Operating a radio communications network in most countries is subject to licensing by national telecommunications regulators, both for its type of use and the radio frequency spectrum it utilises, especially as radio frequency spectrum is a scarce resource and needs to be used efficiently.
Operating a commercial mobile radio network practically always requires a specific operating license. In case of private radio networks, i.e. Professional Mobile Radio (PMR), the interpretation of the licensing requirements is country specific and the opinion of the national regulator should thus always be consulted before setting up a TETRA network. In most cases a private radio system requires only a frequency license.
Radio Frequency license
Usage of radio frequencies is practically always controlled either by the national radiocommunications regulator or alternatively some frequency band specific frequency management body to whom the regulator has delegated the management responsibility. Upon successful application, the regulator will grant right to use specific radio frequencies for a specified purpose within a specified region. Radio frequency licenses are not normally issued free of charge and the cost of the license can vary greatly depending on country and type of usage. For details of the procedures and fees regarding a radio frequency license the national regulator should be consulted.
TETRA standards and radio spectrum
The TETRA standard was developed to provide optimal performance in the frequency range 300 to 1000 MHz and outside this range the performance has not been verified. In practice, TETRA system deployments and product developments concentrate on only a few frequency bands as a result of European harmonisation and also de facto global spectrum harmonisation. This reduced number, but widely available number, of radio frequency bands has greatly contributed to developing the current multi-vendor market for TETRA with multiple suppliers delivering interoperable products for the same radio frequency bands. Interestingly, if the radio frequency spectrum for TETRA was fragmented, there would be a risk that some frequency spectrum allocations would only have products available from one supplier, thus defeating the benefits of an open standard supported by multiple vendors. This is not a situation that users would usually appreciate.
The TETRA standards have recently been updated to Release 2 which includes the wideband TETRA Enhanced Data Service (TEDS) air interface that can support 50 kHz, 100 kHz and 150 kHz channel widths. In Europe the TEDS capable channels are already taken into account in PMR spectrum decisions even though those channels are not yet readily available for use in all countries.
Radio spectrum for TETRA in Europe
The fast roll-out of TETRA in Europe partly resulted from the fact that a virgin frequency band was allocated for the emergency services based on agreement between the EU and NATO. As a result, European Public Safety and Security forces are using the radio frequency band 380-385//390-395 MHz for operation of their TETRA networks.
It is worth noting that the build-up of shared national Public Safety multi-agency radio networks has significantly contributed to the overall spectrum efficiency of the Public Safety services via the following mechanisms:
– one shared and trunked network for all agencies is always much more efficient use of spectrum
– the spectrum efficiency of TETRA – 4 slots in 25 kHz – meant a major improvement
– the agencies have now vacated or are vacating the VHF/UHF spectrum that they used earlier
Within this emergency service TETRA spectrum allocation most of the radio frequencies are reserved for Trunked Mode Operation (TMO). The Direct Mode Operation (DMO) frequencies are typically allocated at the lower end of the radio frequency band (from 380 MHz upwards) and specific frequencies for Air-Ground-Air (AGA) operation are allocated at the upper end of the band (from 385//395 MHz downwards) to allow international compatibility.
For the European non-emergency services, TETRA frequencies are mainly allocated in the 410 to 430 MHz band with some countries allocating frequencies in the 450 to 470 MHz band. Countries that are not members of NATO can sometimes allocate radio frequencies in the 385-390//395-399.9 MHz band for TETRA users.
Radio spectrum for TETRA elsewhere
In Asia Pacific and South America the so-called 800 MHz band, i.e. frequencies 806-824//851-869 MHz are available for Digital PMR systems like TETRA. In some distinct areas like South Korea, South-East Asia, the Hong Kong SAR, Venezuela, etc., radio frequencies in the 380-400 and/or 410-430 MHz bands have been allocated to TETRA. China has reserved frequencies in the 350 to 370 MHz range for national security radio networks using TETRA. In all cases the allocations and overall availability of radio frequencies needs to be verified by the national regulator concerned.
European frequency management
Within the EU and the European Conference of Postal and Telecommunications Administrations (CEPT) region the usage of radio spectrum is very much harmonized based on the work done under the working groups of CEPT. The harmonisation is guided via published Electronic Communications Commission (ECC) Decisions previously known as European Radiocommunications Committee (ERC) decisions, that each of the member state will recognise to implement if they so decide, i.e. the final decisions are done at the national level. The Decisions, Reports and Recommendations of the ERC/ECC are published at the website of the European Communications Committee www.cept.org/ecc and the European Communications Office www.cept.org/eco The following Decisions are significant to TETRA:
– ECC/DEC/(08)05 Digital Public Protection and Disaster Relief (PPDR)
within the 380 – 400 MHz range
– ECC/DEC/(06)06 Narrow Band Digital Land Mobile PMR/PAMR
in the 80 MHz, 160 MHz and 400 MHz bands
– ECC/DEC/(04)06 Wide Band Digital Land Mobile PMR/PAMR
in the 400 MHz and 800/900 MHz bands (amended 2009)
– ERC/DEC/(01)19 Frequency bands for the Direct Mode Operation (DMO)
for the Emergency Services
– ECC/DEC/(06)05 Frequency bands for Air-Ground-Air operation (AGA)
for the Emergency Services
It should be noted that current European spectrum identifications are made technology neutral and hence the ECC Decisions may include also frequency bands that are not intended for TETRA usage.
Type approvals and market surveillance
Taking radio equipment into use requires official approval to ensure that the devices do not cause harmful interference. The traditional method to conduct approval has been type approval testing in each country. Currently the approvals in the EU and CEPT regions are harmonized throughout the region to build a wider open market. The basis on which the harmonized market is provided is the EU Radio and Telecommunications Terminal Directive 1999/5/EC. To bring radio equipment to market in the EU the supplier has to declare its conformance to Harmonised European standards, a declaration based on test reports from an authorised laboratory. As a visible sign of conformance the equipment carries the CE mark.
The standards with which the conformance of TETRA equipment has to be verified and declared are the harmonised TETRA standards for TMO and/or DMO (EN 303 035-1 and EN 303 035-2), the harmonised Electromagnetic Compatibility standards EN 301 489-1 and EN 310 489-18 and the standards controlling the radiation level to protect human health EN 50360 and EN 50361. The latter standard defines the Specific Absorption Rate (SAR) measurement method to verify that the electromagnetic radiation levels meet international health standards. Conformance to all the above listed standards is required to be entitled to use the CE mark.
In the countries where the CE mark is the passport to the market, the regulators conduct market surveillance in the supply chain to check that only CE marked equipment are brought to the market.
European Communications Committee (ECC) – www.cept.org/ecc
European Communications Office (ECO) – www.cept.org/ eco
ERO Frequency Information System (EFIS) – www.efis.dk
Links to websites of European radio regulators – www.ero.dk–> CEPT Administrations –> CEPT Administrations’ websites
U.S. Federal Communications Commission – FCC Radio Spectrum Home Page – www.fcc.gov/encyclopedia/radio-spectrum-allocation
U.S. National Telecommunications and Information Administration – Office of Spectrum Management – www.ntia.doc.gov/osmhome/osmhome.html