Nokia Technologies Oy

Nokia Solutions and Networks Oy

Nokia Corporation

Michal Cierny

Cassio Ribeiro

Timo Erkki Lunttila

Esa Tapani Tiirola

Kari Juhani Hooli

Zexian Li

Juha Sakari Korhonen

Klaus Hugl

Jarkko Kneckt

Cássio Ribeiro

Cassio Barbosa Ribeiro

Sakari Korhonen

The application relates to improved hidden node detection for Long Term Evolution LTE Licensed-Assisted Access LAA. Channel State Information CSI measurements can be seen as one existing solution that could be used for obtaining information about the existence of a hidden node. However, relying on CSI reporting alone is rather unreliable. One of the reasons for this is that the CSI measurements and reporting do not take into account the regulatory requirements such as LBT. A further possible way to detect hidden nodes is to perform LBT (clear channel assessment CCA) at the transmitter (e.g. eNB) and receiver (e.g. UE) at the same time. However, there is still the need for an improved solution for how to detect hidden nodes preventing LTE LAA uplink operation and complicating coexistence. These problems are solved by ensuring that interference from non-hidden nodes (such as WLAN nodein FIG.) is not measured. Therefore the serving eNB detects a free channel during LBT procedure, i.e. that non-hidden nodes are not transmitting, and informs the UE which performs the hidden node detection measurements, by downlink scheduling, whether the serving eNB is active in the current subframe. The UE then performs the measurements only in subframes of the channel occupied by the serving eNB. Thereby, the UE only captures interference coming from hidden nodes.

Hidden node detection in LTE licensed assisted access

There is provided a method comprising determining, at a first access point, whether a carrier from a plurality of carriers is a primary listen-before-talk carrier or a secondary listen-before-talk carrier and providing information using the carrier, said information comprising an indication of whether the respective carrier is a primary listen-before-talk carrier or a secondary listen-before-talk carrier.

Multi-channel listen-before-talk arrangements for licensed-assisted access in LTE

A method and apparatus can be configured to determine that a sub-symbol slot is an unoccupied sub-symbol slot. The unoccupied sub-symbol slot corresponds to an unoccupied operating channel. The unoccupied sub-symbol slot is located within the duration of a first symbol. The method may also comprise transmitting a reservation signal in at least one sub-symbol slot between the unoccupied sub-symbol slot and the beginning of a second symbol. The number of sub-symbol slots within the duration of the first symbol is larger than one.

Method and apparatus for improving a time granularity when deploying a wireless system

One embodiment is directed to a method for operating base stations in a heterogeneous network. The method may include receiving, by a first base station, an indication for a second base station to use flexible time division duplex mode (), assessing an amount of interference that will be caused by the second base station ()-(), deciding how to adjust a transmission power of the second base station (), and sending the second base station a request to adjust the transmission power ().

Set up and maintenance framework for flexible time division duplex operation in heterogeneous network

Device discovery may be important in a variety of communication systems including, for example, wireless communication systems. Thus, certain embodiments may provide a device to device beacon design that may provide for efficient interference management and resource allocation. For example, a method may include preparing a proximity communication request including information about a device to device communication state of a discovered user equipment or resource usage of the discovered user equipment. The method may also include transmitting the proximity communication request to a base station.

Device to device beacon, user equipment discovery, and resource allocation

Methods, apparatuses, and computer program products for indication of reference symbol (RS) transmission power change in a network are provided. One method includes reducing transmission power, and signaling information about the changes in RS transmission power to associated user equipments via a control channel. In one embodiment, the information may comprise an indication about the subframes in which the RS transmission power changes in comparison to a reference value, or the information may comprise specific RS transmission power values as well as information regarding in which subframes the specific RS transmission power values are going to be used.

Method for indication of reference symbol transmission power change in cellular network

Channel reservation in time division duplex for devices in systems involving, for example user devices and access points, may be accomplished using channel reservation request messages, such as request-to-send (RTS) messages and channel reservation grant messages, such as clear-to-send (CTS) messages. A method for channel reservation may include preparing a frame including at least one channel reservation request message and at least one channel reservation grant message. The preparing may include multiplexing the at least one channel reservation request message and the at least one channel reservation grant message at least by frequency-division multiplexing. The method may also include transmitting the frame from a first node to a second node, wherein the channel reservation request message and the channel reservation grant message relate to communications between the first node and the second node.

Growing community of inventors

Helsinki, Finland

Michal Cierny