In performing wireless communication between terminals to perform time difference measurement and propagation time measurement, first and second terminals that transmit a signal at least once in attempting space-time synchronization are included. The first terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the second terminal, adds a positive or negative phase to the measured reception phase, and makes a report to the second terminal. The second terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the first terminal, and makes a report to the first terminal. The first and second terminals obtain a time difference or propagation time according to a reception phase measured by a local device and reported from a counterpart, and obtain additional information based on a phase reflected in the time difference or propagation time.

A signal distribution system includes: a first signal divider arranged to generate a first output oscillating signal according to a first input oscillating signal; a second signal divider arranged to generate a second output oscillating signal according to the first input oscillating signal; a first transmitting channel coupled to the first signal divider and the second divider for transmitting the first input oscillating signal to the first signal divider and the second signal divider; and a second transmitting channel coupled to the first signal divider and the second divider for transmitting a second input oscillating signal to the first signal divider and the second signal divider; wherein the first input oscillating signal has a first frequency, the second input oscillating signal has a second frequency, and the second frequency is smaller than the first frequency.

A system and method of effecting time synchronization between disparate nodes on a network where at least one node has knowledge of the true network time, at least one other node requires synchronization to the true network time, and a third node is utilized to facilitate the synchronization process.

Components, systems, and methods for determining propagation delay of communications in distributed antenna systems are disclosed. The propagation delay of communications signals distributed in the distributed antenna systems is determined. If desired, the propagation delay(s) can be determined on a per remote antenna unit basis for the distributed antenna systems. The propagation delay(s) can provided by the distributed antenna systems to a network or other system to be taken into consideration for communications services or operations that are based on communications signal delay. As another non-limiting example, propagation delay can be determined and controlled for each remote antenna unit to uniquely distinguish the remote antenna units. In this manner, the location of a client device communicating with a remote antenna unit can be determined within the communication range of the remote antenna unit.

In some embodiments, Satellite Positioning System (SPS) time information associated with at least one SPS may be maintained at a UE, which may also receive time information from a Wireless Wide Area Network (WWAN). In some embodiments, the UE may determine a corrected SPS time information for a first time based, in part, on the received WWAN time information, where the corrected SPS time information corrects the SPS time information associated with the at least one SPS maintained at the UE. The UE may initiate transmission of SPS timing assistance information to an associated device over a Wireless Personal Area Network (WPAN), wherein the SPS timing assistance information comprises the corrected SPS time information for the first time.

A method of synchronizing the transmission and receipt of messages by radios within a wireless communications network. It is assumed that the radios have chip scale atomic clocks, which are externally synchronized, such as by GPS, but only at the beginning of a mission. Each radio defaults to a sleep mode, in which its receive and transmit circuitry is inactive. Each radio stores a channel plan of pre-determined base transmit times, and calculates a worst case time drift between clocks and a propagation delay value between combinations of radios. At each base transmit time, if a radio has an outgoing message to transmit, it subtracts propagation delay from the base transmit time, and transmits only at that time. Also, for each base transmit time, each radio subtracts time drift, thereby determining a receive time window during which it listens for messages from other radios.

A method includes: adjusting, by a base station based on a timing adjustment amount, an access timing advance corresponding to user equipment to obtain a target timing advance, where the access timing advance is a timing advance obtained when the user equipment randomly accesses the base station; determining, by the base station based on the target timing advance, whether the user equipment meets a trigger condition; and if the user equipment meets the trigger condition, sending, by the base station, a trigger signal to the user equipment, where the trigger signal is used to trigger the user equipment to send a first random access request to the base station.

WTRUs, access points (APs) and methods thereon are disclosed. A method on a WTRU may include receiving a message from an AP that comprises a beamformee capability element; sending a second message to the AP that comprises a beamformer capability element; and receiving, from the AP, a third message in response to the second message that indicates a group to which the WTRU is assigned. The group may be based on the beamformer capability element and the group may indicate UL transmission information to be used by the WTRU. A method on an AP may include determining a group for multiple WTRUs based on a received beamformer capability element. A method on a WTRU may include sending to an AP a message with a low overhead preamble for UL MU-MIMO. The low overhead preamble may include LTFs that enable the AP to distinguish the WTRU from other WTRUs.

A radio control device includes, a transmission unit that transmits, to the radio relay device, a first frame which has a plurality of subframes each having a fixed time length, the plurality of subframes including one or more subframes that store respective identifiers of the plurality of radio devices and the radio relay device, a reception unit that receives a second frame which has one or more subframes that store the identifiers of the plurality of radio devices and the radio relay device from the radio relay device, and a detection unit that detects a time difference between a transmission time point of the subframe that stores the identifiers of the respective devices in the first frame and a reception time point of the subframe that stores the identifiers of the respective devices in the second frame received.

Provided herein are various improvements to communication systems and satellite-carried communications. In one example, a method provides communication coverage for at least an endpoint device within a cell. The method includes detecting access preamble communications transferred by the endpoint device during a random access slot of a base station by at least applying a selected quantity of successive sets of processing windows in accordance with a round-trip minimum communication delay expected between the base station and the cell, with each of the successive sets shifted in time by a selected duration. The method also includes determining a round-trip differential communication delay for the endpoint device based on which of the successive sets corresponds to detection of symbol groups of the access preamble communications, and handling return communications transferred by the endpoint device based at least on a combination of the round-trip minimum communication delay and the round-trip differential communication delay.