for fixed line and mobile services, creating numbering resources by vacating fixed line levels, mandating dialling of the prefix “0” for calling mobile numbers from fixed line shifting data-only mobile numbers from 10-digit to 13-digit numbering and switching over from the 10-digit to 11-digit scheme for mobile numbers were explored.

However, TRAI is of the view that migration to a unified numbering scheme, which involves large-scale changes in the existing network, is not recommended at this stage. However, sufficient numbering resources can be made available for fixed line and mobile services through alternative methods listed in its recommendations.

The regulator also recommends that all SIM-based M2M connections using 10-digit mobile numbering series should be shifted to the 13-digit numbering series allocated by DoT for M2M communications at the earliest. The mobile numbering resources surrendered by telecom service providers (TSPs) who have closed down their wireless operations may be reallocated to those TSPs who need more numbering resources.

For the creation of sufficient numbering space, TRAI recommends that the following scheme should be adapted:

  • Dial all fixed to mobile calls with the prefix “0”.
  • No change in the dialling plan for fixed to fixed, mobile to fixed, and mobile to mobile calls.
  • A total time of one month may be given to all TSPs to implement this scheme.

Allocation of numbers

At present, the allocation of mobile switching centre (MSC) codes numbering series to TSPs is done following a VLR (visitor location register)-based criterion. Recently, DoT has also started withdrawing scarcely utilised/unutilised MSC code numbering series allocated to TSPs in different licensed service areas. These withdrawn MSC codes are being reallocated to TSPs with a growing subscriber base.

In this regard, TRAI is of the view that the present allocation criterion is fair, stringent and justified. Therefore, it recommends that the present criterion of utilisation for allocation of the numbering resources should be continued. Further, TRAI recommends that sparingly used MSC codes (less than 10 per cent utilisation after two years of allocation) may be withdrawn and reallocated to another TSP whose subscriber base is growing.

Annual numbering return

It is important to devise mechanisms to have a good monitoring system for the effective utilisation of numbering resources. One possibility is that all service providers making use of the numbering resources may be required to submit a detailed return on numbering resource utilisation to the numbering plan administrator every year. The administrator may then carry out the numbering audit of usage of numbers by service providers based on these returns. In view of the above, TRAI recommends that the annual return on the utilisation of numbering resources should be submitted to the numbering plan administrator by all TSPs, both for mobile as well as fixed line numbering series. The format used for filing this return may be similar to details currently given by service providers for allocation of a fresh block of numbers. In addition to annual submission, this return should be submitted every time service providers make a request for a fresh block of numbers.

Automated allocation of numbering resources

In 2010, TRAI, in its “Efficient Utilisation of Numbering Resources”, had recommended automated allocation of numbering resources. While this recommendation was accepted by DoT, the entire process of allocation of numbers is still manual and no automation has been done. To this end, TRAI recommends that an automated allocation of numbering resources using a number management system software may be introduced to speed up the process of allocation in an efficient and transparent manner.

Revision of numbering plan and consolidation of short codes

The NNP, 2003 has been amended several times since its introduction and some major changes have also been made. However, it is difficult to formulate a single document that incorporates all the changes. For instance, the allocation of short codes for emergency services, travel-related information and for other non-commercial use by the general public is done by DoT. While DoT issues the allocation letters for each short code, no consolidated list is available on its website. To address this issue, TRAI recommends that a revised and new NNP be issued at the earliest and a consolidated addendum to the NNP should be issued every year, which should include all newly allocated numbering resources for fixed line as well as mobile services. Further, a consolidated list of short codes should be issued at the earliest and the short code allocations, that are not in use should be withdrawn.

By Kuhu Singh Abbhi