Confined Space Radio Design
Confined space radio design is an important activity which should be completed well in advance of the system build. From a radio communications perspective a confined space is anywhere where a reasonable line of sight cannot be maintained between radio devices and a transmitting mast.
This could refer to very cramped and restricted spaces, including those underground such as road tunnels, underground railways, utility tunnels and mines. However, it also covers spaces that may in themselves be relatively large and open, but are nevertheless cut off from major masts by complex layouts or obstacles such as thick concrete.