Matching and Discovery Algorithms in Internet of Things: Open Issues, Challenges, and Future Directions

The Internet of Things (IoT) is rapidly becoming a defining technology, connecting real-world objects to digital services and creating smart environments. Recent advancements have significantly enhanced human life, making it more comfortable and convenient. As a cutting-edge field, IoT represents a key area of growth alongside the evolution of information technology. IoT facilitates the exchange of data and communication across networks, devices, and individuals, equipping everyday objects with applications and sensors for efficient operation. This enables a platform for intelligent everyday items, making information-driven communication and smart processes part of routine life. A variety of heterogeneous systems and protocols have been developed to support innovative IoT services. With the daily increase in IoT devices and services, finding and accessing these services becomes critical. Traditional service discovery methods struggle to address this issue effectively. Service discovery involves locating relevant services based on user needs. Despite its importance in IoT, existing approaches to service discovery have not been thoroughly or consistently explored. The surge in connected devices and the absence of unified standards for IoT increase the challenge of identifying and selecting appropriate services. Numerous studies have been conducted to examine service discovery within IoT. This paper offers a comprehensive analysis of various service discovery algorithms, introducing a new classification based on service types and application areas. It also highlights current gaps, challenges, and future research directions in this field.