Wide-Area Protection (WAP) is a new concept applied to wide-area multi-source information. WAP utilizes Phasor Measurement Units (PMUs), which are becoming commonly used in networks, primarily within transmission systems. Recently, Wide-Area Monitoring, Protection, Automation, and Control (WAMPAC) applications have increased as aresult of the progress of PMUs in the power system. PMUs offer information about the dynamic performance occurring within the network by giving fast, synchronously measured voltage and current data, and an accurate, common time reference. WAP applications vary and include protection for interconnection lines, backup protection, and enhancement of conventional protection systems. The main objective of this paper is to design and simulate a WAP, that serves as a backup to conventional protection on high-voltage lines. Wide Area Backup Protection (WABP) has been designed to detect faults on the high-voltage transmission lines using the data received from PMUs available at select networks. The proposed WABP method utilizes Positive Sequence Voltage Magnitudes (PSVM) and Positive Sequence Current Angles (PSCA). Different experimental Hardware in Loop (HIL) tests are implemented to evaluate the proposed technique in the IEEE 14-bus system model. The results show that the proposed WABP technique detected all types of faults inside the selected protection zones and had a stable performance for external faults, but the primary protection still has a faster response.