Abstract:
A method and apparatus for sending a channel quality indication (CQI) via a shared channel while a wireless transmit/receive unit (WTRU) is in a Cell_FACH state without having a dedicated channel allocated for the WTRU are disclosed. A WTRU performs a measurement of at least one parameter and generates a CQI based on the measurement. The WTRU then transmits the CQI via a random access channel (RACH). The CQI may be transmitted using an RACH preamble. A plurality of signature sequences may be divided into a plurality of groups. The WTRU may select one group based on the CQI and randomly select a signature sequence among signature sequences in the selected group for transmitting the RACH preamble. The CQI may be appended to the RACH preamble. The CQI may be transmitted via a control part or a data part of the RACH message.
Abstract:
A method and apparatus for assigning a cell and resource blocks (e.g. subcarriers, timeslots, orthogonal codes, etc.) to a wireless transmit/receive unit (WTRU) in a wireless communication system including a resource management unit and a plurality of cells having resource blocks are disclosed. The WTRU is currently associated with a particular one of the cells-. Path losses between the WTRU and cells neighboring the particular cell are determined. The average level of inter- cell interference on each resource block at each cell neighboring the particular cell is then determined. A signal -to -interference ratio (SIR) is then determined to support a guaranteed bit rate of the WTRU on an uplink.
Abstract:
In a wireless communication system including at least one wireless transmit/receive unit (WTRU) and at least one Node-B (NB), an activation or deactivation state is determined for each of a plurality of HARQ processes. A signal that includes the activation or deactivation state for each of the HARQ processes is transmitted to the WTRU. In response to receiving the signal, the WTRU activates or deactivates a particular HARQ process in accordance with the activation or deactivation state for each of the HARQ processes contained in the received signal. The activation of HARQ processes is considered for non-scheduled transmissions.
Abstract:
A list of candidate basic service sets (BSSs) or access points (APs) is included in a medium access control (MAC) message which is received at a wireless transmit/receive unit (WTRU). The list includes an identity of each candidate BSS or AP and a preference indicator which indicates an extent that the candidate BSS or AP is preferred for selection and whether the candidate BSS or AP shall not be considered for selection. A BSS or AP is selected by the WTRU using the list.
Abstract:
Methods for sharing radio resource allocation information between access points (APs) in a wireless local area network include: sending resource allocation information from a first AP to at least one other AP; directly requesting resource allocation information from a first AP by a second AP; or requesting resource allocation information for a first AP by a second AP through a centralized entity. A similar method may also be used to allocate radio resources among APs.
Abstract:
A method for changing a channel in a wireless local area network (WLAN) to alleviate congestion and high interference levels, the WLAN having an access point (AP) and at least one station, begins by determining a list of candidate channels. A channel is selected from the candidate list and is evaluated against predetermined criteria. If the selected channel meets the predetermined criteria, then all of the stations communicating with the AP are disassociated and the AP is changed to the selected channel. If the selected channel does not meet the predetermined criteria, then the selected channel is removed from the candidate list and the selecting step is repeated if there are additional candidate channels.
Abstract:
A silent measurement period (SMP) for a selected channel in an allowable channel set (ACS) of the access point (AP) is set. During the SMP, the AP does not serve wireless transmit/receive units (WTRUs) within its coverage area and reserves its channels for other BSSs. A normal operating channel of the AP is changed to the selected channel upon initialization of the SMP (225). Characteristics of the selected channel is measured during the SMP (235). The operating channel of the AP is changed back to the normal operating channel when the duration of the SMP expires (245).
Abstract:
This invention relates to wireless local area networks, and particularly to the IEEE 802.11 family of standards. It consists of a method and apparatus that can be implemented in access points (APs) and subscriber wireless transmit/receive units (WTRUs), in order to allow an AP to initiate re-association of a WTRU to itself or a different AP. The invention improves the robustness of the network by enabling more efficient load balancing, congestion control, and roaming, without compromising the user experience.
Abstract:
A method for communicating a list of handover candidates in a wireless local area network from a station to a serving access point (AP) begins by determining a list of handover candidate APs at the station. The candidate list is sorted at the station and is sent to the serving AP. The sending step can include sending the candidate list to the serving AP upon the expiration of a predetermined period of time or upon receipt at the station of an event trigger. The method can also include the step of requesting a candidate list from the station by the serving AP.
Abstract:
A method for seamless channel change in a wireless local area network having a station (STA) and an access point (AP) begins by sending a channel change intention message from the AP to the STA. A channel change response message is sent from the STA to the AP, informing the AP whether the STA will follow the channel change. The AP determines whether to proceed with the channel change, and performs the channel change if the determination is positive.