Multilink in Wi-Fi 7: Multi-link Operation

Multi-link operation (MLO) technology enables flexible management of frequency resources to reduce latency and increase transmission speed and reliability. Within this research area, the team develops and analyzes new data transmission methods for next-generation wireless networks.

Research by the Wireless Networks Lab members considers all types of Multi-link devices (MLDs). In typical MLDs, medium access on each channel is independent. To improve efficiency and reduce overhead, the devices use aggregation — transmitting multiple packets in a single frame. Given limited packet buffers, the selection of the aggregation size is important for such transmissions. The WNL members have developed an algorithm for controlling the aggregation size, which reduces overhead and increases device throughput. The algorithm works even when MLDs use more than two channels simultaneously. Furthermore, it has been shown that packet duplication with this algorithm can provide benefits in cases where groups of packets are lost during transmission.

Some devices, such as smartphones, may experience co-channel interference. Such MLDs are called NSTR MLDs and cannot access the wireless medium independently. Most often, these devices transmit either on one channel at a time or synchronously on two channels. A large-scale analysis of several channel access methods in heterogeneous Wi-Fi 7 networks has been conducted for these devices. The methods that perform better in terms of throughput and fairness in most scenarios, as well as the supporting mechanisms for them, have been identified. Moreover, a mathematical model based on discrete-time Markov chains was constructed to estimate the throughput of heterogeneous networks with single-link and multi-link devices. In addition, for the standardized NSTR MLD medium access method, an algorithm has been developed that determines a channel selection strategy for transmission that maximizes throughput.

List of relevant papers:


      2024
    1. Evgeny Khorov, Ilya Levitsky , Vyacheslav Loginov, Vladislav Paroshin. Packet Duplication for Improving Throughput of the Multi-Link Devices in Wi-Fi 7 Networks. //Journal of Communications Technology and Electronics. – 2024. – С. 1-4. https://doi.org/10.1134/S1064226924700128.
    2. Evgeny Khorov, Ilya Levitsky , Vyacheslav Loginov, Vladislav Paroshin. Aggregation Algorithm to Increase Throughput of Multi-link Wi-Fi 7 Devices. //IEEE Wireless Communications Letters. – 2024. https://doi.org/10.1109/LWC.2024.3474294.

      3. 2022
    3. Evgeny Khorov, Ilya Levitsky , Ivan Startsev, Nikolay Korolev, Boris Bellalta. Study of Multi-Link Channel Access Without Simultaneous Transmit and Receive in IEEE 802.11be Networks. //IEEE Access. – 2022. – Т. 10. – С. 126339-126351. https://doi.org/10.1109/ACCESS.2022.3225978.
    4. Evgeny Khorov, Ilya Levitsky , Nikolay Korolev. Analytical Model of Multi-link Operation in Saturated Heterogeneous Wi-Fi 7 Networks. //IEEE Wireless Communications Letters. – 2022. – Т. 11. – №. 12. – С. 2546-2549. https://doi.org/10.1109/LWC.2022.3207946.

      5. 2021
    5. Evgeny Khorov, Ilya Levitsky , Nikolay Korolev. Analyses of NSTR Multi-link Operation in the Presence of Legacy Devices in an IEEE 802.11be Network. //2021 IEEE Conference on Standards for Communications and Networking (CSCN). – IEEE, 2021. – С. 94-98. https://doi.org/10.1109/CSCN53733.2021.9686164.