Abstract: The invention relates to a method and arrangement for detecting congestion in a communications network (120). A receiving node (130) receives (710) data packets from a sending node (110) over a communications link (140). First and second parts (320, 330) of a frequency spectrum (310) of a time delay of the data packets are determined (720). The first part comprises non-congestion related low frequency components. The second part comprises congestion related and non-congestion related low frequency components when a load level of the communications network is above a threshold value (220) but substantially no congestion related low frequency components when the load level is below the threshold value. Then reference jitter level (yr) and congestion jitter level (yg) corresponding to the first and second parts respectively are estimated (740). Finally, congestion state information is determined (750) by comparing said congestion jitter level to said reference jitter level.

Abstract: The invention relates to a method and arrangement for detecting congestion in a communications network (120). A receiving node (130) receives (710) data packets from a sending node (110) over a communications link (140). First and second parts (320, 330) of a frequency spectrum (310) of a time delay of the data packets are determined (720). The first part comprises non-congestion related low frequency components. The second part comprises congestion related and non-congestion related low frequency components when a load level of the communications network is above a threshold value (220) but substantially no congestion related low frequency components when the load level is below the threshold value. Then reference jitter level (yr) and congestion jitter level (yg) corresponding to the first and second parts respectively are estimated (740). Finally, congestion state information is determined (750) by comparing said congestion jitter level to said reference jitter level.

Abstract: A method and telecommunications node for implementing Tandem-Free Operation (TFO) between a pair of TFO partners in a telecommunications network. At call setup, a TFO negotiation is performed between the partners. Thereafter, if TFO is interrupted in at least one direction, state information and synchronization of the sending and/or receiving partner is maintained in the interrupted direction. An interruption may occur, for example, if a tone or announcement is to be sent. At the end of the interruption, sending and receiving of TFO frames is resumed with the same phase that was present before the interruption.

Abstract: In a method for the transmission of data packets (D) from a transmitter (TR) to a receiver (RE) identification of transmitted data packets are stored. Defective data packets (D) are detected by the receiver (RE), status messages (S) which request defective data packets for retransmission are sent from the receiver (RE) to the transmitter (TR) and retransmissions of requested data packets are performed according to the status messages (S). The transmitter (TR) evaluates a first status message (S11) with an identification of at least one first requested data packet and retransmits the first data packet. The transmitter (TR) then initializes a timing unit according to the retransmission of the first data packet, wherein the timing unit or a threshold for the timing unit is attributable to the first data packet.

Abstract: A method and telecommunications node for implementing Tandem-Free Operation (TFO) between a pair of TFO partners in a telecommunications network. At call setup, a TFO negotiation is performed between the partners. Thereafter, if TFO is interrupted in at least one direction, state information and synchronization of the sending and/or receiving partner is maintained in the interrupted direction. An interruption may occur, for example, if a tone or announcement is to be sent. At the end of the interruption, sending and receiving of TFO frames is resumed with the same phase that was present before the interruption.

Abstract: By adaptively relocating a transmitting point between a base station and a base station controller, e.g., an RNC, optimal ARQ performance is achieved. The adaptation may be based on one or more of many factors such as the distance between a network element and a user equipment. As one example, for a mobile radio near a base station, the transmitting point where the ARQ protocol terminated in the radio network is located in that base station so that ARQ packet retransmissions are performed quickly. For a mobile radio in or about to be in soft handover, the transmitting point where the ARQ protocol terminated in the radio network is located in a base station controller coupled to the base stations involved in (or soon will be involved in) soft handover so that robust ARQ packet retransmissions are provided.

Abstract: A method of controlling the sending of data packets from a Base Station (BS) of a Radio Access Network (RAN) to a UE, where the BS is one of a set of BSs transmitting identical data to the UE and each said data packet has a sequence number. The method comprises implementing at the BS an Automatic Repetition reQuest (ARQ) mechanism for resending data packets erroneously received by the UE and, upon receipt of an ARQ status message from the UE, advancing a transmission window of the BS so that its lower region covers the packet having the highest sequence number for which an ARQ acknowledgement has nor yet been received. Where a single BS is transmitting in the downlink direction, and a soft handover set exists for an uplink reverse channel, downlink sending buffers of the BSs of the soft handover set may be synchronized by the exchange of ARQ messages between BSs.

Abstract: The present invention provides flow control for route switching in a communications system using retransmissions. It is well suited for a cellular mobile radio communications system, particularly a Universal Mobile Telecommunications System, UMTS.

Abstract: In a UMTS Terrestrial Radio Access Network (UTRAN), a method of switching from a current common channel to a dedicated channel for a UE. The method comprises estimating the round trip delay for data packets travelling between the UE and a peer node with which the UE is communicating. The product of the estimated round trip delay and the bandwidth of the common channel or the dedicated channel is determined and a threshold defined on the basis of that product. A switch from the common channel to a dedicated channel is initiated when the fill level of the RLC buffer(s) in the UTRAN for the UE reaches or exceeds said threshold.

