  Next generation Wi-Fi networks are expected to support real-time applications
that impose strict requirements on the packet transmission delay and packet
loss ratio. Such applications form an essential target for the future Wi-Fi
standard, namely IEEE 802.11be, the development process of which started in
2019. A promising way to provide efficient real-time communications in 802.11be
networks requires some modification of the uplink OFDMA feature originally
introduced in the IEEE 802.11ax amendment to the Wi-Fi standard. This feature
allows the access point to reserve channel resources for upcoming urgent
transmissions. The paper explains why uplink OFDMA random access of 802.11ax
does not perfectly fit the requirements of real-time applications and proposes
an easy-to-implement modification of the channel access rules for future
802.11be networks. With extensive simulation, it is shown that this
modification together with a new resource allocation algorithm outperforms the
existing ways to support real-time applications, especially for a heavy load
and a high number of users. In particular, they provide extremely low delays
for real-time traffic, while the throughput for non-real-time traffic is
reduced insignificantly.
