Methods and systems for synchronized infrared real time location

A system for determining a location and an identity of a portable device, the system comprising:

• means for transmitting timing synchronization information including a plurality of RF transceivers and a backbone network, a time server generating the timing synchronization information;
• wherein each of the plurality of RF transceivers is coupled to the backbone network and periodically transmits a request to the time server to receive the timing synchronization information;
• a plurality of stationary infrared (IR) base stations, the plurality of IR base station being configured to receive timing synchronization information and to concurrently transmit corresponding IR location codes in a common time period based on the received timing synchronization information, each IR location code representative of a location of the corresponding IR base stations and
• a plurality of portable devices, at least one portable device configured to 1) receive the timing synchronization information, 2) enter a sleep mode, 3) enter a wake-up mode in the common time period to detect the IR location codes concurrently transmitted by the IR base stations and 4) if one of the IR location codes is detected, transmit an output signal including a portable device ID representative of the portable device and the detected IR location code.

A method for transmitting a location and an identity of a portable device:

• determining whether the portable device is in a range of an RF base station associated with the portable device, the RF base station transmitting timing synchronization information;
• if the portable device is in range of the RF base station receiving the timing synchronization information from the base station by a radio frequency (RF) receiver;
• causing the portable device to enter a wake-up mode in a time period determined by the timing synchronization information;
• detecting at least one IR location code received from at least one infrared (IR) base station in the time period determined by the received timing synchronization information, the at least one IR base station transmitting the corresponding IR location code in the time period based on the timing synchronization information;
• and
• transmitting an output signal including a portable device ID representative of the portable device and the detected IR location code;
• if the portable device is not in the range of the RF base station associated with the portable device, transmitting a request for RF base station association to one or more RF base stations within range of the portable device;
• and
• receiving an RF base station association from among the one or more RF base stations.