An Electromagnetic Field Communications System for Wireless Networks for producing
an electromagnetic field within a structure is disclosed. The electromagnetic field
is produced by using common conductive elements already present within virtually
all pre-existing residential commercial, industrial buildings. These conductors,
which may include electrical ground shields, wiring, pipes, sprinkler conduits
or structural members, are excited with a signal, and become the cavity which contains
the electromagnetic field. In preferred embodiments of the invention, signals are
generated using the High Frequency, Very High Frequency and lower UHF bands (3
to 30, 30 to 300 and up to 400 MHz). The invention may be used to create a local
area network inside the field and within the structure. Devices that include receivers
tuned to the electromagnetic field may then be connected and networked. The system
may be operated without causing interference to other conventional radio devices
outside the structure in the HF band.
