| Patent application number | Description | Published |
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| 20100098025 | Method and appartus for handover between IEEE 802.16E and 802.16M systems - Methods for a mobile station to handover between IEEE 802.16e and 802.16m systems are provided. The mobile station is served by an IEEE 802.16e-only base station or an IEEE 802.16e zone of a 16e/16m-conexistence base station. In a zone-switch based handover procedure, the mobile station first performs an IEEE 802.16e legacy handover procedure such that the mobile station handovers from the serving base station to an IEEE 802.16e zone of a target base station. The mobile station then performs a zone-switch procedure such that the mobile station switches from the IEEE 802.16e zone to an IEEE 802.16m zone of the target base station. In a direct handover procedure, the mobile station performs an IEEE 802.16m handover procedure such that the mobile station handovers from the serving base station to the IEEE 802.16m zone of the target base station directly. | 04-22-2010 |
| 20100110983 | Downlink network synchronization mechanism for femtocell in cellular OFDM systems - A method of downlink synchronization for a femto base station in a cellular orthogonal frequency division multiplexing (OFDM) system is provided. The femto base station first scans one or more received reference signals transmitted from a plurality of neighboring macro base stations. The femto base station then determines a desired reference signal from the received one or more reference signals based on the scanning result. Finally, the femto base station configures its downlink radio signal transmission time based on the desired reference signal such that the femto base station is synchronized with the plurality of neighboring macro base stations. | 05-06-2010 |
| 20100111029 | Fast feedback contention-based data transmission in wireless communications systems - A fast feedback mechanism is provided in a contention-based data transmission procedure. A Subscriber Station (SS) transmits a data burst to a base station (BS) using a selected data grant in a previous uplink (UL) frame. The SS also starts a timer associated with the data transmission. The data grant is selected from a plurality of data grants granted by the BS for contention-based access. In response to all received data grants in the previous UL frame, the BS broadcasts an acknowledgement (ACK) in a subsequent downlink (DL) frame. The ACK comprises a reception status message that indicates the detection result of the data grants. With the novel fast feedback mechanism, when data collision occurs, upon receiving the detection result indicator, the SS proceeds by retransmitting data without continuing wait for the entire timeout period. As a result, the total latency due to the data collision is reduced. | 05-06-2010 |
| 20100159991 | Reliable femtocell system for wireless communication networks - A Femto Base Station (FBS) includes a communication functionality and a reliability functionality. A control entity within the reliability functionality detects an FBS reliability compromising event (for example, an unscheduled loss of external power to the FBS). As a result of detecting the FBS reliability compromising event, the control entity sends a message (an “FBS Reliability Compromising Event Compensation Message” or “FBSRCECM”) to the communication functionality. The FBSRCECM initiates an action that compensates for the FBS reliability compromising event. In many examples, the action is the initiating of a handover from the FBS to another base station. The reliability functionality typically includes a rechargeable battery that powers the FBS for a time until the handover is completed gracefully. By performing a graceful handover, cellular network reliability is improved as compared to situations in which a conventional FBS simply stops working and connections handled by the conventional FBS are broken. | 06-24-2010 |
| 20100220674 | Method and apparatus for communicating carrier configuration in multi-carrier OFDM systems - A message contains global carrier configuration is provided in a wireless multi-carrier orthogonal frequency division multiplexing (OFDM) system. The global carrier configuration contains global carrier configuration information such as the center frequencies for multiple available RF carriers of different base stations in the OFDM network. In one embodiment, the global carrier configuration comprises information of single or multiple carrier groups, each carrier group comprises single or multiple contiguous RF carriers, and each carrier group is associated with a multi-carrier configuration index that refers to carrier configuration information contained in a carrier configuration lookup table and a frequency assignment index that refers to a global frequency location contained in a frequency assignment lookup table. | 09-02-2010 |
| 20100254344 | Mechanism of dynamic resource transaction for wireless OFDMA systems - A method of dynamic resource transaction in wireless OFDMA systems is proposed. In macro-femto overlay network architecture, network and traffic condition varies dynamically. Dynamic resource transaction is a powerful mechanism to achieve effective interference mitigation and flexible radio resource management to enhance resource utilization as well as to improve link performance. Dynamic resource transaction can be performed by signaling or message exchange through backhaul network or air-interface connections. The signal or message through backhaul network can be directly exchanged among multiple base stations or be routed through a centralized self-organizing network (SON) server. In one embodiment, dynamic resource transaction is used to achieve adaptive reservation region configuration, a solution to avoid interference and frequent handover for high-speed mobile stations. | 10-07-2010 |