Abstract: A method of handling the transmission of Radio Link Control (RLC) Protocol Data Units (PDUs) from a Radio Access Network (RAN) of a mobile telecommunications system to User Equipment (UE). At a Gateway of the RAN, RLC Service Data Units (SDUs) are segmented into RLC PDUs for transmission to one or more Base Stations (BSs) of a set of BSs belonging to a handover link set. RLC PDUs received from one or more of those BSs are combined into RLC SDUs for transmission to a core network of the system. Each of the BSs buffers the RLC PDUs received from the Gateway and/or the UE. An Automatic Repetition Request (ARQ) mechanism is implemented at each of the BSs to facilitate reliable transmission of RLC PDUs between the UE and the Gateway.

Abstract: A method of scheduling packets for transmission over the air interface of a UMTS Terrestrial Radio Access Network (UTRAN) in the case where a pair of Radio Network Controllers (RNCs) are acting as separate serving and controlling (drift) RNCs for a mobile terminal. The method comprises sending from the controlling RNC to the serving RNC, allocated scheduling priorities together with packet sizes accepted for transmission with those priorities by the controlling RNC. Subsequently the serving RNC send to the controlling RNC, packets of sizes accepted by the serving RNC together with respective allocated priorities.

Abstract: Methods, systems, and arrangements enable packet scheduling in accordance with quality of service (QoS) constraints for data flows. In a Universal Mobile Telecommunications System (UMTS) network environment, for example, a Medium Access Control (MAC) layer schedules packet transmission of various data flows to meet stipulated criteria, including permitted transport format combinations (TFCs) from a TFC set (TFCS). In first embodiment(s), the TFC is selected based on guaranteed rate transmission rates, weighted fair queuing (WFQ) transmission rates, QoS class, transport block set size (TBSS), and optionally queue fill levels. These first embodiment(s) also further refine the selection process using backlog memories corresponding to previously unmet guaranteed and/or fair transmission rates. In second embodiment(s), memory requirements are reduced by selecting a TFC based on guaranteed rate transmission rates, QoS class, TBSS, and queue fill levels, without accommodating backlogs.

Abstract: The present invention provides flow control for route switching in a communications system using retransmissions. It is well suited for a cellular mobile radio communications system, particularly a Universal Mobile Telecommunications System, UMTS.

Abstract: The present invention relates to retransmissions in a communications system, and more especially it relates to a cellular mobile radio system, particularly to a Universal Mobile Telecommunications System, UMTS. RLC configurations are adapted to radio conditions and UE locations.

Abstract: In a method for the transmission of data packets (D) from a transmitter (TR) to a receiver (RE) identification of transmitted data packets are stored. Defective data packets (D) are detected by the receiver (RE), status messages (S) which request defective data packets for retransmission are sent from the receiver (RE) to the transmitter (TR) and retransmissions of requested data packets are performed according to the status messages (S). The transmitter (TR) evaluates a first status message (S11) with an identification of at least one first requested data packet and retransmits the first data packet. The transmitter (TR) then initializes a timing unit according to the retransmission of the first data packet, wherein the timing unit or a threshold for the timing unit is attributable to the first data packet.

Abstract: In a UMTS Terrestrial Radio Access Network (UTRAN), a method of switching from a current common channel to a dedicated channel for a UE. The method comprises estimating the round trip delay for data packets travelling between the UE and a peer node with which the UE is communicating. The product of the estimated round trip delay and the bandwidth of the common channel or the dedicated channel is determined and a threshold defined on the basis of that product. A switch from the common channel to a dedicated channel is initiated when the fill level of the RLC buffer(s) in the UTRAN for the UE reaches or exceeds said threshold.

Abstract: A method of controlling the sending of data packets from a Base Station (BS) of a Radio Access Network (RAN) to a UE, where the BS is one of a set of BSs transmitting identical data to the UE and each said data packet has a sequence number. The method comprises implementing at the BS an Automatic Repetition reQuest (ARQ) mechanism for resending data packets erroneously received by the UE and, upon receipt of an ARQ status message from the UE, advancing a transmission window of the BS so that its lower region covers the packet having the highest sequence number for which an ARQ acknowledgement has nor yet been received. Where a single BS is transmitting in the downlink direction, and a soft handover set exists for an uplink reverse channel, downlink sending buffers of the BSs of the soft handover set may be synchronized by the exchange of ARQ messages between BSs.

Abstract: A method of controlling the flow of data, in respect of a given mobile terminal, between a Radio Network Controller (RNC) and a NodeB of a UMTS Terrestrial Radio Access Network (UTRAN) where an Automatic-Repeat-Request (ARQ) mechanism is implemented between the NodeB and said mobile terminal to provide for the retransmission of unsuccessfully transmitted data. The method comprises generating control messages at the NodeB and sending these control messages to the RNC, each control message enabling the RNC to identify which data should next be sent to the NodeB.

Abstract: A method of handling the transmission of RLC PDUs from a Radio Access Network (RAN) of a mobile telecommunications system to User Equipment (UE). At a Gateway (GW) of the UTRAN, RLC SDUs are segmented into RLC PDUs for transmission to one or more Base Stations (BSs) of a set of BSs belonging to a handover link set, and RLC PDUs received from one or more of those BSs into RLC SDUs are combined for transmission to a core network of the system. At the or each said BS, RLC PDUs received from the GW and or the UE are buffered. An ARQ mechanism is implemented at the or each BS to facilitate reliable transmission of RLC PDUs between the UE and the GW.