JP2001157246A - Position registration method for wireless communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an algorithm of a position registration method suitable for a communication terminal fixedly in use in place of a conventional algorithm of acquiring a base station by a communication terminal having been developed on the presumption of movement. SOLUTION: In the position registration method for a wireless communication terminal that is fixedly in use, the wireless communication terminal receives control information sent from each base station over a prescribed time, records the number of reception times and an average reception electric field strength of each base station, and selects a base station whose average reception electric field strength is highest for a 1st ranking of a position registration candidate among the base stations whose number of reception times reaches a reference number of times. Even when an incoming call hit rate of the wireless communication terminal is improved and the wireless communication terminal is fixedly placed at a place where a radio wave is unstable, the wireless communication terminal can surely acquire the base station and conducts stable communication with a center device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a location registration method for a wireless communication terminal installed in a vending machine, an electric / gas meter, and the like, and more particularly, to a location registration method for a base station capable of performing stable communication. It was made.

[0002]

2. Description of the Related Art Conventionally, in mobile communication terminals such as cellular phones and PHSs, location registration is performed with respect to the nearest base station.
A call from a mobile communication terminal or an incoming call to a mobile communication terminal is performed through a base station whose location is registered.

A PHS having an area of 100 to several hundred meters in radius
A large number of base stations are installed in various places such as underground malls and buildings while dubbing a part of the area. The PHS terminal that performs position registration receives control information from a plurality of surrounding base stations, measures the received electric field strength, and performs position registration for the base station with the highest received electric field strength.

[0004] In recent years, PHS terminals are installed in vending machines, gas meters, power meters, and the like, and are used to automatically transmit sales data and measurement data.

FIG. 7 shows a PHS installed in a vending machine 71.
A system for collecting sales data by the communication device 72 is shown. Sales data of vending machine 71 is PHS communication device
72, and the PHS communication device 72
The center device 75 is called through the base station 73, and sales data is transmitted via the public line 74.

[0006] As described above, in the PHS communication apparatus 72 which is fixedly used, the location registration is performed in the same manner as that of the mobile terminal, and the control information is received from the surrounding base station for a certain period of time and the reception is performed. The electric field strength is measured, and the position is registered with the base station 73 having the strongest electric field strength.

[0007]

However, a PHS communication terminal fixedly used in a vending machine, a meter, or the like often reduces the incoming call rate especially when the terminal is installed on a high floor of a building or a rooftop. However, even if a call is made from the center device to the communication terminal, a state in which connection is difficult to occur frequently occurs.

As a result of the investigation by the inventors, it has been found that there is a problem in the location registration method.

[0009] In a place where buildings stand, the measured value of the radio wave intensity fluctuates quite frequently with time due to reflection and interference of radio waves. If location registration with a base station is performed by a conventional method in a place where the radio wave strength is unstable, the location may be temporarily registered with a base station having a strong electric field strength, which may cause a decrease in the incoming call rate. Has brought.

The present invention has been made based on such knowledge, and is suitable for a communication terminal that is fixedly used in place of a conventional algorithm for capturing a base station of a communication terminal developed on the premise of movement. The purpose of the present invention is to provide an algorithm for a location registration method.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for registering a position of a wireless communication terminal which is fixedly used.
The wireless communication terminal receives control information transmitted from each base station over a certain period of time, records the number of receptions and the average received electric field strength for each base station, and the number of receptions has reached the reference number of times. Among the base stations, the base station having the highest average received electric field strength is selected as the first position candidate for position registration.

[0012] Therefore, even if the incoming call rate of the wireless communication terminal is improved and the wireless communication terminal is fixedly installed in a place where radio waves are unstable, the base station is reliably captured and stable communication with the center device is achieved. It can be performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A PHS communication terminal that implements a location registration method according to an embodiment captures control information of each base station for a certain period of time, and records an average electric field strength and the number of receptions for each base station in a measurement list. I do.

FIG. 2A shows this measurement list, in which “CS” represents the code of the base station (CS) and “field strength” represents the average field strength of control information received from the base station. And the “number of times” indicating the number of times control information received from the base station are recorded.

FIG. 5 shows that the PHS communication terminal receives control information from base station A, base station B and base station C in order. Since each base station is synchronized between the base stations, it does not transmit control information at the same timing.

The PHS communication terminal operates for a certain period of time (here, 3
10 ms), the control information of each base station is captured, and the number of receptions and the average electric field strength are recorded in the measurement list. Each base station transmits control information every 100 ms. Therefore, when all the control information of each base station is normally received, the PHS communication terminal receives at least three times of control information from each base station within 310 ms.
In the case of FIG. 5, control information is received three times from the base station A, four times from the base station B, and three times from the base station C within 310 ms.

FIG. 6 shows a case where there is an abnormality and the PHS communication terminal cannot receive all the control information of each base station. Here, the case where the control information from the base station has not arrived is indicated by a dotted line. This PHS communication terminal receives control information twice from the base station A, four times from the base station B, and twice from the base station C within 310 ms.

FIG. 1 shows an operation procedure of the PHS communication terminal for performing position registration.

Step 1: The PHS communication terminal sets a timer to measure a predetermined time (310 ms). Step 2: Receives control information from the base station.

