## 1 Introduction  
Since fifth-generation mobile communication systems (5G) can provide high performance such as high data rate or capacity, ultra-low latency, and massive connectivity, 5G is expected to be applied to various applications [1]. Although sixth-generation mobile communication systems are being researched for extreme high performance over 5G, one of the most important concepts is network dependability. If a wireless sensor network (WSN) is not able to report critical alerts due to a network failure such as the crash of a node and battery exhaustion, it has been pointed out that it may cause severe failures with dangerous consequences. Examples of such critical applications are health monitoring, ambient intelligent systems, and environmental monitoring. Therefore, when using WSNs in critical applications, it is important to verify their reliability properties based on heuristic strategies such as \"what-if analysis\" and \"robustness checking\" at design time [2]. In addition to trustworthiness, dependability of WSN is also related to attributes like safety and security [3]. Therefore, the proper management of these attributes could avoid economic losses and danger to people or to the system [4, 5]. Taking this into account, since WSNs provide easier access to communication channels than wired networks, measures should be taken not only for the crash of a node and battery exhaustion, but also for human-induced wiretapping such as packet sniffing and attacks such as jamming.  
Although countermeasures against wiretapping and attacks have been studied individually, countermeasures against cybererrorists who can wiretap and attack simultaneously are necessary. Typically, countermeasures against wiretapping and attacks are implemented with cryptography [6] and authentication [7] at higher layers. To make a wireless system more dependable, it is necessary to take additional measures at lower layers.  
We propose that a terminal with multiple radio access technologies (RATs), such as a cellular phone, defined as an integrated terminal, communicates using multiple RATs. If multiple RATs are used for communication, even if one RAT is attacked by a cybererrorist, the receiver can recover the original information by using the information received from the sender via the other RATs. However, if the sender transmits the same information using multiple RATs, the cybererrorist can obtain the original information with only one RAT wiretapping. Therefore, we propose the forward error correction (FEC) coding of information. There are still issues. If there are not enough RATs available, countermeasures against wiretapping and attacks cannot be realized simultaneously.  
If there are two RATs available, the sender encodes in a way that the cybererrorist cannot obtain the original information even if one RAT is wiretapped. If the cybererrorist attacks one RAT instead of wiretapping, the receiver cannot obtain the original information. We use shortened code as an FEC code. Shortened code is obtained by adding a simple modification to a known code [8]. We propose to use distance information between the sender and the receiver as the shortened information used for the encoding and decoding of shortened code.  
The mutual information is used as an evaluation index of the attack resistance. It is a measure of the mutual dependence between the two variables [9]. It is the index suitable for evaluating how much information can be shared between the sender and the receiver under an attack. The secrecy capacity is used as an evaluation index of the wiretapping resistance. It is defined as the maximum transmission rate between the sender and the receiver with no information available to the cybererrorist [10].  
The remainder of this paper is organized as follows. Section 2 presents related work. In Section 3, the system configuration of the proposed dependable wireless system is described. Performance evaluations are provided in Section 4. Conclusions and suggestions for future research are presented in Section 5.