Abstract: A device and method for controlling data unit communications between a sender and a receiver, and flexibly responding to a potential data loss event. Data to be sent are divided into data units and transmitted from the sender to the receiver. If the receiver fails to receive a data unit, the sender retransmits the data unit using a flow control procedure using adaptive parameters. The sender inserts a mark in each transmitted data unit indicating whether each data unit is an original transmission or a retransmission. For each data unit correctly received, the receiver inserts the corresponding mark in an acknowledgment data unit and sends the acknowledgment to the sender. The sender determines whether the correctly received data unit was an original transmission or a retransmission based on the mark or by comparing the round-trip time for the acknowledged data unit with a predetermined round-trip time for an original transmission.

Abstract: A method and device for handling received data units at the receiving peer of a predetermined data unit exchange protocol at a given layer is described, where said method and device carry out a limited ARQ mechanism for received data units, and are characterised by providing the possibility of storing corrupted copies of received data units, and providing a data unit to an upward release handler on the basis of one or more stored corrupted copies of a given data unit after a triggering event terminating the operation of the retransmission request procedure for the given data unit.

Abstract: The present invention relates to a method and system of transmissions and retransmissions of packet data in a communications system, where the communications system uses switched channels, switching between rates or channels of different characteristics, and connection control and management in such a system. Particularly, the invention relates to radio resource management in a Universal Mobile Telecommunications System, UMTS, or WCDMA system allowing for use of compatible protocols for non-switched and switched channels.

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.

Abstract: A method and an apparatus for transmitting error-tolerant data is disclosed employing the ARQ technique, wherein the retransmission of erroneous data is performed up to the point where the remaining amount of errors is acceptable (for instance because the erorrs will not be perceived by the recipient of the information, which can be a person or a higher level protocol with additional error correction capabilities). The number of data blocks (RLC) detected as erroneous is employed to define a reliability measure (RM) and a request for retransmission of the erroneous data blocks is performed until a desired reliability threshold (RT) is reached. An additional threshold with a higher value than the first one can be employed to request for optional retransmission when the reliability measure (RM) is between the first and the second threshold. The retransmission will be performed only if further conditions such as channel availability are met.

Abstract: A data unit sender and method of controlling a data unit sender are presented, in which a time-out monitoring procedure implements a first, longer time-out period (SRTO), and a second, shorter time-out period (QRTO), where a retransmission is executed after the shorter time-out period if the available transmission capacity value for unsent data is greater or equal to the size of a designated data unit that is to be retransmitted as a result of said time-out monitoring procedure.

Abstract: A method of controlling a queue buffer (2), said queue buffer (2) being connected to a link (1) and being arranged to queue data units (30) that are to be sent over said link (1) in a queue (20), comprising: determining (S1) a value (QL; QL?av#191) of a length parameter related to the length of said queue (20), comparing (S2) said value (QL; QL?av#191) with a length threshold value (L?th#191; min?th#191; max?th#191) and performing (S3) a congestion notification procedure if said value (QL; QL?av#191) is equal to or greater than said length threshold value (L?th#191; min?th#191; max?th#191), and an automatic threshold adaptation procedure (S4, S7), where said automatic threshold adaptation procedure (S4, S7) is arranged to automatically adapt said length threshold value (L?th#191; min?th#191; max?th#191) on the basis of one or more characteristics of said link (1).

Abstract: The present invention relates to a data unit sending means and a method for controlling a data unit sending means, where data units of a first protocol (L2_ARQ) embed data units of a second protocol (L3) belonging to a higher layer, and said data units of said first protocol (L2_ARQ) are held in a send buffer means. According to the invention, the data units of the second protocol (L3) are discriminated, and the data units of the first protocol (L2_ARQ) that embed a particular data unit of the second protocol (L3) are associated with said particular data unit of the second protocol (L3), and the contents of the send buffer means is managed in accordance with said association.

Abstract: A device and method for controlling data unit communications between a sender and a receiver, and flexibly responding to a potential date loss event. Data units are transmitted from the sender to the receiver, and the receiver returns an acknowledgment data unit for each data unit received. If the receiver falls to receive a data unit, the sender retransmits the data unit in accordance with a data unit loss response procedure. If the potentially lost data unit is subsequently received, the sender determines whether the correctly received data unit was the initial data unit or the retransmission. If the correctly received data unit was the retransmission, the sender continues to transmit subsequent data units in accordance-with the date unit loss response procedure. However, if the correctly received data unit was the initial data unit the sender transmits subsequent data units in accordance with an excessive delay response procedure.

Abstract: A device and method for controlling data unit communications between a sender and a receiver, and flexibly responding to a potential data loss event. Data to be sent are divided into data units and transmitted from the sender to the receiver. The receiver acknowledges correct receipt of the data units by returning acknowledgment data units to the sender. If the receiver fails to receive a data unit, the sender retransmits the data unit using a flow control procedure using adaptive parameters and the acknowledgment data units. If the receiver then correctly receives and acknowledges the data unit, the sender determines whether the data unit was correctly received as a result of the original transmitting step or the retransmitting step. If the former (i.e., the original transmitting step), an excessive delay response procedure is selectively performed. If the latter (i.e., the retransmitting step), a data unit loss response procedure is selectively performed.

