What does Mbps-SP mean

3.3 AP and 3.3 Client The Client Tx/Rx Rate occasionally displays 48Mbps/11Mbps-SP, or /2Mbps-SP, etc.
Mbps-SP.JPG
What does the SP indicate ?

Thx,
S

Short Preamble

but this does not configured to accept short: why then?
imagem.jpg

Is the screenshot of the CPE or AP?

mode ap and continues in some client in short pre.