FIELD OF THE DISCLOSURE

The present invention relates to the control of transmission and reception points in a mobile communication network.

BACKGROUND

Different names are used for base stations in mobile communication networks operating according to different standards, for example Node B in UMTS, evolved NodeB (eNB) in LTE, Access Point (AP) in WiFi. Also, different names are used in case the base stations have a different set of functionalities compared to normal base stations, e.g. “remote radio heads”, “repeater”, “home (e)NB” or “small cells”. In context of the present invention these different types of base stations are referred to generally as “transmission points” when the downlink (tower to handset) is concerned and “reception points” when the uplink (handset to tower) is concerned, respectively.

These transmission points may be arranged to build a single frequency network (SFN) and therefore appear as one single cell to the mobile devices. In addition, transmission points can be added to and removed from a set of transmission points that are currently transmitting data to a specific mobile device (user equipment, UE) according to UE's movement to cover the area where the UE is expected to move next, i.e. with regard to transmission to a specific UE some transmission points are switched on and some are switched off according to UE's movement. If there is no need for a transmission point to transmit to any UE it may also be totally switched off (powered down, standby).

In the context of this invention the term SFN may be understood as a set of synchronously operating transmission/reception points that typically cover an area of larger extension, but also as a sub set of transmission/reception points from this larger set (so-called SFN Clusters).

The current invention may be especially useful in a network of transmission and reception points in which transmission points are setup to build an SFN. However, the invention is beneficial also in networks where transmission points generally transmit in an unsynchronized manor or appear as individual cells to a mobile device.

The current invention concerns network node interactions to efficiently collect uplink (UL) traffic in the network from multiple reception points and dynamically controlling reception points to participate in UE-specific UL routing.

In known mobile networks, techniques have been deployed that use multiple transmission and/or reception points in the network to increase efficiency or data rate of a UE's communication link.

In UMTS (3G, CDMA based), a soft handover (SHO) specified, where a single UE maintains several links to different base stations and transmits data individually to these in the UL. The links are explicitly established by the network, the UE encodes data individually for every link and all participating base stations forward received data to the radio network controller for combination of the data to a single UL data stream.

In LTE there is a concept of dual connectivity that allows a single UE to deliver data to (and receive data from) multiple base stations simultaneously. The UE uses distinct radio resources configured for each of the cells to transmit different data to the base stations. Every involved base station forwards received data further to the network and no dynamic selection of forwarding function from a group of receiving base stations is known.

Other concepts in LTE are carrier aggregation and coordinated multipoint (CoMP) in which a single UE transmits data in parallel on different carriers (i.e. different frequencies) or to different cells, but in both cases the reception points are co-located (in the same eNodeB) so that any kind of backhaul coordination is obsolete.

US 2013/0089034 A1 describes a method and base station to select one out of a plurality of base stations to serve a UE in UL. A single base station already serving the UE in DL controls the method, which involves by the UE sending reference signals in UL to multiple base stations. The base stations receive and decrypt (decode) the signals and send the received signal strength to the controlling base station for selection of the one base station to serve the UE in UL. The selection is fixed; the selected base station serves the UE.

The application does not describe a dynamic (repeated) selection of the currently best base station as well as the selection of multiple base stations to serve a UE. Also, the selected base station will be solely responsible for UL data forwarding and thus there is no mentioning of different involvements the base station can have with respect to the UL transmission.

WO 2012/095759 describes a method, a serving base station and a cooperating base station for combining UL data traffic received by the cooperating base station and by the serving base station taking into account decoding soft output values and certainty values. The cooperating base station sends received UL data as soft output and certainty values to the serving base station, which combines the UL data with corresponding values it received itself.

The application does not describe dynamic configuration techniques. The combination of data from different base stations is described. The principle is similarly used already in UMTS for soft handover.

US 2006/0286996 proposes a method for selecting a base station serving a UE for the UL from a candidate set of base stations. The selection is done by the UE based on UL reception in the base station, which UL reception may be estimated by the UE from power control commands received from the base station, HARQ feedback received from the base station or transmit power in the DL. The UE sends signals on dedicated control channels (one for each candidate base station) or the UE multiplexes dedicated signals onto one common control channel. In any case, base station specific signals are sent and the UE is configured to explicitly address the base stations.

The application does not describe multiple base stations receiving and measuring the same (not base station specific) signals and providing their measurement to a central unit in the network for selection of multiple “serving” base stations (that is data forwarding base stations).

