RESOURCE ALLOCATION IN MULTI-BAND WIRELESS NETWORKS WITH TRAFFIC PRIORITIZATION

Abstract

The article investigates the technical capabilities and features of the new generation of wireless networks—the Wi-Fi 7 (IEEE 802.11be) standard, known as Extremely High Throughput (EHT). Primary attention is given to the implementation of the key technology Multi-Link Operation (MLO), which aims to provide a maximum throughput of up to 46 Gbit/s and significantly reduce latency. MLO technology allows stations (STA) and access points (AP) to simultaneously use multiple channels across different frequency bands (2.4, 5, and 6 GHz) for data transmission and reception. This is achieved through the simultaneous use of different channels, load distribution, and adaptive switching between frequencies, which enhances connection reliability.

Different operating modes of Multi-Link Devices (MLD), classified by the number of radio interfaces and transmission type, are considered. Devices with a single radio interface are highlighted: MLSR (Multi-Link Single-Radio) and its enhanced version EMLSR (Enhanced Multi-Link Single-Radio). MLSR uses a single radio module to monitor multiple channels, but transmission occurs on one channel at a time. EMLSR manages channel switching more efficiently and can dynamically manage configurations (Nss, MCS, BW) for each channel, reducing latency. For devices with multiple radio interfaces (MLMR), the asynchronous mode STR-MLMR (Simultaneous Transmit and Receive Operation) and the synchronous mode NSTR-MLMR (Nonsimultaneous Transmit and Receive Operation) are investigated. STR-MLMR, having two or more radio modules, ensures simultaneous reception and transmission on different channels, which significantly increases throughput and is suitable for intensive traffic. NSTR-MLMR allows only reception or only transmission at any given moment across all channels, which is used to avoid inter-channel interference. The EMLMR (Enhanced Multi-link Multi-Radio) mode is also considered, which is an enhancement of STR-MLMR with the capability for dynamic modification of individual channel parameters and resource allocation.

The operation of the Wi-Fi network was simulated in the NS3 simulator across three main scenarios, including device operation in SL (Single Link), EMLSR, and STR-MLMR modes. The simulation confirmed that multi-link devices significantly outperform single-link (SL) devices in performance, increasing throughput and reducing latency. In conditions of competition for channel access, the STR-MLMR mode proved to be the most productive due to the capability for simultaneous operation on multiple channels. The study also confirmed the more efficient operation of multi-link devices in the presence of competing SLDs.

Based on the comparison results, the EMLSR and STR-MLMR modes are considered the most promising for application. STR-MLMR provides high throughput and medium latency, requiring a more complex implementation, whereas MLSR and EMLSR are simpler but have lower throughput. NSTR-MLMR is suitable for conditions of high interference, but it has lower throughput compared to asynchronous modes. The research emphasizes the importance of correctly selecting the multi-link access mode according to network requirements.