Landmarks in public safety radios rough draft
AM bases - 1920s FM - ? mobiles 1930s backpack radios - ? 1935 repeaters - 1939 ? lunch box size portables - ? 1945 1950s - paging systems 1955 ? - earliest interops channels 153.83 46.30 154.265 154.28 154.295 155.34 155.475 1960s - transistors brought multi channels and hand held portables and UHF 1980s - trunked systems and data terminals 1990s - cellphones 1995 ? - P25 2000 - ( ? faster paging systems ? ) & vtacs / utacs / itacs 2005 ? - cheaper satellite phones 2006 ? - GPS makes travel routing much much easier - ? but very few public safety use it ? 2013 - narrowbanding of VHF & UHF provides 100% more channels -- You received this message because you are subscribed to the Google Groups "massfire" group. To unsubscribe from this group and stop receiving emails from it, send an email to massfire+unsubscr...@googlegroups.com. To post to this group, send email to massfire@googlegroups.com. Visit this group at https://groups.google.com/group/massfire. For more options, visit https://groups.google.com/d/optout.