KR101101898B1 - Channel assigning method for avoiding channel interference - Google Patents

Abstract

According to the present invention, a channel allocation method for avoiding channel interference includes checking a neighbor cell of a frequency allocation request cell when the radio network controller identifies a frequency allocation event, and checking whether the radio network controller includes all of the neighbor cells. Process, when the network controller includes all of the neighbor cells, checking channel information of each neighbor cell, checking channel information to identify a channel not used by the neighbor cell, and using the neighbor cell. Allocating a channel out of the non-contiguous channels; if the radio network controller does not include all of the neighbor cells; inspecting a neighbor radio network controller including the non-adjacent cells; Requesting channel information, and the adjacent wireless network The present invention relates to a channel allocation method for avoiding channel interference including receiving channel information of the neighbor cells from a network controller and confirming channel information of each neighbor cell.

 Channel interference, cell selection, channel assignment, channel interference avoidance, channel information

Description

Channel assignment method to avoid channel interference {CHANNEL ASSIGNING METHOD FOR AVOIDING CHANNEL INTERFERENCE}

1 illustrates a structure of a mobile communication system, and

2 is a flowchart illustrating a flow of allocating a frequency of a cell that has received a frequency allocation request according to an embodiment of the present invention.

According to the present invention, when a cell allocates a channel to a portable terminal, a method of allocating a channel having the least channel interference to the portable terminal in consideration of information on a channel in use of the neighbor cell and considering mutual relationship between neighbor cells.

In the conventional channel allocation method for reducing interference, when the mobile terminal needs to request a channel or allocate a channel to the mobile terminal, the wireless network controller arbitrarily selects a channel that is not in use among the frequencies allocated to the cell design. Assign a channel to the portable terminal.

1 is a diagram illustrating the structure of a general mobile communication system.

The mobile communication system includes a core network (CN) 100, a plurality of radio network subsystems (RNS) 110, 120, and a user terminal (UE) 130. It is composed. A Radio Network Subsystem (RNS) 110 and a Radio Network Subsystem (RNS) 120 may include a Radio Network Controller (RNC) and a plurality of base stations (Node Bs). It is composed.

Radio Network Subsystem (RNS) 110 is comprised of a radio network controller 111 and a base station 113, a base station 115, and a base station 117, and a radio network subsystem (RNS). Subsystem (120) includes a Radio Network Controller (RNC) 121, a base station 123, a base station 125, and a base station 127.

Radio Network Controllers (RNCs) 111 to 121 are controlled by a serving RNC (Serving RNC) or Drift RNC (DRNC) or control according to their operation. RNC (Controlling RNC, hereinafter referred to as "CRNC"). The SRNC refers to a Radio Network Controller (RNC) that manages information of each terminal and is also responsible for data transmission with the core network 100. The DRNC means that the data of the terminal is different from the SRNC. When a radio network controller (RNC) transmits and receives an SRNC, the radio network controller (RNC) becomes a radio network controller (RNC), and the CRNC controls a radio base station (RNC: Radio Network Controller). to be.

In FIG. 1, when the information of the terminal 130 is managed by a radio network controller (RNC) 111, the radio network controller (RNC) 111 performs an SRNC on the terminal 130. When the terminal 130 moves and data of the terminal 130 is transmitted and received through the wireless network controller 121, the radio network controller (RNC) 121 determines that the DRNC of the terminal 130 The Radio Network Controller (RNC) 111 that controls the base station 113 in communication with the terminal 130 becomes the CRNC of the base station 113.

The user terminal sets a channel using channel information about a specific cell managed by the base station, and transmits and receives data using the set channel. Therefore, the user terminal recognizes only the physical channel configured for each cell, and the distinction between the base station and the cell is meaningless. Hereinafter, the base station and the cell will be used interchangeably.

In areas where cells overlap, or where cell design is ineffective, the wireless network controller assigns a channel randomly among the available channels to the same channel or adjacent channel without considering channel allocation information or channel information currently used between adjacent cells. Mutual interference may occur, resulting in loss of data.

