Terminology » WLAN » Understanding 802.11ax RU and 802.11be MRU

Understanding 802.11ax RU and 802.11be MRU

wireless lan wifi resource unit wifi 7 multi ru

Wi-Fi 6 (802.11ax) and Wi-Fi 7 (802.11be) have introduced advanced features to improve the efficiency and performance of wireless communication. Two such features are Resource Units (RUs) in WiFi 6 and Multi-RUs (MRUs) in WiFi 7.

802.11ax Resource Unit (RU)

Resource Units (RUs) are a key feature of WiFi 6 that allow more efficient use of the available spectrum through Orthogonal Frequency Division Multiple Access (OFDMA). OFDMA divides a channel into smaller sub-channels or RUs, which can then be allocated to different users or devices. This results in the following benefits:

  • Improved efficiency: By dividing the channel, multiple users can simultaneously communicate, reducing latency and increasing throughput.
  • Flexible channel allocation: RUs can vary in size (e.g., 26, 52, 106, 242, 484, 996 tones), allowing dynamic allocation based on the traffic demand.

802.11be Multi-RU (MRU)

WiFi 7 builds upon Wi-Fi 6 by introducing Multi-RU (MRU), which enhances the flexibility of resource allocation.

  • Multiple Resource Units per User: Unlike Wi-Fi 6, where a single RU is allocated to a user, Wi-Fi 7 allows multiple RUs to be combined and allocated to a single user. This can significantly increase the throughput for high-demand users.
  • Increased Efficiency: MRUs help in utilizing non-contiguous frequency chunks, which may result from interference or varying spectrum availability. This leads to better spectrum efficiency and less interference.
  • Support for Wider Channels: MRUs can span across wider channels (e.g., 160 MHz and 320 MHz) to maximize data transmission rates.

Differences Between 802.11ax RU and 802.11be MRU

Features802.11ax (WiFi 6) RU802.11be (WiFi 7) MRU
DefinitionDivides channel into sub-channels (RUs) for usersCombines multiple RUs for a single user
Resource allocationAllocates a single RU per userAllows multiple RUs per user
Channel sizesSupports 20, 40, 80, 160 MHz channelsSupports 20, 40, 80, 160, 320 MHz channels
RU sizes26, 52, 106, 242, 484, 996 tonesMultiple RUs with non-contiguous frequency blocks
EfficiencyImproves efficiency for multiple usersEnhances efficiency and throughput for high-demand users
ApplicationSuitable for balanced load scenariosIdeal for dynamic traffic and high-density environments
Interference handlingLimited to contiguous RUsCan use non-contiguous frequency blocks to avoid interference
Maximum throughputLimited by single RU allocationHigher throughput with MRU combining

Conclusion

The evolution from RUs in Wi-Fi 6 to MRUs in Wi-Fi 7 reflects the increasing demand for high-efficiency, high-capacity wireless networks. WiFi 7’s MRU feature allows for greater flexibility, increased throughput, and better handling of complex and congested environments, making it a superior choice for future wireless communication needs.