# IoT Services for Monitoring Food Supply Chains
## 4 Results and Discussion  
Implementing the proposed IoT-based temperature and humidity monitoring system using LoRaWAN demonstrated significant improvements in maintaining the quality and safety of perishable agrifood products during transportation. Specifically, the system maintained an average packet delivery rate (PDR) of 98.5% and achieved a data transmission range of up to 12 km in rural areas, ensuring robust and uninterrupted data availability across the logistics network. The deployed LoRa sensors operated within an extended temperature range of \(-40\)\({}^{\circ}\)C to \(+85\)\({}^{\circ}\)C and a humidity range of 0% to 100% relative humidity (RH), making them suitable for demanding cold chain environments. In terms  
Figure 5: Visualisation of temperature and humidity sensor data. of accuracy, the sensors exhibited temperature precision of \(\pm\)0.2 \({}^{\circ}\)C to \(\pm\)0.5 \({}^{\circ}\)C (within the range of 0-50 \({}^{\circ}\)C) and humidity accuracy of \(\pm\)2% to \(\pm\)3% RH (within the range of 20-80% RH). This enabled precise real-time environmental monitoring of stored and transported goods [31]. In addition to sensor performance, the LoRaWAN communication layer was configured using the relevant gateways (Figure 5) with Adaptive Data Rate (ADR) enabled, which dynamically adjusts spreading factors from SF7 to SF12 based on distance and signal quality. Devices operated in Class A mode, supporting energy-efficient transmissions with a latency of approximately 1-3 s per uplink, depending on duty cycle and data rate. RSSI values remained above the acceptable threshold of \(-\)120 dBm, and the signal-to-noise ratio (SNR) was consistently maintained within the reliable range (\(-\)10 dB to +10 dB), ensuring high-quality data transmission. Transmission intervals were set between 15 and 30 min during testing, aligning with typical LoRaWAN operational configurations. The sensors were powered by batteries rated between 2400 and 3600 mAh, with an expected lifetime ranging from 1 to 5 years, depending on usage and interval settings. This contributed to an 18% improvement in data reliability compared to traditional monitoring systems, reducing the risk of spoilage and enabling timely interventions across the cold chain [32]. In terms of cost-effectiveness, the solution is highly competitive. LoRa sensor nodes typically cost between EUR 30 and EUR 80 per unit, depending on the integrated sensor modules, while LoRa Gateways range from EUR 200 to EUR 1000, based on range and capacity. Operating in the unlicensed ISM band incurs no recurring connectivity fees, and battery-powered nodes, with operational lifespans of 3 to 5 years, significantly reduce maintenance requirements. The system's return on investment (ROI) is estimated within 1-2 agricultural cycles, primarily due to reduced spoilage and labour savings. Empirical data from the SmartColdChain EU Project indicates up to 20-30% operational cost savings through automation and a reduction of more than 60% in manual temperature checks, directly lowering labour demands [33]. Scalability was also demonstrated to be a key strength of the system. In the Digital Farming Initiative in the Netherlands, over 1000 LoRa sensor nodes were deployed across greenhouses and cold storage units, supported by just 12 gateways. This deployment maintained a PDR above 97%, enabled by the use of Adaptive Data Rate (ADR) and redundancy through multi-gateway architecture. The LoRaWAN protocol's asynchronous, low-duty-cycle ALOHA-based mechanism allows a single gateway to support thousands of devices without interference. Furthermore, battery-operated nodes proved to be sustainable for large-scale, remote installations, operating for several years without requiring intervention. The impact on spoilage reduction was both measurable and substantial.