Method for setting the retransmission timeout period in a packet switched communication network
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsReiner Ludwig, Hannes Ekström
Life of this patent
Estimating the term…
Abstract
The present invention relates to a method for updating the value of a time-out period in a data unit sender. The updating comprises deriving an intermediate value from the n most recently measured values of a response time, augmenting the intermediate value, reducing the current value of the time-out period, determining the maximum from among at least the augmented intermediate value and the reduced current value of the time-out period, and setting a new value of the time-out period to set a maximum value.
Claims45
A method for updating the value of a time-out period (RTO) in a data unit sender that is arranged to send data units to a given data unit receiver, said given data unit receiver implementing a feedback mechanism according to which said given data unit receiver sends feedback messages to said data unit sender, said feedback messages containing information on the receipt of data units sent by said data unit sender, said data unit sender implementing a retransmission mechanism according to which said data unit sender retransmits data units in dependence on said feedback messages, said retransmission mechanism comprising a time-out feature according to which said data unit sender retransmits a given data unit if said data unit sender does not receive within said time-out period a feedback message indicating the correct receipt of said given data unit, and said data unit sender furthermore implementing a response time determining mechanism for repeatedly determining a response time (RTT) indicative of the time that passes between the sending of a data unit to said given data unit receiver and the receiving of a feedback message relating to said data unit from said given data unit receiver, said method comprising:
- a value setting procedure for setting a new value of said time-out period, said procedure taking into account the n most recent values of said response time, n being a positive integer, the value setting procedure comprising:
- deriving (S1) an intermediate value (IV) from said n most recent values of said response time in accordance with a predetermined derivation procedure (Der),
- augmenting (S2) said intermediate value according to a predetermined augmenting procedure (Aug),
- reducing (S3) the current value of said time-out period according to predetermined time-out period reducing procedure (Red),
- determining the maximum from among at least said augmented intermediate value and said reduced current value of said time-out period, and
- setting a new value of said time-out period to said maximum value.
(canceled)
A data unit sender for sending data units to one or more data unit receivers that implement a feedback mechanism according to which said data unit receivers send feedback messages to said data unit sender, said feedback messages containing information on the receipt of data units sent by said data unit sender, said data unit sender comprising:
- a retransmission element for implementing a retransmission mechanism according to which said data unit sender retransmits data units in dependence on said feedback messages, said retransmission mechanism comprising a time-out feature according to which said data unit sender retransmits a given data unit if said data unit sender does not receive within said time-out period a feedback message indicating the correct receipt of said given data unit,
- a response time determination element for implementing a response time determining mechanism for repeatedly determining a response time (RTT) indicative of the time that passes between the sending of a data unit to a given data unit receiver and the receiving of a feedback message relating to said data unit from said given data unit receiver,
- a value setting element for setting a new value of said time-out period taking into account the n most recent values of said response time, n being a positive integer, the value setting element comprising:
- an element for deriving an intermediate value from said n most recent values of said response time,
- an element for augmenting said intermediate value according to a predetermined augmenting procedure,
- an element for reducing the current value of said time-out period according to predetermined time-out period reducing procedure,
- an element for determining the maximum from among at least said augmented intermediate value and said reduced current value of said time-out period, and
- an element for setting a new value of said time-out period to said maximum value.
Dependencies are inferred from the claim text.