TRC Revises the National Numbering Plan for Mobile Services

The 2024 revision of the Cambodian mobile numbering plan responds to sustained growth in the number of mobile subscribers, in machine-to-machine connections and in the range of services that require dedicated numbering resources. The Telecommunication Regulator of Cambodia adjusted the allocation of number ranges to accommodate this growth, to align with international best practice and to ensure that the numbering plan can support the evolution of mobile services over the coming years.

The revision has practical implications for operators, service providers, enterprise customers with large numbering ranges and international counterparts that route calls or messages to Cambodian numbers. It also affects the maintenance of directories, address books and, in some cases, technical configuration in enterprise environments.

The mobile numbering plan defines the ranges of numbers that may be used for mobile services, distinguishing between numbers allocated to specific operators, ranges reserved for machine-to-machine and internet-of-things applications and ranges reserved for future use. The regulator assigns numbering resources to operators on the basis of demonstrated need, projected demand and efficient utilisation of previously assigned resources.

The revision adjusts the allocation to reflect current subscriber levels, expected growth and the emergence of new use cases. Some ranges have been extended, others have been re-assigned and specific ranges have been earmarked for machine-to-machine and enterprise applications where addressing requirements differ from those of ordinary consumer subscriptions.

The revision has been designed to preserve continuity for existing subscribers to the extent possible. Numbers already in use are expected to remain valid, and number portability arrangements between operators are expected to continue to function without material disruption. Where changes to the length or structure of certain ranges are contemplated, transitional arrangements are provided to give operators, subscribers and international counterparts time to adjust.

Operators are expected to keep their internal systems, including customer databases, billing systems, routing tables and interconnection arrangements, aligned with the revised plan. Coordination between operators and with international counterparts is important to avoid problems in routing calls and messages during the transition.

The revision recognises the growing importance of machine-to-machine and internet-of-things applications, which typically require large numbers of subscriber identifiers but generate much lower average traffic per identifier than ordinary consumer subscriptions. Dedicated numbering ranges for such applications can support efficient use of numbering resources and enable operators to design pricing and service models that are appropriate for machine-to-machine use.

Enterprises with large planned deployments of connected devices should engage early with operators on the numbering resources that will be used, on the addressing and routing arrangements that will apply and on the possible use of alternative identifiers where the underlying use case does not require traditional numbering.

Changes to the numbering plan may affect international routing arrangements, particularly where international carriers rely on specific number ranges to identify Cambodian traffic. The regulator has communicated the revised plan through international coordination mechanisms, and Cambodian operators are expected to inform their international partners of relevant changes so that routing tables can be updated in a timely way.

Directory services, contact management applications and enterprise systems that interact with Cambodian numbers may also need to be updated. Enterprises should verify that their systems recognise the current structure of Cambodian mobile numbers, that address books maintained for their staff and customers are updated where necessary and that any validation rules applied to Cambodian numbers reflect the revised plan.

Consumers are typically less affected by changes to the numbering plan than are operators and enterprises, but they may nevertheless be affected in specific ways. Where a subscriber is asked to update a number, for example following a range change, operators are expected to provide clear communication, to explain the reason for the change and to support subscribers in updating their contacts, saved services and linked accounts.

Awareness of the numbering plan can also help consumers identify calls from mobile numbers, to distinguish between local mobile and fixed numbers, and to avoid confusion in the event of unfamiliar formats.

The regulator monitors the use of numbering resources on an ongoing basis and may adjust the plan again in response to further changes in the market. Operators are expected to report on the utilisation of the ranges assigned to them, to return unused ranges where appropriate and to justify requests for additional resources on the basis of demonstrated demand and efficient use.

Future evolution of the plan may address further categories of use, including new applications for internet-of-things and specific services that require dedicated identifiers. Operators and enterprises are encouraged to engage with the regulator's consultation processes when the plan is revised again.

For operators, the revision requires coordinated updates to network configuration, customer systems, marketing communications and interconnection arrangements. Programme management is important to ensure that changes are implemented in the right sequence and that testing is conducted to verify that calls and messages route correctly across all affected paths. Documentation of the changes should be maintained to support internal governance and regulator engagement.

For enterprises, the revision calls for a review of any systems that store, validate or route Cambodian mobile numbers. Contact centres, customer relationship management systems, marketing automation platforms and communication tools should be tested to ensure that they operate correctly with the revised numbering structure. Machine-to-machine deployments should be reviewed to ensure that they use appropriate ranges and that scaling plans are consistent with the availability of numbering resources.

Lex Civora advises operators, enterprises and international counterparts on the interpretation and application of the revised numbering plan, on the negotiation of numbering-related arrangements and on engagement with the regulator on the allocation and use of numbering resources.