Showing papers by "Johan Torsner published in 2007"

A method and a device for saving power in a wireless user terminal

Abstract: A method for use in a cellular system with a controlling node and user terminals, UEs. In the system, UEs can assume one of at least two states, a non-listening state, i.e. a state during which a UE does not listen for data from its controlling node, and a listening state, an “on duration” state. According to the method a UE in the system is able to alternate between said two states according to a certain scheme, the scheme according to which a UE in the system alternates between said two states being dependent on whether or not data units which are transmitted between the UE and its controlling node are received entirely and correctly within an initially allocated resource for each data unit.

Opportunistic Uplilnk Scheduling for 3G LTE Systems

Abstract: In this paper we propose a heuristic opportunistic scheduler that is consistent with the resource allocation constraints of the uplink channel for 3G long term evolution (LTE) systems. Retransmission processes as well as channel conditions are taken into account in the formation of the scheduling decision. The heuristic scheduler could be seen a reasonable choice for solving the constrained resource allocation maximization problem since it is computationally feasible and can find a practical solution. We also formulate an integer programming problem that provides a theoretical optimal solution. The heuristic scheduler was found to perform relatively well when compared to the optimal solution.

High Speed Packet Access Evolution - Concept and Technologies

Abstract: In this paper we present the main concepts of high speed packet access evolution currently being standardized in 3GPP. In general HSPA evolution consists of introduction of MIMO, higher order modulation, and protocol optimizations and optimizations for voice over IP. We describe these improvements in detail and show that HSPA Evolution can reach performance comparable to those of long term evolution of UMTS terrestrial radio access network in a 5 MHz deployment.

Hardq synchronization method for lte

Abstract: A method and apparatus according to the present invention addresses and/or prevents lost protocol synchronization in HARQ systems caused by ACK/NACK errors. One embodiment detects lost synchronization errors for NDI-based retransmission protocols and restores synchronization by sending an explicit RESET message. In response to the RESET message, the transmitter aborts the transmission of a current PDU and transmits a new PDU and corresponding NDI. Another embodiment prevents protocol synchronization errors by sending scheduling grants on a packet by packet basis. The receiver sends a subsequent explicit scheduling grant to the transmitter based on an error evaluation of a received PDU. The transmitter will not send the next PDU unless it receives the subsequent explicit scheduling grant.

A method and nodes for providing adaptive segmentation

Abstract: A method and nodes for providing adaptive segmentation in a higher protocol layer interacting with a lower protocol layer. An adaptable segmentation limit (200, 204), defining a threshold of a largest Protocol Data Unit (PDU) that is to be submitted to a lower protocol layer, is deployed at a higher protocol layer interacting with the lower protocol layer. For each Service Data Unit (SDU; 201, 203) arriving at the higher protocol layer, it is determined if the respective SDU can fit into the segmentation limit or not. Each SDU that do not fit into the segmentation limit is segmented into PDUs (205, 206) which are smaller than or equal to the segmentation limit, while no segmentation is performed on SDUs that fit into the segmentation limit.

Method and arrangement for transmitting cq1 on the uplink

Abstract: A method for transmitting data flows between a network element and a number of receivers over a first channel. The method comprises the steps of: performing a link adaptation for the transmission of a data flow by said network element, and transmitting the data flow, transmitting an indication of a channel quality required for reception of the data flow on a second channel, receiving by said receivers said indication of channel quality, measuring a link quality by said receivers by monitoring a pilot channel, comparing said measured link quality with said received indication of the channel quality, and transmitting to said network element result of said comparison of said measured link quality with said received indication of the channel quality, if said result is lower than a predetermined value. The invention also relates to a network element and a user equipment.

Technique for uplink data transmissions in communication networks

Abstract: The invention relates to a technique for uplink data transmissions in, e.g., mobile networks. A method embodiment for performing the technique in a transmitter (122) comprises the steps of allocating, for a first transmission (T1') as the transmission power for an uplink control channel (UCOCH), the smaller of an available transmission power and a desired transmission power for the uplink control channel; and allocating, for at least one subsequent transmission (T2') triggered by a feedback indication (128), zero transmission power to the uplink control channel (UCOCH).

