# US 2019/0173658 A1 · Latency reduction in tdd systems with carrier aggragation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0173658 A1 - Document ID: US20190173658A1 - Status: Published application - Kind: A1 - Application number: 16/272,773 - Filed: 2019-02-11 - Published: 2019-06-06 - Earliest claimed: 2016-08-11 - Assignees: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V. - Applicants: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V. - Inventors: Thomas FEHRENBACH; Dennis WIERUCH; Bernd HOLFELD; Thomas WIRTH; Cornelius HELLGE; Lars THIELE; Thomas HAUSTEIN - Web page: https://patentgrep.com/patent/US20190173658A1 ## CPC - H04L 5/1469: {using time-sharing} - H04L 5/001: {the frequencies being arranged in component carriers} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 5/0094: {Indication of how sub-channels of the path are allocated} - H04L 5/0098: {Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands} - H04W 56/001: {Synchronization between nodes} - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract The present invention is concerned with different novel concepts for reducing latency in data transmission. These concepts may be exploited by a transceiver configured to perform wireless data communication with a third party device by aggregating time division duplex carriers having different temporal distribution of uplink times and downlink times. These concepts may further be exploited by an apparatus configured to perform data transmission or reception via allocations of transmission resources of aggregated carriers in units of transmission time intervals into which the aggregated carriers are subdivided, wherein the aggregated carriers are temporally subdivided into the transmission time intervals in a temporal grid, respectively, wherein the aggregated carriers' grids are temporally mutually offset. ## Claims ### Claim 1 Transceiver configured to perform wireless data communication with a third party device by aggregating time division duplex (TDD) carriers comprising different temporal distribution of uplink times and downlink times. ### Claim 2 (depends on 1) Transceiver of claim 1, wherein the TDD carriers are temporally structured into consecutive frames of a frame length which is equal between the TDD carriers, and wherein the frames of a first and a second of the TDD carriers are temporally shifted to each other. ### Claim 3 (depends on 2) Transceiver of claim 2, wherein temporally overlapping frames of the TDD carriers provide a temporal alternation between uplink and downlink phases which is equal between the TDD carriers. ### Claim 4 (depends on 2) Transceiver of claim 2, wherein the frames of the first and the second of the TDD carriers are temporally shifted to each other by an amount smaller than a frame length. ### Claim 5 (depends on 2) Transceiver of claim 2, further configured to switch between different frame configurations at transitions between immediately consecutive frames of the TDD carriers so that the temporally overlapping frames of the TDD carriers are of the equal frame configuration, the different frame configurations differing in temporal alternation between uplink and downlink phases. ### Claim 6 (depends on 5) Transceiver of claim 5, wherein the different frame configurations between which the transceiver switches form a group of frame configurations, wherein at least a majority of frame configurations of said group provides, in one or more contiguous and—relative to the frame borders—temporally collocated frame segments an equal scheduling of uplink and/or downlink, wherein the frames of the first and second TDD carriers are temporally mutually shifted by a time amount corresponding to a temporal length of the one or more contiguous and—relative to the frame borders—temporally collocated frame segments. ### Claim 7 (depends on 1) Transceiver of claim 1, wherein the different frame configurations between which the transceiver switches form a group of frame configurations equally subdivided into a sequence of subframes, each subframe being associated with at least one of an uplink mode, a downlink mode and a special mode, the special mode corresponding to a predetermined below-subframe temporal distribution of uplink and downlink, wherein at least a majority of the group of frame configurations differs in association of the subframes to the uplink mode, the downlink mode and the special mode with one or more contiguous and—relative to the frame borders—temporally collocated frame segments within which the subframes' association to the uplink mode, the downlink mode and the special mode being such that there is no—with respect to the frame borders—temporally collocated pair of subframes in the one or more contiguous and—relative to the frame borders—temporally collocated frame segments, of which one is associated with uplink mode while the other of the pair is associated with the downlink mode, wherein the frames of the first and second TDD carriers are mutually shifted by n times a subframe length with n corresponding to the number of subframes the one or more contiguous and—relative to the frame borders—temporally collocated frame segments is long, or the minimum number of subframes which when mutually temporally shifting two instantiations of the one or more contiguous and—relative to the frame boarders—temporally collocated frame segments of any of the group of frame configurations, results in an absence of any pair of subframes within a first instantiation and—after temporal shift—temporally collocated subframes within the second instantiation among which both are of the uplink mode, or both of the downlink mode. ### Claim 8 (depends on 1) Transceiver of claim 1, being a base station, wherein the third party device is a mobile terminal and the transceiver is configured to configure the TDD carriers and send configuration signals for correspondingly configuring the TDD carriers at the third party device, to the third party device via at least one of the TDD carriers. ### Claim 9 (depends on 8) Transceiver of claim 8, wherein the base station is configured to blank subcarriers at an edge of a frequency band of one or more carriers being spectrally adjacent to at least one of the TDD carriers being aggregated, wherein