the area "Smart City & Internet of Things" is a very interesting and broad research area. An interesting research topic in this area would be the development of smart city services, in particular citizen services in smart cities, based on the principles of name-based networking. This is also referred to as Information Centric Networking (ICN), Content Centric Networking or Named Data Networking. This idea can be called as a research topic:
"The smart city vision based on the information centric networking"
If you use the URNs on the Internet instead of URLs (that is, hostname-based-networking), you already have a kind of "name-based networking". However, a URN must be mapped to one or more IP addresses using one special resolver.
The idea - the use of a special resolver - to map a name to several computers (host) addresses is, for example, within the ENUM concept. With ENUM it is possible to use the classic telephone numbers on the Internet. The use of DOIs on the Internet is also a simple way of name-based networking.
The idea of name-based networking has an important advantage: a name can be mapped to multiple computers / host addresses, and these computers can be mobile, also be installed on mobile cars.
Some ideas for the use of URNs ( only on the Internet) can be found in my work LoST (in German).
Through the use of URNs, important services can be made available in IoT. In Smart Cities, URNs could be used to implement various citizen services, for example, for Smart Health Applications.
Some examples of the ICN-based smart city services can be found in RFC 7476: Information-Centric Networking: Baseline Scenarios; See the section: 2.9. Smart City
https://tools.ietf.org/html/rfc7476
Here are my literature suggestions for the topic:: The smart city vision based on the ICN:
draft-zhang-iot-icn-challenges-02: ICN based Architecture for IoT - Requirements and Challenges