Method for mapping logical channel on shared channel

Abstract: According to the invention data in a number of logical downlink intended for one or more mobile terminals are received in a first mapping unit, where at least a first High Speed Radio Network Temporary identity is allocated to these logical downlink channels addressing a group of mobile terminals for allowing transmission of channel data for reception by mobile terminals. A mobile terminal then reads, from a Broadcast Control Channel, necessary information including a High Speed Radio Network Temporary identity allocated to at least one logical downlink channel, where at least said first identity exists among possible identities. It then listens to a high speed shared control channel for the read identity. In case it detects the identity, the terminal follows a scheduling command, receives data on a high-speed downlink shared channel and processes said data.

Transfer of buffered data from a source base station to a target base station

Abstract: A radio base station (28) suitable for performing a handover operation for a LTE-variant of a radio access network comprises a transceiver (34) and a status report requester (60). The transceiver (34) is configured to facilitate wireless transmission between the radio base station (28) and a wireless terminal (30) over an air interface, including transmission of a radio link bearer for the connection over a downlink from the radio base station to the wireless terminal. The status report requester (60) is configured to determine, according to one or more pre-defined criteria, whether to request from the wireless terminal a status report for a radio bearer prior to the radio base station transferring user data for the connection to another radio base station in conjunction with a handover.

Method and arrangement for alignment of protocol data units in a wireless communication system

Abstract: The present invention relates to a method and arrangement for communicating a Protocol Data Unit (PDU) between a transmitter unit and a receiver unit in a wireless communication network Said PDU comprising protocol headers associated with at least a first and a second protocol layers involved in the communication and a payload to be communicated The method comprises the step of interacting between the at least first and second protocol layers, such that the sum of the bits of the protocol headers is n-bit aligned such as octet aligned independently of non-alignment of at least one of the protocol headers comprised in the PDU

Single bit segmentation indicator

Abstract: Data units according to the first transmission format are divided into data units according to the second transmission format. A single-bit segmentation indicator inserted into the header of a data unit according to the second transmission format indicates whether the data unit according to the first transmission format ends in a data unit according to the second transmission format.

Improved mac-d multiplexing in utran hsdpa wireless networks

Abstract: UTRAN MAC-d multiplexing of data from multiple logical channels to a single MAC-d flow is supported while reducing overhead and achieving octet alignment in MAC-d PDU length. In one embodiment, the C/T field of a multiplexed MAC-d PDU is eliminated, and the logical channels multiplexed into the MAC-d flow are mapped to a MAC-hs PQ in at least the NodeB (and preferably in the UE as well). In other embodiments, the C/T field is retained, and an octet-aligned length indicator is transmitted from the RNC to the UE. In one embodiment, the length indicator is octet-aligned by padding the MAC-d PDUs. In another embodiment, transmitters and receivers in the path from RNC to UE are configured with an offset to add to the length indicator to achieve octet alignment. The padding or offset is (8-n) bits, where n = the number of bits in C/T field.

A method for recovery from a failed handover procedure in a telecommunication system

Abstract: The present invention relates to a method, a user equipment and a network node in a cellular radio network. According to the method of the present invention, the network units detects a failed transmission of a handover command to the UE, which is still having a uplink channel available, and further receives a RRC message from the UE indicating the loss of a serving cell and indicating the strongest cell. The network unit prepares and initiates a new serving cell re-establishment and sends to the UE a RRC reconfiguration message. The UE can then continue normal operation in the new cell.

Reducing state transition time from power saving state

Abstract: The present invention relates to a method and an arrangement for reducing a state transition time from a power saving state for a user equipment (18) in a communication network. The state transition time is reduced by retaining in the user equipment (18) one or more information parameter, such as the radio network temporary identifier for a high speed downlink shared channel (H-RNTI), when performing a state transition to said power saving state so as to enable a time reduction when said user equipment switches back from said power saving state.

