46 results about "Hierarchical cell structure" patented technology

A hierarchical cell structure (HCS) cellular communications system includes a macro cell encompassing a smaller micro cell that employ the same frequency band. The macro cell includes a macro cell base station, and the micro cell includes a micro cell base station. An uplink communication cell boundary between the macro cell and the micro cell is established, and a downlink communication cell boundary between the macro cell and the micro cell is established. A radio network controller determines whether a condition exists in the HCS system which indicates that the uplink and downlink micro cell boundaries should be unbalanced. If the condition is met or exists, the power and / or antenna beam tilt of a downlink transmission from the micro cell base station is reduced to unbalance the uplink and downlink micro cell boundaries. Alternatively, the radio network controller may employ an offset value to mathematically reduce mobile detected pilot power levels associated with the micro base station.

A method for carrying out an idle handoff from a macrocell to a microcell (picocell) in a hierarchical cell structure includes the steps of: a) allocating different frequency assignments (FA) to the macrocell and the microcell in a same service band, to construct the hierarchical cell structure; b) transmitting cell structure information of neighboring base stations and pseudo noise (PN) code from base station to mobile station; c) checking whether the mobile station is in the hierarchical cell by using the cell structure information of neighboring base station; and d) checking whether a value of the pseudo noise (PN) code is greater than T_ADD and greater than Ec / Io of the macrocell by periodically searching the pseudo noise (PN) code of the microcell, to carry out an idle handoff to the microcell, wherein the T_ADD represents a value of base station pilot strength required for the base station of neighboring set to be included in a candidate set, the Ec represents an pilot energy accumulated during one pseudo noise (PN) chip period, and the Io represents a total power spectrum density within a reception bandwidth.

An apparatus and a method of a macro terminal for controlling interference in a wireless communication system of a hierarchical cell structure are provided. The method includes setting measurement reporting configuration for a blanking trigger per measurement identifier allocated by a macro base station, measuring a receive signal strength of a neighbor base station, comparing the measured receive signal strength value with a reference receive signal strength value of the measurement reporting configuration for the blanking trigger, and according to a comparison result, transmitting to the macro base station, a measurement report message comprising a measurement identifier corresponding to the measurement reporting configuration for the blanking trigger of a pico base station.

A method for mitigating interference at a small base station in a hierarchical cell structure is provided. In the method, the small base station checks a sub-frame allocated to macro user equipment by using a downlink signal received from a macro base station when an interference candidate user equipment list is received. The interference candidate user equipment list contains information on the macro user equipment adjacent to a femto cell controlled by the small base station. Then the small base station allocates other sub-frame to femto user equipment located in the femto cell by avoiding the sub-frame allocated to the macro user equipment.

A method and an apparatus for obtaining a small cell identifier in a wireless communication system having a hierarchical cell structure are provided. The method includes obtaining a small cell identifier of a terminal in a wireless communication system of a hierarchical cell structure, transmitting resource information allocated for a Random Access Channel (RACH) of a terminal to a small base station, receiving state information regarding the RACH of the terminal from the small base station, determining at least one small base station adjacent to the terminal using the state information regarding the RACH, and transmitting cell IDentifier (ID) information of the determined small base station to the terminal.

An improved device and method for determining when to start a timer that applies a temporary offset to a signal quality measurement of a cell that is a candidate for reselection in a 3GPP Hierarchical Cell Structured wireless communications system. For a cell ranking criterion R, the timer is started to apply the temporary offset according to present invention rules that insure that the temporary offset is not applied until a candidate is eligible for reselection, preventing premature expiration of the timer and unintended cell reselection. A present invention mobile unit that uses the improved method includes a housing, a central processor, a timer for applying the temporary offset, and a memory. The memory includes computer code that applies the claimed invention rules for starting the timer.

A method of transmitting data for reducing interference in a hierarchical cell structure including a macro base station (BS) providing multi carriers and a femto BS providing a single carrier includes performing a channel scan within an interfered carrier to acquire channel state information and neighbor femto BS information if interference with the femto BS occurs; transmitting a channel measurement report including the channel state information and the neighbor femto BS information to the macro BS; and transmitting data through a carrier changed by receiving carrier change information from the macro BS.

