JP6770557B2 - Self-configuration and optimization of adjacent cells in wireless telecommunications networks - Google Patents

Description

The present invention relates to self-configuration and optimization of adjacent cells in a wireless telecommunications network.

FIG. 1 of the attached drawing shows a wireless telecommunications network. Here, many communication cells (A, B, C, D) are defined in this wireless telecommunications network, and the wireless base station 2 provides a service to each of them. Each communication cell covers a geographical range, and a wide range can be covered by combining many cells. The illustrated mobile terminal 4 is communicating in cell A and can move around the system 1.

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

An important concept in such a network is a cell and its adjacent cells. It is typical for the mobile terminal 4 to move around between cells during a phone call, repeatedly moving from one cell to one of its adjacent cells. For both the network 1 and the mobile terminal 4, in order to make the handover between cells reliable, a list of known adjacent cells, a so-called "neighbor cell set", is important. .. The network 1 can store information about a set of adjacent cells for each mobile terminal. When a mobile terminal crosses a cell boundary using an adjacent cell set, the mobile terminal is evaluated and handed over from one cell to another. It is easy to see that the cell boundaries are not well defined and are actually somewhat blurry, and that the base station ranges will overlap each other.

In the existing system, the mobile terminal 4 detects and measures cell operating parameters for adjacent cells by receiving signals from the surroundings. The measured operating parameters are typically physical layer identifiers, such as scrambled codes, signal strength, signal quality, and timing information that are not uniquely assigned to a cell. The mobile terminal measures the operating parameters of each adjacent cell and reports it to network 1. If it is determined that the quality of an adjacent cell is better than the current serviced cell, the network performs a handover from the serviced cell to the selected adjacent cell. Then, the adjacent cell becomes the cell in service to the mobile terminal.

Typically in a WCDMA® (wideband code division multiple access) system, a common pilot channel (CPICH) from peripheral cells is used to determine id (scramble code) and timing information. The mobile terminal detects the Pilot Channel) transmission.

The identity of each cell is important when mobile reports adjacent cell signal quality measurements to the network. Today, 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, which may make them indistinguishable from each other.

Since the physical layer identifier of a cell is not uniquely determined, the introduction and maintenance of neighboring cell sets cannot be fully automated. In order to resolve the conflict that there are multiple adjacent cells that use the same non-uniqueness identifier as the cell in service, it is necessary to do the work manually.

An object of the present invention is to reduce the cost of designing and maintaining an adjacent cell set. It is based on the addition of a step that requires the mobile terminal to perform additional work, uniquely identify adjacent cells in the wireless network, and have the mobile terminal report its identity to the network. Embodiments of the present invention are intended to reduce human hand intervention. The method can be carried out as part of an operational support system and base station, or can be carried out only in the RBS. This method is effective for wireless telecommunications technologies such as GSM®, WCDMA®, and LTE.

Indicates a cellular wireless telecommunications network. Indicates a mobile terminal and a base station. The steps of the method of carrying out one aspect of the present invention are shown. The steps of the method of carrying out one aspect of the present invention are shown. The steps of the method of carrying out one aspect of the present invention are shown. The steps of the method of carrying out one aspect of the present invention are shown.

In contrast to the disadvantages of the prior solutions, the present invention provides methods and architectures for maintaining adjacent cell sets within a mobile cellular network.

FIG. 2 is a schematic diagram showing a mobile terminal 4 and a base station 2 communicating via an 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 via the transmission / reception unit 26 and the antenna 28. The control unit 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: man machine interface) 44, a wireless transmission / reception unit 46, and an antenna 48. The control unit of the mobile terminal 4 functions to control communication between the transmission / reception unit 46 communicating with the air interface 6 and the base station 2 via the antenna 48. Communication with the user of the device is performed using the man-machine interface 44. Examples of the man-machine interface 44 include a keypad, a microphone, a loudspeaker, and a display device. 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 according to convention.

