JP2020123982A - Self configuration and optimization of adjacent cells in wireless telecommunications network - Google Patents

Abstract

To reduce the cost of design and maintenance of adjacent cell sets.SOLUTION: A radio base station that is providing services to a first cell in a radio network makes a mobile terminal detect a unique cell identity of a second cell related to a non-unique cell identity received in the second cell and report the detection, and thereby, receives the unique identity of the second cell adjacent to the first cell (119). On the basis of the received unique cell identity of the second cell adjacent to the first cell, an adjacent cell set of the first cell is updated (121).SELECTED DRAWING: Figure 6

Description

The present invention relates to neighbor cell self-configuration and optimization in wireless telecommunication networks.

FIG. 1 of the accompanying drawings illustrates a wireless telecommunication network. Here, a large number of communication cells (A, B, C, D) are defined in this wireless telecommunication network, and the radio base station 2 provides a service to each. Each communication cell covers a geographical range, and a large range can be covered by combining many cells. The illustrated mobile terminal 4 is in communication in cell A and is capable of moving around the system 1.

The base station 2 includes many receiving units and transmitting units, and provides a radio coverage area to one or more cells. Each base station 2 is connected to a network "backbone", or core network infrastructure (not shown), which enables communication between the base station and other networks. In the example system of FIG. 1, one base station is shown for each cell.

An important concept in such a network is a cell and its neighboring cells. The mobile terminal 4 typically roams between cells during a call, repeatedly moving from one cell to one of its neighbors. In order to make the handover between cells reliable for both the network 1 and the mobile terminal 4, a known list of neighboring cells, that is, a so-called “neighbour cell set” is important. .. The network 1 can store information about a neighboring cell set for each mobile terminal. When a mobile terminal crosses a cell boundary using a neighboring cell set, the mobile terminal is evaluated and handed over from one cell to another. It will be readily appreciated that the cell boundaries are not well-defined and are in fact somewhat blurry, and that the ranges of base stations will overlap each other.

In the existing system, the mobile terminal 4 receives signals from the surroundings to detect and measure cell operating parameters for adjacent cells. The measured operating parameter is typically a physical layer identifier, eg, scrambling code, signal strength, signal quality, timing information that is not uniquely assigned to a cell. The mobile terminal measures the operating parameters of each neighboring cell and reports it to the network 1. If it is determined that the quality of a neighbor cell is better than the current serving cell, the network performs a handover from the serving cell to the selected neighbor cell. Then, the adjacent cell becomes a cell in service to the mobile terminal.

Typically in a WCDMA (wideband code division multiple access) system, a common pilot channel (CPICH) from neighboring cells to determine id (scramble code) and timing information. Pilot Channel) transmission detected by the mobile terminal.

When a mobile reports neighboring cell signal quality measurements to the network, the identity of each cell is important. Currently, cell identities (scramble codes) are reused in multiple cells. Reusing identities means that cells in service may have the same identity information as neighboring cells, and thus cells may not be distinguishable from each other.

Since the physical layer identifier of a cell is not uniquely determined, it is not possible to completely automate the introduction and maintenance of a neighboring cell set. In order to resolve the conflict that there are multiple neighboring cells that use the same non-unique identifier as the serving cell, it is necessary to perform the work manually.

The present invention aims to reduce the cost of designing and maintaining neighboring cell sets. It is based on adding the steps of the mobile terminal performing additional work, requiring unique identification of neighboring cells in the wireless network and having the mobile terminal report its identity to the network. Embodiments of the present invention are intended to reduce human intervention. The method may be implemented as part of the operations support system and base station, or may be implemented only at the RBS. This method is effective for wireless telecommunication technologies such as GSM (registered trademark), WCDMA (registered trademark), and LTE.

1 illustrates a cellular wireless telecommunication network. 3 shows a mobile terminal and a base station. 5 illustrates steps of a method for practicing one aspect of the present invention. 5 illustrates steps of a method for practicing one aspect of the present invention. 5 illustrates steps of a method for practicing one aspect of the present invention. 5 illustrates steps of a method for practicing one aspect of the present invention.

In contrast to the shortcomings of the previous solutions, the present invention provides a method and architecture for maintaining neighboring cell sets in a mobile cellular network.

FIG. 2 is a schematic diagram showing the mobile terminal 4 and the base station 2 that communicate via the air interface 6. The base station 2 includes a control unit 22, an input/output (I/O) interface 24, a wireless transmission/reception unit 26, and an antenna 28. The control unit communicates with the mobile terminal through the air interface 6 and the transmission/reception unit 26 and the antenna 28. The controller 22 also communicates with other telecommunications networks via the I/O interface 24.