A method and apparatus for reselecting a cell in the network with the hierarchical cell structure, are provided. According to an embodiment, the method includes measuring a received signal code power of each of a current serving cell and adjacent cells; and designating the current serving cell as a candidate cell for a next serving cell in a cell reselection process, if the received signal code power of the current serving cell is the strongest of all the cells.

A method and an apparatus for interworking between base stations using a GateWay (GW) in a wireless communication system of a hierarchical cell structure are provided. In the method, a message requesting Internet Protocol (IP) information of a target eNB is received from a source eNB. The IP information of the target eNB is obtained. The source eNB is mapped to the target eNB and the mapping is stored. IP information of the GW is transmitted to the source eNB instead of the IP of the target eNB.

In a radio mobile communication system adopting a hierarchical cell structure comprising a plurality of layers having respective cells of different sizes, the threshold value of the number of times of cell reselections and / or the threshold value of the time required to measure the number of times of cell reselections are set for each layer. A mobile station device compares the number of times of cell reselections in a specific time and / or the time required for the number of times of cell reselections to reach a specific value with the threshold values and selects a transfer target cell.

Disclosed is a method and apparatus for cell selection, which can prevent the occurrence of an error in the cell selection in a mobile communication system supporting the hierarchical cell structure. The method includes: when the number of times of cell reselection during a cell reselection time period given to a particular User Equipment (UE) located within a micro cell exceeds a predetermined maximum number of times, determining if a sum of actual occupancy time intervals of the particular UE in Node Bs, services of which the particular UE has used up to then, is smaller than a predetermined value; and when the sum of actual occupancy time intervals of the particular UE in Node Bs, services of which the particular UE has used up to then, is smaller than the predetermined value, determining that the UE is in a low speed state and maintaining the micro cell as a service cell for the UE.

An apparatus and method for transmitting / receiving system information in a wireless communication system with a hierarchical cell structure are provided. A method for transmitting system information in a micro Base Station (BS) in a wireless communication system in which at least one micro cell exists within a macro cell includes transmitting first system information to a Mobile Station (MS) communicating with a macro BS within a micro cell and an MS communicating with a micro BS within the micro cell, and transmitting second system information to the MS communicating with the micro BS within the micro cell.

The present application discloses a measurement control method, a user equipment, a control node, and a system, relates to the field of wireless communications, and can reduce handover signaling and improve a handover success rate. The method of the present application mainly includes: receiving measurement configuration information sent by a control node, where the measurement configuration information includes a list of first-type cells, the type of first-type cells, a list of second-type cells, the type of second-type cells, hierarchical cell structure (HCS) priorities, a frequency of first-type cells, or a dedicated parameter for evaluating an event trigger threshold; detecting cell signal quality or signal strength of a cell; and determining, according to the cell signal quality or signal strength and the measurement configuration information, whether to report an event or a measurement result to the control node. The present application is mainly used in a process of mobility management.

In a radio communication system of hierarchical cell structure in which macrocells provided by a macro base station and femto cells provided by a femto base station are overlapped on each other, a method and a system for handing over a terminal are provided. To be specific, if load of a serving base station increase or decreases more than a predetermined extent, a method and a system adaptively adjust the handover between macro base stations, between femto base station, or between femto base station and macro base station.

The invention discloses a method and controller for balancing load among cells of a multiband time division-synchronous code division multiple access (TD-SCDMA) system. The method comprises the following steps: acquiring a balanced candidate cell list according to an intrasystem cell adjacent to a cell in which a terminal is currently stayed; determining the actual frequency band priority level, hierarchical cell structure (HCS) priority level and load priority level of each cell; acquiring the total priority level weight of each cell; sequencing all the cells in the intrasystem balanced candidate cell list; and enabling each cell to carry out an acceptance operation. The controller comprises an intrasystem balanced candidate cell list acquisition module, a priority level determination module connected with the intrasystem balanced candidate cell list acquisition module, a total priority level weight determination module connected with the priority level determination module, a cell sequencing module connected with the total priority level weight determination module and an acceptance module connected with the cell sequencing module, thus the invention ensures that the purpose of balancing load among cells which are in different frequency bands and have different HCS layers is realized.

