Wireless communication system

Abstract

A method for communication includes transmitting a first uplink message from a first remote node ( 200, 300, 400 ) to a central node ( 100 ) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

1 . A method for wireless event reporting, comprising:
 transmitting periodic status messages from a remote node to a central node in a wireless communication system, said periodic status messages not comprising synchronization requests;   in response to the periodic status messages, transmitting acknowledgment messages from the central node to the remote node, the acknowledgement messages comprising time-stamps; and   synchronizing the remote node with the central node using the time-stamps comprised in said acknowledgement messages, thereby obviating the need for receiving and processing dedicated synchronization messages.   
     
     
         2 . The method for wireless event reporting according to  claim 1 , wherein synchronizing the remote node comprises aligning a value of a local clock at the remote node with a system clock maintained by the central node. 
     
     
         3 . The method for wireless event reporting according to  claim 2 , wherein synchronizing the remote node comprises aligning a frequency of the local clock with an actual frequency of the system clock using the time-stamps. 
     
     
         4 . The method for wireless event reporting according to  claim 3 , wherein the periodic status messages are transmitted with a fixed interval between the status messages, and wherein adjusting the frequency comprises computing a frequency adjustment using the time-stamps and the fixed interval without performing a division operation. 
     
     
         5 . A wireless event reporting system, comprising:
 a remote node, which is configured to transmit periodic status messages, said periodic status messages not comprising synchronization requests; and   a central node, which is configured to transmit acknowledgment messages to the remote node in response to the periodic status messages, the acknowledgement messages comprising time-stamps,   wherein the remote node is configured to synchronize with the central node using the time-stamps comprised in said acknowledgement messages, thereby obviating the need for receiving and processing dedicated synchronization messages.   
     
     
         6 . The wireless event reporting system according to  claim 5 , wherein the remote node comprises a local clock, and is configured to align a value of the local clock with a system clock maintained by the central node using the time-stamps. 
     
     
         7 . The wireless event reporting system according to  claim 6 , wherein the remote node is configured to align a frequency of the local clock with an actual frequency of the system clock using the time-stamps. 
     
     
         8 . The wireless event reporting system according to  claim 7 , wherein the periodic status messages are transmitted with a fixed interval between the status messages, and wherein the remote node is configured to compute a frequency adjustment using the time-stamps and the fixed interval without performing a division operation.