Media access control for MIMO wireless network
AssigneeCisco Technology, Inc.
InventorsOzgur Gurbuz, David Pignatelli, David Stephenson, Eldad Perahia, Bretton Douglas, Ender Ayanoglu
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Abstract
The MAC layer of a wireless communication standard is modified to facilitate MIMO (multiple input multiple output) processing and thereby increase capacity and/or spectral efficiency. In one implementation, the IEEE 802.11a standard is modified in this way. A contention free period (CFP) is divided between MIMO communications and non-MIMO communications. An access point may maintain a list of nodes operating in MIMO mode and nodes operating in non-MIMO mode.
Claims23
In a wireless communication system having nodes operating in a Multiple Input Multiple Output (MIMO) mode and nodes operating in a non-MIMO mode, a method for operating an access node, the method comprising:
- maintaining a list of nodes operating in a MIMO mode and nodes operating in a non-MIMO mode;
- dividing a contention free period into non-overlapping subperiods;
- and
- within a designated contention free period, polling MIMO-mode nodes and non-MIMO-mode nodes for transmissions in said corresponding non-overlapping subperiods of said contention free period;
- wherein said access node communicates with nodes operating in said MIMO mode during one of said non-overlapping subperiods and communicates with nodes operating in said non-MIMO mode during another of said non-overlapping subperiods.
In a wireless communication network, a method of operating a Multiple Input Multiple Output (MIMO)-capable subscriber node, said method comprising:
- receiving a MIMO beacon;
- measuring MIMO transmission conditions based on said MIMO beacon;
- during a contention period, requesting an access point for permission to switch between a MIMO mode and a non-MIMO mode;
- and
- upon receiving permission, switch between said MIMO mode and said non-MIMO mode;
- wherein requesting said access point for permission to switch between said MIMO mode and said non-MIMO mode occurs in response to said measured MIMO transmission conditions.
In a wireless communication system having nodes operating in a Multiple Input Multiple Output (MIMO) mode and nodes operating in a non-MIMO mode, a computer program product for operating an access node, the computer program product comprising:
- code that maintains a list of nodes operating in a MIMO mode and nodes operating in a non-MIMO mode;
- code that divides a contention free period into non-overlapping subperiods;
- code that, within a designated contention free period, polls MIMO-mode nodes and non-MIMO-mode nodes for transmissions in said corresponding non-overlapping subperiods of said contention free period, wherein said access node communicates with nodes operating in said MIMO mode during one of said non-overlapping subperiods and communicates with nodes operating in said non-MIMO mode during another of said non-overlapping subperiods;
- and
- a computer-readable storage medium that stores the codes.
In a wireless communication network, a computer program product operating a Multiple Input Multiple Output (MIMO)-capable subscriber node, said computer program product comprising:
- code that receives a MIMO beacon;
- code that measures MIMO transmission conditions based on said MIMO beacon;
- code that, during a contention period, requests an access point for permission to switch between a MIMO mode and a non-MIMO mode;
- code that, upon receiving permission, switches between said MIMO mode and said non-MIMO mode;
- and
- a computer-readable storage medium that stores the codes;
- wherein requesting said access point for permission to switch between said MIMO mode and said non-MIMO mode occurs in response to said measured MIMO transmission conditions.
In a wireless communication system having nodes operating in a Multiple Input Multiple Output (MIMO) mode and nodes operating in a non-MIMO mode, apparatus for operating an access node, said apparatus comprising:
- a MIMO-capable physical layer transceiver;
- and
- a Medium Access Control (MAC) layer block that maintains a list of nodes operating in a MIMO mode and nodes operating in a non-MIMO mode, and within a designated contention free period, polls MIMO-mode nodes and non-MIMO-mode nodes for transmissions in corresponding non-overlapping subperiods of said contention free period;
- wherein said access node communicates with nodes operating in said MIMO mode during one of said non-overlapping subperiods and communicates with nodes operating in said non-MIMO mode during another of said non-overlapping subperiods.
In a wireless communication network, apparatus for operating a Multiple Input Multiple Output (MIMO)-capable subscriber node, said method comprising:
- a MIMO-capable physical layer transceiver;
- and
- a Medium Access Control (MAC) layer block that, during a contention period, requests an access point for permission to switch between a MIMO mode and a non-MIMO mode upon receiving permission, switches between said MIMO mode and said non-MIMO mode;
- wherein said MAC layer block receives a MIMO beacon;
- measures MIMO transmission conditions based on said MIMO beacon, and requests said access point for permission to switch between said MIMO mode and said non-MIMO mode occurs in response to said measured MIMO transmission conditions.
Dependencies are inferred from the claim text.