About: http://webisa.webdatacommons.org/152913202

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	In existing PTT systems, a person desiring to talk, i.e. have the floor, will press the PTT button and the wireless device will only indicate the availability of the PTT channel with an affirmative or negative audible signal.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com