# All about Delay-Tolerant Networking (DTN) Contributions to Future Internet
## 3 Related Work
### Information-Centric Networking (ICN) and Named Data Networking (NDN)
#### 3.2.1 DTN-ICN in IoT  
The DTN-ICN convergence can offer a resilient architecture paradigm for IoT environments. It can enable efficient data dissemination, enhance reliability, and provide seamless communication within the dynamic, intermittently connected, and resource-constrained IoT ecosystems.  
Efforts to evaluate the performance of NDN, DTN, and NoD architectures have been made within dynamic IoT networks [65; 66]. Regarding the latter case, the authors identify tradeoffs (content retrieval delay, cache hit ratio, delivery ratio) within each approach with various packet sizes and numbers of nodes in stationary and mobile IoT networks. The work by [67], which is extended in [68; 69], e.g., to include anomaly detection techniques for prediction and propose an adaptive NoD multiprotocol SDN solution for smart cities within the REWIRE project ([[https://www.fed4](https://www.fed4) fire.eu/demo-stories/oc9/rewire/]([https://www.fed4](https://www.fed4) fire.eu/demo-stories/oc9/rewire/) accessed on 4 March 2024). The system was evaluated in the large-scale CityLab ([[https://www.fed4](https://www.fed4) fire.eu/testbeds/citylab/]([https://www.fed4](https://www.fed4) fire.eu/testbeds/citylab/) accessed on 4 March 2024) and w.iLab ([[https://www.fed4](https://www.fed4) fire.eu/testbeds/w-ilab-t/]([https://www.fed4](https://www.fed4) fire.eu/testbeds/w-ilab-t/) accessed on 4 March 2024) testbeds with extended metrics similar to [67]. Another paper [70] presents an architecture based on NDN-DTN to enhance data retrieval from intermittently connected devices, such as those found in the IoT and sensor networks operating in remote areas. Through real-world WiFi-based experiments, the authors demonstrated significant improvements in the interest satisfaction ratio and average delay, particularly in environments characterized by a low delivery ratio and contact duration. In a different study [71], the authors employed the BP as an underlying transport mechanism for the Constrained Application Protocol (CoAP), thus deviating from the default UDP, which is used in IoT scenarios. Furthermore, in [72], fog computing and IoT were integrated, thus introducing the concept of \"content islands\". The authors developed a publish/subscribe system and a prototype over DTN to facilitate data and computation sharing utilizing MQTT and IBR-DTN. Similar works that utilize and leverage MQTT with DTN are also highlighted for IoT case studies in Section 3.3.  
Modifications to ICN architectures have also been explored to achieve delay and disruption tolerance. In [73], the authors propose an ICN-over-LoRa framework within DTN-constrained IoT environments. They considered varying RTTs to facilitate end-to-end ICN communication from internet consumers to LoRa nodes. Additionally, in [74], the concept of _reflexive forwarding/pushing_ is introduced as an extension to the Content-Centric Networking (CCN) and NDN protocol architectures, thus aiming to mitigate issues associated with independent interest-data message exchanges in scenarios involving the transfer of large data volumes. The paper by [75] also focuses on CCN but regarding data transmission and modifying caching during short network contacts through CCN content discovery. Furthermore, in [76], the RICE network layer framework is proposed for remote function invocation within ICN, thereby aiming to reduce polling overhead and introduce function-oriented capabilities. This includes employing the programming-oriented concept of \"thunks\" and introducing a 4-way handshake for security enhancement. Moreover, several works leverage the functionality of DTN architectures, such as the UMOBILE architecture [77] and the RIFE integrative architectural platform [78]. These frameworks bring together IP, ICN, and DTN into unified frameworks while also offering QoS-enhanced services.