Common

The common use of the radio spectrum is the one that is carried out without the need for prior authorization of the Administration.

However, in spite of this, the common use of the spectrum has to be adjusted to certain technical conditions and limitations. These parameters and other utilization characteristics are indicated in the corresponding National Utilization Notes UNs of the National Frequency Allocation Table (CNAF). Any use that does not comply with what is indicated in the CNAF constitutes fraudulent use of the spectrum and is considered illegal. In addition to delimiting the frequency bands allowed for these applications, the CNAF indicates limitations of the transmitted power, sometimes of the transmitted power spectral density or radiation characteristics of the antenna, certain requirements may also be indicated to ensure compatibility with other applications, such as the use of special techniques such as dynamic channel selection, LBT techniques or other spectrum access and interference mitigation techniques.

In addition to what is stated in the abovementioned UN Notes to the CNAF, all devices and apparatus operating in common use bands must have a corresponding conformity assessment, i.e. be approved in accordance with the provisions of the UN Treaty. Royal Decree 188/2016, which incorporates into Spanish law the Directive (EU) 2015/1535 of the European Parliament and of the Councilestablishing a procedure for the provision of information in the field of technical regulations and rules on information society services. The common use shall not cause interference to other uses of the spectrum and is not entitled to protection against interference caused by other uses whatever their condition.

Under this modality there are many applications, very different in their purpose and in the technical characteristics, although it can be said that all of them have in common the low power allowed (generally below 10 mW).

La Commission Implementing Decision 2013/752/EC and the Recommendation of CEPT ERC/REC 70-03 They relate to short-range devices operating according to harmonised conditions of use under consideration of common use. These provisions are contained in several UN notes of the CNAF relating to this type of application.

Numerous commonly used applications include inductive loop applications, generic short-range devices, medical implants in animals and people, wireless microphones, PMSE devices in general (Programme Making and Special Events), model control (ground and water), aeromodelling, remote control and alarms via radio, short-range video, TLPR devices (Tank level Probing Radar), UWB devices (Ultra Wide Band) and PMR446 mobile radio system, as well as radio frequency identification (RFID) devices, industrial, scientific and medical applications (ICM bands).

Also included under the consideration of common use are applications as widespread nowadays as local area networks (RLANs), better known for wi-fi networks, in the 2.4 GHz and 5 GHz frequency bands, and with the technical limitations established the corresponding UN notes of the CNAF.

The so-called citizen band CB-27, is another of the uses of the spectrum under the consideration of regulated common use in the UN-3 of the CNAF. This application has its specific frequency band around 27 MHz with 40 channels of 10 kHz bandwidth, intended exclusively for such use.