KR100276720B1 - How to calculate paging load in cellular system - Google Patents

Abstract

Disclosed is a method for calculating a paging load in a cellular system. In this method, the system administrator can determine the number of call messages (Np) and the number of short messages (Ns) transmitted on one paging channel of the base station, the number of call answer messages received from the access channel corresponding to one paging channel, The number of outgoing request messages is measured, and then the total number of slots (or frames) of the paging channel is calculated, and the number of slots (or number of frames) for overhead messages of the paging channel is calculated. The number of slots (or frames) for the paging channel's call message is then calculated using the measured number of call messages, and the number of slots (or frames) for the short message on the paging channel is measured using the measured number of short messages. Number) and calculate the number of slots (or frames) for the base station acknowledgment and channel allocation messages of the paging channel using the measured number of call response messages and the number of call request messages. As a result, the load ratio of the paging channel is calculated using the sum of the calculated slot numbers (or frame numbers) and the total number of slots (or frames) of the paging channel.

Description

How to calculate paging load in cellular system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellular mobile telecommunication system, and more particularly to a base station in a common air interface (CAI) of a mobile communication system using a code division multiple access (CDMA) technique. A method for calculating a paging load in a cellular system, which measures the load on the capacity of a paging channel for sending a message to a mobile phone.

The cellular mobile communication system divides the entire service area into a plurality of base station areas to form cells, which are small service areas, and centrally controls these base stations with a mobile switching center (MSC). This allows the subscriber to continue the call while moving from cell to cell.

1 is a block diagram of a cellular system using a code division multiple access technique. As shown, a base transceiver station (BTS) 20, 30, 40 which provides a mobile communication service to a subscriber through a mobile telephone (MT) 10 and a plurality of base stations are controlled. A base station controller (BSC) 50, a mobile switching center (MSC) 60 that connects the base station controller to a public switched telephone network (PSTN) or another base station controller. do.

An idle mobile phone that is not conducting a call performs commands such as overhead, paging, commands, and channel allocation by searching for a paging channel transmitted from the base station. Calls the mobile phone over the paging channel and the mobile phone answers the call over the access channel. Therefore, the capacity of the paging channel is a very important factor in the call connection of mobile phones.

A base station can use up to seven paging channels in relation to the load of the paging channel. In order to accurately calculate the number of paging channels to be used by the base station, the base station includes the load of the paging channel in proportion to the increasing subscriber and its load. It is necessary to accurately calculate the capacity of the paging channel to be possible and to select the number of paging channels necessary for it.

Conventionally, in order to calculate the exact capacity and load of a paging channel, the load of the paging channel is calculated using the statistics, taking into account statistics such as a mobile switching center or a short message service system that sends a message through the paging channel. It was. However, in the paging load calculation method according to the prior art operating as described above, the content of the paging load may vary according to each base station, and because the paging channel load for each base station needs to be investigated and calculated, the exact paging channel There was a problem that it could not respond quickly by calculating the load of.

Accordingly, an object of the present invention, which is designed to solve the problems of the prior art operating as described above, is to calculate statistics related to the capacity of a paging channel internally to a base station paging channel device and to calculate an accurate load amount of a current paging channel for each base station. The present invention provides a method for calculating paging load in a cellular system.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention and the accompanying drawings.

1 is a block diagram of a cellular system using code division multiple access techniques.

2 is a flowchart of a paging load calculation method according to the present invention;

3 shows the ratio of slots for calculating the load rate of the paging channel according to the invention;

<Explanation of symbols for the main parts of the drawings>

10: mobile phone 20, 30, 40: base station

50: base station controller 60: mobile switching center

1: overhead message 2: call message

3: short message

4: Base station Ack command and channel assignment message

A preferred embodiment of the paging load calculation method in the cellular system according to the present invention, which was devised to achieve the above object,

The system manager receives the number of general page messages (Np) and the number of short messages (Ns) transmitted on one paging channel of the base station, and the calls received from the access channel corresponding to one paging channel. Measuring the number of paging response messages Nr and the number of originating messages No;

Calculating a total number of slots (or frames) Nst or Nft of the paging channel;

Calculating a slot number (or frame number) for an overhead message of the paging channel;

Calculating the number of slots (or frames) for the paging channel's paging message using the measured number of paging messages Np;

Calculating a slot number (or frame number) for the short message of the paging channel using the measured number of short messages (Ns);

Number of slots (or frames) for the base station Ack Order and Channel Assignment messages of the paging channel using the measured number of call answer messages (Nr) and the number of outgoing request messages (No) Number); And

Calculating a load rate of the paging channel using the sum of the slot number (or frame number) for each message and the total slot number (or frame number) of the paging channel.

