Methods for robust wireless communication for nodes located in vehicles

Abstract

A communication method for a wireless communication network in a vehicle is disclosed where the network includes a plurality of sensor nodes and a receiving node. The method includes wirelessly transmitting first sensor data from a first sensor node and second sensor data from a second sensor node using first and second frequency channels, and receiving the first and second sensor data at the receiving node. The method can include rearranging the order of transmitting sensor data, and aggregating sensor data at the sensor nodes. The method can include testing the quality of the wireless links; and using the links with the best quality whether indirect or direct links. The receiving node can simultaneously receive data from more than one node using different frequencies. The nodes can transmit data in parallel using different frequencies. The network can include helper nodes. The wireless communication network can be designed as a tree.

We claim: 
     
         1 . A communication method for a wireless network in a vehicle, the wireless network including a plurality of wireless sensor nodes and a wireless receiving node, the plurality of wireless sensor nodes including a first wireless sensor node and a second wireless sensor node, the wireless communication method comprising:
 wirelessly transmitting first sensor data on a first set of frequency channels from the first wireless sensor node;   transmitting each subsequent packet of first sensor data from the first wireless sensor node on a subsequent frequency of the first set of frequency channels starting over from the first frequency of the first set of frequency channels after using the last frequency of the first set of frequency channels;   wirelessly transmitting second sensor data on a second set of frequency channels from the second wireless sensor node;   transmitting each subsequent packet of second sensor data from the second wireless sensor node on a subsequent frequency of the second set of frequency channels starting over from the first frequency of the second set of frequency channels after using the last frequency of the second set of frequency channels; and   receiving the first sensor data and the second sensor data at the wireless receiving node.   
     
     
         2 . The wireless communication method of  claim 1 , further comprising:
 transmitting sensor data from each of the plurality of wireless sensor nodes in a particular order; and   periodically rearranging the order of transmitting sensor data from each of the plurality of wireless sensor nodes.   
     
     
         3 . The wireless communication method of  claim 1 , further comprising:
 receiving the second sensor data at the first wireless sensor node;   aggregating the current first sensor data with the latest received second sensor data at the first wireless sensor node;   transmitting the aggregated first sensor data and second sensor data from the first wireless sensor node;   receiving the first sensor data at the second wireless sensor node;   aggregating the current second sensor data with the latest received first sensor data at the second wireless sensor node; and   transmitting the aggregated second sensor data and first sensor data from the second wireless sensor node.   
     
     
         4 . The wireless communication method of  claim 1 , further comprising for each of the plurality of wireless sensor nodes:
 sensing whether the current frequency channel for transmission is currently being used by another wireless sensor node of the plurality of wireless sensor nodes;   if the current frequency channel is not being used, then using the current frequency channel for wirelessly transmitting;   if the current frequency channel is being used, then switching to the subsequent frequency channel and sensing whether the subsequent frequency channel is currently being used until an unused frequency channel is found, then using the unused frequency channel for wirelessly transmitting.   
     
     
         5 . The wireless communication method of  claim 1 , further comprising:
 testing the quality of all of the wireless communication links in the wireless network;   for each of the plurality of wireless sensor nodes, using only the wireless communication link between that wireless sensor node and the receiving node with the best quality.   
     
     
         6 . The wireless communication method of  claim 1 , further comprising for each wireless node of the plurality of wireless sensor nodes:
 sensing the interference level of the wireless communication links between that wireless node and each of the other wireless nodes for each of the frequency channels for that wireless node;   sensing the interference level of the wireless communication link between that wireless node and the receiving node for each of the frequency channels for that wireless node;   using the frequency channels for that wireless node with the lowest interference levels.   
     
     
         7 . The wireless communication method of  claim 6 , further comprising for each wireless node of the plurality of wireless sensor nodes:
 periodically re-sensing the interference level of the wireless communication links between that wireless node and each of the other wireless nodes for each of the frequency channels for that wireless node;   periodically re-sensing the interference level of the wireless communication link between that wireless node and the receiving node for each of the frequency channels for that wireless node; and   using the frequency channels for that wireless node with the lowest re-sensed interference levels.   
     