The existing wireless network controller does not define a specific method of selecting which channel and also selects and allocates a channel arbitrarily without checking channel information of a neighbor cell.

Accordingly, there is a need for an inter-cell channel allocation method that checks channels used by adjacent cells by a controller of a wireless network controlling a base station and considers mutual interference by adjacent channels.

Accordingly, an object of the present invention is to provide a method of checking channel information of adjacent cells not included in a wireless network controller and selecting a channel by avoiding channel interference.

Another object of the present invention is to provide a method for confirming channel information of a neighbor cell by requesting channel information of a neighbor cell to avoid channel interference to the neighbor radio network controller.

Another object of the present invention is to provide a channel selection method for communicating with a neighboring radio network controller and selecting channel information not used by a neighboring cell to avoid channel interference of the neighboring cell.

The method of the present invention for achieving the above object is a channel allocation method for avoiding channel interference, the wireless network controller is a step of checking the neighbor cell of the frequency allocation request cell when receiving a frequency allocation request from the base station, the wireless network controller Checking whether all neighbor cells are included; if the radio network controller includes all neighbor cells, checking channel information used by each neighbor cell; checking channel information of the neighbor cell; A process of checking a channel that is not used by a cell and checking whether the channel is not used, and if the channel is not used, selecting and assigning a channel by using a predetermined channel selection method among channels not used by the adjacent cell. Channel assignment that avoids channel interference, including In providing a method.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Prior to the description of the present invention, channel information refers to a channel used by a base station included in a radio network controller and information of available channels, and the radio network controller checks the channel information by transmitting and receiving the neighboring radio network controller. .

The structure of a mobile communication system according to an embodiment of the present invention is the same as that of FIG.

Referring to FIG. 1, a radio network controller (RNC) 111 to 121 allocates a channel frequency to a plurality of base stations managed by the neighbor cell. The base station provides a channel frequency allocated from a radio network controller (RNC) to the portable terminal of the user. In addition to the normal function, the base station examines a neighbor cell of a cell that has been requested for frequency allocation and Check that the network controller includes all neighbor cells. If the neighbor cells of the cell that has been requested for frequency allocation are not included in the radio network controller, the neighbor radio network controller including the neighbor cell not included in the radio network controller is examined and the channel information of the neighbor cell is requested to the neighbor radio network controller.

After completing the request for channel information of the neighbor cell to the neighbor radio network controller, the radio network controller receives the channel information of the neighbor cell from the neighbor radio network controller and checks the channel information of each neighbor cell to identify a channel not used by the neighbor cell. do. After checking channel information of each neighboring cell, it selects and allocates a channel by using a predetermined method among unused channels. The channel allocation method will be described later with reference to FIG. 2.

2 is a flowchart illustrating a flow of allocating a channel of a cell receiving a frequency allocation request according to the present invention.

Referring to FIG. 2, in step 201, the radio network controller checks occurrence of a frequency allocation event to the base station. If no frequency allocation request is received from the base station in step 201, the wireless network controller proceeds to step 203 and re-confirms the frequency allocation request from the base station after waiting.

If it is determined in step 201 that the base station receives a frequency allocation request from the base station, the wireless network controller proceeds to step 205 and examines the neighboring cell of the frequency allocation request cell. All check if the cell is included in the radio network controller. Step 207 is a process of identifying neighbor cells in order to allocate a frequency of the requested cell. If all neighbor cells are included in the wireless network controller, the wireless network controller proceeds to step 215. Check the channel information used by neighboring cells.

If the neighboring cell of the cell for which frequency allocation request is requested is not included in the wireless network, the wireless network controller proceeds to step 209 to identify a cell that is not included in the wireless network controller. Examine the neighbor radio network controller including the neighbor cell.

When the inspection of the neighbor radio network controller including the neighbor cell is completed in step 209, the radio network controller proceeds to step 211 and requests channel information including channel information including the channel used by the neighbor cell included in the neighbor radio network controller.

