Controlling mobile station response to a common rate control command
View Patent ↗A wireless communication system ( 20 ) includes an overload control technique that comprises selectively controlling whether a mobile station ( 30 - 40 ) will respond to a common rate control command. In a disclosed example, a statistical rate control is used such that each mobile station responds to the relative grant based upon a probability that the mobile station should respond. A disclosed example includes selecting two control parameters that influence the probability that a mobile station will respond. The probability in one example is dependent on the data rate currently being used by the mobile station when receiving the relative grant.
1. A method of communicating, comprising:
selectively controlling whether a mobile station will respond to a common rate control command that is transmitted to a plurality of mobile stations; and
controlling a probability that the mobile station will respond to the common rate control command wherein the probability comprises
P ( r )= K exp(− r /μ)− K exp(− R max /μ),
where
r is an uplink data rate of the mobile station;
R max corresponds to at least one uplink data rate associated with a response to the common rate control command;
μ corresponds to a rate of controlling mobile stations using the common rate control command; and
K= 1/(1−exp(− R max /μ)).
2. The method of claim 1 , wherein R max comprises a maximum allowable uplink data rate for the plurality of mobile stations.
3. The method of claim 1 , wherein as μ increases, the number of mobile stations within the plurality of mobile stations that will respond to the common rate control command increases.
4. The method of claim 1 , wherein μ comprises one of R max , R max /2, R max /3 or R max /4.
5. The method of claim 1 , comprising transmitting selected values of R max and μ, respectively, as at least part of the common rate control command.
6. The method of claim 1 , comprising
receiving values of R max and μ; and
responsively determining P(r).
7. The method of claim 6 , comprising determining whether to respond to the common rate control command based on the determined P(r).
8. The method of claim 7 , comprising
determining whether the determined P(r) is greater than a random number;
responding to the common rate control command if the determined P(r) is greater than the random number; and
not responding to the common rate control command if the determined P(r) is less than the random number.
9. A method of communicating, comprising:
selectively controlling whether a mobile station will respond to a common rate control command that is transmitted to a plurality of mobile stations, wherein the common rate control command comprises a non-serving relative grant; and
controlling a probability that the mobile station will respond to the common rate control command using the relationship
P ( r )= K exp (− r /μ)+1 −K
where
r is a data rate of the mobile station;
μ is selected to control a rate at which mobile stations will respond; and
K= 1/(1−exp(− R max /μ)) where
R max is indicative of at least one acceptance mobile station data rate.
10. A method of communicating, comprising:
selectively responding to a common rate control command received at a mobile station; and
determining a probability P for responding to the received common rate control command using the relationship:
P ( r )= K exp(− r /μ)− K exp(− R max /μ),
where
r is an uplink data rate of the mobile station;
R max corresponds to at least one uplink data rate associated with a response to the common rate control command;
μ corresponds to a rate of controlling mobile stations using the common rate control command; and
K= 1/(1−exp(− R max /μ)).
11. A method of communicating, comprising
selecting a value for at least one parameter used for determining a probability that a mobile station will respond to a common rate control command;
transmitting the selected value as part of the common rate control command; and
the selected parameter comprises at least one of μ or R max and a probability P that a mobile station will respond to the common rate control command is determined by
P ( r )= K exp(− r /μ)− K exp(− R max /μ),
where
r is an uplink data rate of the mobile station;
R max corresponds to at least one uplink data rate associated with a response to the common rate control command;
μ corresponds to a rate of controlling mobile stations using the common rate control command; and
K= 1/(1−exp(− R max /μ)).