As a public safety communications official with over 30 years experience in this field I must say that I feel the only way a nationwide public safety communications system is going to become a reality is for the Federal Government to take the bull by the horns and make it happen without relying on State and Local Governments to be responsible for building out any part of the system. They must decide on which frequency band the system is going to operate in along with ensuring there are enough sites to provide 95% coverage in medium to heavy buildings (I personally would like to see a nationwide system in the 400 MHz range for voice, especially since many federal government and military agencies are already using 400 MHz equipment and systems, but I doubt this will happen since there is such a huge push for 700 MHz broadband). There must also be a funding mechanism to not only pay for the infrastructure installed by the feds, but there must be a funding mechanism to allow state and local agencies to come on board, plus pay for any annual reoccurring costs associated with the system maintenance. Regardless of what frequency band and system is selected It MUST be attractive to the State and Local Governments to get them to switch over to the system. I understand this has been attempted a couple of times over the years, with P25 being one of the ideas, but the problem has been and continues to be that once someone comes up with what seems to be a good idea whether it is APCO, IAFC, IACP, etc. and get all of the blessings of the various organizations, the FCC and Congress, plus the funding necessary to build out a system someone else comes out with a solution that is less expensive than the previous one that looks better to some State and Local Governments, so they continue to want to do their own thing.
It is extemely hard to get all of the various levels of government together to agree on the same thing and I personally do not think I will see this happen before I retire, but I hope I am wrong. I personally think there is a huge push for LTE in public safety because many of the vendors feel it is going to be much more attractive to public safety agencies because it will allow for many more features and functionality than that of P25, EDACS, MotoTRBO, NEXEDGE, LTR and some of the other LMR Systems. I guess we will have to wait and see....