The mobile terminal 4 includes a control unit 42, a man machine interface (MMI) 44, a wireless transmission/reception unit 46, and an antenna 48. The control unit of the mobile terminal 4 functions to control communication with the base station 2 via the transmitting/receiving unit 46 communicating with the air interface 6 and the antenna 48. Interaction with the user of the device is done using the man-machine interface 44. Examples of the man-machine interface 44 include a keypad, a microphone, a loudspeaker, a display device, and the like. The mobile terminal may be a communication device that has only a machine-to-machine interface. Such aspects of base stations and mobile terminals are designed to operate in a conventional manner.

However, the base station 2 and the mobile terminal 4 operating according to the invention are adapted to carry out the method of the invention described below with reference to FIGS. It will be appreciated that the various functional units may be provided by the controller, or other specific part of the device, or the network 1.

A method of practicing the present invention will now be described with reference to the flowcharts of FIGS. FIG. 3 shows the steps performed by the mobile terminal 4. The first step of the method is step 101, where the mobile terminal 4 determines parameter measurements for neighboring cells. Next, the mobile terminal reports the measurement information to the base station (step 103).

Referring to FIG. 4, the base station 2 receives the measurement information from the mobile terminal 4 (step 107). Here, the measurement information is related to the cell identity (not unique) detected by the mobile terminal 4, respectively. If the information from the mobile terminal 4 contains measurements from cell identities that were not previously members of the neighboring cell set, the mobile terminal 4 may also be required to retrieve a unique cell identity (step 113). The unique cell identity is sent from the base station at a much less frequent period than the physical layer identity. To receive and decode this information, mobile terminal 4 may have to briefly interrupt communication with the serving cell. Once the unique cell identity is retrieved (step 115), this information is sent to the serving cell (step 117). When the serving cell receives the unique cell identity (step 119), the newly discovered neighbor cell is now added to the neighbor cell set (step 121) to establish a transmission connection to that neighbor cell. Good. In a cellular network in which some mobile terminals identify new neighboring cells, some filtering is performed on the measurement data so that it can be detected under exceptional propagation conditions, eg mobile terminal 4 being in an airplane. Clearly, it may be desirable to prevent adding distant cells that have been dropped.

In another example, the mobile terminal 4 is capable of providing unique identity information to the base station 2 without having to receive a command to that effect from the base station 2.

Referring to FIG. 6, the base station 2 receives the unique identity information (step 119) and then updates the neighbor cell set. In this way, the neighboring cell set includes unique identity information about the cell, and the cell is determined as a neighboring cell that is a candidate cell for the handover of the mobile terminal 4.

Utilizing a unique cell identifier (UCID) means that there is explicit information about the identity of the neighbor cell, thereby eliminating the confusion about the neighbor cell. The non-unique cell identity, which is fast and requires a small amount of resources for most measurements, facilitates efficient utilization of resources among mobile terminals 4 and sudden handovers to neighboring cells. Only if a new neighbor cell is detected or if the auditing of the relationship between the non-unique cell identity and the unique cell identity is considered appropriate, the mobile terminal 4 will assign a more cumbersome unique cell identifier. You will be asked to search.

The relationship of all cells can be evaluated continuously. Inputs to this evaluation are mobile terminal reports, mobile terminal events, network events, and operator inputs. The result of the evaluation is that cells (or cell relationships) will retain various properties. It can be seen that the cells (relationships) are in various states.

A major advantage of embodiments of the present invention is that it eliminates the need for human intervention in the process of maintaining neighboring cell sets. The operator can leave the neighbor cells completely idle and let the system define the neighbor cells.

Cell lookup associates a unique cell identity (UCID) with the address of the node that implements the cell. For example, in LTE, which is usually DNS, a cell identity is associated with an IP address. The IP address then points to the RBS that implements the cell.

