Cooja is a network simulator that is related to the Contiki OS. Many Contiki Cooja Mini Projects are handled efficiently by our researchers, to experience high quality projects you can simply rely on us. The following are some intriguing project topics and plans that could be more appropriate for IoT-based research and progression and they can be benefit from the efficiencies of Contiki and Cooja: 

1. Energy-Efficient IoT Networking: For IoT devices, novel energy-effective networking protocols have to be created and simulated. It is most significant to consider the preservation of network performance and credibility in addition to enhancing the durability of the network. Through the utilization of Cooja, assess your solutions based on different network scenarios.
2. Secure IoT Communication: To secure IoT networks from general hazards such as illicit access, manipulation, and eavesdropping, model and apply safety protocols. In order to simulate assaults and evaluate your safety approaches’ strength, employ Cooja.
3. IoT-based Smart Agriculture: The major aim of this topic is to develop a simulation based on smart agriculture system which performs various operations such as automatic irrigation, weather prediction, and tracking of soil moisture by utilizing IoT devices. The scalability, effectiveness, and strength of the system against network faults have to be assessed.
4. Smart City Applications: Specifically for various applications like traffic management, pollution tracking, and smart lighting, model a smart city network framework through the employment of IoT devices. To evaluate energy utilization, scalability, and performance, consider the simulation of deployment in Cooja.
5. IoT and Blockchain Integration: In order to accomplish decentralized and protective data management, the combination of blockchain mechanisms with IoT has to be explored. By concentrating on safety issues and scalability, simulate a network of IoT devices that utilize blockchain to perform and interact.
6. Wireless Sensor Network (WSN) Optimization: To enhance WSNs’ different factors like sensor placement, routing, and data aggregation, create methods. In various conditions, simulate and assess the efficiency of your methods through the use of Cooja.
7. Dynamic Network Configuration: On the basis of varying network needs and constraints, apply and simulate a system, particularly for dynamic arrangement of IoT devices. Energy-saving modes, on-the-fly safety strategy updates, or adaptive routing protocols could be included in this project.
8. Multi-protocol IoT Networks: In a single IoT network, the interoperability and resemblance of various interaction protocols must be investigated. For evaluating the performance effect and complications, simulate the network which combines diverse protocols such as Bluetooth Low Energy, 6LoWPAN, and ZigBee.
9. Indoor Positioning System: By employing IoT sensors, model an indoor positioning system. The placement of this system in a building has to be simulated. Regarding the ecological barriers and number of sensors, assess the credibility, scalability, and preciseness of the system.
10. Fog Computing for IoT: For minimizing bandwidth utilization and latency, aim to process data nearer to IoT devices by creating a fog computing framework. To examine possible issues and performance efficiencies, the framework deployment in a business platform or smart city should be simulated.
11. Machine Learning for IoT: In several applications such as smart home automation, anomaly identification, and predictive maintenance, apply the methods of machine learning on IoT devices. For the network simulation and the assessment of energy and computation expenses of on-device machine learning, employ Cooja.
12. IPv6 over Low-Power Wireless Personal Area Networks (6LoWPAN) Optimization: With the intention of solving issues like header compression, interoperability with IPv6 networks, and fragmentation, consider the improvement of 6LoWPAN to achieve greatest performance in the applications of IoT.

Are there any step by step guides available that explain how to configure MQTT SN on Contiki for IoT applications?

Yes, there are numerous steps encompassed in the configuration of MQTT-SN on Contiki, specifically for IoT applications. Various procedures such as arranging the MQTT-SN packages, dealing with the Cooja simulator, and linking to a server/broker could be included in the configuration. By considering information from different sources, we offer a well-formatted instruction:

1. Install MQTT-SN Packages: Initially, the mqtt-sn-contiki package must be downloaded and extracted into your Contiki directory. In your creation platform or VM, this directory originated at home/user/Contiki.
2. Open the Cooja Simulator: After that, direct to the tools directory of Contiki like (contiki/tools/cooja). By utilizing the command ant run, execute the Cooja simulator. Then, develop a novel simulation into Cooja.
3. Create and Configure Motes: There will be a requirement to append motes for the simulation by defining their relevant C files that originated in the directory of Contiki. For the capabilities of both subscriber and publisher, use main_core.c to segregate motes for them. Generally, you will require a wide range of routers.
4. Connect the Border Router and Broker/Server: You have to confirm that the MQTT server/broker such as Mosquitto is executing and linked to the clients appropriately, in addition to assuring whether the extensive router is linked, once you arrange the motes. To start the broker and link it to the Cooja simulation, execution of particular commands might be included.
5. Run the Simulation: The process of simulation can be executed in Cooja after arranging all the aspects. By means of the broker, in what way the MQTT-SN interaction evolves among the subscriber and publisher can also be analyzed.

It will be more beneficial to look for reliable repositories or mentors for more in-depth guidelines, commands, and file paths. One of the best instances is the GitHub repository aignacio/mqtt-sn-contiki_example that encompasses different files that are considered as more essential for simulation execution, such as project-conf.h, mqtt_sn.c, and main_core.c and also provides a realistic instance based on MQTT-SN with Contiki-OS.