An apparatus and a method manage power of a small base station. Whether a notify message indicating that a subscribed terminal enters a macro base station that includes an off-small base station is received from the macro base station under a closed access mode is determined. When the notify message is received, whether a service is providable to the subscribed terminal is determined. When the service is providable to the subscribed terminal, the small base station is turned on. During the closed access mode or when a load of a macro cell is large during an open access mode, when a terminal that should be serviced does not exist in the neighborhood of a small base station, an interference and power consumption unnecessarily generated may be reduced by turning off the small base station.

The invention relates to a wireless communication system and discloses a cell selection method and equipment inside a layered cell structure to ensure that terminals can be more reasonably distributed inside layered cells of different levels. Through taking the duration of a DRX cycle as one of the factors selected within an HCS cell, the invention can more reasonably distribute each terminal in each layer of cells of the HCS. When other factors are not changed, a cell with larger coverage area is selected for a terminal with longer DRX cycle. According to the DRX cycle, cell selecting function can be realized inside network side equipment or a terminal. If the moving speed of a terminal is known, the DRX cycle and the speed of the terminal can be combined and are used as one of the factors selected inside the HCS cell.

A method for providing a multicast service from a macrocell or a microcell to a mobile station in a mobile communication system having a hierarchical cell structure in which a given area is divided into at least one macrocell and at least one microcell overlapping with each other. The mobile station receives a multicast service by accessing the macrocell or the microcell according to a carrier-to-interference ratio (C / I) for the multicast service measured in a macrocell area and according to an existence or non-existence of a concurrent call currently in service. When there is no concurrent call currently in service, the mobile station receives the multicast service by accessing the macrocell in an area where the measured C / I is equal to or greater than a required C / I. However, when there is a concurrent call currently in service, the mobile station receives the multicast service by accessing the macrocell or the microcell based on the current cell and the C / I.

Disclosed is a method and apparatus for cell selection, which can prevent the occurrence of an error in the cell selection in a mobile communication system supporting the hierarchical cell structure. The method includes: when the number of times of cell reselection during a cell reselection time period given to a particular User Equipment (UE) located within a micro cell exceeds a predetermined maximum number of times, determining if a sum of actual occupancy time intervals of the particular UE in Node Bs, services of which the particular UE has used up to then, is smaller than a predetermined value; and when the sum of actual occupancy time intervals of the particular UE in Node Bs, services of which the particular UE has used up to then, is smaller than the predetermined value, determining that the UE is in a low speed state and maintaining the micro cell as a service cell for the UE.

An apparatus and method for transmitting / receiving system information in a wireless communication system with a hierarchical cell structure are provided. A method for transmitting system information in a micro Base Station (BS) in a wireless communication system in which at least one micro cell exists within a macro cell includes transmitting first system information to a Mobile Station (MS) communicating with a macro BS within a micro cell and an MS communicating with a micro BS within the micro cell, and transmitting second system information to the MS communicating with the micro BS within the micro cell.

An initial access procedure in a wireless communication of a hierarchical cell structure includes operations of a mobile station (MS). The operations of the MS include transmitting an initial access message; obtaining information of a small cell Base Station (BS) which receives the initial access message, from a response message received from a macro BS; attempting to decode a reference channel transmitted by the small cell BS; and when successfully decoding the reference channel, setting a downlink channel with the small cell BS.

In a radio mobile communication system adopting a hierarchical cell structure comprising a plurality of layers having respective cells of different sizes, the threshold value of the number of times of cell reselections and / or the threshold value of the time required to measure the number of times of cell reselections are set for each layer. A mobile station device compares the number of times of cell reselections in a specific time and / or the time required for the number of times of cell reselections to reach a specific value with the threshold values and selects a transfer target cell.

An apparatus and a method of a macro terminal for controlling interference in a wireless communication system of a hierarchical cell structure are provided. The method includes setting measurement reporting configuration for a blanking trigger per measurement identifier allocated by a macro base station, measuring a receive signal strength of a neighbor base station, comparing the measured receive signal strength value with a reference receive signal strength value of the measurement reporting configuration for the blanking trigger, and according to a comparison result, transmitting to the macro base station, a measurement report message comprising a measurement identifier corresponding to the measurement reporting configuration for the blanking trigger of a pico base station.

