Required for wireless connectivity where American Messaging Paging Signal is available. This is a true Plug and Play Device that works well where a strong wireless signal is available. No connection is needed to a host PC. This unit simply plugs into the LED Display, and all custom messages can be sent using any internet equipped computer. Call us to determine if your location has an adequate signal. Click here to see wireless coverage map but also Call us to determine if your location has an adequate signal.