In the following description of the present invention, if 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. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification. Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention.

2 is a flowchart illustrating a paging load calculation method according to the present invention. As shown, in step s110, the system manager obtains the number of call messages and short messages transmitted in one paging channel, and the number of call answer messages received from an access channel corresponding to one paging channel. And the number of outgoing request messages. In step s120, the total number of slots per hour of the paging channel is calculated, in step s130, the number of slots per hour for the overhead message of the paging channel is calculated, and in step s140, per hour for the paging channel's call message. After calculating the number of slots, calculating the number of slots per hour for the short message of the paging channel in step (s150), and calculating the number of slots per hour for the base station acknowledgment and channel allocation message of the paging channel in step (s160), In step S170, the load rate of the paging channel is calculated over time by using the sum of the number of slots per hour for the messages and the total number of slots per hour of the paging channel.

After the mobile phone detects which base station it is in via a pilot channel transmitted from the base station, it synchronizes the time of the mobile phone with the base station's time through the synchronous channel, and then the paging channel. Navigate. The paging channel consists of a number of time slots, one slot consists of a number of frames, and since the mobile phone searches for the slot corresponding to it, the slot for the mobile phone corresponds to itself. It is very important to synchronize with the base station in order to accurately find the.

Important messages transmitted by the paging channel include overhead and paging messages, and base station acknowledgment and channel assignment messages.If a paging channel is supported, short messages transmitted from the short message center are also transmitted. .

Information on various configuration changes of the system is transmitted through an overhead message of a paging channel, which includes a system parameter message, an access parameter message, and a neighbor list message. ) And a CDMA Channel List Message. The system parameter message consists of the configuration and registration parameters of the paging channel, parameters for pilot signal acquisition, etc. The access parameter message contains information on the configuration of the access channel and control parameters, and the neighbor base station list message is used for handoff. The information of the neighbor base station, the offset of the pilot signal (Offset) and the configuration information of the neighbor base station, etc. are included, and the CDMA channel list message includes information on the CDMA frequency allocation including the paging channel.

When the base station sends a call message to the mobile phone, the mobile phone responds with a call answer message through the access channel corresponding to the paging channel, and the base station then sends the base station Ack command and channel assignment message to the mobile phone to prepare for the call. Also, when the mobile phone sends outgoing request message through the access channel, the base station sends a base station acknowledgment message and channel assignment message to the mobile phone to prepare for the call.

The paging load calculation method according to the present invention calculates the size of various messages transmitted by the paging channel and calculates the ratio to the total size of the paging channel, thereby calculating the paging load. Hereinafter, the operation of the present invention will be described by way of example.

In this example, if 22 base stations (BTS) are connected to one base station controller (BSC), and 7 base station controllers are connected to one mobile switching center, one mobile switching center has 154 (22 x 7) base stations. Connect At busy time, the number of call messages per hour (Np) measured for one paging channel is 231,150, and the number of call response messages (Nr) is 3,983, and the message is transmitted at 9600bps. Assume a paging channel.

In step (s110), the system administrator determines the number of call messages and short messages transmitted in one paging channel, the number of call response messages and the number of call request messages received from an access channel corresponding to one paging channel. Measure

Where Nst is the number of slots of the paging channel available in one hour, Nft is the number of frames of the paging channel available in one hour, Np is the number of hourly paging messages transmitted on one paging channel, and Nr is one The number of call response messages per hour received from the access channel, No is the number of outgoing request messages per hour received from one access channel, and Ns is the number of short messages per hour transmitted on one paging channel.

In step S120, the slot number (frame number) of the paging channel available at one time may be obtained by Equation 1. However, one frame has a time of 20 ms and one slot includes four frames.

