An outdoor SDR testbed was developed to evaluate the performance of narrowband data communication in TV White Space (TVWS) spectrum, addressing spectrum congestion in the crowded ISM band used by large-scale IoT deployments. Field experiments were conducted in a suburban environment under both line-of-sight (LOS) and non-line-of-sight (NLOS) propagation conditions, transmitting data between a gateway and wireless nodes at various locations using a custom GNU Radio benchmark tool built for the testbed. The system achieved throughput of up to 97 Kbps with packet error and packet loss rates under 1% over NLOS paths, demonstrating that TVWS spectrum which penetrates obstacles and terrain far better than higher-frequency bands can reliably support low-data-rate IoT applications over long, obstructed ranges. The work also produced a reusable benchmark tool for evaluating SDR-based communication systems more broadly.
