Research On Low-energy Cross-technology Communication Protocol

The rapid development of the Internet of Things(Io T)technology has caused the close coexistence of a large number of Io T devices.At the same time,the emergence of composite chips with multiple different communication modules provides new opportunities for mutual cooperation between heterogeneous wireless communication protocols.Based on the composite chip of WiFi and Bluetooth,we innovatively allows the WiFi and Bluetooth protocols in the composite chip to cooperate with each other,and uses the WiFi protocol in the composite chip to assist the Bluetooth protocol in the channel selection of frequency hopping,so that the Bluetooth frequency hopping to a better quality channel to increase the communication rate of Bluetooth.Besides,based on the existing WiFi to Bluetooth cross-technology communication(CTC),we utilize Bluetooth Low Energy(BLE)to assist WiFi for idle listening to save energy.Current Bluetooth protocols use random frequency hopping mostly,which cannot guarantee to select a good quality channel.In addition,because WiFi and Bluetooth work in the same frequency band,their channels overlap with each other.The WiFi and Bluetooth modules in the same composite chip share the same wireless communication environment.This paper studies WiFi-assisted Bluetooth frequency hopping communication.Based on the characteristics of WiFi's broadband and orthogonal frequency division multiplexing(OFDM),this paper uses WiFi finegrained channel state information to evaluate the signal-to-noise ratio(SNR)of the Bluetooth channel.The channel state information on the subcarriers in the WiFi channel that overlaps the Bluetooth channel is used to calculate the signal and noise of the Bluetooth channel,thereby calculating the signal-to-noise ratio.Based on the Bluetooth channel SNR evaluation,the Bluetooth is guided to frequency hopping to the higher SNR Channel.This paper conducted a lot of experiments to compare the performance of WiFi-assisted Bluetooth frequency hopping and random Bluetooth frequency hopping.The experimental results show that the received signal strength and SNR of the channel selected by WiFi-assisted Bluetooth frequency hopping are higher than that selected by random Bluetooth frequency hopping.The correct receiveing rate of WiFi-assisted Bluetooth frequency hopping improves 16.67%compared with random Bluetooth frequency hopping.The WiFi protocol has the advantages of wide frequency band and high speed,but its operating power and idle listening power are also very high.To our known,the idle listening power of WiFi is 77 times that of Bluetooth.In addition,with the development of CTC,there is direct communication from WiFi to Bluetooth.So this paper studies Bluetooth-assisted WiFi idle listening.Based on the existing WiFi-toBluetooth CTC,this paper designs the following non-transparent auxiliary idle listening scheme.By modifying the data payload of the WiFi sender,Bluetooth can correctly decode the WiFi signal.And a flag is set in the data packet to indicate whether to request sending data.The address field is set to indicate the destination address of the requested communication.The Bluetooth receiver determines whether to start local WiFi according to the flag and address in the received data packet.In order to avoid modifying the WiFi sender,this paper analyzes the process of WiFi bit sequence conversion decoding in Bluetooth,and designs a transparent auxiliary idle listening solution.Further,the virtual addresses are used to improve the performance of the transparent auxiliary idle listening solution.And the related issues of virtual address design are analyzed,including maximizing the number of available addresses,maximizing the minimum distance between addresses,and minimizing the number of bits used to encode addresses.We proved that these problems are NP-hard problems,and the corresponding approximation algorithms are designed.Experimental results show that the Bluetooth-assisted idle monitoring scheme saves about 30% of energy consumption on average.And in condition of good SNR,the false alarm rate is as low as 5%,and the false alarm rate is as low as 0%.