Enhanced CoAP resource discovery - Application layer interfaces and highly targeted query filters
| Autor | Jawad Ahmad |
| Date | 11. March 2019 |
| Degree | Master |
| Topic | Overcoming CoAP's Resource Discovery Limitations |
| Title | Enhanced CoAP resource discovery - Application layer interfaces and highly targeted query filters |
| Abstract | Constrained Application Protocol (CoAP) has the potential to be a key actor in improving the Internet of Things (IoT) ecosystem. Despite its strengths, CoAP’s standardization is still under development; thus, CoAP suffers from a lack in maturity in certain regards. Resource discovery is such an aspect where CoAP’s standard methodology exhibits inad- equacy. This deficiency is exemplified by a use-case scenario where employing standard methodology of CoAP’s resource discovery is shown to be inefficient in terms of both time and space. One of the most significant shortcomings of the standard methodology, in par- ticular, is its incapability to filter resources based on individual attribute values. This thesis presents a solution to this limitation by implementing a query processing layer on top of a standard CoAP server, allowing highly targeted resource filtering. In addition to decreasing the payload sizes through the use of complex filters, the proposed implementation exercises the use of Concise Binary Object Representation (CBOR). The performance evaluation has shown that CBOR reduces payload sizes by as much as 45% when compared to plain-text encodings such as JavaScript Object Notation (JSON). The performance evaluation also revealed that for queries that targeted 92% of the total resources, a reduction of up to 54% response sizes as compared to a standard CoAP server was seen. The proposed implemen- tation is shown to have successfully filtered resources by attribute values while being time and space efficient. |