US 2002/0118665 describes a system and method in which signals sent from a UE in UL are received by multiple base stations (one target and multiple non-target) and forwarded by non-target base stations to a target base station for combination and determination of necessity of power adjustment in the UE. The non-target base stations have received a UE-specific code-pattern to decode the UL signals transmitted by the UE.

The application does not describe different roles for a participating (non-target) base station that allow various levels of involvement beyond that of a data forwarding base station, which is the only non-target base station behaviour described in the patent. Base stations are not dynamically configured to forward, store or not forward data and/or participate in measurements on the UL signals to prepare potential higher involvement when channel conditions change. A request for later forwarding of specific data that was stored in a base station is not mentioned.

SFNs used for downlink (DL) data transmission are well known. Such SFNs are DL-only, e.g. the DVB-T broadcasting technique, and do not provide for any uplink (UL) transmission capability.

A system that has multiple reception points receiving UL-traffic from a UE and being coordinated so that just sufficient parallel UL data is provided to a coordination entity to guarantee successful reception is not presently known.

The multipoint reception concepts of 3G and LTE systems are such that base stations are configured to receive UE's UL-traffic and it is expected that all such base stations forward received data for data combining (if applied). An UL transmission from a UE to multiple reception points using common UL-signals without base station-specific adaption of the UL-signals is not disclosed in the known prior art; especially in combination with an efficient selection of the reception points to measure UE's UL signals, and/or to forward respective data.

Permanent forwarding of UL traffic by all reception points receiving such UL-signals to a coordination entity would be inefficient, especially in a system in which the best reception points are changing dynamically.

US 2015/049649 A1 describes a small cell network in which nodes may be switched off to reduce interference where nodes in an off state may still continue to transmit or receive particular signals for discovery purposes. A UE reports detected discovery signals to a coordinating network node which may decide to turn on a particular small cell node.

US 2014/0204871 A1 describes a network in which a primary base station, other base stations and a mobile station communicate in a coordinated manner with information about a result of measuring a pilot signal is transmitted to the primary base station. US 2014/0133415 A1 describes uplink multiflow operations where nodes and UEs receive and transmit from/to multiple cells.

The present invention provides a method of controlling a mobile communication network, the method comprising, an uplink controlling entity, in response to reception quality measurement reports sent by a plurality of reception points within the mobile communication network following a transmission of data by a user equipment device, the reception quality measurement reports being responsive to the reception of the transmission, configuring the reception points within the mobile communication network such that each of the multiple reception points is configured to exhibit a participation behaviour with respect to at least one of subsequent measurement reporting and payload reporting with regard to transmissions from the user equipment device, the participation behaviour being dependent on the reception quality measurement report.

In a further aspect, the invention provides a network equipment entity for controlling uplink traffic in a mobile communication network, wherein the entity is arranged to receive reception quality measurement reports from a plurality of reception points of the mobile communication network following a transmission of data by a user equipment device and in response to configure the reception points to forward data received from the user equipment device and to send reception quality measurement reports, wherein each of the multiple reception points is configured to exhibit a participation behaviour with respect to at least one of subsequent measurement reporting and payload reporting with regard to transmissions from the user equipment device, the participation behaviour being dependent on the reception quality measurement report and wherein different reception points are configured differently such that only selected reception points receiving data signals from the user equipment device forward the data while others transmit only a reception quality report.

In a still further aspect, the invention provides a mobile communication network reception point arranged to receive data signals from a user equipment and to measure a reception quality of the received signals, wherein the reception point is further arranged to send a reception quality measurement report to an uplink controlling entity and to receive a configuration message from the uplink controlling entity to implement a participation behaviour with respect to at least one of subsequent measurement reporting and payload reporting with regard to transmissions from the user equipment device, the participation behaviour being dependent on the reception quality measurement report wherein the configuration message may command the reception point to transmit a reception quality measurement report of data received from the user equipment device but not the data.

In a yet further aspect, the invention provides a mobile communication network comprising a plurality of transmission and reception points and network equipment including an uplink controlling entity wherein the plurality of reception points are each arranged to transmit a reception quality measurement report to the uplink controlling entity in response to data received from a user equipment device and the uplink controlling entity is arranged to configure each reception point in response to the reception quality measurement report received from that reception point to exhibit a participation behaviour with respect to at least one of subsequent measurement reporting and payload reporting with regard to transmissions from the user equipment device, the participation behaviour being dependent on the reception quality measurement report such that selected ones of the reception points forward data received from the user equipment device and other reception points transmit further reception quality measurement reports only.

Preferred aspects of the invention are provided according to the dependent claims.