| 20100272051 | Method and apparatus of carrier assignment in multi-carrier OFDM systems - In a carrier assignment procedure, a mobile station and its serving base station exchange and negotiate carrier deployment and multi-carrier capability information, and make a well-informed carrier assignment decision based on the negotiation result. The carrier assignment procedure ensures that the assigned secondary carriers are not only supported by both the serving BS and the MS, but are also desirable under additional requirements and considerations. Furthermore, the carrier assignment decision may be updated based on additional considerations such as channel quality measurement and network load condition over the assigned carriers. Such updated assignment decision may be made by the base station in unsolicited manner, or based on a carrier re-assignment request from the mobile station. | 10-28-2010 |
| 20100272067 | Carrier assignment with mobility support in multi-carrier OFDM systems - Carrier pre-assignment is applied in multi-carrier handover operation to mitigate the impact to the user experience during handover and to achieve various objectives of call admission control in wireless multi-carrier OFDM networks. With carrier pre-assignment, a mobile station communicates its multi-carrier information to a target base station. The target base station pre-assigns secondary carriers to fulfill the requirements of the mobile station. In a first embodiment, a break-before-entry (BBE) multi-carrier handover procedure with carrier pre-assignment is provided. In a second embodiment, an entry-before-break (EBB) multi-carrier handover procedures for both inter-FA and intra-FA with carrier pre-assignment are provided. The multi-carrier handover procedures with carrier pre-assignment may be applied to 2-to-2 or N-to-N carriers handover situation. Because target secondary carriers are pre-assigned before handoff, the mobile station is ready for data transmission over multiple carriers after handover without additional carrier assignment procedure. | 10-28-2010 |
| 20100272218 | METHOD AND APPARATUS FOR COORDINATED MIMO SIGNAL TRANSMISSION AMONG MULTIPLE CELLS IN WIRELESS OFDM SYSTEMS - A FFR (fractional frequency reuse)-based network MIMO (multiple-input multiple-output) transmission architecture in a cellular system that employs cell sectoring using directional antennas. Each cell is sectorized into three outer sectors using three directional antennas which transmit in three different directions using three different frequency subbands. The cell sectors are arranged based on a frequency partition scheme so that three sectors in three neighboring cells form a coordinated group for network MIMO transmission. A regular and a rearranged frequency partition are described. Further, a practical implementation of SON (self organizing network)-based three-cell FFR-based network MIMO for a wireless OFDM system is described. In this implementation, a server connected to multiple base stations (BSs) defines multiple coordinated groups for coordinated MIMO transmission, and the BSs within each coordinated group negotiate a common radio resource region (a composite time-frequency region), and selects a serving mobile station to participate in the coordinated MIMO transmission. | 10-28-2010 |
| 20110097998 | System and methods for enhancing coexistence efficiency for multi-radio terminals - A method of scheduling transmitting and receiving communication slots for co-located radio devices is provided. A Bluetooth (BT) device first synchronizes its communication time slots with a co-located radio module, and then obtains the traffic pattern of the co-located radio module. Based on the traffic pattern, the BT device selectively skips one or more TX or RX time slots to avoid data transmission or reception in certain time slots and thereby reducing interference with the co-located radio module. In addition, the BT device generates a co-located coexistence (CLC) bitmap and transmits the CLC bitmap to its peer BT device such that the peer BT device can also skip data transmission or reception in certain time slots affected by the co-located radio module. The skipped time slots are disabled for TX or RX operation to prevent interference and to achieve more energy saving. | 04-28-2011 |
| 20110158118 | Measurement and carrier group based optimization in wireless OFDM multi-carrier communication systems - In a wireless OFDM multi-carrier communication system, a mobile station obtains measurement result of a first received signal strength indication (RSSI) of a first preamble signal transmitted from a base station over a first radio frequency (RF) carrier. The mobile station also obtains signal offset information between the first RF carrier and a second RF carrier of the base station. In response to the measurement result and the signal offset information, the mobile station estimates a second RSSI of a second preamble signal transmitted by the base station over the second RF carrier without performing scanning over the second RF carrier. In one novel aspect, the mobile station identifies a carrier group containing multiple carriers that belong to the same base station. Measurement optimization, initial cell selection and cell reselection optimization, report reduction, and other carrier group based optimization can be achieved in the multi-carrier system based on identified carrier group. | 06-30-2011 |