Claims (25)

A method of operating a mobile terminal in a wireless telecommunication system defining a plurality of communication cells, the method comprising:
Communicating with a radio base station servicing the first communication cell;
Determining at least one operating parameter for the second communication cell;
Reporting parameter information regarding each of the operating parameters for the second communication cell to the radio base station of the first communication cell,
Detecting unique cell identifier information for the second communication cell;
Reporting unique cell identifier information for the second communication cell to the radio base station of the first communication cell. The method of claim 1, wherein the at least one operating parameter comprises one or more of a coded code, a signal strength measurement, a signal quality measurement, and timing information. The step of detecting unique cell identifier information and the step of reporting unique cell identifier information are performed at predetermined intervals in response to receiving a command from the radio base station of the first communication cell. Or the method described in 2. The step of detecting unique cell identifier information and the step of reporting unique cell identifier information are performed in response to receiving a command from the radio base station of the first communication cell. the method of. The method of claim 4, further comprising receiving a list of communication cells from the radio base station of the first communication cell, the list including the second communication cell and the plurality of further communication cells. Method. Method according to any one of the preceding claims, wherein the second communication cell is adjacent to the first communication cell. The method according to any one of the preceding claims, further comprising detecting unique cell identifier information for a plurality of further communication cells and reporting the information to the radio base station of the first communication cell. The described method. A mobile terminal for use in a wireless telecommunication system defining a plurality of communication cells, said mobile terminal operable according to the method of any one of the preceding claims. A mobile terminal used in a wireless telecommunication system defining a plurality of communication cells, wherein the mobile terminal comprises a control unit for communicating with a radio base station that provides a service to the first communication cell,
The control unit is
Determining at least one operating parameter for the second communication cell,
Reporting parameter information about each of the operating parameters for the second communication cell to the radio base station of the first communication cell,
Detecting unique cell identifier information for the second communication cell,
A mobile terminal, which reports unique cell identifier information for the second communication cell to the radio base station of the first communication cell. The mobile terminal according to claim 9, wherein the at least one operating parameter includes one or more of a scramble code, a signal strength measurement, a signal quality measurement, and timing information. The movement according to claim 9 or 10, wherein the control unit detects and reports unique cell identifier information at predetermined intervals according to reception of a command from the radio base station of the first communication cell. Terminal. The mobile terminal according to claim 9 or 10, wherein the control unit detects and reports unique cell identifier information in response to receiving a command from the radio base station of the first communication cell. The control unit receives a list of communication cells from the radio base station of the first communication cell, and the list includes the second communication cell and the plurality of further communication cells. Mobile terminal. The mobile terminal according to any one of claims 9 to 13, wherein the second communication cell is adjacent to the first communication cell. The said control part detects the unique cell identifier information with respect to several further communication cells, and reports the said information to the said radio base station of the said 1st communication cell, The any one of Claims 9-14. Mobile terminal. A method for controlling resources in a wireless telecommunication system defining a plurality of communication cells, the method comprising:
Communicating with a mobile terminal operating in a first communication cell;
Receiving parameter information regarding at least one operating parameter for the second communication cell from the mobile terminal;
Defining a neighbor cell list including the second communication cell for the mobile terminal,
Further comprising determining from the received parameter information whether unique cell identity information is required for the second communication cell,
If the unique identity information is needed,
Defining a handover candidate cell list including the second communication cell for the mobile terminal;
Sending an instruction to the mobile terminal;
Receiving unique cell identifier information about the second communication cell from the mobile terminal. 17. The method of claim 16, wherein the at least one operating parameter comprises one or more of scrambling code, signal strength measurement, signal quality measurement, and timing information. 18. The method of claim 16 or 17, wherein the second communication cell is adjacent to the first communication cell. 19. The method according to any of claims 16-18, further comprising receiving unique cell identifier information for a plurality of further communication cells from the mobile terminal. In a wireless telecommunications network that defines multiple communication cells,
Communicating with a mobile terminal operating in a first communication cell,
Receiving parameter information about at least one operating parameter for the second communication cell from the mobile terminal,
For the mobile terminal, define a neighbor cell list including the second communication cell,
Determining from the received parameter information that unique cell identity information is required for the second communication cell,
If the unique identity information is needed,
Defining a handover candidate cell list including the second communication cell for the mobile terminal;
Sending a command to the mobile terminal,
A network including network resources for receiving unique cell identifier information for the second communication cell from the mobile terminal. 21. The network of claim 20, wherein the at least one operating parameter includes one or more of scrambling code, signal strength measurement, signal quality measurement, and timing information. The network according to claim 21 or 22, wherein the second communication cell is adjacent to the first communication cell. The network according to any one of claims 20 to 22, wherein the network resource receives from the mobile terminal unique cell identifier information for a plurality of further communication cells. The network according to any one of claims 20 to 23, wherein the network resource is provided by a radio base station. The wireless telecommunication network according to any one of claims 20 to 24, further comprising the mobile terminal according to any one of claims 16 to 19.