Research papers in data access control frameworks for the Internet of Things (IoT) focus on designing mechanisms to regulate and secure access to sensitive data generated and exchanged by heterogeneous IoT devices. IoT environments often involve a massive number of interconnected devices, sensors, and gateways with varying capabilities, creating challenges in enforcing fine-grained, scalable, and context-aware access control. Traditional access control models, such as Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC), have been adapted for IoT to address issues like dynamic device joining, resource constraints, and mobility. Researchers have proposed lightweight and distributed frameworks that leverage edge computing, fog computing, and blockchain technology to reduce latency, enhance security, and provide decentralized trust management. Policy-based access control approaches are widely explored, enabling context-aware and situation-driven permissions based on device attributes, environmental conditions, and user roles. Cryptographic techniques, including attribute-based encryption (ABE), identity-based encryption (IBE), and lightweight symmetric or asymmetric key schemes, are frequently integrated to enforce secure access without imposing high computational or communication overhead. Emerging works also incorporate machine learning for anomaly detection and adaptive access decisions, ensuring protection against insider threats, unauthorized access, and collusion attacks. Furthermore, hybrid models combining blockchain, smart contracts, and edge-assisted policy enforcement are gaining attention for providing transparency, auditability, and tamper-resistant access control in large-scale IoT networks. Despite these advancements, challenges persist in achieving scalability, interoperability among heterogeneous IoT platforms, dynamic policy management, and energy-efficient enforcement suitable for constrained devices. Overall, the literature underscores that designing effective data access control frameworks is essential for ensuring privacy, security, and trust in IoT ecosystems while balancing performance, scalability, and resource constraints.