Disclosed is a method for transmitting, by a user equipment (UE), signals via a device-to-device (D2D) link in a wireless communication system. Specifically, the method comprises the steps of: transmitting a control signal for the D2D link including a timing adjustment value for the D2D link based on a reference timing to a target UE without applying the timing adjustment value; and transmitting a data signal for the D2D link to the target UE with applying the timing adjustment value. Here, the timing adjustment value for the D2D link is same as a timing adjustment value for an uplink to a base station (BS).

An interface conversion device of a mobile communication system includes: a delay amount measurement unit that measures a delay amount from a difference between an input time at which the mobile communication system has acquired a periodically transmitted time-synchronization signal and an output time at which the mobile communication system outputs the time-synchronization signal; a memory that stores delay amount history information including the measured delay amount; a variation evaluation unit that measures a variation amount indicating an instantaneous variation of the delay amount, using the delay amount history information and evaluates whether the variation amount is within an allowable range; and an anomaly detection unit that detects a communication anomaly in the mobile communication system on the basis of a result of the evaluation.

Disclosed are methods and systems for obtaining measurements of a range between devices based on a Round Trip Time (RTT) for an exchange messages. In particular, described are techniques for sharing channel parameters between or among wireless transceiver devices to assist in initiating exchange of signals between neighboring wireless transceiver devices.

Methods, apparatuses, and computer programs are provided for propagation delay compensation. A method for a UE includes receiving a configuration to provide a propagation delay notification for a propagation delay estimation; determining when the notification should be transmitted; transmitting the propagation delay notification; and determining a corresponding action based on the configuration of a relation between uplink reference signals and downlink reference signals. Methods are also provided for a radio node such as a base station.

There is provided a technique for calibrating the envelope tracking circuitry of the wireless interface of an electronic device to compensate for any delay mismatch between the IQ signal path and the envelope path. Thee desired levels of input test signals are determined to assure that they are sensitive to any delay mismatch which may be in the system. The propagation delay from the signal generator to the signal analyzer of the envelope tracking system is estimated and delay compensation is performed. To reduce the noise of the measurement, distortion in the received signal may also be determined and noise compensation may also be performed. Based on these determinations, the envelope tracking circuitry may be calibrated by introducing an appropriate delay in either the envelop path or the IQ signal path.

Disclosed are techniques for determining round-trip times (RTTs) between a user equipment (UE) and multiple base stations. In an aspect, the UE transmits an RTT measurement signal whose arrival time is measured by each of the base stations, and each of the base stations returns an RTT response signal whose arrival times are measured by the UE. In another aspect, the base stations each transmit an RTT measurement signal and the UE returns an RTT response signal. The receiver of the RTT measurement signal may include the measured arrival time in a payload of the RTT Response signal. Alternatively, the measured arrival time(s) of the RTT Measurement signal(s) and the transmission time(s) of the RTT Response signal(s) are sent in a separate message. The RTT signals can be wideband signals using low reuse resources.

A measurement apparatus includes a communication device configured to obtain a packet being transmitted between a server apparatus and a communication apparatus in a network, a memory, and a processor coupled to the memory and configured to calculate round-trip time between the communication apparatus and the server apparatus, and measure a data transfer rate between the communication apparatus and the server apparatus based on a data volume included in a second packet having a length equal to or greater than the threshold and transmitted to the communication apparatus from the server apparatus, a period of time from time at which the second packet is acquired to time at which an acknowledgement packet transmitted in response to the second packet is acquired, and the round-trip time.

A method of synchronizing signals is disclosed. The method comprises using a clock tracking system to convert a future event target time specified in a time base of a master device into the local unsynchronized time bases of one or more slave devices. Each of the slave devices then generates an event signal at the converted time, such that a coordinated delivery of synchronized signals is achieved.

Systems and methods for improved content streaming and downloading. The system enables content to be transmitted to wireless base stations (WBSs) using unicast on the core network side of a cellular network to avoid incompatibilities associated with network broadcast technologies such as Evolved Multimedia Broadcast Multicast Services (eMBMS) and Long-Term Evolution Broadcast (LTE-B). At the same time, the system enable content to be broadcast, or transmitted to multiple user equipment (UE) in a single transmission to reduce wireless bandwidth consumption. The system can include a commodity server to receive requests from WBSs, place them in a chronological list based on network latency, and then transmit content to each WBS in a synchronized unicast manner. Each WBS can then transmit the content to a plurality of UEs with minimal buffer required due to the “pre-synchronization.”

Embodiments are provided for syncing multiple electronic devices for collective audio playback. According to certain aspects, a master device connects (218) to a slave device via a wireless connection. The master device calculates (224) a network latency via a series of network latency pings with the slave device and sends (225) the network latency to the slave device. Further, the master devices sends (232) a portion of an audio file as well as a timing instruction including a system time to the slave device. The master device initiates (234) playback of the portion of the audio file and the slave devices initiates (236) playback of the portion of the audio file according to the timing instruction and a calculated system clock offset value.