Abstract: The invention relates to a method for selecting a window size for a packet switched connection between a first and a second party. The associated window is used by a sending party for a window based congestion control mechanism for avoiding or handling congestion on a communication path. The invented method enables to adapt the size of an initial window, a loss window, and a restart window based on information available in the network to increase the utilisation of transmission capacity.

Abstract: The invention relates to a method and a device for improving the processing time of received data in packet oriented applications during a transmission via communication networks, in particular via an IP network and a mobile communication network such as the Global System for Mobile Communication (GSM), Universal Mobile Telecommunication System (UMTS) or General Packet Radio Service (GPRS). The received data packets of the second protocol layer, for instance, the RLP frames, are combined to form data packets of the first protocol layer, for instance to PPP frames, directly by the receiver in the second protocol layer. The completely and correctly combined data packets are then released to the first protocol layer. During the release of the data packets to the first protocol layer, a difference is made between two modes. The intra-flow mode is a mode, wherein all completely generated data packets are released, i.e. independent from whether the data packets belong to the same or to two different data flows.

Abstract: A method and device for handling received data units at the receiving peer of a predetermined data unit exchange protocol at a given layer is described, where said method and device carry out a limited ARQ mechanism for received data units, and are characterised by providing the possibility of storing corrupted copies of received data units, and providing a data unit to an upward release handler on the basis of one or more stored corrupted copies of a given data unit after a triggering event terminating the operation of the retransmission request procedure for the given data unit.

Abstract: This proxy for at least one end-to-end data flow in a network comprises an estimation unit, for estimating (40) the current minimum data load necessary to occupy the bandwidth available to the flow in the network. The estimation unit outputs a flow's pipe capacity estimation. This proxy also comprises a comparison unit, for comparing (42) the estimated pipe capacity with a predetermined capacity threshold, a decision unit for deciding (44, 46) to proxy the end-to-end flow if the estimated pipe capacity lies above the capacity threshold, and a routing unit, for routing the flow according to the decision.

Abstract: A method and device for determining a parameter (RTO) associated with a retransmission time-out feature in a data unit transmitter implementing a protocol (TCP) that provides an acknowledgment feature and a retransmission time-out feature, where according to one aspect decreasing values of the round trip time (RTT) are treated differently with respect to their influence on a mean deviation parameter (RTTVAR) than increasing values of the round trip time, where according to another aspect weight values (g, h, w) used in the determination of the parameter (RTO) are chosen such that at least one of them is time variable, and where according to a further aspect the parameter (RTO) is also calculated on the basis of a value (SR) indicative of the number of spurious time-outs in the communication.

Abstract: A device and method for controlling data unit communications between a sender and a receiver, and flexibly responding to a potential data loss event. Data to be sent are divided into data units and transmitted from the sender to the receiver. If the receiver fails to receive a data unit, the sender retransmits the data unit using a flow control procedure using adaptive parameters. The sender inserts a mark in each transmitted data unit indicating whether each data unit is an original transmission or a retransmission. For each data unit correctly received, the receiver inserts the corresponding mark in an acknowledgment data unit and sends the acknowledgment to the sender. The sender determines whether the correctly received data unit was an original transmission or a retransmission based on the mark or by comparing the round-trip time for the acknowledged data unit with a predetermined round-trip time for an original transmission.

Abstract: A method and device for determining a parameter (RTO) associated with a retransmission time-out feature in a data unit transmitter implementing a protocol (TCP) that provides an acknowledgment feature and a retransmission time-out feature, where according to one aspect decreasing values of the round trip time (RTT) are treated differently with respect to their influence on a mean deviation parameter (RTTVAR) than increasing values of the round trip time, where according to another aspect weight values (g, h, w) used in the determination of the parameter (RTO) are chosen such that at least one of them is time variable, and where according to a further aspect the parameter (RTO) is also calculated on the basis of a value (SR) indicative of the number of spurious time-outs in the communication.

Abstract: The present invention relates to a method and system of transmissions and retransmissions of packet data in a communications system, where the communications system uses switched channels, switching between rates or channels of different characteristics, and connection control and management in such a system. Particularly, the invention relates to radio resource management in a Universal Mobile Telecommunications System, UMTS, or WCDMA system allowing for use of compatible protocols for non-switched and switched channels.

Abstract: A method of processing a data unit of a first protocol layer for transmission in a data unit based communication system is described, comprising the steps of passing to a second protocol layer a given data unit of said first protocol layer that is to be transmitted, determining a numeric value of a numerically quantifiable parameter associated with said given data unit of said first protocol layer, embedding said given data unit of said first protocol layer into one or more data units of said second protocol layer, performing transmission control for said one or more data units of said second protocol layer in accordance with said numeric value of said numerically quantifiable parameter.

Abstract: The present invention relates to a data unit sending means and a method for controlling a data unit sending means, where data units of a first protocol (L2_ARQ) embed data units of a second protocol (L3) belonging to a higher layer, and said data units of said first protocol (L2_ARQ) are held in a send buffer means. According to the invention, the data units of the second protocol (L3) are discriminated, and the data units of the first protocol (L2_ARQ) that embed a particular data unit of the second protocol (L3) are associated with said particular data unit of the second protocol (L3), and the contents of the send buffer means is managed in accordance with said association.