REVIEW OF RELATED LITERATURE 

This section presents a synthesis of existing literature related to the group’s research topic. It explores previous studies, theories, and scholarly findings that provide context and support for the investigation. The review highlights key concepts, identifies gaps in current knowledge, and establishes the relevance of the research. All sources included have been critically evaluated for credibility, relevance, and alignment with the group’s research focus. 

Urban areas in Cagayan de Oro City often experience congestion at parking facilities, especially during peak hours when multiple vehicles compete for limited spaces. Manual verification and the absence of automated slot detection contribute to long queues, delays, and inefficiencies. Drivers frequently spend excessive time searching for available spots, which increases traffic, causes frustration, and reduces overall operational efficiency. Multi-slot parking management is further challenged by limited space awareness and the lack of a system that dynamically communicates real-time availability to users. 

To address these challenges, a low-cost automated solution integrating RFID, wireless communication, Arduino microcontrollers, and IR sensors is well-suited for urban parking environments. RFID enables quick vehicle identification, reducing the need for manual checks. Wireless modules like nRF24L01 allow real-time updates across multiple parking zones without extensive wiring, while Arduino platforms provide flexible, programmable control of sensors and actuators. IR sensors accurately detect vehicle presence in each slot, ensuring precise availability updates. The proposed system focuses on multi-slot assistance, an RFID-enabled gate, and wireless communication between sensors and displays, offering a responsive, scalable, and user-friendly parking solution adapted to the local constraints of Cagayan de Oro City. 

RFID-Based Smart Parking Systems 

RFID technology has become a cornerstone in modern parking management systems due to its ability to enhance security, reduce manual verification, and optimize space utilization. In high-traffic areas such as malls or campuses, vehicle queuing and inefficient slot allocation create delays and user frustration. RFID systems automate identification, enabling faster entry and exit, minimizing human intervention, and providing accurate slot availability information (Jiang et al., 2024 & Koya et al., 2024). 

Jiang et al. (2024) addressed the challenge of inaccurate space predictions by integrating RFID tags with driver boards, cameras, encoders, and path-planning modules. They report that “Integrating RFID tags with driver boards and path-planning modules significantly reduced prediction errors and improved real-time parking management” (p. 118). Similarly, Koya et al. (2024) developed an RFID-based system aimed at reducing waiting times in large facilities while improving revenue collection, noting that security and scalability remain critical concerns. Bodele et al. (2022) highlighted the benefits of combining RFID with IoT, automating check-in/check-out processes, enabling real-time tracking, and allowing fast payments via LCD interfaces. Active tags extend communication range, while passive tags offer cost-effective solutions for smaller implementations. Dichoso et al. (2022) confirmed the feasibility of large-scale deployment in a mall environment, showing high service capacity, profit potential, and convenience, though they noted dependency on RFID technology and cost as potential limitations. 

While these studies consistently demonstrate RFID’s ability to improve authentication efficiency and reduce manual workload, cross-linking with wireless and IoT research reveals additional challenges. Low-power wireless layers (Araujo, 2023; Kharade et al., 2024) can affect RFID uptime, and IoT-dependent systems introduce failure points when connectivity is unstable. Across these studies, strengths include faster gate processing, improved space visibility, and automation of administrative tasks. Weaknesses involve susceptibility to tag cloning, cost considerations, and limited scalability beyond controlled environments. 

Given these findings, our controlled prototype will utilize HF RFID tags for their short-range accuracy and lower interference risk, paired with basic anti-clone measures. Testing will focus on simulated gate operations and latency measurement within the prototype environment, ensuring the system meets target efficiency, security, and cost parameters before potential use. 

Wireless Communication in Parking Systems 

Wireless communication technologies, including Wi-Fi, Bluetooth, RFID, and IoT networks, play a pivotal role in modern parking systems by enabling real-time monitoring, management, and automation of vehicle spaces. In high-traffic areas, such as campuses or urban streets, delays caused by manual verification and inefficient slot searching are common. Wireless communication allows parking systems to transmit real-time slot availability to users, thereby reducing congestion, saving fuel, and improving overall traffic flow (Araujo, 2023 & Kharade et al., 2024). 

