Patent ID: 7277671

Claim:
A wireless response system, comprising: a base unit and a plurality of handheld response units, said base unit having a wireless base transceiver, each said response unit having a wireless response transceiver, said wireless base transceiver communicating with each said wireless response transceiver over a wireless communication link, each of said response units comprising a plurality of keys for entry of actual user responses and a key press timer, said base unit comprising a base unit timer; said response units sending transmissions to said base unit over said wireless communication link, said transmissions including actual user responses and a value of said key press timer, the actual user responses being entered in the respective response unit by a user operating one of said keys; wherein said base unit determines a derived time of response for at least some of said response units and compares the derived times of responses for said at least some of said response units with each other to establish an order in which actual user responses were entered for said at least some of said response units; and the derived time of response being determined for a response unit at said base unit at least from the value of said key press timer that is received by said base unit from that response unit and from a value of said base unit timer when a transmission is received from that response unit, the value of said key press timer being obtained at the corresponding one of said response units and sent to said base unit, the value of said key press timer being a difference between time that a response is entered at that response unit and time that the corresponding transmission is sent to said base unit, wherein the derived time of response is a function of the time of entry of an actual user response.