Android - What does "H" mean in the signal indicator?

Let's state all the possible letters in the signal indicator, in descending speed (indicated speeds are roughly theoretical maximum):

• 5G = 20 Gbps
• LTE+ = 300 Mbps
• LTE = Long Term Evolution (commonly and falsely known as 4G), 100 Mbps
• H+ = HSDPA Plus, 10 Mbps
• H = either HSDPA (3.5G) or HSPA+ (3.95G), depending on your network provider, 2 Mbps
• 3G = UMTS (3G), 384 kbps
• E = EDGE (2.5G), 40 kbps
• G = GPRS (2G), 14 kbps
• (no letter) = voice only, no data connection, 2.4 kbps

and also:

• R = roaming (this means you're not on your home network)

(source for some of this.)

It's HSDPA which if I'm not mistaken is referring to 3.5G.