Araujo (2023) developed a low-power NB-IoT wireless detection system using magnetic sensors and an STM32 microcontroller to monitor on-street parking. The system detects magnetic field deviations caused by vehicles, providing updates with minimal energy consumption. The author notes, “The finite state machine algorithm successfully maintained real-time detection while keeping power usage low” (p. 5). While the projected battery life of 490 days falls short of the 10-year target, the approach highlights the potential for sustainable smart-city integration. Similarly, Kharade et al. (2024) designed an IoT-based wireless system using IR sensors, Arduino boards, LCDs, and nRF24L01 transceivers, which wirelessly displays vacant slots at entrances. Their scalable solution supports multi-lane and multilevel parking, though sensor accuracy can be affected by obstructions and lighting, and the system lacks RFID-based authentication. 

Sk. Fiamuddin et al. (2021) proposed a Wireless Sensor Network (WSN)–based approach integrating IR sensors and Arduino platforms to detect available slots and relay information via smartphones. By eliminating physical RFID cards, the system reduces manual search time and leverages cloud connectivity for real-time monitoring. However, the dependency on internet access and lack of security measures pose limitations for scalability and reliability. Ramos et al. (2024) combined UHF-RFID, IoT cloud databases, ultrasonic sensors, and mobile applications in an Automated Parking System, receiving high ISO/IEC 25010 evaluation scores for usability, reliability, and security. While effective for guiding vehicles, the reliance on consistent power and internet connectivity restricts deployment in low-resource environments.

Across these studies, wireless communication demonstrates the ability to provide real-time updates, reduce manual labor, and improve driver convenience. However, challenges such as IR sensor reliability, battery life, connectivity dependency, and interference with RFID systems persist. Integrating low-power wireless modules with RFID-enabled gates and Arduino platforms can address these issues while maintaining cost efficiency and scalability. Overall, wireless communication is a key enabler for automated parking systems, but practical deployment requires careful consideration of connectivity, power management, and sensor accuracy under real-world conditions. In this study, HF/UHF concepts apply in principle to the short-range wireless data exchange between the entrance and rear units via the nRF24L01, ensuring synchronized RFID authentication and slot availability updates in the prototype. 

Arduino-Based Automated Parking Systems 

Arduino-based automated parking systems leverage microcontrollers and sensors to manage vehicle entry, exit, and space availability efficiently. They offer a low-cost, flexible solution suitable for small-scale deployments such as campus lots, where budget and infrastructure may be limited (Kumari et al., 2024 & Dass et al., 2023). By automating detection, counting, and display of available slots, these systems reduce congestion, minimize manual verification, and provide a clear operational workflow from vehicle detection to access control. 

Kumari et al. (2024) developed an Arduino-based system using IR sensors for vehicle detection, a servo motor for gate control, and an LCD display for slot availability. The authors note, “The modular design allowed for clear integration of sensing, processing, and display, improving operational efficiency” (p. 57). While the prototype effectively updated slots in real time and proposed enhancements such as GSM booking and automatic number plate recognition, limitations included a lack of empirical testing, scalability plans, and security measures, as well as susceptibility to environmental interference. Similarly, Dass et al. (2023) combined Arduino boards, IR sensors, servo motors, LCDs, and IoT modules to detect vehicles and automate gate access. Their system further proposed mobile app integration, AI-based predictions, and cashless payments for enhanced scalability, but environmental factors affecting IR sensors and the absence of robust cybersecurity features posed practical challenges. 

Across these studies, Arduino platforms demonstrate strengths in modularity, cost efficiency, and ease of iteration. However, cross-linking with RFID and wireless research reveals potential dependencies: IR sensor reliability may be compromised under occlusion or poor lighting, and wireless communication modules such as nRF24L01 can influence end-to-end response times. Weaknesses include limited real-world deployment, untested scalability beyond small prototypes, and minimal attention to security and maintenance planning. Overall, Arduino-based systems provide a strong foundation for rapid prototyping and campus-scale automation, yet successful deployment requires addressing sensor robustness, environmental resilience, data security, and integration with broader wireless or RFID-enabled systems. In the present system, these concepts are applied by integrating IR detection, servo-controlled entry, LCD displays, and nRF24L01 wireless communication with RFID authentication to enhance slot tracking and access control in a small-scale prototype. 

IoT Integration in Parking Solutions 

The Internet of Things (IoT) has transformed parking management by enabling real-time monitoring, automated data collection, and smart decision-making. IoT-based systems connect sensors, microcontrollers, and cloud platforms to optimize space utilization, reduce congestion, and improve driver convenience (Chafiq et al., 2023; Alam et al., 2023). In resource-limited urban areas or campuses, IoT integration offers low-cost, flexible deployment for multi-slot monitoring, reducing the need for manual intervention while supporting sustainability goals through reduced vehicle idling and emissions. 

