## 3 Field Trialed System
### Local Private Network  
This section describes the architecture of the local private network used in the smart farming trial for remote areas. Figure 1 shows the trial network topology at a high level. The topology enables remote control of a tractor via multiple local access points and via the internet. It also offers a connection to and inside a smart barn for remote surveillance. More specifically, the optical and thermal cameras and air quality sensors allowed us to \begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt}} \hline \hline
**Security Objectives** & **Requirements and Potential Solutions** \\ \hline Communications security & Access technology specific confidentiality, authenticity, integrity, and replay protection solutions. 3 GPP security and Wi-Fi security cover essentially wireless channels. The 3 GPP specifications [39] extend protection to backhaul and support application layer communication. \\ \hline End-to-end & Application layer solutions, including SSH, TLS, and SRTP, secure critical communications when infrastructure cannot be completely trusted. In private networks where edge computing is used, for example, for accelerating computation or interoperability, end-to-end security may not be feasible. These cases demand that security breakpoints in the edge are trusted. \\ \hline Network and subsystem authorizations & Practical access control requires easy solutions to distribute credentials, that authorize access to networked assets—services and data stored in the network. Fine-grained service specific access control mitigates potential insider and malware attacks. Firewalls, which enforce authorizations, are needed in network borders and in many hosts within the network. Network credentials, such as eSIM, can be delivered, for example, through QR codes. Application credentials, for example, through delegated authorization, such as OAuth2. \\ \hline Resilience & Solutions to assure availability under denial of service attacks or in congestion situations. Reactive security, access control, and traffic prioritization solutions as well as sufficient and redundant capacity, such as satellite links, should be applied when possible. \\ \hline Secure cooperation & Secure networked business models require trusted external partners. Access to partners’ external assets must be secure and integrity verified. Externals access to assets and functions in smart farm should be restricted by time and capabilities to minimize insider threats. \\ \hline Security posture of subsystems & Technical and procedural approaches to manage and verify that different devices in farm and tractors are secure, for example, are enforcing security policies and are running trusted up-to-date software. The network is monitored to detect security policy and integrity violations indicating security breaches or malware. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Objectives for cyber and network security architecture. monitor the welfare of the animals and the quality of their surroundings inside the cow shed. Soil sensors provided environmental information about the field. The trial topology is a hybrid combination of multiple ad hoc network bubbles. Figure 2 shows the setup of the trialed ad hoc private network. Here, the Bittium Tactical Wireless IP Network (TAC WIN MESH) [41] offers the backbone network for three local 4G access points and one local 5G access point. The backbone network is built with three tactical nodes, for example, tactical routers with radio heads. These routers can automatically reroute any given data from the source to the destination via alternative routes, if the primary route fails. One tactical router has a wired connection to the internet. The internet connection is then shared with the office and with the end users of the access points. Every tactical router has a wired connection to either a 4G or a 5G access point, or both. Next to the office, there is a 5G stand-alone access point for wireless users. It uses a stand-alone 5G core for authentication.