the one or more carriers comprise at least another one of the aggregated TDD carriers or another carrier via which the base station communicates with a further third party device. ### Claim 10 (depends on 2) Transceiver of claim 2, wherein the transceiver supports different frame configurations out of which the frames of the first TDD carrier and the frames of the second TDD carrier are selected so that frames of the first TDD carrier are of a first frame configuration and the frames of the second TDD carrier are of a second frame configuration, wherein the transceiver is configured to adapt the amount by which the frames of the first and the second TDD carriers are temporally shifted to each other depending on the selection of the first and second frame configurations out of the different frame configurations. ### Claim 11 (depends on 1) Transceiver of claim 1, being a system comprising at least two base stations and a backhaul network, wherein the third party device is a mobile terminal and the transceiver is configured to communicate with the third party device via a first TDD carrier at a first base station and via a second TDD carrier at a second base station, and wherein the transceiver is further configured to configure the first and second TDD carriers and send configuration signals for correspondingly configuring the first and second TDD carriers at the third party device, to the third party device via at least one of the TDD carriers. ### Claim 12 (depends on 11) Transceiver of claim 11, wherein at least one of the at least two base stations is configured to communicate with the third party device or another third party device over a further TDD carrier within a frequency band spectrally adjacent to a frequency band of one of the first and second TDD carriers with the further TDD carrier and the at least one of the first and second TDD carriers differing in temporal distribution of uplink times and downlink times, wherein the transceiver is configured to blank subcarriers at a frequency subband at an end of the respective frequency band of at least one of the further TDD carrier and the at least one of the first and second TDD carriers. ### Claim 13 (depends on 1) Transceiver of claim 1, being a system comprising at least two base stations and a backhaul network, wherein the third party device is a mobile terminal and the transceiver is configured to provide a first TDD carrier at a first base station and a second TDD carrier at a second base station, to configure the first and second TDD carriers and to send first configuration signals for correspondingly configuring the first and second TDD carriers at the third party device, to the third party device via the first TDD carrier, and sending second configuration signals for correspondingly configuring the second TDD carrier at the third party device, to the third party device via the second TDD carrier, wherein the transceiver is configured to send the first configuration signals to the third party device less frequently than the second configuration signals. ### Claim 14 (depends on 11) Transceiver of claim 11, wherein the first and second TDD carriers share the same frequency band or are on different frequency bands. ### Claim 15 (depends on 14) Transceiver of claim 14, wherein the first and second TDD carriers are on frequency bands separated from each other by more than 5 GHz. ### Claim 16 (depends on 11) Transceiver of claim 11, wherein at least one of the first and second base stations communicates via the respective one of the first and second TDD carriers with the third party device with spatially confined downlink transmissions over the TDD carrier onto a spatial beam, wherein the transceiver is configured to communicate with another third party device over a further TDD channel spatially confined to a further spatial beam, the further TDD carrier differing in temporal distribution of uplink times and downlink times from the respective TDD carrier. ### Claim 17 (depends on 16) Transceiver of claim 16, wherein the respective TDD carrier and the further TDD carrier share the same frequency band. ### Claim 18 (depends on 1) Transceiver of claim 1 being a mobile terminal, wherein the third party device is a base station and the transceiver is configured to receive configuration signals from the third party device via at least one of the TDD carriers and configure the TDD carriers depending on the configuration signals. ### Claim 19 (depends on 1) Transceiver of claim 1, being a mobile terminal, wherein the third party device is a system comprising at least two base stations and a backhaul network, wherein the transceiver is configured to communicate with the system via a first TDD carrier at the first base station and via a second TDD carrier at a second base station, wherein the transceiver is configured to receive configuration signals from the system via at least one of the TDD carriers and configure the first and second TDD carriers depending on the configuration signals. ### Claim 20 (depends on 1) Transceiver of claim 1, being a mobile terminal, wherein the third party device is a system comprising at least two base stations and a backhaul network, wherein the transceiver is configured to communicate with the system via a first TDD carrier at the first base station and via a second TDD carrier at a second base station, wherein the transceiver is configured to receive first configuration signals from the system via at least one of the TDD carriers and second configuration signals from the system via at least one of the TDD carriers and configure the first and second TDD carriers depending on the first and second configuration signals and configure the first TDD carrier depending on the first configuration signal, wherein the transceiver is configured to derive the first configuration signals from the first TDD carrier less frequently than the second configuration signals from the second TDD carrier. ### Claim 21 (depends on 19) Transceiver of claim 19, wherein the first and second TDD carriers share the same frequency band. ### Claim 22 (depends on 8) Transceiver of claim 8, wherein the configuration signals comprise one or more of user allocation signals allocating spectrotemporal segments of the TDD carriers