Method and apparatus for accessing wireless sensor network

Abstract

A method and apparatus for accessing a wireless sensor network are provided in embodiments of this invention. The technical solution provided in embodiments of this invention includes: when receiving a first beacon frame, stopping channel scan temporarily, and establishing a new channel scan sequence according to operating channels of a current wireless sensor network recorded in the beacon frame. Non-operating channels are not included in the new channel scan sequence. Time for performing subsequence channel scan is reduced, so that the process of accessing the current wireless sensor network of a device node expecting for network can be accelerated.

What is claimed is: 
     
         1 . A method for accessing a wireless sensor network, comprising:
 performing, by a device node, channel scan from a first channel according to a predefined channel scan sequence;   pausing, by the device node, the channel scan when receiving a first beacon frame returned sent from a beacon sending node during the channel scan, wherein the beacon frame carries with includes operating channels of a current wireless sensor network;   deleting, by the device node, channels except the operating channels from the predefined channel scan sequence;   constructing, by the device node, a new channel scan sequence;   scanning, by the device node, for operating channels that have not been scanned according to the new channel scan sequence;   receiving, by the device node, beacon frames during the scan of operating channels that have not been scanned;   determining, by the device node, a parent node for accessing the wireless sensor network according to the first beacon frame and the beacon frames received during the scan of operating channels that have not been scanned; and   selecting, by the device node, an operating channel to access the wireless sensor network on the operating channel through the parent node.   
     
     
         2 . The method according to  claim 1 , wherein the first beacon frame further comprises a first channel link quality parameter of an operating channel where the beacon frame comes from; the beacon frames received during the scan of operating channels that have not been scanned further comprises channel link quality parameters of corresponding operating channels;
 wherein, determining a parent node for accessing the wireless sensor network according to the first beacon frame and the beacon frames received during the scan of operating channels that have not been scanned comprises:   determining the parent node for accessing the wireless sensor network according to the first channel link quality parameter contained in the first beacon frame and channel link quality parameters of corresponding operating channels contained in the beacon frames received during the scan of operating channels that have not been scanned.   
     
     
         3 . The method according to  claim 1 , wherein the selecting an operating channel for the device node expecting for network comprises:
 synchronously switching channels with the parent node according to the new channel scan sequence to complete a second-round channel scan;   determining an operating channel for the device node expecting for network according to second channel link quality parameters carried on beacon frames received during the second-round channel scan process.   
     
     
         4 . The method according to  claim 3 , wherein the synchronous switch comprises:
 performing channel scan on the same channel synchronously by the device node expecting for network and the parent node according to the new channel scan sequence, and performing channel scan through synchronously switching to a next identical channel according to the new channel scan sequence until completing channel scan of channels in the new channel scan sequence.   
     
     
         5 . The method according to  claim 3 , wherein determining an operating channel for the device node expecting for network according to second channel link quality parameters carried on beacon frames received during the second-round channel scan process comprises:
 selecting a channel having the best channel quality according to the second channel link quality parameter values as the operating channel for the device node expecting for network.   
     
     
         6 . An apparatus, comprising:
 a readable storage medium comprising instructions to:   perform channel scan from a first channel according to a predefined channel scan sequence;   pause the channel scan when receiving a first beacon frame returned sent from a beacon sending node during the channel scan, wherein the beacon frame includes operating channels in of a current wireless sensor network;   delete channels except the operating channels from the predefined channel scan sequence;   construct a new channel scan sequence;   scan channels that have not been scanned according to the new channel scan sequence;   receive beacon frames during the scan of operating channels that have not been scanned;   determine a parent node for accessing the wireless sensor network according to the first beacon frame and the beacon frames received during the scan of operating channels that have not been scanned;   select an operating channel; and   a processor coupled with the readable storage medium, configured to execute the instructions retained in the readable storage medium, and access a wireless sensor network on the operating channel through the parent node.   
     
     
         7 . The apparatus according to  claim 6 , wherein the first beacon frame further comprises a first channel link quality parameter of an operating channel where the beacon frame comes from; the beacon frames received during the scan of operating channels that have not been scanned further comprises channel link quality parameters of corresponding operating channels;
 wherein the readable storage medium further comprises instructions to: determine the parent node for accessing the wireless sensor network according to the first channel link quality parameter contained in the first beacon frame and channel link quality parameters of corresponding operating channels contained in the beacon frames received during the scan of operating channels that have not been scanned.   
     
     
         8 . The apparatus according to  claim 6 , wherein the readable storage medium further comprises instructions to: synchronously switch channels with the parent node according to the new channel scan sequence to complete a second-round channel scan;
 determine an operating channel for the device node expecting for network according to second channel link quality parameters carried on beacon frames received during the second-round channel scan process.   
     
     
         9 . An apparatus, comprising:
 a readable storage medium comprising instructions to:   perform a first-round channel scan according to a predefined channel scan sequence;   select a beacon sending node of a current wireless sensor network as a parent node;   determine a second channel scan sequence according to operating channels in the current wireless sensor network;   synchronously switch channels with the parent node according to the second channel scan sequence to perform a second-round channel scan;   determine an operating channel for a device node expecting for network according to second channel link quality parameters carried on beacon frames received during the second-round channel scan; and   a processor coupled with the readable storage medium, configured to execute the instructions retained in the readable storage medium, and access the wireless sensor network on the operating channel through the parent node.   
     
     
         10 . The apparatus according to  claim 9 , wherein the readable storage medium further comprises instructions to:
 scan from a first channel according to a predefined channel scan sequence;   pause the channel scan when receiving a first beacon frame sent from a beacon sending node during the channel scan, wherein, the beacon frame carries with operating channels in a current wireless sensor network;   delete channels except the operating channels of the beacon sending nodes from the predefined channel scan sequence;   construct a second channel scan sequence;   scan channels that have not been scanned according to the second channel scan sequence;   receive beacon frames during the scan of operating channels that have not been scanned; and   determine a parent node for accessing the wireless sensor network according to the first beacon frame and the beacon frames received during the scan of operating channels that have not been scanned.   
     
     
         11 . The apparatus according to  claim 10 , wherein the beacon frame received during the first-round channel scan further comprises a first channel link quality parameter of an operating channel where the beacon frame comes from;
 wherein the readable storage medium further comprises instructions to:   determine the parent node for accessing the wireless sensor network according to the first channel link quality parameter contained in the first beacon frame and channel link quality parameters of corresponding operating channels contained in the received beacon frames during the scan of operating channels that have not been scanned.   
     
     
         12 . The apparatus according to  claim 9 , wherein the readable storage medium further comprises instructions to:
 perform a first-round channel scan from a first channel according to a predefined channel scan sequence, until every channel in the channel scan sequence has been scanned;   construct a second channel scan sequence according to beacon frames received on operating channels during the first-round channel scan process, wherein the beacon frames carry with first channel link quality parameters of channels where those beacon frames come from;   select a beacon sending node as a parent node from beacon sending nodes sending the beacon frames according to the first channel link quality parameters.   
     
     
         13 . The apparatus according to  claim 12 , wherein the readable storage medium further comprises instructions to:
 compare operating channels where the received beacon frames come from with the predefined channel scan sequence;   delete from the predefined channel scan sequence, channels except the operating channels where the received beacon frames come from, to construct a second channel scan sequence.   
     
     
         14 . The apparatus according to  claim 12 , wherein the readable storage medium further comprises instructions to:
 store a second predetermined threshold;   select channels having first channel link quality parameters exceeding the second predetermined threshold from operating channels of beacon sending nodes in the current wireless sensor network to construct the second channel scan sequence.