The present document specifies the DECT derivative DECT-ISM for implementation in the 2@45 GHz ISM band [9]@ [10] and [11]. The main difference between DECT and DECT-ISM is the addition of frequency hopping patterns fulfilling the FCC part 15 rules [10]. The prime objective for specifying DECT-ISM is to allow for introduction of a DECT-based technology in countries that have no spectrum allocated for DECT@ but allow frequency hopping applications in the ISM band. The 2@4 GHz ISM band is available in all major markets worldwide. DECT-ISM will@ compared to DECT@ have limitations in range due to restrictions imposed by the ISM band rules [9]@ [10] and limitations in quality of service mainly due to the fact that the ISM band is unprotected@ while the DECT band is exclusively allocated for DECT. See further clause 4.1. The ISM band is unprotected in that sense that it allows for uncoordinated usage of a variety of incompatible communication devices and also industrial@ scientific and medical devices.