A method and apparatus for determining propagation delay of a first path and or of a second path which connect a first transceiver unit associated with a first clock to a second transceiver unit associated with a second clock in a communications network. The apparatus comprises a control unit configured to cause the first transceiver unit to transmit a first signal to the second transceiver unit over the first path and to receive a reply to the first signal from the second transceiver unit over the second path, and to transmit a second signal to the second transceiver unit over the second path and to receive a reply to the second signal from the second transceiver unit over the first path. The apparatus further comprises a receiving unit configured to receive a first time reference representing the time of transmission of the first signal from the first transceiver unit, a second time reference representing the time of receipt of the first signal at the second transceiver unit, a third time reference representing the time of transmission of the reply to the second signal from the second transceiver unit and a fourth time reference representing the time of receipt of the reply to the second signal at the first transceiver unit. The apparatus further comprises a determining unit configured to determine a propagation delay of the first path and or of the second path using the first time reference, the second time reference, the third time reference and the fourth time reference.

A method includes sending, by a master beacon device and one or more beacon repeater devices, ultra-wideband (UWB) beacon frames. The UWB beacon frames are transmitted as interleaved pairs of UWB beacon frames. Each interleaved pair includes a first UWB beacon frame and a second UWB beacon frame. For each interleaved pair, the first UWB beacon frame and the second UWB beacon frame are transmitted with a master time delay. The method further includes receiving, by one or more tag devices, at least one of the interleaved pairs of UWB beacon frames.

A paging frame may be determined based on a first value divided by a second value and a WTRU identifier modulo the second value. The second value may be based on a discontinuous reception (DRX) cycle value.

The invention is directed to a method of synchronizing transmission between two nodes in a wireless network. The method comprises the steps of obtaining an expected interference profile for each node; and agreeing a synchronized transmission schedule between the nodes, where the expected interference profile of the or each node meets predetermined criteria.

A method and apparatus for determining propagation delay of a first path and or of a second path which connect a first transceiver unit associated with a first clock to a second transceiver unit associated with a second clock in a communications network. The apparatus comprises a control unit configured to cause the first transceiver unit to transmit a first signal to the second transceiver unit over the first path and to receive a reply to the first signal from the second transceiver unit over the second path, and to transmit a second signal to the second transceiver unit over the second path and to receive a reply to the second signal from the second transceiver unit over the first path. The apparatus further comprises a receiving unit configured to receive a first time reference representing the time of transmission of the first signal from the first transceiver unit, a second time reference representing the time of receipt of the first signal at the second transceiver unit, a third time reference representing the time of transmission of the reply to the second signal from the second transceiver unit and a fourth time reference representing the time of receipt of the reply to the second signal at the first transceiver unit. The apparatus further comprises a determining unit configured to determine a propagation delay of the first path and or of the second path using the first time reference, the second time reference, the third time reference and the fourth time reference.

Disclosed are a method and an apparatus for receiving a frame. A method for receiving a frame in a wireless LAN comprises the steps of: an AP transmitting, to a plurality of STAs, a downlink PPDU including downlink data for each of the plurality of STAs, through a plurality of channels; and the AP receiving, from each of the plurality of STAs, a plurality of block ACK frames transmitted based on a block ACK transmission control field, wherein the downlink PPDU includes the block ACK transmission control field, and wherein each of the plurality of block ACK frames may include ACK information related to downlink data.

A method and a system for synchronizing time information in an ad-hoc network are disclosed. According to the present invention, provided is a method for synchronizing time information in an ad-hoc network as a method by which a plurality of nodes included in an ad-hoc network synchronize a time, the method comprising the steps of: transmitting, by a first node, time information obtained by correcting an initial time using a first self-correcting value at an nth beacon interval, wherein the first self-correcting value is a self-correcting value or a local averaging value at an (n1)th beacon interval; and correcting, by a second node which has received the time information from the first node at the nth beacon interval, time information by calculating a second self-correcting value and a local average value, wherein the first self-correcting value is either the self-correcting value or the local averaging value calculated at the (n1)th beacon interval, and the local averaging value of the second node is an averaging value of time information of one or more neighboring nodes of the second node.