In step 211, when the neighbor cell completes a request for information on the channel being used by the neighbor cell, the radio control network controller proceeds to step 213 to receive the requested channel information from the neighbor radio network controller. When the reception of the requested channel information from the wireless network controller in step 213 is completed, the wireless network controller proceeds to step 215 to check the information of the channel used by each neighboring cell.

When the channel information of the neighbor cell is confirmed in step 215, the wireless network controller proceeds to step 217 to identify a channel not used by the neighbor cell, and the wireless network controller proceeds to step 219 to determine a channel not used by the neighbor cell. Check if it exists. If there is no channel that is not used by the neighbor cell as a result of the check in step 219, the wireless network controller proceeds to step 221 and allocates a channel among the used channels and when the cell not used by the neighbor cell is checked, the wireless network controller goes to step 223. In step S, the neighboring cell is allocated to a channel not used by the neighbor cell and the present algorithm is terminated.

If there is a channel not used by the neighboring cell as a result of the test of step 219, the wireless network controller proceeds to step 225 to check channel information not used by the neighboring cells in order of the magnitude of the frequency of the cell pre-allocated when designing the cell. A method of allocating channels by giving priority to each other, for example, a method of assigning priorities in order of increasing frequency intervals of allocated cells, or allocating channels in order of decreasing frequency intervals, and adjacent cells. The channel is selected by selecting a channel in a predetermined manner of randomly selecting frequencies among the frequencies of the unused channels, and the present algorithm is terminated.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, in the case of adjacent cells or overlapping cells, co-channel or adjacent channel interference occurs. As a method for avoiding such channel interference, the present invention relates to a method of confirming channel information of a neighbor cell of a cell to be assigned and transmitting a channel to and from a neighbor radio network controller under the control of a radio network controller, and assigning a channel not used by the neighbor cell. To provide convenience to the user.

Claims (5)

In the channel allocation method for avoiding channel interference, Checking, by the radio network controller, an adjacent cell of the frequency allocation request cell when receiving a frequency allocation request from a base station; Checking that the radio network controller includes all of the neighbor cells; Checking channel information used by each of the neighbor cells when the radio network controller includes all of the neighbor cells; If the radio network controller does not include all of the neighbor cells, checking channel information on neighbor cells not included in the self through a neighbor radio network controller including a neighbor cell not included in the neighbor cell; Checking channel information of the neighbor cell to identify a channel not used by the neighbor cell and checking whether there is a channel not in use; And And if the unused channel exists, selecting and assigning a channel using a predetermined channel selection method among channels not used by the neighboring cell. The method of claim 1, The process of confirming channel information about a neighbor cell not included in the self through the neighbor wireless network controller, Checking a neighbor radio network controller that is a radio network controller including the neighbor cell if the radio network controller does not include all of the neighbor cells; Requesting channel information used by the neighbor cell from the neighbor radio network controller; Checking channel information used by each neighbor cell when receiving channel information used by the neighbor cell from the neighbor radio network controller; Checking channel information used by the neighboring cell to identify a channel not used by the neighboring cell and checking whether the unused channel exists; And And allocating a channel by a predetermined channel allocation method among channels not used by the neighbor cell. The method according to claim 1 or 2, If the unused channel does not exist, the channel is selected and used by any method among the channels being used by the neighbor cell. If the unused channel is checked during use of the selected channel, the unused channel is not used. Channel assignment method for avoiding channel interference further comprising the step of selecting and assigning a channel that does not. 3. The method of claim 2, When the neighbor radio network controller receives the channel information used by the neighbor cell from the radio network controller, the neighbor radio network controller transmits the channel information used by the neighbor cell to the radio network controller. Channel assignment method. The method according to claim 1 or 2, The predetermined channel selection method may be performed by checking the channel information used by the neighboring cell in order of increasing frequency of the frequency of the cell according to the order of magnitude of the interval of the frequency of the cell, which is pre-allocated when designing a cell. A method of allocating channels by giving priority to the cells in order of decreasing frequency interval, and a method of allocating a channel by randomly selecting a frequency among channels of a channel not used by the adjacent cell. Assignment method.

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