초록 ▼

A communication system such as an OFDM or DMT system has nodes which are allowed to transmit continuously on one or just a few of the system's frequency sub-channels, while the other nodes avoid putting any signal into those sub-channels. Simple low data rate nodes are allowed to use a small number

A communication system such as an OFDM or DMT system has nodes which are allowed to transmit continuously on one or just a few of the system's frequency sub-channels, while the other nodes avoid putting any signal into those sub-channels. Simple low data rate nodes are allowed to use a small number of sub-channels while more complicated nodes use the remainder. A control protocol allows the sharing in time of communications using overlaid and non-overlaid multi-carrier communication techniques. The sharing in time can be done using TDMA, CSMA or polling techniques. In each case, mechanisms are provided for bringing new nodes into the network and for insuring the time alignment of overlaid transmissions. Reliable transmissions are insured through acknowledgement and retransmission facilities.

대표청구항 ▼

1. A communication system comprising:a first node for receiving a first signal;a plurality of second nodes for receiving a second signal; anda coordinator node for alternately transmitting in a first mode and in a second mode, wherein:the first mode generates the first signal having a first pluralit

1. A communication system comprising:a first node for receiving a first signal;a plurality of second nodes for receiving a second signal; anda coordinator node for alternately transmitting in a first mode and in a second mode, wherein:the first mode generates the first signal having a first plurality of non-overlapping sub-channels conveying information, the first plurality of non-overlapping sub-channels collectively corresponding to the first node to receive the first signal,the second mode generates the second signal representative of a second plurality of non-overlapping sub-channels conveying information, and a plurality of groups of one or more sub-channels of the second plurality of non-overlapping sub-channels, each group corresponding to one of the plurality of second nodes to receive the second signal, andthe plurality of second nodes simultaneously receives and processes the second signal, wherein processing the second signal generates, for each information-conveying group of one or more sub-channels corresponding to the one of the plurality of second nodes, a data stream representative of the information conveyed thereby. 2. The system of claim 1, wherein the coordinator node is for separating the first and second signals by at least one beacon. 3. The system of claim 2, wherein:the coordinator node is for transmitting a first mode start beacon prior to transmitting the first signal and a first mode end beacon after transmitting the first signal; andthe coordinator node is for transmitting a second mode start beacon prior to transmitting the second signal and a second mode end beacon after transmitting the second signal.