Point to Multi-point Service
Point-to-multipoint communication is a term that is used in the telecommunications field which refers to communication which is accomplished via a specific and distinct type of multipoint connection, providing multiple paths from a single location to multiple locations. Point-to-multipoint telecommunications is most typically (2003) used in wireless Internet and IP Telephony via gigahertz radio frequencies.
P2MP systems have been designed both as single and bi-directional systems. A central antenna or antenna array broadcasts to several receiving antennas and the system uses a form of Time-division Multiplexing to allow for the back-channel traffic. Also known as a “multidrop” link, a multipoint link is a link that connects two or more nodes. Also known as general topology networks, these include ATM and Frame Relay links, as well as X.25 networks when used as links for a network layer protocol like IP. Unlike broadcast links, there is no mechanism to efficiently send a single message to all other nodes without copying and retransmitting the message.
A point-to-multipoint link is a specific type of multipoint link which consists of a central connection endpoint (Main Point) that is connected to multiple peripheral Remotes. Any transmission of data that originates from the central Main Point is received by all of the peripheral Remotes while any transmission of data that originates from any of the peripheral Remotes is only received by the central Main Point. This term is also often used as a synonym for multipoint, as defined above.