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I've read about there being range limitations when using TDMA digital modes, like DMR, due to clock drift in the base and mobile stations. The issue seems to be the slot timing verses distance and length of transmissions. See section 10.2.3.1.3 on page 112 in the following link to one of the ESTI DMR standards. https://www.etsi.org/deliver/etsi_ts/102300_102399/10236101/02.03.01_60/ts_10236101v020301p.pdf Anybody have any experience with this or did the detailed calculations for their installation? I've seen comments where some have gone to FDMA type modes to avoid this issue.

It is unclear if the FCC would consider permitting any digital voice modes in the GMRS in the near future, particularly since they just released new rules in 2017. If they did consider this, should they permit a particular mode, such as P25, dPMR, DMR, NXDN, (other?), some, or all? Should it be limited to simplex/direct mode, or should repeaters be included?

Related to this topic: https://forums.mygmrs.com/topic/1971-san-diegola-600-repeater-owners-ix-from-nxdn-idas-equipped-yacht/?hl=nxdn Vessel just passed by the bay area and started interfering with our 600 repeater again this morning. Yacht is now headed to the Seattle/Port Angeles area today. See this for current position: https://www.marinetr...7/vessel:LONIAN Only seems to effect 600 repeater inputs.

A week or two ago we started receiving an IDAS/NXDN beacon on our two 600 repeaters (Oakland and Sunol CA; San Francisco Bay Area) - signal was about -79 dBm into Oakland and -100 dBm into Sunol Peak on 467.600 MHz. This would occur every four seconds, for about one second. There was occasional voice traffic as well. This was trashing most of our users. No FCC ID. What a surprise..... After several days of direction-finding (and avoiding the Oakland protests/riots) we located this station on a Yacht that was in dry dock in Oakland CA. It was part of an on-board trunked or advanced-conventional IDAS/NXDN repeater system for their crew of 24; its a big yacht. Crew was Australian. IDAS RAN=31, TGID 1-148 was common. The yacht staff was cooperative and after testing with them, they agreed to disable the repeater system until the left the bay region (they found direct mode worked just fine). The system was enabled again once they left the bay region for San Diego. They indicated they would have their two-way radio company remove this channel from their repeater system when they were back at home. Repeater owners in southern California might also be affected by this signal on 467.600. Listen to your input channel (place your repeater in carrier squelch temporarily to hear this). If you are affected, let me know and I can provide their cell number to you. Or, if you have IDAS/NXDN, the contact on board is Ryan. Vessel remains in the San Diego area as of now (7/1/2020 3:33 PM). Location: https://www.marinetraffic.com/en/ais/details/ships/shipid:5662034/mmsi:319139700/imo:9800087/vessel:LONIAN