1072 results about "Radio Link Control" patented technology

A method and apparatus are provided for reducing excessive retransmission delays which may occur due to the loss of the last packet of a transmission buffer in a Radio Link Control (RLC) layer of a mobile communication system. The method includes receiving a Service Data Unit (SDU) from a higher layer, dividing the SDU into a plurality of Packet Data Units (PDUs), and storing the PDUs in a buffer, setting a poll bit for a last PDU from among the PDUs stored in the buffer, the poll bit requesting a status report, and repeatedly transmitting the last PDU having the setup poll bit at least twice from a sender to a receiver, regardless of whether there is a request for retransmission of the last PDU.

The present invention relates to a wireless communication system, and more particularly, discloses a method and an apparatus for transmitting and receiving duplicate data in a multicarrier wireless communication system. According to one embodiment of the present invention, a method in which a transmitter, which supports carrier aggregation for performing communication using N (N≧2) component carriers, transmits duplicate data, comprises the steps of: generating, in a media access control (MAC) layer of the transmitter, N duplicate data using radio link control (RLC) protocol data units (PDUs) from an RLC layer, and simultaneously transmitting, to a receiver, the respective N duplicate data on the N component carriers through respective N hybrid automatic repeat and request (HARQ) entities.

A data communication having at least one data flow is established over a wireless interface between a radio network and a user equipment node (UE). A medium access control (MAC) layer located in a radio network node receives data units from a higher radio link control (RLC) layer located in another radio network node. Some or all of a header of a RLC data units associated with the one data flow is analyzed at the MAC layer. Based on that analysis, the MAC layer determines a priority of the data unit relative to other data units associated with the one data flow. The MAC layer schedules transmission of higher priority data units associated with the one data flow before lower priority data units associated with the one data flow. The priority determination does not require extra priority flags or signaling.

A method and apparatus are provided for defining terminal behavior in a case where the terminal detects that it cannot receive the HS-DSCH from a serving cell reliably when the DCCH is mapped to HS-DSCH (e.g. does not receive any radio link control (RLC) acknowledged mode feedback for the uplink measurement reports or in general the common pilot channel (CPICH) level drops too low in the serving HS-DSCH cell). The terminal is autonomously moved to a cell forward access channel (CELL_FACH) state and uplink signaling is initiated on a random access channel (RACH) to inform a network node and ask for HS-DSCH re-establishment in a suitable cell (preferably in the one being strongest one in the active set or according to the measurements done prior the connection from the serving HS-DSCH cell was lost), or setting up a regular R′99/R′5 DPCH in order to restore the RRC signaling connection in the CELL_DCH state.

A method for inserting a PDU LI in an RLC is disclosed. According to the preferred embodiment, if a current PDU size corresponds to the total size of components of the PDU and the current PDU has information indicating that the current PDU size corresponds to the total size of components of the PDU, a component of the next PDU does not include information indicating that the current PDU size corresponds to the total size of components of the PDU. Therefore, the next PDU is free from unnecessary insertion of the LI value so that waste of network resources can be prevented and overhead required for processing unnecessary LI values also can be reduced.

An unacknowledged mode (UM) radio link control (RLC) entity receives RLC protocol data units (PDUs) delivered through one or more logical channels and re-orders the received PDUs by referring to their sequence numbers and by using a receive window and a timer to minimize delivery delay time, to reduce missing PDUs received from each logical channel, and to process the PDUs by avoiding duplicate PDUs.

User equipment (UE) can detect a Radio Link Control (RLC) unrecoverable error and a Radio Link (RL) failure. The two errors are handled differently while the UE is in a dedicated channel (DCH) state. The RL failure leads to execution of Radio Access Bearer (RAB) release steps, characterized by utilizing respective timer values to determine if associated RABs should be released. The RLC unrecoverable error is not permitted to execute the RAB release steps. This prevents unnecessary dropping of services. The UTRAN can optionally include and set the indicators to command the UE to perform the indicated RLC re-establishmentprocedure.

A method, system and transmitting side protocol entity is disclosed for sending packet data units for unacknowledged mode services in a mobile communication network. A retransmission parameter is set to a desired value in order to prevent retransmission of packet data units in a handover situation. The transmitting side acknowledged mode radio link control entity purges from the retransmission buffer based on status reports from a user equipment The packet data units that have been acknowledged by user equipment. A status report includes the sequence number of the highest packet data unit expected by the user equipment, and therefore the status report indicates the sequence number of the radio link control packet data units that have been received at the user equipment (either correctly or incorrectly). All the remaining packet data units in the retransmission buffer are scheduled for transmission and transmitted to the new node.

