The 'WAPECSization' of the GSM frequencies

Mobile broadband spectrum is at the heart of connecting people with an increasing range of internet services which demand high capacity and are expected to be available anywhere and everywhere. Consumers are now a big step closer to this not only with the well-known 'Digital Dividend' initiatives (see Aljo van Dijken's article in this Newsletter) but also with the final approval of three new CEPT reports defining the technical conditions for the introduction of the new wider-bandwidth LTE and WiMAX technologies in the major European mobile frequency bands, namely in the 900 MHz and 1800 MHz bands.

Digital Dividend implementation still faces hurdles in some countries, and new applications are considered to be hungry for bandwidth. So this move to update existing mobile bands is an important additional development. The CEPT reports are also a very important milestone in the implementation of the so-called "WAPECS" concept, the new flexible European approach based on technology and service neutral regulation. This is a change from the old approach of regulators trying to "pick winners" in a fast-developing technology and market environment.

These CEPT reports were produced in response to the Mandate issued by the European Commission to CEPT in order to assess the feasibility of introducing in Europe new wide band mobile technologies in the frequency bands traditionally used by GSM. GSM is the technology which triggered the explosive growth of mobile phones in Europe in the 1990s, and its further enhancements, the latest ones being GPRS and EDGE.

It should be noted that the technical conditions for the introduction of UMTS (the first ‘3G’ technology) in these “GSM bands” were developed by CEPT/ECC in 2008 and later included in one of the WAPECS-oriented Decisions of the European Commission (2009/766/EC) addressing the use of the 900 and 1800 MHz bands. This EC Decision, which will soon be complemented with the LTE and WiMAX entries based on the findings of the new CEPT reports, is binding for the EU Member States, all of them also being CEPT members.

The presence of the “old” GSM technology appeared to be the main technical difficulty challenging CEPT/ECC in this work since GSM was still regarded as the reference mobile technology in these frequency bands which must be protected against possible interference from newcomers. CEPT/ECC had therefore to apply a different technical approach from the so-called "Block Edge Mask" (BEM) concept used in its previous reports for the 2.5 GHz, 3.6 GHz and 2 GHz mobile bands where no legacy narrow band technologies existed. It was necessary to consider separately 12 scenarios involving different pairs of systems expected to be operating within the 900 and 1800 MHz bands in the foreseeable future (e.g. GSM-WiMAX, LTE-UMTS etc.).

In addition, technical compatibility between LTE and WiMAX against one another as well as protection of other systems working in the adjacent frequency bands would also need to be ensured. These “other systems” for which CEPT/ECC has successfully carried out the compatibility studies included GSM-R(RE), PMR/PAMR (e.g. TETRA, TAPS, CDMA), DECT, METSAT (a meteorological system), radio microphones and fixed service. The last but by no means the least task performed by CEPT/ECC in response to this EC Mandate was compiled in a separate CEPT report dedicated to the compatibility between UMTS-900 and the aeronautical systems (both the current DME system and the future L-DACS 12 systems planned for deployment by 2025).

Based on the results of its studies, CEPT concluded that both LTE and WiMAX can be introduced in the 900 and 1800 MHz band currently used for GSM without causing interference to any other system provided the technical conditions it has developed are respected.

This important and technically difficult work carried out by CEPT/ECC in a very limited timeframe will be significantly beneficial to both European regulators who have got a clear technical roadmap for further WAPECSization of the GSM frequency bands and European consumers who will benefit in the coming years from a greatly increased user experience in these frequencies.

Alexander Gulyaev
ECO Expert in Spectrum Management

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