Wi-Fi 8 Distributed MIMO Data Rate Calculator & Formula : 802.11bn

In the upcoming Wi-Fi 8 standard, one of the most powerful tools for maximizing throughput is the deployment of distributed MIMO architectures across multiple access-points (APs) and spatial streams. D-MIMO is the most likely and transformative feature of Wi-Fi 8. Instead of one massive access point (AP) with many antennas, it allows multiple, geographically separate APs to work together as a single, virtual massive antenna system.

Purpose of this calculator is to calculate the aggregated throughput from multiple APs coordinating to serve a single client.

EXAMPLE: 802.11bn Wi-Fi 8 Data Rate Calculator for D-MIMO:

Scenario: A user is in a room with three Wi-Fi 8 APs, each a simple 4x4 (4 spatial streams) device. They coordinate using D-MIMO to serve the user’s laptop over a single 320 MHz channel using 4096-QAM.

• INPUTS:

  • N_AP = 3 (Number of Coordinated APs)
  • N_SS for each AP = 4 (For 4x4 MIMO), So the total SSs = 4 x 3 = 12 spatial streams.
  • N_SD = 4080 (for 320 MHz)
  • Code rate, R = 5/6 = 0.833
  • N_BPSCS = 12 (for 4096 QAM)
  • Symbol period (T_OFDM)= 13.6 µs

• OUTPUT:

  • IEEE 802.11bn Maximum throughput or data rate = 35.98 Gbps

Wi-Fi 8 Data Rate Formula as per IEEE 802.11bn D-MIMO

The following formula or equation is used for the Wi-Fi 8 data rate or throughput calculation:

Note : User can try other values of N_SD (Number of Data Subcarriers as per other channel bandwidths), Number of spatial streams, N_BPSCS (Number of coded bits per subcarrier per stream), and Code rate (R) to see the impact on data rate or throughput.

References :

1. IEEE 802.11bn Task Group documents (preliminary): The official discussions are happening here.
2. Academic Research Papers on arXiv: Search for “Coordinated Multi-AP,” “Distributed MIMO,” and “802.11bn.”