Number of frames: Nft = 45000 slots × 4 = 180000 frames

Number of slots: Nst = 3600s / 80ms = 45000 slots

In step S130, the slots per time for the overhead message can be obtained by Equation 2. However, for 1.2 seconds, the length of the system parameter message is 3 half frames, the length of the access parameter message is 2 half frames, the length of the CDMA channel list message is 1 half frame, and the length of the extended system parameter message is Since it is 2 half frames and the length of the extended neighbor base station list message is 4 half frames, the overhead message occupies 6 frames for 1.2 seconds.

3600: (slots per hour for overhead messages) = 1.2: 6

(Slots per hour for orderhead messages) = 3600 × 6 / 1.2

= 18000 frames = 4500 slots

In step s140, the number of slots per time for the call message may be obtained by Equation 3 using the number Np of the call messages measured in step s110. However, if the number of call messages (Np) per hour is measured to be 231,150, the number of call messages generated per one slot (80ms) is about 5, and the size of the call messages according to the standard is (70 + 58 × N In this case, if N is an average of 5, the size of the call message for 5 paging numbers is 360 bits (= 70 + 58 x 5), which is 2 frames, or 0.5 slots, at a speed of 9600 bps.

Np: (Number of slots per hour for call messages) = 5: 0.5

(Slots per hour for call messages) = Np × 0.5 / 5

= 0.1 × Np

That is, (slots per hour for call messages) = 0.1 × 231150

= 23,115 slots

In step s150, the number of slots per hour for the short message may be obtained by Equation 4 using the number Ns of the short messages measured in step s110. However, if the number of short messages (Ns) per hour transmitted in one paging channel is measured to 2070, one short message is 50 bytes in size, so one short message is 2.5 frames.

(Slots per hour for short messages) = 2.5 × Ns

That is, (slots per hour for short messages) = 2.5 × 2070 = 5175 frames

= 646.875 slots

In step s160, the number of slots per time for the base station Ack command and the channel assignment message may be obtained by Equation 5 using the number of call response messages and the number of call request messages measured in step s110. However, if the number of base station acknowledgment (or channel assignment messages) is the sum of the number of call answering messages and the number of outgoing request messages, and it is measured as 1.328 in 1.2 seconds, the base station acknowledgment (or channel assignment messages) is one paging. One command (or message) is sent once for a channel. Since the size of the base station Ack command according to the standard is (48 + 64 × N) bits, the size of the base station Ack command for one command is 112 bits (= 48 + 64), which is one frame, that is, the size of 0.25 slot. Similarly, since the size of the channel assignment message according to the standard is (46 + 85 x N) bits, the size of the channel assignment message for one message is 131 bits (= 46 + 85), which is 1 frame, that is, the size of 0.25 slot. Thus, the base station acknowledgment and channel assignment messages are 0.5 slots.

(Slots per hour for base station acknowledgment and channel assignment messages) = 0.5 × Nr

That is, (slots per hour for base station acknowledgment and channel assignment messages)

= 0.5 × 3984 = 1992 Slots

In step S170, the hourly loading rate of the paging channel may be obtained by Equation 6. However, the number of slots per time for the actual message is the sum of the number of slots per time obtained in the above steps s120 to s150.

(Hourly load on the paging channel)

= (Slots per hour for the actual message) / (total slots per hour) × 100

(Slots per hour for the actual message)

= (Slots per hour for overhead messages) + 0.1 Np + 2.5 Ns + 0.5 Nr

That is, (slots per hour for the actual message) = 4500 + 23115 + 646.875 + 1992

= 30253.875 slots

(Hourly load on the paging channel) = 30253/45000 × 100

= 67.23%

That is, in this example, one paging channel has a load rate of 67% per hour.

Figure 3 shows the ratio of slots for calculating the load rate of the paging channel according to the present invention, as shown, the number of slots (1) (2) (3) for the actual message relative to the total number of slots (5). By calculating the ratio of (4), the load ratio of the paging channel can be obtained.

