Harmonized Calculation Method
Harmonized Calculation Method (HCM) is an internationally coordinated procedure for determining the field strength in the transmission area of radio services. The introduction by European telecommunications administrations took place through the HCM agreement with the aim of making optimal use of the specified frequency spectrum also near the border and preventing harmful interference.
“The representatives of the administrations of Austria, Belgium, the Czech Republic, Germany, France, Hungary, the Netherlands, Croatia, Italy, Liechtenstein, Lithuania, Luxembourg, Poland, Romania, the Slovak Republic, Slovenia and Switzerland have, in accordance with Article 6 of the Regulations for the radio service concluded this agreement on the coordination of frequencies between 29.7 MHz and 39.5 GHz in order to prevent mutual harmful interference in the fixed radio service and in the mobile land radio service and to use the frequency spectrum primarily on the basis of mutual agreements optimize."
In Germany, the Federal Network Agency is the responsible administrative authority; she is currently (February 2009) also the managing administration for the HCM agreement. The current version of the HCM agreement was approved by correspondence in 2013 by the administrations involved and came into force on July 1, 2013.
The field strength curves taken from ITU -R recommendation P.1546 form the basis of the HCM .
Application of the Harmonized Calculation Method
To prevent harmful interference, the state border and usually an x-km borderline in the country of the coordination partner are subjected to a field strength calculation using the HCM algorithm. The calculated value qualifies the frequency at a specific location as a fully or partially usable resource (budgeting of system parameters).
A typical area of application is the observation of disturbances in neighboring cellular mobile radio networks . If the network is expanded, this can affect the neighboring network. In digital networks such as GSM or UMTS, harmful interference increases the bit error rates dramatically. There is a division into preferred frequencies (GSM) or division into preference code sets (UMTS). As a result of the system, the networks are thus decoupled through budgeting. With different radio systems (e.g. GSM vs. UMTS) that meet at national borders, simple budgeting of resources ( frequency with GSM or scrambling code with UMTS) is problematic. The restriction often has cost-intensive consequences for the operator's network expansion at national borders.
A clear sign of a non-harmonized radio network is an automatic unintentional logging into foreign networks at national borders.
Web links
Individual evidence
- ↑ HCM Agreement 2008 (former Vienna Agreement 1999)