Method and apparatus for using dynamic subchannels in a communications network
A method and apparatus for attaining the benefits of both an adjacent subchannel assignments and distributed subchannel assignments. That is, the following is a method and apparatus for providing dynamic subchannel assignments that provide the benefits of both adjacent subchannel assignments and distributed subchannel assignments.
1. A method of allocating subcarriers to subchannels in a communications network comprising:
establishing, by one or more transmitters and one or more receivers of the communications network, a plurality of dynamic subchannels to which subcarriers can be dynamically assigned, wherein said plurality of dynamic subchannels comprise both adjacent subchannels and frequency diversity with some subchannels being adjacent to one another and others distributed elsewhere in a subcarrier;
performing, by the one or more transmitters and one or more receivers of the communications network, link maintenance operations on the at least one dynamic subchannel, wherein the link maintenance operations include restricting transmission of probes to the subcarriers of the dynamic subchannel where a particular subcarrier on which probes are sent changes as subcarriers are assigned into and out of a dynamic subchannel performing link maintenance; and
switching, by the one or more transmitters and one or more receivers of the communications network, the subcarriers assigned to the at least one dynamic subchannel periodically in order to ensure that the link maintenance operations are performed over a predetermined period of time.
2. The method of claim 1 , wherein switching of the subcarriers occurs from symbol to symbol.
3. The method of claim 1 , wherein switching of the subcarriers occurs from burst to burst.
4. The method of claim 1 , wherein the switching of the subcarriers is a physical layer operation such that a media access control scheduler of the communications network is not burdened by the switching.
5. The method of claim 1 , wherein the performing the link maintenance operations over the predetermined period of time allows each of the one or more receivers within the communications network to observe a channel estimate for all subcarriers and from all of the one or more transmitters of the communications network.
6. The method of claim 1 , wherein the link maintenance operations monitor all of the subcarriers used by the one or more transmitters and one or more receivers of the communications network.
7. The method of claim 6 wherein the link maintenance operations include transmission, by the one or more transmitters, of channel assessment probes on the subcarriers of the dynamic subchannel.
8. The method of claim 7 , wherein the channel assessment probes include error vector magnitude probes.
9. The method of claim 7 , wherein the channel assessment probes include receiver determined probes.
10. The method of claim 7 , wherein the channel assessment probes include silent probes.
11. The method of claim 1 , wherein the switching of the subcarriers occurs in accordance with a predetermined pattern.
12. The method of claim 11 , wherein the predetermined pattern ensures that most of the subcarriers are characterized by the link maintenance operation.
13. The method of claim 11 , wherein the predetermined pattern ensures that all of the subcarriers are characterized by the link maintenance operation.