2.8.3 Implications of technology trends

The major implications on numbering of the four technology trends and implications mediated via changes in the market structure are depicted below:

Technology implications on numbering

Geographical numbering plans were once a necessity, but today a growing number of countries have stopped demanding a relation between numbers and geographical location. This enables a more efficient use of an increasingly scarce resource, and facilitates number portability for subscribers moving to a new location. Moreover, convergence between local and long distance calls makes it less necessary to inform about geographical location of subscribers.

The growing penetration of mobile subscribers has encouraged this development. First, growth in the number of mobile phone has increased the total demand for numbers, which potentially can lead to number scarcity in some regions. Second mobile phones are used from many different locations and numbering and tariff schemes for mobile phones are most often national and not regional.

Geographic numbering plans and even national numbering plans are also challenged by VoIP. VoIP services can be provided at any location where the Internet can be accessed. The VoIP operator does not need to be present in a particular country. The operator can acquire numbers from the UK numbering plan, for example, and offer them to subscribers in any other country.

A particular problem related to VoIP is tracing of emergency calls. At present, it is not possible to trace an emergency call from a VoIP phone. The call may therefore be routed to a wrong location (even in a wrong country). It is possible to assign a physical address to a VoIP number, but the same VoIP number may be used from many different locations just as mobile phones are (nomadic use).

Another issue related to mobile communication is cross portability of numbers. Number portability is essential for new market entrants, as subscribers are much more reluctant to change operator if they are unable to keep their number. Number portability is important for both new market entrants offering their services by use of existing technologies, and for operators building their service provision on new alternative infrastructures.

Number portability between fixed and mobile services could potentially lead to increased competition between fixed and mobile services, as it then becomes more attractive to give up the fixed-line subscription and substitute with a mobile. Cross portability will lead to less transparency in tariffs, as it will become impossible for a consumer to distinguish between calls to fixed and mobile phones. A similar problem arises with respect to national and in particular international settlements between operators. As long as termination charges in fixed and mobile networks differ, it is necessary for operators to distinguish between calls to fixed and mobile subscribers.

Furthermore it is doubtful if cross portability is necessary to facilitate competition between fixed and mobile services. There are now more mobile than fixed subscribers in many countries. This indicates that mobile phone services have been able to compete without offering number portability.

The situation may be different with regard to VoIP. The penetration of VoIP subscribers is still much lower than that of mobile subscribers, and the service offered by VoIP is more similar to fixed telephony. In this case lower prices are the main advantage. Therefore cross portability between POTS and VoIP will be an important measure in order to facilitate development of VoIP.

Convergence between Internet and telephony implies a need for a coordination of numbering plans. VoIP can be offered without allocation of numbers from the E.164 numbering plan. Domain names, IP addresses or service specific identification addresses may be used instead. However, it is not possible to call a VoIP subscriber from an ordinary phone without allocation of a number which can be recognized by the traditional fixed telecom network.

ENUM – tElephone Number Mapping addresses this problem by offering a method for conversion of telephone numbers to IP-addresses and visa versa. ENUM is supported by a number of VoIP operators and is being implemented in a number of countries. So far three countries (Austria, Poland and Romania) have reached the stage of production, while trials are implemented in Finland, France, Germany and Japan (Ripe ENUM working group http://enumdata.org/). ENUM is supported by international organizations such as ITU and the EU and is expected to be the future standard for connection between IP networks and PSTN networks.

However, current experiences have revealed a number of critical issues related to use of ENUM. All of these are related to the fact that ENUM is developed outside the formal regulatory framework. ENUM may be adopted through agreement among major Internet service providers without any Governmental involvement. On the other hand the E.164 numbering plan is administered by the national regulatory agencies. Therefore the allocation of responsibilities regarding the administration of E.164 numbers and the administration of the E.164-subdomain within .arpa must be clearly defined[1].

Endnotes

[1] Annette Hillebrand a.o.: Business Models and ENUM – Opportunities and Challenges EuroCPR 2005.