Hope i made it clear....
RP-SMA connectors were introduced to separate professional and commercially available equipment, preventing unintentional or intentional connection of high-gain professional antennas with SMA connectors and commercial wireless equipment with RP-SMA connectors, violating federal or international laws. Today, however, both type of connectors are readily available.
RP-SMA connectors are widely used by
Wi-Fi equipment manufacturers to comply with specific local regulations {Section 15.203 Antenna requirement}, e.g., the
FCC, which were intended to make it difficult for consumers to connect antennas with
gain and thereby breach compliance. However, RP-SMA equipped antennas are now widely available.
http://en.wikipedia.org/wiki/SMA_connector#[member='Reverse']_polarity_SMA
IMO, the RP-SMA connector type is a restricted one where you cannot use high gain antennas which are intended for professional use.
