## 5 Enhancing QoS and QoE in ICN
### Name Resolution and Routing  
Name resolution in ICN involves matching an object name to a server or source that can supply that object to a requester. This can be achieved through hierarchical namespaces, resembling domain names in DNS, or through flat namespaces, where each content name is globally unique. Hierarchical namespaces enable scalable and efficient name resolution by utilizing hierarchical routing tables, while flat namespaces often rely on distributed lookup mechanisms like distributed hash tables (DHTs). Efficient name resolution ensures that content requests are quickly directed to the correct network locations, contributing to the scalability and decentralization of ICN architectures. Routing means constructing a path to transfer the object from the server to the client. In ICN, routers route packets based on content names instead of destination IP addresses. Content-centric routing and interest-based forwarding prioritize delivering content efficiently by caching and forwarding content toward the nearest or most suitable locations. Plus, content-based routing decisions optimize content delivery by considering factors such as content popularity, proximity, and network conditions. One aspect that sets apart various ICN approaches is their treatment of name resolution and routing. These functions may either be interlinked or operate separately from each other. [PERSON] et al. [73] and [PERSON] et al. [74] presented QoS-aware forwarding strategies for NDN environments. In [73], an ant colony optimization-based forwarding strategy was proposed, which utilized both forward and backward ants (interest and data packets) to rank interfaces and then selected the best interface to forward incoming Interests. To improve data transmission efficiency, this framework incorporated computed probability metrics from all available interfaces into a roulette wheel selection mechanism. Thismethodology enabled the inclusion of interfaces exhibiting reduced probability metrics (pheromone levels) in the decision process, ensuring a more equitable dispersion of network traffic. On the other hand, [PERSON] et al. [74] proposed a QoS-aware algorithm that extended the NDN model to embed QoS information into request and corresponding data packets and utilized multi-hop and multi-path forwarding techniques to meet the QoS constraints. [PERSON] et al. [75] proposed a multi-path selection strategy for the PSIRP architecture, considering bandwidth and error rate constraints. This solution facilitates QoS-aware routing decisions within individual network domains. The strategy specifically targets the requirements of on-demand video-streaming applications by prioritizing increased bandwidth allocation and minimizing packet loss while also including configurable limits on permissible path counts. The authors also studied the interaction between their model and a video-on-demand streaming service to deliver high-definition content. Scalable video technology (H.264/SVC) [76] was used to provide a layered representation of the content (three SNR-scalable layers, 1080p). To evaluate QoE, the Pseudo-Subjective Quality Assessment (PSQA) [77] approach was used, and the proposed method was shown to improve QoE and path computation. [PERSON] et al. [78] presented an optimization technique leveraging particle swarm intelligence, which analyzes historical data from content object transmissions to dynamically adjust routing likelihoods in forwarding tables (FIB). This method enables intelligent path selection by directing user requests toward the most efficient content source (publisher or server) among redundant providers of identical data, balancing QoS parameters during decision-making. Another swarm optimization technique was employed by [PERSON] et al. [79]. By mapping user QoE to specific QoS metrics, they calculated satisfaction levels and determined forwarding probabilities for router interfaces. This method allowed for dual-path content discovery, significantly improving routing success. [PERSON] et al.