A method, along with corresponding devices (11 12) and a system (11 12), by which in-sequence delivery of data blocks, sent wirelessly by a sending terminal (11), is provided to a radio link control layer (12a) of a receiving terminal (12) by a media access control layer service (12b) of the receiving terminal (12), where the data blocks are communicated according to a protocol, such as WCDMA, in which a media access control layer (11b) of the sending terminal (11) includes as a service the transmission of the data blocks and possible retransmission of the same data blocks in response to ACK/NAK signaling by a corresponding service included in a media access control layer of the receiving terminal. No data block sequence number is used in the ACK/NAK signaling.

Reset of one or more state variables of a User Equipment (UE) RLC layer is carried out by signaling reset from a radio link control layer of a source radio network controller (RNC) to a radio link control layer of the UE during a seamless control relocation procedure in which a possible loss of synchronization and consequent disruption in communication between the UE and a target RNC is avoided.

A radio link control (RLC) layer provides RLC entity information to a medium access control (MAC) layer. The RLC entity information indicates that the RLC layer has service data unit (SDU) data to be transmitted. After providing the RLC entity information, the RLC layer receives an unexpected data interruption that requires the RLC layer to discard or interrupt transmitting the SDU data. After the unexpected data interruption, the MAC layer requests at least a protocol data unit (PDU) from the RLC layer in response to the RLC entity information. The RLC layer then submits to the MAC layer at least one padding PDU in response to the MAC request. The padding PDU is submitted in place of the discarded SDU data. Alternatively, the affected SDU data is not discarded until the next transmission time interval (TTI).

A mobile station includes a radio link control unit for outputting or inputting data that are transmitted or received via a radio channel to or from a higher-level protocol layer, a media access control unit for outputting or inputting the data via a logical channel to or from the radio link control unit, a physical layer control unit for outputting or inputting the data via a transport channel to or from the media access control unit, and for controlling radio communications, and a radio resource control unit for outputting or inputting control data to or from the radio link control unit, media access control unit, and physical layer control unit. The mobile station multiplexes report information therefrom into a channel for packet data transmission so as to transmit it to a base station. The base station carries out assignment of radio resources using the report information.

One or more median filter circuits are used to filter radio link control measurements corresponding to one or more radio link parameters of interest, such as received signal quality or round trip delay measurements, such as might be used by a base station to trigger mobile station handoff. As such measurements are particularly susceptible to measurement outliers arising from rapid but short-lived changes in radio link propagation paths, for example, the application of median filtering to such measurements is particularly advantageous. That is, by operation of median filtering, which is a non-linear filtering process, outliers in a stream of control measurements, such as are caused by instantaneous changes in channel fading or other propagation phenomena, are discarded rather than averaged in with the other measurements. Non-linear filtering as implemented by exemplary median filtering does not impair or otherwise limit the bandwidth of the underlying control measurements.

The invention relates to a method for settling an error in a radio link control entity which processes data transmitted by a cellular network to a user equipment, comprising the following steps: the user equipment receives a message from a control entity of the cellular network, said message including data identifying the radio link control entity which is in error, the user equipment re-initializes the radio link control entity according to the data included in the message. Particular application for settling unrecoverable errors affecting a radio link controller of a user equipment in a UMTS network.

The invention provides a method of handing over user equipment from a source cell to a target cell in a cellular communications network. The cellular communications system comprises a plurality of control units. The method comprises the steps of receiving a message indicating if the operation of the radio link control protocol is to be continued or reset when changing cell, resetting the operation of the radio link control protocol if the message indicates that the current radio link control protocol is to be reset, or continuing the operation of said radio link control protocol if the message indicates that the radio link control protocol is to be continued.

A system and method is provided for inserting, in a radio link control entity, at least one service data unit to a protocol data unit of an appropriate size. The method also includes providing at least one indicator including a length indicator for indicating that a first data octet of the protocol data unit is a first octet of a first service data unit and at least one other octet of the protocol data unit is the last octet of another service data unit, the first service data unit being either the same or different from the other service data unit.

Methods and apparatus are provided for modulating ACK/NACK persistence to improve data traffic performance. In one implementation, a method for control of automatic repeat requests between a transmitting terminal (102) and a receiving terminal (104) comprises: defining (1404) a buffer window of a buffer, the window to buffer multiple higher layer data blocks each segmented into multiple physical layer data blocks, the window beginning at a current higher layer block in which at least one physical layer block has not been received; obtaining (1406) an indication of whether physical layer blocks are completely received; determining (1408), based on the obtaining step, that a subsequent higher layer block within the window has been completely received; and discarding (1410) the current higher layer block when a time delay of the current higher layer block exceeds an estimate of a delay tolerance corresponding to a higher layer application.