Chafiq et al. (2023) developed an IoT-enabled parking system using Arduino technology to provide real-time slot updates and reduce the time spent searching for parking. The authors note, “The system effectively minimized congestion and emissions, demonstrating the potential of IoT in low-resource urban settings” (p. 203). Alam et al. (2023) conducted a survey of IoT-based parking infrastructures, highlighting sensor technologies, communication protocols, and architectural models, and identified gaps in security, scalability, and performance under limited connectivity. Building on these insights, Jakkaladiki et al. (2023) integrated ensemble deep learning with IoT to improve predictive accuracy and automate data exchange, achieving higher responsiveness and more precise forecasting, though network dependence may limit deployment in low-infrastructure contexts. Tan et al. (2023) introduced a user-centered IoT parking system with mobile app integration, enabling real-time reservation, slot redirection, and secure payments. Their controlled trials demonstrated 100% detection accuracy and sub-10-second response times, but real-world scalability, long-term hardware durability, and data privacy were not fully evaluated. 

Across these studies, IoT systems consistently improve automation, predictive monitoring, and user convenience. However, cross-linking with wireless and Arduino research indicates potential challenges: connectivity instability can disrupt real-time updates, while cloud-based systems introduce failure points absent in local, offline implementations. Strengths include enhanced operational efficiency, automated data logging, and user-centered features, whereas weaknesses involve reliance on stable network connectivity, untested large-scale deployment, and cybersecurity concerns. Overall, IoT integration demonstrates strong potential for campus and urban parking solutions, but successful implementation requires addressing scalability, security, and reliability under constrained or variable connectivity conditions.

 In the present system, IoT principles are applied through sensor-to-controller communication and wireless data transfer, but unlike full cloud-based designs, it operates locally to maintain reliability even without internet access. This hybrid approach retains the efficiency benefits of IoT while mitigating network dependency. 

User-Centric Smart Parking Management 

User-centric smart parking systems focus on enhancing driver convenience and efficiency through personalized guidance, predictive analytics, and real-time interaction. These systems integrate machine learning, mobile sensing, and IoT technologies to reduce search time, prevent improper parking, and improve overall user satisfaction (Yan et al., 2024; Park, 2021; Cahyadi et al., 2023). In campus or urban environments, where traffic congestion and limited space awareness are common, such systems can substantially reduce frustration and improve operational efficiency. 

Yan et al. (2024) developed U-Park, a machine learning–driven system for Electric Shared Micromobility Services (ESMS), which predicts destinations and parking availability with over 97.6% accuracy. The system improved the likelihood of securing a parking spot by up to 29.66% and operates without requiring direct user input. The authors note, “Its data-driven architecture proactively aligns parking recommendations throughout the user’s journey” (p. 5). Park (2021) introduced D-PARK, a BLE beacon–based system leveraging mobile sensing to provide high-resolution localization and intent-based notifications. D-PARK achieved parking spot–level accuracy of approximately 2 meters and reduced service operation time by 6.8×, highlighting the value of integrating user behavior and intent into smart parking systems.

Cahyadi et al. (2023) reviewed the broader landscape of AI, IoT, and WSN-based smart parking solutions, emphasizing that predictive and adaptive models improve space detection and reduce search time, but real-world deployment remains constrained by cost, system interoperability, outdoor reliability, and data privacy challenges. Cross-linking these findings with RFID, wireless, and Arduino research shows that user-centric approaches amplify operational benefits, but success depends on reliable sensor data, connectivity, and robust infrastructure. Strengths of these systems include improved personalization, predictive efficiency, and enhanced driver experience. Weaknesses involve high dependency on stable network or cloud infrastructure, limited field validation, and challenges in large-scale or outdoor deployment. 

Overall, user-centric smart parking systems demonstrate the growing importance of aligning technological innovations with driver needs. Future campus-level applications, like multi-slot wireless parking with RFID gates, can benefit from these insights by integrating lightweight predictive guidance and real-time display cues while mitigating infrastructure dependency and maintaining low-cost scalability. In the present system, these principles can be applied to provide real-time RFID-based access control and slot availability display, improving user convenience while maintaining low-cost, scalable implementation.