Patent ID: 7239625

Claim:
A method for sequential transmission and asynchronous reception for use in transmitting data packets from a plurality of sensors in a demand control ventilation system to a Gateway Controller, each sensor transmitting its own data packet, comprising: (1) sequentially transmitting a data packet from each of the plurality of sensors for a preselected transmission period at a preselected number of frequencies within a preselected frequency band by use of a narrow band Frequency Shift Key (“FSK”) system; (2) tuning the Gateway controller to receive at each of the preselected number of frequencies in the preselected frequency band in an asynchronous manner wherein the Gateway controller is tuned to a particular frequency within the preselected number of frequencies for a reception period that is from approximately one-half to approximately 100% of a total transmission period required to complete step (1); and (3) repeating steps (1) and (2) until the Gateway controller receives the first data packet from each of the plurality of sensors for a chosen interval; (4) repeating steps (1) through (3) a preselected number of times for a chosen time period so that the Gateway controller receives a preselected number of data packets from the plurality of sensors; wherein step (1) is repeated a preselected number of times for each of the plurality of sensors; and wherein the data packets include information concerning carbon dioxide (“CO2”) concentration, humidity, temperature and a sensor identification.