A DHT-Based Scalable Approach for Device and Service Discovery

Web service technology becomes popular in a growing number of applications. The field of application reaches from smart home over factory automation up to smart cities. One of the main aspects of this technology is a dynamic device and service discovery. For this purpose, the WS-Discovery standard is used. WS-Discovery supports two modes: an infrastructure-based and an ad hoc mode. The infrastructure-based mode requires a service proxy, which represents a single point of failure. The ad hoc mode is based on the multicast and static response time values. Therefore, it shows a low scalability. In this work, we present a novel discovery approach, which bases on distributed hash tables (DHTs). DHTs are often utilized in peer-to-peer networks and represent a well-established technology. The search for devices and services is performed using hash values. The benefit of this approach is a high scalability, deterministic behavior, and flow control. The suggested approach can be applied for networks of any size. Since this approach uses unicast messages, it is not limited to local networks allowing the device and service discovery over multiple subnets or even over the Internet.