Change 1 to ED-110B, Interoperability Requirements Standard for Aeronautical Telecommunication Network Baseline 1, addresses three different improvements aiming at: 1.permitting the selection and acceptance of CPDLC messages, containing HF, SAT and UHF frequencies by ANSPs at the Oceanic/ Continental boundaries and the acceptance of these CPDLC messages by flights, leaving the Continental EUR airspace and entering the Oceanic airspace. Currently, Annex B (CPDLC P/OICS for ATN Baseline 1), Table P-10, specifies the “Out of Scope (I)” status of the frequency parameter for HF, SAT, UHF, making it impossible for flights, leaving Continental EUR airspace and entering the Oceanic airspace to transfer the voice channels, using CPDLC. 2.optimizing the transfer of CPDLC connections. Currently, Data Link Initiation Capability service description (section 4.1.4) requires that, for a transfer of data communications between ATSUs, the T-ATSU initiates a DLIC-Contact request prior to uplinking UM160 NDA by the T-ATSU (CDA). This change requires the ground systems switching this sequence and aligning on GOLD procedures: first send the NDA message and then initiate the DLIC-Contact request. 3.optimizing the transfer of voice communications within the same ATSU. Currently, ATS Communication Management service description (section 4.1.4) requires that for any transfer and/or Change of Frequency, even with No Change in the established CPDLC connection, the T-ATSU sends UM183 (freetext) containing facility designation, facility name and facility function as defined in 3.3.7.6.2.3. In practice, this should not be systematically required, as in many cases, facility name and functions remain the same. This change makes it optional to send this message for transfer with no change of CPDLC connection.