A gas barrier film comprising a resin substrate provided thereon at least one layer of a ceramic film, wherein the density ratio Y satisfies 1\u2267Y\u22670. Coordination procedures between and among 2nd and 3rd Tier deployments include the use of beacons transmitted by the 2nd Tier for clearing access to spectrum occupied by 3rd Tier users and multiple 3rd Tier deployments sharing resources using a group-listen before talk protocol, rather than a per-node LBT protocol. The carbon source provides carbon atoms for growing diamond and can include a diamond seed material for diamond growth.