to different users, and frame setting signals indicating a temporal distribution of uplink times and downlink times within one or more upcoming frames of the TDD carriers. ### Claim 23 (depends on 1) Transceiver of claim 1, wherein the TDD carriers are temporally structured into consecutive frames of a frame length which is equal between the TDD carriers, wherein temporally overlapping frames of the TDD carriers are temporally registered to each other to temporally coincide, wherein the transceiver is configured to switch between different frame configurations at transitions between immediately consecutive frames of the TDD carriers, wherein the different frame configurations between which the transceiver switches, form a group of frame configurations equally subdivided into a sequence of subframes, each subframe being associated with one of an uplink mode, a downlink mode and one or more special modes, the one or more special modes corresponding to a predetermined below-subframe temporal distribution of uplink and downlink, wherein the group of frame configurations comprises a first subset of frame configurations differing in distribution of, and frequency of, subframes associated with the uplink and downlink modes, and a second subset of frame configurations, the second subset comprising at least one inverted frame configuration for each frame configuration of the first subset. ### Claim 24 (depends on 1) Transceiver of claim 1, wherein the aggregated TDD carriers are selected so that a percentage of times an uplink is available to the transceiver on the aggregated TDD carriers and/or a percentage of times a downlink is available to the transceiver on the aggregated TDD carriers, is increased relative to each of the TDD carriers individually. ### Claim 25 Apparatus configured to perform data transmission or reception via allocations of transmission resources of aggregated carriers in units of transmission time intervals (TTI) into which the aggregated carriers are subdivided, wherein the aggregated carriers are temporally subdivided into the transmission time intervals in a temporal grid, respectively, wherein the aggregated carriers' grids are temporally mutually offset. ### Claim 26 (depends on 25) Apparatus of claim 25, wherein the aggregated carriers' grids are temporally mutually offset at an amount being a non-integer multiple of the transmission time intervals. ### Claim 27 (depends on 26) Apparatus of claim 26, wherein the non-integer multiple is smaller than one. ### Claim 28 Apparatus configured to perform data transmission or reception via allocations of transmission resources of aggregated carriers, wherein at least one of physical layer channels of the aggregated carriers, radio frame bases of physical broadcast channels of the aggregated carriers, and physical random access channels of the aggregated carriers are temporally mutually offset. ### Claim 29 (depends on 25) Apparatus of claim 25, comprising at least one base station and being configured to select for the inbound data ready to be transmitted at a predetermined time instant, one of the aggregated carriers such that the one of the aggregated carriers comprises a predetermined transmission time interval which starts earliest on or after the predetermined time instant, and transmit the inbound data in the predetermined transmission time interval. ### Claim 30 (depends on 25) Apparatus of claim 25, being a mobile terminal and being configured to select for the inbound data ready to be transmitted at a predetermined time instant, one of the aggregated carriers such that the one of the aggregated carriers comprises a predetermined transmission time interval which starts earliest on or after the predetermined time instant, and request at the base station system a transmission of the inbound data in the predetermined transmission time interval. ### Claim 31 Base transceiver configured to communicate with user entity transceivers via one or more carriers, the base transceiver configured to allocate transmission resources of the one or more carriers to the user entity transceivers for communication with the user entity transceivers in units of transmission time intervals into which the one or more carriers are temporally subdivided, and temporally adjust the begin and/or end of transmission time intervals of at least one of the one or more carriers depending on one more signals received from one of the user entity transceivers. ### Claim 32 (depends on 31) Base transceiver system of claim 31, configured to perform the temporal adjustment by determining a time past between a first interrogation signal sent by the base transceiver system and a first response signal sent by the one of the user entity transceiver responsive to the first interrogation signal, and on the basis of a prolongation of a time past between a second interrogation signal sent by the base transceiver system and a second response signal sent by the one of the user entity transceivers responsive to the second interrogation signal, relative to the first time delay, or a time past between a second response signal sent by the one of the user entity transceivers subsequent to the first response signal, upon the base transceiver system having informed the one of the user entity transceivers on the first time delay on the one hand and a reference arrival time of the second response signal determined by the base transceiver system on the basis of the temporal grid. ### Claim 33 (depends on 31) Base transceiver system of claim 31, configured to perform the adjustment depending on a time at which the one of the user entity transceivers is free to send a random access signal during a window of a physical resource channel in a state of synchronization between base transceiver system and user entity transceiver. ### Claim 34 (depends on 31) Base transceiver system of claim 31, configured to perform the adjustment depending on higher layer signaling. ### Claim 35 (depends on 31) Base transceiver of claim 31, configured to set a clock depending on the one or more further signals received from the one user entity transceiver so that the end or beginning of subsequent transmission time intervals are aligned to the clock with leaving idle times between aligned transmission