However, the base station 2 and the mobile terminal 4 that operate according to the present invention are designed to carry out the method of the present invention described below with reference to FIGS. 3 to 6. It will be appreciated that various functional units can be provided by the control unit, or other specific unit in the device, or network 1.

Here, a method of carrying out the present invention will be described with reference to the flowcharts of FIGS. 3 to 6 and FIG. FIG. 3 shows the steps performed by the mobile terminal 4. The first step of this method is step 101, where the mobile terminal 4 determines the parameter measurement for the peripheral cells. Next, the mobile terminal reports the measurement information to the base station (step 103).

Looking at 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. If the information from the mobile terminal 4 contains measurements from cell identities that were not previously members of the adjacent cell set, the mobile terminal 4 may also be required to search for a unique cell identity (step). 113). Unique cell identities are transmitted from the base station at a much less frequent cycle than physical layer identities. In order to receive and decrypt this information, the mobile terminal 4 may have to interrupt communication with the cell in service for a short time. Once a unique cell identity has been retrieved (step 115), this information is sent to the serviced cell (step 117). When a serviced cell receives a unique cell identity (step 119), adding a newly discovered adjacent cell here to the adjacent cell set (step 121), even if a send connection to that adjacent cell is established. Good. In a cellular network where some mobile terminals identify new adjacent cells, the measurement data is filtered in some way so that it can be detected under exceptional propagation conditions, for example, the mobile terminal 4 is in an airplane. It is clear that it may be desirable to prevent the addition of distant cells that have been made.

In another example, the mobile terminal 4 can provide the base station 2 with unique identity information without having to receive a command to that effect from the base station 2.

Looking at FIG. 6, base station 2 receives unique identity information (step 119) and then updates the adjacent cell set. As described above, the adjacent cell set includes unique identity information for the cell, and such a cell is determined as an adjacent cell which is a candidate cell for handover of the mobile terminal 4.

Utilizing a unique cell identifier (UCID: unique cell identifier) means that there is clear information about the identity of the adjacent cell, thereby eliminating confusion about the adjacent cell. The non-unique cell identity, which is fast for most measurements and requires a small amount of resources, facilitates efficient use of resources in the mobile terminal 4 and abrupt handover to adjacent cells. Only when a new adjacent cell is detected, or when auditing the relationship between the non-unique cell identity and the unique cell identity seems appropriate, the mobile terminal 4 gives the more cumbersome unique cell identifier. You are required to search.

The relationships 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 the cell (or cell relationship) will retain various properties. This can also be seen as the cells (relationships) in various states.

A major effect of embodiments of the present invention is to eliminate the need for human intervention in the process of maintaining adjacent cell sets. It is possible for the operator to leave the adjacent cell completely alone and leave it to the system to determine the adjacent cell.

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

Claims (27)