A mobile communications system includes a plurality of cell segments each allocated primary carriers to carry circuit-switched traffic and packet data carriers for carrying packet-switched traffic. The packet data carriers include two sets of carriers, a main set of carriers (F1, F2, or F3) and a secondary set of carriers (F4, F5, and F6). The main packet data carriers (F1, F2, and F3) are allocated to corresponding cell segments. The secondary carriers (F4, F5, and F6) are allocated to high capacity segments, which may be segments having high bursty traffic or segments in which a hierarchical cell structure is implemented. For high bursty cell segments, the main carriers (F1, F2, and F3) are used to carry control signaling for performing selection or reselection. However, in such high bursty cell segments, the secondary carriers (F4, F5, and F6) are not used for performing cell segment selection or reselection.

A method, device and system for arranging symbols to be sent in the frequency axis and for sending signals to a radio terminal inside an area using one or a plurality of carrier frequency bands, in a radio communication system with a hierarchical cell structure. The method includes detecting by a device at least one carrier frequency band signal pertaining to a transmission system other than that of its own station. A sending-symbol synchronization is detected based on at least one received signal upon detecting the carrier frequency band signal pertaining to the transmission system other than that of its own station. The signal is sent based on the derived symbol sending timing.

An apparatus and a method of a macro terminal for controlling interference in a wireless communication system of a hierarchical cell structure are provided. The method includes setting measurement reporting configuration for a blanking trigger per measurement identifier allocated by a macro base station, measuring a receive signal strength of a neighbor base station, comparing the measured receive signal strength value with a reference receive signal strength value of the measurement reporting configuration for the blanking trigger, and according to a comparison result, transmitting to the macro base station, a measurement report message comprising a measurement identifier corresponding to the measurement reporting configuration for the blanking trigger of a pico base station.

A method for providing a multicast service from a macrocell or a microcell to a mobile station in a mobile communication system having a hierarchical cell structure in which a given area is divided into at least one macrocell and at least one microcell overlapping with each other. The mobile station receives a multicast service by accessing the macrocell or the microcell according to a carrier-to-interference ratio (C / I) for the multicast service measured in a macrocell area and according to an existence or non-existence of a concurrent call currently in service. When there is no concurrent call currently in service, the mobile station receives the multicast service by accessing the macrocell in an area where the measured C / I is equal to or greater than a required C / I. However, when there is a concurrent call currently in service, the mobile station receives the multicast service by accessing the macrocell or the microcell based on the current cell and the C / I.

A mobile communication capable of re-selecting a cell in accordance with a residual amount of a battery so that the number of times of re-selecting a cell is reduced in accordance with the residual amount of the battery is provided. Information on a plurality of cells having different priorities in a hierarchical cell structure (HCS) is received and a cell measuring reference is re-set in accordance with the received cell information or the residual amount of the battery so that the mobile communication terminal is connected to a cell selected among the cells measured in accordance with the re-set measuring reference. A cell is re-selected in accordance with information received from the connected cell or cells adjacent to the connected cell and a cell measuring reference is re-set so that cells of low priorities are measured in accordance with the residual amount of the battery. Therefore, it is possible to reduce the number of times of re-selecting a cell and to thus reduce the residual amount of the battery.

The object of the present invention is to achieve smooth hand-over in the radio communication system with a hierarchical cell structure that executes data transmission using orthogonal carrier frequency bands. In the sending radio station to arrange sending symbols in a frequency axis and send signals using one or a plurality of carrier frequency bands, on detecting there having been received one or more carrier frequency band signals pertaining to a transmission system other than that of its own station (SO1), the symbol synchronization will be detected based on the received signal (SO2), and the signal to be sent, will be sent at the symbol sending timing derived based on the detected symbol synchronization (SO3). Therefore, by the correlation between the carrier frequency band signals of the transmission system other than that of its own station and the signal of the station of its own, signals causing no mutual interference can be sent at the symbol sending timing, while the receiving radio station can simultaneously receive signals of a plurality of carrier frequency bands and demodulate the signals. For this reason, smooth hand-over can be achieved.