     
         8 . The wireless communication method of  claim 1 , further comprising for each wireless node:
 testing the quality of the direct wireless communication path between that wireless node and the receiving node;   testing the quality of indirect wireless communication paths between that wireless node and the receiving node using one or more other wireless nodes as intermediate nodes;   determining the wireless communication paths with the highest quality between that wireless node and the receiving node.   
     
     
         9 . The wireless communication method of  claim 8 , further comprising, when an indirect wireless communication path between a source wireless node and the receiving node through an intermediate node provides the highest quality communication path between the source wireless node and the receiving node,
 receiving sensor data from the source wireless node at the intermediate node;   aggregating the sensor data from the source wireless node with the sensor data from the intermediate node at the intermediate node;   transmitting the aggregated sensor data of the source wireless node and the intermediate node from the intermediate node;   receiving the aggregated sensor data of the source wireless node and the intermediate node at the receiving node.   
     
     
         10 . The wireless communication method of  claim 8 , wherein the wireless network further comprises a wireless helper node, the method further comprising:
 testing the quality of indirect wireless communication paths between that wireless node and the receiving node using the helper node; and   testing the quality of indirect wireless communication paths between that wireless node and the receiving node using the helper node and one or more wireless sensor nodes.   
     
     
         11 . The wireless communication method of  claim 10 , further comprising, when an indirect wireless communication path between a source wireless node and the receiving node through the helper node provides the highest quality communication path between the source wireless node and the receiving node,
 receiving sensor data from the source wireless node at the helper node;   transmitting the sensor data of the source wireless node from the helper node;   receiving the sensor data of the source wireless node at the receiving node.   
     
     
         12 . The wireless communication method of  claim 8 , further comprising:
 transmitting sensor data from each of the plurality of wireless nodes in a particular order; and   periodically rearranging the order of transmitting sensor data from each of the plurality of wireless nodes.   
     
     
         13 . The wireless communication method of  claim 8 , further comprising:
 simultaneously receiving sensor data from more than one of the plurality of wireless nodes at the receiving node.   
     
     
         14 . The wireless communication method of  claim 8 , further comprising:
 while one of the plurality of sensor nodes is transmitting data to the receiving node, simultaneously transmitting sensor data between other of the plurality of wireless nodes.   
     
     
         15 . The wireless communication method of  claim 1 , further comprising:
 simultaneously receiving sensor data from more than one of the plurality of wireless nodes at the receiving node.   
     
     
         16 . The wireless communication method of  claim 1 , further comprising:
 while one of the plurality of sensor nodes is transmitting data to the receiving node, simultaneously transmitting sensor data between other of the plurality of wireless nodes.   
     
     
         17 . The wireless communication method of  claim 1 , further comprising:
 designing a tree having the receiving node as a root node and having a plurality of branches coupling the receiving node to each of the plurality of sensor nodes;   transmitting sensor data from each of the plurality of sensor nodes to the receiving node along the branches of the tree.   
     
     
         18 . The wireless communication method of  claim 17 , wherein designing a tree comprises:
 determining the quality of the direct wireless communication path between each of the plurality of wireless nodes and the receiving node;   determining the quality of indirect wireless communication paths between each of the plurality of wireless nodes and the receiving node using one or more other wireless nodes as intermediate nodes;   designing the tree based on the determined quality of the wireless communication paths between each of the plurality of wireless nodes and the receiving node.   
     
     
         19 . The wireless communication method of  claim 18 , wherein the wireless network further comprises a wireless helper node, the method further comprising:
 determining the quality of indirect wireless communication paths between each of the plurality of wireless nodes and the receiving node using the helper node; and   determining the quality of indirect wireless communication paths between each of the plurality of wireless nodes and the receiving node using the helper node and one or more wireless sensor nodes.   
     
     
         20 . The wireless communication method of  claim 18 , further comprising:
 while one of the plurality of sensor nodes is transmitting data to the receiving node, simultaneously transmitting sensor data between other of the plurality of wireless nodes.