# Decentralizing Private Blockchain-IoT Network with OLSR
## 2 Related Work  
Blockchain essentially is a distributed ledger based on peer-to-peer (P2P) communication, which significantly improves the traditional centralized models. One of the most representative applications that benefit from decentralization is voting as in [17]. The authors proposed an online blockchain-based voting platform that enforces immutability and transparency. In [18; 19], the blockchain technology is used for the Internet of Vehicles (IoV). The results show significant advantages in security, data storage, and real-time response. The authors of [20; 21] discussed adopting different blockchains for healthcare services. They showed that the private blockchain is a popular trust-preserving solution within the healthcare ecosystem. The authors of [22] introduced an Ethereum blockchain-based healthcare management for a large amount of medical data and different workflows for medical procedures. A blockchain-based healthcare framework in [23] allows local networks to submit transactions to a blockchain network. The local networks stretch from IoT devices encircling patients, established as the Internet of Medical Things, to the local healthcare service provider. In the IoT field, many works use the private blockchain in decentralized IoT systems. However, the underlying network is commonly omitted or regarded as an infrastructure-based wireless network. For example, in the blockchain-based smart home in [24], the system's backbone comprises several cluster headers, which manage private blockchains for their cluster. The underlying network in each cluster is not discussed, while IoT devices in each cluster are connected to a Wi-Fi access point or a cellular base station as default. In another smart home with blockchain [9], the Raspberry Pi Model 3B and DHT11 sensor are used to monitor temperature and humidity with a DHT11 sensor. The monitoring results are presented to the Blynk App on the smartphone. However, the system runs over a Wi-Fi access point, according to the smartphone screenshot. The blockchain-based healthcare systems described above are usually built over infrastructure networks, as illustrated. In [12], the authors considered different underlying networks in a real-world private Ethereum application. In this work, the Wi-Fi and 3G cellular networks are involved in a blockchain-based flood monitoring and detection system. A comparison work in [25; 26] indicates that decentralized generated mesh networks have a higher efficiency to cover irregular spaces than centralized generated ones. A decentralized network could automatically adapt according to local information, which is capable of avoiding SPoF. Thus, decentralized ad hoc networks may be an alternative to build blockchain networks with higher robustness. Several works in the literature consider a combination of ad hoc networks and blockchains. In [27], a self-managed vehicular ad hoc network that uses routing with smart contracts is proposed. The authors found the feasibility of performing various applications, such as traffic regulation, vehicle tax, and vehicle insurance, on blockchain platforms with proper routing. The work in [28] manages group keys dynamically with blockchain for an unmanned aerial vehicles ad hoc network. The keys can be recovered from neighbors when lost or attacked. In that sense, blockchain provides immutable storage here. Moreover, a smart contract-based contractual routing protocol is proposed in [29] for the ad hoc network. The proposed protocol has a higher tolerance on the transmission delay or malicious nodes in a decentralized manner. The authors of [30] proposed a blockchain-enabled Stackelberg competition mechanism to improve the performance of the QoS-OLSR protocol. On-chain smart contract is integrated into off-chain QoS-OLSR protocol to motivate participants, utilizing the monetary feature. A blockchain-embedded OLSR protocol is presented in [31; 32] to solve security problems on routing issues.