As described above, the present invention can calculate the load ratio of the paging channel for each time based on the statistically measured data. Statistical data considered in the present invention is the total number of paging (Np) transmitted on one paging channel, the number of call response messages (Nr) received from an access channel corresponding to one paging channel and the transmission of one paging channel Number of short messages (Ns). Therefore, by calculating the statistical data on the number of messages, it is possible to calculate the load rate of the paging channel for each system.

The present invention can be variously modified and can take various forms and only the specific embodiments thereof are described in the detailed description of the invention. It is to be understood, however, that the present invention is not limited to the specific forms mentioned in the detailed description of the invention, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood to do.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention calculates statistics related to the capacity of a paging channel internally to a base station paging channel element, measures an accurate load rate of the current paging channel for each base station, and reports the result to a higher system, thereby allowing the operator to report to the base station. It is possible to adjust the transmission rate and number of necessary paging channels and the number of repetition of paging channel messages in advance.As a result, various problems caused by loss of unnecessary paging channel messages or overloading of paging channel can be eliminated in advance. There is an effect that can improve the quality of.

Claims (12)

Measuring, by the system administrator, the number of call messages and short messages transmitted on one paging channel of the base station, the number of call answer messages and the number of outgoing request messages received from an access channel corresponding to one paging channel; ; Calculating the total number of slots (or frames) of the paging channel; Calculating a slot number (or frame number) for an overhead message of the paging channel; Calculating the number of slots (or number of frames) for the paging channel's paging message using the measured number of paging messages; Calculating a slot number (or frame number) for the short message of the paging channel using the measured number of short messages; Calculating the number of slots (or the number of frames) for the base station acknowledgment and channel allocation messages of the paging channel using the measured number of call response messages and the number of call request messages; And And calculating a load rate of a paging channel using the sum of the number of slots (or frame numbers) for each message and the total number of slots (or frames) of the paging channel. The method of claim 1, wherein the calculating of the total number of slots of the paging channel comprises calculating, over a period of time, the number of slots of the available paging channel. The method of claim 1, wherein the calculating of the number of slots for the overhead message comprises: for a predetermined time, the number of slots for the system parameter message and the number of slots for the access parameter message, the number of slots for the neighbor base station list message, and the CDMA. A method for calculating paging loads in a cellular system that calculates the sum of the slot numbers for channel list messages. The paging in the cellular system of claim 1, wherein the calculating of the number of slots for the general paging message is performed in consideration of the number of paging messages transmitted on one paging channel and the size of paging messages for a predetermined time. Load calculation method. The method of claim 4, wherein the number of slots for the general call message is: A method for calculating paging loads in a cellular system, calculating 0.1 × (number of call messages transmitted on one paging channel). The method of claim 1, wherein the calculating of the number of slots for the short message comprises: A method of calculating a paging load in a cellular system during a predetermined time period, considering the number of short messages transmitted in one paging channel and the size of one short message. The method of claim 6, wherein the slot number for the short message is: A method of calculating paging load in a cellular system, calculating 2.5 × (the number of short messages transmitted on one paging channel). The method of claim 1, wherein the calculating of the number of slots for the base station acknowledgment command and the channel assignment message comprises: the number of base station acknowledgment commands (or channel assignment messages) transmitted during a predetermined time, the size of the base station acknowledgment command and the channel assignment A method of calculating paging load in a cellular system that calculates a message size. 10. The method of claim 8, wherein the number of base station Ack commands (or channel assignment messages) is calculated as the sum of the measured number of call response messages and the number of outgoing request messages. The method of claim 8, wherein the number of slots for the base station Ack command and the channel assignment message, A method of calculating paging load in a cellular system, counting as 0.5 x (number of call response messages received from an access channel corresponding to one paging channel). The method of claim 1, wherein the calculating of the load rate of the paging channel comprises: Paging load calculation method in a cellular system for a certain time, calculating (sum of slot numbers for a message) / (total slot number of a paging channel) x 100. The method of claim 11, wherein the load rate of the paging channel, {(Slots per hour for overhead messages) + 0.1 × (total number of paging transmitted on one paging channel) + 2.5 × (number of short messages sent on one paging channel) + 0.5 × (one access channel Number of call response messages received from the system)} / (total number of slots of the paging channel) x 100, paging load calculation method in a cellular system.