A method of operating an LTE mobile terminal in an LTE wireless communication network including a plurality of LTE communication cells.
Within each LTE communication cell, non-unique cell identities and unique cell identities are transmitted,
The non-unique cell identity is a non-unique physical layer cell identity within the LTE radio communication network, and the unique cell identity is different from the non-unique cell identity and is adjacent within the LTE radio communication network. Uniquely identify the cell
The non-unique cell identity is transmitted within one LTE cell at the first interval, the unique cell identity is transmitted within the LTE cell at the second interval, and the first interval and the said. The second interval is set so that the unique cell identity is transmitted less frequently than the non-unique cell identity.
The LTE wireless communication network stores a set of adjacent cells including known adjacent cells of the first LTE communication cell.
A step of communicating with a radio base station that provides a service to the first LTE communication cell,
The step of determining the non-unique cell identity of the second LTE communication cell, and
A step of reporting the non-unique cell identity of the second LTE communication cell to the radio base station,
When the second LTE communication cell is not included in the adjacent cell set of the first LTE communication cell, the second LTE communication cell among the plurality of LTE communication cells is transmitted from the radio base station. In the step of receiving the instruction to acquire the unique cell identity of
The step of acquiring the unique cell identity of the second LTE communication cell, and
A method comprising reporting the unique cell identity of the second LTE communication cell to the radio base station of the first LTE communication cell. The step of determining the non-unique cell identity of the second LTE communication cell and the step of reporting the non-unique cell identity of the second LTE communication cell to the radio base station receive the instruction. The method of claim 1, which precedes the step of The step of determining the non-unique cell identity of the second LTE communication cell based on the signal detected in the physical layer, and
With the step of obtaining a unique cell identity before Symbol second LTE communication cells A method according to claim 2. The non-unique cell identity of the second LTE communication cell reported is associated with at least one operating parameter of the second LTE communication cell, the at least one operating parameter being signal strength, signal quality, and the like. And the method of claim 1, comprising at least one of the timing information. The method of claim 1, wherein the step of acquiring and reporting the unique cell identity is performed in response to the command from the radio base station of the first LTE communication cell. The method according to claim 1, wherein the second LTE communication cell is adjacent to the first LTE communication cell. To enable the establishment of a transmit connection to the newly discovered second LTE communication cell, the unique cell identity of the second LTE communication cell is given to the radio base station of the first LTE communication cell. The method of claim 1, comprising a step of reporting. An LTE mobile terminal used in an LTE wireless communication network including a plurality of LTE communication cells.
Within each LTE communication cell, non-unique cell identities and unique cell identities are transmitted,
The non-unique cell identity is a non-unique physical layer cell identity within the LTE radio communication network, and the unique cell identity is different from the non-unique cell identity and is adjacent within the LTE radio communication network. Uniquely identify the cell
The non-unique cell identity is transmitted within one LTE cell at the first interval, the unique cell identity is transmitted within the LTE cell at the second interval, and the first interval and the said. The second interval is set so that the unique cell identity is transmitted less frequently than the non-unique cell identity.
The LTE wireless communication network stores a set of adjacent cells including known adjacent cells of the first LTE communication cell.
The LTE mobile terminal includes a control unit, and the control unit
Communicate with a radio base station that provides services to the first LTE communication cell,
Determine the non-unique cell identity of the second LTE communication cell and
Report the non-unique cell identity of the second LTE communication cell to the radio base station.
When the second LTE communication cell is not included in the adjacent cell set of the first LTE communication cell, the second LTE communication cell among the plurality of LTE communication cells is transmitted from the radio base station. Received the instruction to acquire the unique cell identity of
Acquire the unique cell identity of the second LTE communication cell and
An LTE mobile terminal that reports the unique cell identity of the second LTE communication cell to the radio base station of the first LTE communication cell. The control unit
Acquire the non-unique cell identity of the second LTE communication cell and
The LTE mobile terminal according to claim 8 , wherein the non-unique cell identity of the second LTE communication cell is reported to a radio base station that provides a service to the first LTE communication cell. The control unit
The non-unique cell identity of the second LTE communication cell acquired and reported is related to detecting and reporting at least one operating parameter of the second LTE communication cell, said at least one operating. The LTE mobile terminal according to claim 9 , wherein the parameter includes at least one of signal strength, signal quality, and timing information. The control unit
The LTE mobile terminal according to claim 9 , wherein the non-unique cell identity of the second LTE communication cell is acquired in the physical layer . The control unit
Wherein the unique cell identity of the second LTE communication cell to report, LTE mobile terminal according to claim 9. The LTE mobile terminal according to claim 8 , wherein the acquisition and reporting of the unique cell identity is executed in response to the command from the radio base station of the first LTE communication cell. The LTE mobile terminal according to claim 8 , wherein the second communication cell is adjacent to the first communication cell. The control unit