time intervals and temporally neighboring transmission time intervals. ### Claim 36 (depends on 31) Base transceiver system of claim 31, configured to communicate with the user entity transceivers via an aggregation of an anchor carrier at a first base transceiver and component carriers at a second base transceiver, and send configuration signals for configuring the anchor and component carriers at the user entity transceiver, to the user entity transceiver via the anchor carrier, wherein the at least one carrier the end and/or beginning of TTIs of which is temporally adjusted is the component carrier. ### Claim 37 User entity transceiver configured to communicate with a base transceiver system via allocated transmission resources in units of transmission time intervals into which one or more carriers are temporally subdivided, the user entity transceiver being configured to temporally adjust the begin and/or end of transmission time intervals of at least one of the one or more carriers to be aligned to a local clock by depending on the local clock, send one or more signals to the base station system on the basis of which the base station system is to perform the temporal adjustment on a base transceiver system's side, and temporally adjust the begin and/or end of transmission time intervals of the at least one of the one or more carriers to correspond to the local clock on an user entity transceiver's side. ### Claim 38 (depends on 37) User entity transceiver of claim 37, configured to respond to a first interrogation signal sent by the base transceiver system by sending a first response signal to the base transceiver system, perform the temporal adjustment by responding to a second interrogation signal sent by the base transceiver system by sending a second response signal to the base transceiver system in a manner delayed relative to the responding to the first interrogation signal by a time delay (ΔT=Δt2−Δt1) depending on the wanted clock setting, or receiving an information on a communication delay from the base transceiver system subsequent to the responding to the first interrogation signal, determining a reference sending time on the basis of the temporal grid and the communication delay and sending a second response signal to the base transceiver system delayed relative to the reference sending time depending on the local clock, adjusting of the end/beginning of the transmission time intervals depending on the local clock setting on the User entity transceiver's side. ### Claim 39 (depends on 37) User entity transceiver of claim 37, configured to depending on the local clock, set a time at which the user entity transceiver sends a random access signal during a window of a physical resource channel in a state of synchronization between base transceiver system and the user entity transceiver. ### Claim 40 (depends on 1) Transceiver according to claim 1, being a base station system comprising one or more base stations with a plurality of antenna ports and configured to distribute uplink times and downlink times of the aggregated TDD carriers onto the plurality of antennas such that exclusively uplink times are attributed to a first subset of the plurality of antennas and exclusively downlink times are attributed to a second subset of the plurality of antennas, the first and second subset being disjoint. ### Claim 41 (depends on 1) Transceiver according to claim 1, being a mobile terminal and the third party device is a base station system comprising one or more base stations with a plurality of antenna ports, the transceiver configured to distribute uplink times and downlink times of the aggregated TDD carriers onto the plurality of antennas such that exclusively uplink times are attributed to a first subset of the plurality of antennas and exclusively downlink times are attributed to a second subset of the plurality of antennas, the first and second subset being disjoint. ### Claim 42 Base station system comprising a first base station and a second base station, the base station system being configured to perform wireless communication with a mobile terminal by aggregating a first carrier at the first base station and a second carrier at the second base station, configure the first and second carriers, and send first configuration signals for correspondingly configuring the first and second carriers at the mobile terminal, to the mobile terminal via the first carrier, and sending second configuration signals for correspondingly configuring the first and second carriers at the mobile terminal, to the mobile terminal via the second carrier, wherein the base station system is configured to send the first configuration signals to the mobile terminal less frequently than the second configuration signals. ### Claim 43 (depends on 42) Base station system of claim 42, wherein the configuration signals comprise user allocation signals allocating transmission resources of the carriers. ### Claim 44 (depends on 42) Base station system of claim 42, configured to reserve a predetermined fraction of transmission resources of the second carrier so as to be allocated by way of the configuration signals sent over the second carrier, and left not-allocated by way of the configuration signals sent over the first carrier. ### Claim 45 Mobile terminal configured to perform wireless communication with a base station system comprising a first base station and a second base station by aggregating a first component carrier at the first base station and a second component carrier at the second base station, receive first configuration signals from the base station system via at least one of the component carriers and second configuration signals from the base station system via at least one of the component carriers, and configure the first and second component carriers depending on the first and second configuration signals, wherein the mobile terminal is configured to derive the configuration signals from the first component carrier less frequently than the configuration signals from the second component carrier. ### Claim 46 (depends on 45) Mobile terminal of claim 45, wherein the configuration signals comprise user allocation signals allocating spectrotemporal segments of the component carriers.