Abstract:
A method and system for managing a cell sectorized by both an angle in azimuth and a distance from a base station are disclosed. A wireless communication system comprises a base station and a cell. The base station comprises an antenna array for generating a plurality of directional beams which are steerable both in azimuth and elevation. The cell is sectorized into a plurality of sectors defined in accordance with an angle in azimuth and a distance from the base station. At least one directional beam serves each sector. Beams serving adjacent sectors overlap each other, and a softer handover in a cell is performed in the overlapping region.
Abstract:
Apparatus and methods for wireless communication transmission power control are provided. Determination of gain factors and adjustments for physical channel reconfiguration in the context of transmission power control are addressed. Preferably, implementation is in con unction with communication systems in which wireless communications are conducted between wireless transmit receive units (WTRUs) using multiple channels that are concurrently transmitted.
Abstract:
Sub-channels are defined for a physical random access channel of a wireless time division duplex communication system using code division multiple access. The sub-channels carry information between system users and a system network. A series of radio frames have a sequence of timeslots. For a particular timeslot number of the sequence, each sub-channel of the particular timeslot number is uniquely defined by one radio frame of the series.
Abstract:
Measurements for handoff are made by a wireless transmit/receive unit (WTRU) operating with a switched beam antenna in a wireless communication system. The switched beam antenna is a smart antenna generating a plurality of directional beams and an omni-directional beam. The WTRU measures signals from a plurality of cells with the omni-directional beam and/or one or more of the directional beams. The WTRU evaluates and reports to the network measurement of the omni-directional beam or the strongest beam for adding cells to an active set of cells. For removing cells from an active set of cells, the WTRU evaluates and reports to the network measurements of the antenna beam selected for communication with the active set cells.
Abstract:
Measurements for identifying pre-candidate cells are made by a wireless transmit/receive unit (WTRU) operating with a switched beam antenna in a wireless communication system. The switched beam antenna is a smart antenna generating a plurality of directional beams and an omni-directional beam. The WTRU measures signals from cells not in an active set of cells to define a pre-candidate set of cells. Measured signals from cells in the pre-candidate set of cells are compared to a threshold, and the corresponding cells are moved from the pre-candidate set of cells to a candidate set of cells based upon the comparison to the threshold. A measurement report is then sent to the network.
Abstract:
The invention includes a system and methods for orthogonal variable spreading factor (OVSF) code assignment, de-allocation and code tree pruning. The invention also includes OVSF code identification and storage schemes. Embodiments are provided for code tree pruning, code assignment and de-allocation. These embodiments apply to both slotted and non-slotted code division multiple access systems.
Abstract:
Network Allocation Vector (NAV) and "beam access control" (BAC) techniques are provided to address data collision problems in WLANs wherein APs provide wireless network access in a service area defined by multiple sectors via use of a switchable antenna system or the like. Preferably, every time the AP visits a sector and before the AP moves on to the next sector, the AP can set the NAV equal to the time it will take until its next visit. Alternatively, or in addition, a BAC bit is transmitted by an AP to control access to the AP by WTRUs disposed in a service sector in which the BAC is transmitted.
Abstract:
Measurement opportunities are provided to a wireless transmit/receive unit (WTRU) operating with a switched beam antenna in a CDMA wireless communication system. The switched beam antenna is a smart antenna generating a plurality of directional beams and an omni-directional beam. The bursty nature of packet data transmission generates periods of inactivity or low traffic during a call. The WTRU switches to antenna beams other than the selected antenna beam for receiving and measuring signals during these periods of inactivity or low traffic. Moreover, if the network has knowledge of the fact the WTRU is operating using a switched beam antenna, the network can use this information when making decisions on channel allocations, thus providing frequent measurement opportunities to the WTRU in order to support the switched beam antenna operation.
Abstract:
A method and apparatus for establishing a set of cells used to support a soft handoff. The apparatus is used in a wireless communication system including a plurality of cells and at least one wireless transmit/receive unit (WTRU) having at least one beam antenna which is configured to transition between a switch beam mode and an omni-directional beam mode. The WTRU communicates with a serving cell while the beam antenna is in the switch beam mode. The WTRU performs measurements on cells neighboring the serving cell to determine measurement results associated with the cells. The WTRU then determines whether each of the measurement results exceeds a predetermined threshold. A set of cells associated with the measurement results that exceed the predetermined threshold is established. If the number of cells in the set reaches a predetermined number, the beam antenna transitions from the switch beam mode to the omni-directional beam mode.
Abstract:
The present invention is a method for adjusting the uplink transmission power of a WTRU utilizing a switched beam antenna. The method measures the received power of a pilot channel beacon in order to estimate the path loss associated with each directional antenna beam. A beam correction function is calculated based on an estimated gain difference between the beam which is currently used for transmission and the beam to which the WTRU will switch. The transmission power of the WTRU is adjusted according to the beam correction function at the time of beam switching. The beam correction function is equivalent to the response of the WTRU's averaging function to the estimated gain differenceto a step function representing the difference in gain between said first and said second beams, after a beam switch, offset by the same estimated gain difference.the averaged power of a pilot channel beacon received by the WTRU after a beam switch offset by the estimated gain difference between the old beam and the new beam.