Radio communication system

Abstract

A network has wireless access points, each configured for bi-directional communication, using a first radio protocol, with a communication device that has been associated with the access point by an association data exchange. Each access point is also configured to receive, at a first data rate using the first radio protocol, a multicast radio message and to forward the multicast message onto the network. A radio transmitter is configured to send data at a second data rate, using a second radio protocol different from the first radio protocol. A wireless communication unit transmits a multicast radio message at the first data rate using the first radio protocol. It also receives data from the radio transmitter at the second data rate using the second radio protocol and decodes the data.

What is claimed is: 
     
         1 - 41 . (canceled) 
     
     
         42 . A temperature monitoring system comprising:
 a network comprising a plurality of Wi-Fi access points, each Wi-Fi access point being configured for bi-directional Wi-Fi communication with devices that are associated with the Wi-Fi access points, wherein each Wi-Fi access point is further configured to receive messages by radio from devices that are not associated with the Wi-Fi access points and to forward the messages onto the network;   a non-Wi-Fi radio transmitter configured to transmit radio data using a non-Wi-Fi radio protocol; and   a wireless temperature-sensing unit,   wherein the wireless temperature-sensing unit comprises:
 a temperature sensor; 
 a radio transmitter configured to transmit radio messages comprising temperature information derived from the temperature sensor for reception by one or more of the Wi-Fi access points, wherein the wireless temperature-sensing unit is not associated with the one or more Wi-Fi access points; and 
 a radio receiver configured to receive and decode command data transmitted by the non-Wi-Fi radio transmitter using the non-Wi-Fi radio protocol. 
   
     
     
         43 . The temperature monitoring system of  claim 42 , wherein the radio messages comprising temperature information, transmitted by the radio transmitter of the wireless temperature-sensing unit, are multicast radio messages. 
     
     
         44 . The temperature monitoring system of  claim 42 , wherein the radio transmitter of the wireless temperature-sensing unit is configured to transmit the radio messages comprising temperature information at a first data rate, and wherein the radio receiver of the wireless temperature-sensing unit is configured to receive the command data at a second data rate, wherein the second data rate is lower than the first data rate. 
     
     
         45 . The temperature monitoring system of  claim 44 , wherein the second data rate is less than half the first data rate. 
     
     
         46 . The temperature monitoring system of  claim 42 , wherein the Wi-Fi access points are connected to one another by a wired network. 
     
     
         47 . The temperature monitoring system of  claim 46 , wherein the non-Wi-Fi radio transmitter is also connected to the wired network. 
     
     
         48 . The temperature monitoring system of  claim 42 , wherein a maximum data rate supported by the non-Wi-Fi radio protocol is less than a minimum data rate supported by a Wi-Fi protocol used by the Wi-Fi access points. 
     
     
         49 . The temperature monitoring system of  claim 42 , wherein an effective transmission range of the non-Wi-Fi radio transmitter is greater than effective transmission ranges of the Wi-Fi access points when each Wi-Fi access point is communicating with a device associated with the Wi-Fi access point. 
     
     
         50 . The temperature monitoring system of  claim 42 , comprising a plurality of non-Wi-Fi radio transmitters each configured to send radio data using the non-Wi-Fi radio protocol, and arranged to form a network of non-Wi-Fi access points for devices communicating using the non-Wi-Fi radio protocol. 
     
     
         51 . The temperature monitoring system of  claim 42 , comprising a server configured to receive and process the temperature information forwarded from the wireless temperature-sensing unit by one of the Wi-Fi access points. 
     
     
         52 . The temperature monitoring system of  claim 51 , wherein the server is further configured to control the non-Wi-Fi radio transmitter to transmit the command data to the wireless temperature-sensing unit. 
     
     
         53 . The temperature monitoring system of  claim 42 , wherein the wireless temperature-sensing unit is configured to execute a function in response to receiving the command data transmitted by the non-Wi-Fi radio transmitter. 
     
     
         54 . The temperature monitoring system of  claim 42 , wherein the wireless temperature-sensing unit is configured to have a sleep mode and a wake mode, whereby at least some circuitry in the radio receiver or in the radio transmitter or in a processor of the wireless temperature-sensing unit is inactive in the sleep mode, so as to reduce a power consumption of the wireless temperature-sensing unit, and is further configured to switch from sleep mode to wake mode on receiving a wake signal from the non-Wi-Fi radio transmitter. 
     
     
         55 . The temperature monitoring system of  claim 42 , wherein the wireless temperature-sensing unit is configured to be carried by or attached to a movable object. 
     
     
         56 . The temperature monitoring system of  claim 42 , wherein the wireless temperature-sensing unit is further configured to transmit information relating to a position of the wireless temperature-sensing unit, or information from which a position of the wireless temperature-sensing unit can be derived, in a radio message for reception by one or more of the Wi-Fi access points. 
     
     
         57 . The temperature monitoring system of  claim 56 , wherein said position information is derived from a signal received by the wireless temperature-sensing unit from the non-Wi-Fi radio transmitter. 
     
     
         58 . The temperature monitoring system of  claim 42 , wherein the wireless temperature-sensing unit comprises a power amplifier and an antenna and is configured to use the antenna and the power amplifier for transmitting radio messages for reception by one or more of the Wi-Fi access points and for receiving data from the non-Wi-Fi radio transmitter. 
     
     
         59 . The temperature monitoring system of  claim 42 , comprising a plurality of wireless temperature-sensing units each comprising a radio transmitter configured to transmit radio messages comprising temperature information for reception by a respective one or more of the Wi-Fi access points, and further comprising a radio receiver configured to receive and decode command data transmitted by the non-Wi-Fi radio transmitter using the non-Wi-Fi radio protocol. 
     
     
         60 . A wireless temperature-sensing unit comprising:
 a temperature sensor;   a radio transmitter configured to transmit radio messages comprising temperature information derived from the temperature sensor for reception by one or more Wi-Fi access points, wherein the wireless temperature-sensing unit is not associated with the one or more Wi-Fi access points; and   a radio receiver configured to receive and decode command data transmitted by a non-Wi-Fi radio transmitter using a non-Wi-Fi radio protocol.   
     
     
         61 . A method of sensing temperature using a wireless temperature-sensing unit, the method comprising:
 receiving and decoding a command from a non-Wi-Fi radio transmitter, using a non-Wi-Fi radio protocol, at a radio receiver of the wireless temperature-sensing unit;   sensing a temperature using a temperature sensor of the wireless temperature-sensing unit; and   transmitting a radio message comprising temperature information derived from the temperature sensor for reception by one or more Wi-Fi access points from a radio transmitter of the wireless temperature-sensing unit, wherein the wireless temperature-sensing unit is not associated with the one or more Wi-Fi access points.