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: A method of switching from a first to a second transport channel for User Equipment (UE) in a UMTS Terrestrial Radio Access Network (UTRAN) of a UMTS system. The method comprises initiating a channel switch, and initiating a synchronisation of the UE to the second channel. The first channel is maintained during the synchronisation phase such that data may be sent between the UE and UTRAN over the first channel during synchronisation. The first channel is terminated only after synchronisation of the UE to the second channel has been achieved.

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: 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: 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 inspecting a communication link between a UE and a Radio Access Network (RAN) of a mobile teleconmmunications network. A Protocol Data Unit (PDU) containing a loop request is sent from an RLC entity located at a serving RNC of the RAN to a peer RLC entity located at the UE. The loop PDU is received at said peer RLC entity and recognised as containing a loop request. In response to the loop request, the receiving RLC entity automatically sends a response PDU from the RLC entity at the UE to the RLC entity of the RAN.

Abstract: A method of switching from a first to a second transport channel for User Equipment (UE) in a UMTS Terrestrial Radio Access Network (UTRAN) of a UMTS system. The method comprises initiating a channel switch, and initiating a synchronisation of the UE to the second channel. The first channel is maintained during the synchronisation phase such that data may be sent between the UE and UTRAN over the first channel during synchronisation. The first channel is terminated only after synchronisation of the UE to the second channel has been achieved.

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.

Abstract: A technique for providing a secure link when transitioning between pairs of link layer protocol entities in a mobile communication system is disclosed. The first pair of link layer protocol entities includes a first transmitting link layer protocol entity and a first receiving link layer protocol entity. The second pair of link layer protocol entities includes a second transmitting link layer protocol entity and a second receiving link layer protocol entity. The technique is realized by first suspending data transmissions from the first transmitting link layer protocol entity to the first receiving link layer protocol entity, and then initiating data transmissions from the second transmitting link layer protocol entity to the second receiving link layer protocol entity.