You may not see any profile photo at all, and instead just see a blank circle. If you send a message to this person you’ll never get the double tick, instead seeing one tick that represents.

In this case, there are chances that you are not blocked and the person has just uploaded a profile picture. You can look for other signs as well. If you have sent messages to the contact who has blocked, then WhatsApp will always show one check mark and never a tick double tick. In case you are not aware, one tick means that your message has.

WhatsApp uses checkmarks to indicate message delivery and read status. A single grey checkmark signifies that your message has been sent, but when blocked, you will not see the second grey checkmark indicating delivery. Additionally, blocked contacts typically do not reply to your messages.

Abstract. Millimeter wave (mmWave) communication is one of the hottest topics in the fifth- generation communication (5G) research. The influence of blockages on mmWave communication is very serious. This paper provides an overview of the research status of the blockage effect. First, it briefly introduces the impact of natural environment.