METHOD AND APPARATUS FOR ASYNCHRONOUS ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS
A method of transmitting orthogonal frequency division multiple access signals includes transmitting a first stream of data from a first node of a network. The first stream includes a preamble and payload. A second stream of data is transmitted from a second node of the network. The second stream includes a preamble and payload, and the second stream has a shorter total length than the first stream. The transmission of the second stream starts at essentially the same time as the transmission of the first stream. A third stream of data is transmitted from the second node of the network. The third stream includes a preamble and payload. The transmission of the third stream begins at the end of the payload of the second stream and prior to the end of the transmission of the remainder of the payload of the first stream.
1 . A method of transmitting orthogonal frequency division multiple access signals, the method comprising:
transmitting, at a first transmitter of a network, a first burst of data having a first symbol length over a first time interval using a first set of one or more orthogonal frequency division multiple access (OFDMA) subcarriers; and
transmitting, at a second transmitter of the network, a second burst of data having a second symbol length over a second time interval, different in duration than the first time interval, using a second set of one or more OFDMA subcarriers.
2 . The method of claim 1 wherein the first and second time intervals overlap one another.
3 . The method of claim 1 wherein the first and second time intervals begin at different times.
4 . The method of claim 3 wherein the first and second time intervals end at different times.
5 . The method of claim 1 wherein the first and second sets of subcarriers are reserved for data of first and second traffic classes, respectively.
6 . The method of 5 wherein the first traffic class is residential traffic, and the second traffic class is commercial service level agreement (SLA) traffic.
7 . The method of claim 1 , further comprising:
assigning a first codeword to the first burst at a first group of subcarriers and a first symbol slot; and
assigning a second codeword to the first burst at the first group of subcarriers and a second symbol slot succeeding the first symbol slot in time.
8 . The method of claim 1 , further comprising:
assigning a first codeword to the first burst at a first subcarrier and a first group of symbol slots; and
assigning a second codeword to the first burst at the first group of symbol slots and a second subcarrier succeeding the first subcarrier in frequency.
9 . The method of claim 1 , further comprising:
assigning a first codeword to the first burst at a first group of subcarriers and a first symbol slot;
assigning a second codeword to the first burst at the first group of subcarriers and a second symbol slot succeeding the first symbol slot in time;
assigning a third codeword to the second burst at a first subcarrier and a first group of symbol slots; and
assigning a second codeword to the second burst at the first group of symbol slots and a second subcarrier succeeding the first subcarrier in frequency.
10 . A method of transmitting orthogonal frequency division multiple access signals, the method comprising:
a) transmitting a first stream of data from a first node of a network, the stream including a preamble and payload;
b) transmitting a second stream of data from a second node of the network, the second stream including a preamble and payload, the second stream having a shorter total length than the first stream, the transmission of the second stream starting at essentially the same time as the transmission of the first stream; and
c) transmitting a third stream of data from the second node of the network, the third stream including a preamble and payload, the transmission of the third stream beginning at the end of the payload of the second stream and prior to the end of the transmission of the remainder of the payload of the first stream.
11 . An apparatus forming a network node on a network, said apparatus comprising:
a computer processor;
a physical layer interface including a transmitter and a receiver, said physical layer interface configured to provide communication between said apparatus and at least one other network node on the network, said at least one other network node including a network coordinator (NC);
a buffer coupled to said processor, said buffer configured to store schedule orders received from said NC;
a timer;
a bus configured to provide communication between said processor, said physical layer interface, said buffer, and said timer;
a computer readable storage medium having computer-executable instructions stored tangibly thereon, said instructions when executed causing said processor to transmit, at a time based on the stored schedule orders and the timer, a first burst of data having a first symbol length over a first time interval using a first set of one or more orthogonal frequency division multiple access (OFDMA) subcarriers;
wherein the first burst of data has a different symbol length than a second burst of data that is transmitted at one of the other network nodes over a second time interval different in duration than the first time interval.
12 . An apparatus forming a network node on a network, said apparatus comprising:
a computer processor;
a physical layer interface including a transmitter and a receiver, said physical layer interface configured to provide communication between said apparatus, a first recipient network node on the network, and a second recipient network node on the network;
a bus configured to provide communication between said processor and said physical layer interface;
a computer readable storage medium having computer-executable instructions stored tangibly thereon, said instructions when executed causing said processor to:
transmit a first plurality of schedule orders to the first recipient network node, the first schedule orders instructing the first recipient node to transmit a first burst of data having a first symbol length over a first time interval using a first set of one or more orthogonal frequency division multiple access (OFDMA) subcarriers;
transmit a second plurality of schedule orders to the second recipient network node, the second schedule orders instructing the second recipient node to transmit a second burst of data having a second symbol length over a second time interval, different in duration than the first time interval, using a second set of one or more OFDMA subcarriers;
wherein said apparatus is configured as a network coordinator to coordinate asynchronous transmissions for reservation requests of the network nodes.