Method and arrangement for transmitting cqi on the uplink

Abstract: The present invention relates to a method for transmitting data flows between a network element (10) and a number of receivers (20) over a first channel. The method comprises the steps of: performing a link adaptation for the transmission of a data flow by said network element (10), and transmitting the data flow, transmitting an indication of a channel quality required for reception of the data flow on a second channel, receiving by said receivers (20) said indication of channel quality, measuring a link quality by said receivers by monitoring a pilot channel, comparing said measured link quality with said received indication of the channel quality, and transmitting to said network element result of said comparison of said measured link quality with said received indication of the channel quality, if said result is lower than a predetermined value. The invention also relates to a network element and a user equipment.

A method, a network node and a user equipment in a telecommunication system

Abstract: The present invention relates to a method, a user equipment and a network node in a cellular radio network. According to the method of the present invention, the network units detects a failed transmission of a handover command to the UE, which is still having a uplink channel available, and further receives a RRC message from the UE indicating the loss of a serving cell and indicating the strongest cell. The network unit prepares and initiates a new serving cell re-establishment and sends to the UE a RRC reconfiguration message. The UE can then continue normal operation in the new cell.

Mobile telecommunication network

Abstract: The present invention relates to a node and a method thereof for a mobile telecommunication network connectable to a controlling node and wirelessly connectable to mobile terminals. The node is adapted to have an uplink connection to a mobile terminal, wherein the mobile terminal is adapted to have a second uplink connection to at least a second node such that data transmitted from the mobile terminal may be received at the node and at the at least the second node. The node comprises means for estimating whether data transmitted from the mobile terminal received at the at least the second node is received stronger than the data received at said node and means for discarding data received from the mobile terminal if it is estimated that the data is received stronger at the at least the second node than the data received at said node.

Improved protocol synchronization for harq

Abstract: A method and apparatus according to the present invention addresses and/or prevents lost protocol synchronization in HARQ systems caused by ACK/NACK errors. One embodiment detects lost synchronization errors for NDI-based retransmission protocols and restores synchronization by sending an explicit RESET message. In response to the RESET message, the transmitter aborts the transmission of a current PDU and transmits a new PDU and corresponding NDI. Another embodiment prevents protocol synchronization errors by sending scheduling grants on a packet by packet basis. The receiver sends a subsequent explicit scheduling grant to the transmitter based on an error evaluation of a received PDU. The transmitter will not send the next PDU unless it receives the subsequent explicit scheduling grant.

Reducing state transition time

Abstract: The present invention relates to a method and an arrangement for reducing a state transition time from a power saving state for a user equipment (18) in a communication network. The state transition time is reduced by retaining in the user equipment (18) one or more information parameter, such as the radio network temporary identifier for a high speed downlink shared channel (H-RNTI), when performing a state transition to said power saving state so as to enable a time reduction when said user equipment switches back from said power saving state.

NDI-less protocol synchronization for HARQ

Abstract: A method and apparatus according to the present invention addresses and/or prevents lost protocol synchronization in HARQ systems caused by ACK/NACK errors. The embodiment detects lost synchronization errors for NDI-less retransmission protocols. Protocol synchronization errors are prevented by sending scheduling grants (SCH) on a packet by packet basis. The receiver sends a subsequent explicit scheduling grant to the transmitter based on an error evaluation of a received PDU. The transmitter will not send the next PDU unless it receives the subsequent explicit scheduling grant.

Telecommunication system and error control in such system

Abstract: Methods and apparatus for signaling scheduling information in a spatial multiplexing wireless communications system (700), as well as corresponding methods and apparatus for processing such signaling information, are disclosed. An exemplary method for signaling scheduling information comprises scheduling (310, 420) first and second transport blocks (110) for simultaneous transmission during a first transmission interval on first and second data substreams, respectively, and further comprises assigning (320, 430) a single re-transmission process identifier for the first transmission interval and transmitting(330, 440) first scheduling information for the first transmission interval. The first scheduling information comprises the re-transmission process identifier and first disambiguation data. The method further comprises scheduling (360, 470) at least one of the first and second transport blocks (110) for re-transmission during a second transmission interval and transmitting (370, 495) second scheduling information for the second transmission interval, the second scheduling information comprising the re-transmission process identifier and second disambiguation data. The first and second disambiguation data indicate whether the re-transmission of the retransmitted transport block (110) is scheduled for the first or second data substream and may be used by a receiver to determine the same.