To enable the establishment of a transmit connection to the newly discovered second LTE communication cell, the unique cell identity of the second LTE communication cell is given to the radio base station of the first LTE communication cell. The LTE mobile terminal according to claim 8 to report. It is an automatic setting method of adjacent cells in an LTE wireless communication network including a plurality of LTE communication cells.
Within each LTE communication cell, non-unique cell identities and unique cell identities are transmitted,
The non-unique cell identity is a non-unique physical layer cell identity within the LTE radio communication network, and the unique cell identity is different from the non-unique cell identity and is adjacent within the LTE radio communication network. Uniquely identify the cell
The non-unique cell identity is transmitted within one LTE cell at the first interval, the unique cell identity is transmitted within the LTE cell at the second interval, and the first interval and the said. The second interval is set so that the unique cell identity is transmitted less frequently than the non-unique cell identity.
The LTE wireless communication network stores a set of adjacent cells including known adjacent cells of the first LTE communication cell.
The step of communicating with the LTE mobile terminal operated in the first LTE communication cell, and
The step of receiving the non-unique cell identity of the second LTE communication cell at the radio base station that provides the service to the first LTE communication cell, and
When the second LTE communication cell is not included in the adjacent cell set of the first LTE communication cell, the LTE mobile terminal also acquires the unique cell identity of the second LTE communication cell. And the steps to order
The step of receiving the unique cell identity of the second LTE communication cell from the LTE mobile terminal, and
A transmit connection is made by finding a mapping in the lookup map of the unique cell identity of the second LTE communication cell with the network address of the radio base station servicing the second LTE communication cell. Steps to establish and methods including. The step of ordering to obtain the unique cell identity is also
16. The method of claim 16 , which precedes the step of receiving the non-unique cell identity of the second LTE communication cell from the LTE mobile terminal. The non-unique cell identity of the second LTE communication cell received is associated with at least one operating parameter of the second LTE communication cell, the at least one operating parameter being signal strength, signal quality, and the like. And the method of claim 17 , comprising at least one of the timing information. 16. The method of claim 16 , further comprising receiving the unique cell identities of a plurality of additional LTE communication cells from the LTE mobile terminal. The method of claim 16 , wherein the network address is an IP address. 16. The method of claim 16 , wherein each step is performed by a radio base station. An LTE wireless communication network that defines multiple LTE communication cells.
Within each LTE communication cell, non-unique cell identities and unique cell identities are transmitted,
The non-unique cell identity is a non-unique physical layer cell identity within the LTE radio communication network, and the unique cell identity is different from the non-unique cell identity and is adjacent within the LTE radio communication network. Uniquely identify the cell
The non-unique cell identity is transmitted within one LTE cell at the first interval, the unique cell identity is transmitted within the LTE cell at the second interval, and the first interval and the said. The second interval is set so that the unique cell identity is transmitted less frequently than the non-unique cell identity.
The LTE wireless communication network stores a set of adjacent cells including known adjacent cells of the first LTE communication cell.
The network includes network resources, and the network resources are
Communicate with the LTE mobile terminal operated in the first LTE communication cell,
A radio base station that provides services to the first LTE communication cell receives the non-unique cell identity of the second LTE communication cell and receives the non-unique cell identity.
The LTE mobile terminal is instructed to acquire the unique cell identity of the second LTE communication cell as well.
When the second LTE communication cell is not included in the adjacent cell set of the first LTE communication cell, the unique cell identity of the second LTE communication cell is received from the LTE mobile terminal. And
A transmit connection is made by finding a mapping in the lookup map of the unique cell identity of the second LTE communication cell with the network address of the radio base station servicing the second LTE communication cell. An LTE wireless communication network that can be operated to establish. The network resource is
22. The LTE radio communication network according to claim 22, which can be operated to receive the non-unique cell identity of the second LTE communication cell from the LTE mobile terminal. The network resource is
It can be manipulated to receive the non-unique cell identity associated with at least one operating parameter of the second LTE communication cell, the at least one operating parameter being scrambled code, signal strength, signal quality, and. The LTE wireless communication network according to claim 23 , which includes at least one of the timing information. The network resource is
22. The LTE wireless communication network according to claim 22, which can be operated to receive unique cell identities of a plurality of additional LTE communication cells from the LTE mobile terminal. The LTE wireless communication network according to claim 22 , wherein the network address is an IP address. The LTE wireless communication network according to claim 22 , wherein the network resource is provided by a wireless base station.

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