# A Chaotic Compressive Sensing Based Data Transmission Method for Sensors within BBNs
## 1 Introduction
As shown in Figure 1, a BBN that consists of three WBANs is used to monitor vital signs of human beings, battlefield environment data, enemy intelligence, and other information, and such information could be exchanged between WBANs or to be sent to remote control centers. At the same time, in the light of the control signals and feedback commands that are transmitted from remote control centers, soldier nodes could be timely administered and arranged, so that efficient military operations are realized. The data gathered by BBNs vary along with the changes in environment and location. The information monitored by BBN sensors, such as human postures and vital signs, is sent by wireless networks and contributes to drawing up operation plans and making decisions, for example, timely evacuation commands could be instructed beforehand as a result of certain discoveries found in data transmitted by BBNs, so as to avoid unnecessary casualties or economic loss. Moreover, compared with WBANs, BBNs often have larger network scales, longer transmission distances, and wider transmission ranges. Sensor nodes within BBNs not only transmit data caught by themselves, but also forward data collected by other nodes, and such a process causes massive energy consumption. However, BBN sensors are frequently battery-powered, and batteries that are installed on the surface of human bodies or even embedded in the body of individuals are inconvenient to be recharged or replaced. When battery power is exhausted, BBN nodes tend to lose efficiency. Therefore, it is critical to settle energy saving issues when designing data transmission schemes within BBNs, and a practical measure could be to reduce the amount of communication data by compressing the data to be transmitted. Another difficulty to be overcome is to address eavesdropping problems within BBNs. Because BBNs commonly use wireless transmission technology, network links throughout BBNs may be open and vulnerable to eavesdropping. In particular, such networks are often teeming with private data related to human bodies or confidential information concerning militaries, space technologies, etc. Therefore, in the process of BBN data transmission, an encryption scheme is a must to prevent eavesdroppers from obtaining sensitive information so that the security level of data transmission is enhanced. Furthermore, in order to avoid the potential risk brought by the ownership of a master key that is solely possessed by a single node in the network of the cryptosystem, a certain security protection mechanism is needed. For example, it is necessary to ensure that the secret information carried by original signals will not be disclosed when the person who carries critical data is arrested by enemies. A feasible method is concealing critical information in original signals by means of hierarchical authorization for multilevel receivers. At present, the encryption and compression processes of common schemes are independent. Another issue is, when processing images or videos by sensor nodes within BBNs or WBANs, their storage or computing resources barely meet the requirements of the energy, computing, or other resource consumption level brought by the introduction of classical encryption algorithms. How to accomplish data compression, encryption, and critical information concealment efficiently becomes a burning issue to be addressed.