"报文分组通信" can be translated as "packet communication" or "packet-switched communication" in English.
"Packet communication" is a more general term that refers to the transmission of data in the form of packets.
"Packet-switched communication" specifically emphasizes the switching technique used in the network, where data is divided into packets and each packet is independently routed to its destination.
In most contexts, especially when discussing the basic concept of transmitting data in packets, "packet communication" would be sufficient. However, if you want to emphasize the switching mechanism involved, "packet-switched communication" would be more appropriate.