A Network-aware Cross-layer Framework for Real-time LLM Service Orchestration Integrating QoS, QoE, and Academic Quality
Abstract: Large Language Model (LLM) chatbots become integral to modern education and performance is increasingly effective by the volatility of real world network environment, while existing evaluations focus on model accuracy or efficiency of inference in isolation, they often overlook the critical interaction between network Quality of Service (QoS) level and the user aware Quality of Experience (QoE). This paper proposes a Real Time Network Aware Recommendation (RNAR) framework that designed to orchestrate and recommend the optimal LLM service like ChatGPT-4, Gemini, Copilot and DeepSeek based on real time connectivity and academic context. RNAR captures precise interaction metrics such as Time To First Byte (TTFB), Jitter, Packet Loss, Time-to-First-Token (TTFT) and Inter-Chunk Delay (ICD) under diverse network technologies including WiFi, 4G and 5G. RNAR incorporates a multi objective utility model that synthesizes QoS, QoE and an expert validated Academic Quality (AQ) index derived from specialized evaluations in Computer Science and Business Administration and across three educational levels (B.Sc., M.Sc., and Ph.D.). The experimental results from 80 distributed evaluation sessions and among multiple regional locations (Iraq, Sweden and Hungary) shows that RNAR effective in reduce the impact of network instability on service reliability. Performance analysis across the four evaluated services revealed distinct trade-offs: ChatGPT-4 achieved the fastest network responsiveness with a mean TTFB of 257 ms , followed by Copilot with 333 ms , DeepSeek 556 ms and Gemini 1152 ms . While in interaction speed terms, the DeepSeek got a TTFT of 0.008 s , outperforming Copilot 0.027 s , ChatGPT-4 0.055 s and Gemini 0.096 s . These dynamics directly influenced the final recommendation frequency, where ChatGPT-4 was selected in 41.25% of sessions, DeepSeek in 36.25% and Copilot in 22.50%, while Gemini was excluded due to higher latency and jitter sensitivity. This work provides a practical and reproducible framework for ensuring high-performance LLM delivery in bandwidth constrained educational settings. The executable version of the RNAR framework is available at: https://github.com/almuqarm/LLM_Evaluator_Final_Pro/releases/tag/v2.0 and the RNAR implementation code and reproducibility materials are publicly available at https://github.com/al-muqarm/LLM-Recommendation-System.