Step 3: Identify whether the ID of the base station that has received the control information is recorded in the measurement list,
If not recorded, Step 4: Record the base station ID, the measured received field strength and the number of receptions 1 in the measurement list.

Step 5: If the ID of the base station that has received the control information is recorded in the measurement list, the average value of the received field strength of the base station is obtained, and the field strength of the base station in the measurement list is calculated as Overwrite with the calculated average value.

The average value of the received electric field strength is calculated by the following equation (Equation 1) (rounded off to the nearest whole number). Average value = (Received field strength measured this time + Field strength of measurement list x number of times) / (Number of measurement list + 1) (Equation 1)

Step 6: Further, 1 is added to the number of receptions of the base station in the measurement list. Step 7: The order of the measurement list is rearranged in descending order of electric field strength.

In FIG. 2, when the control list of the base station CS-E is received in the state where the measurement list is as shown in FIG. 2A and the measured value of the received field strength is 45 dBμV, the measurement list is rearranged. Is shown. The average value of the received electric field strength of the CS-E is calculated to be 38 dBμV from (Equation 1). Therefore, the ranking in the CS-E measurement list is
As shown in FIG. 2B, it has moved from No. 5 to No. 4. Here, the period during which the PHS communication terminal continuously receives control information of each base station is 510 ms.

Step 8: The procedure from Step 2 to Step 7 is repeated until a fixed time set in the timer elapses. If timeout occurs, Step 9: Calculate the minimum number of receivable times within the timer period.

When the PHS communication terminal is in a state where it can normally receive control information from each base station, the minimum receivable number is determined by the number of base stations that can be normally received within a certain period measured by a timer. It indicates the minimum number of times of reception of the control information. The minimum receivable number does not include reception near the boundary of the predetermined period a, where a (ms) is a certain period measured by a timer and b (ms) is a transmission cycle of control information of the base station. So (because it is uncertain whether it can be received), subtract 10 (ms) from a,
This value is divided by b, and the value after the decimal point is rounded down. That is, the minimum receivable number is calculated by the following equation (Equation 2). Minimum number of receivable times = (a-10) / b (Equation 2) (However, truncation below the decimal point)

A = 310 ms, b = 100 m shown in FIG.
In the case of s, the minimum receivable number is three. Also,
When a = 510 ms and b = 100 ms, the minimum number of receivable times is five.

Step 10: Select base stations on the measurement list
Divide into base stations with the number of receptions equal to or greater than the minimum number of receivable times and base stations with the number of times less than the minimum number of receivable times. A group of base stations whose number of times is less than the minimum number of times of reception is rearranged.

FIG. 3 shows a measurement list (FIG. 3) immediately after the end of the timeout in which the base stations are arranged in the order of the electric field strength.
FIG. 3B shows a state in which the groups of the base stations having the number of receptions equal to or more than the minimum receivable number (5 times) are rearranged from the top and the group of the base stations having the number of times less than the minimum number of receptions are rearranged. Is shown.

Step 12: The top ten base stations in the measurement list are written in a candidate list of base stations for position registration.

FIG. 4 shows a state in which only the top 10 base stations are overwritten on the candidate list (FIG. 4B) from the measurement list of FIG. 4A in which 20 base stations can be recorded. ing.

Step 13: The communication terminal performs location registration with the highest base station in the candidate list. Step 14: If the location registration is successful, the location registration procedure ends.

Step 15: If the location registration is not successful, the location is registered with the next base station in the candidate list.

As described above, the location registration is tried sequentially from the upper base station in the candidate list, and the location registration is performed for the successful base station.

With such an algorithm, a base station capable of receiving control information with a stable electric field strength can be selected as a location registration target.

[0036]

As is apparent from the above description, in the position registration method of the present invention, a fixedly used radio communication terminal can register its position with a base station that transmits control information with a stable electric field strength. It is possible, and the incoming call rate of the wireless communication terminal is improved. Therefore, even when the wireless communication terminal is fixedly installed in a place where the radio wave condition is unstable, it is possible to reliably capture the base station and perform stable communication with the center device.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a procedure of a location registration method according to an embodiment of the present invention;

FIG. 2 is a diagram showing sorting in the order of electric field strength in the measurement list according to the embodiment;

FIG. 3 is a diagram showing sorting of the number of receptions by group in the measurement list according to the embodiment;

FIG. 4 is a diagram showing rewriting from a measurement list to a candidate list according to the embodiment;

FIG. 5 is a diagram showing a situation when a communication terminal normally receives control information from each base station;

FIG. 6 is a diagram showing a situation when a communication terminal cannot normally receive control information from each base station;

FIG. 7 is a diagram showing a system for automatically collecting vending machine sales data using a PHS communication terminal.

[Explanation of symbols]

 71 Vending machine 72 PHS communication equipment 73 Base station 74 Public line 75 Center equipment

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Ken Sugita 4-3-1, Tsunashimahigashi, Kohoku-ku, Yokohama-shi, Kanagawa F-term in Matsushita Communication Industrial Co., Ltd. 5K067 AA25 BB04 DD20 EE02 EE10 EE32 FF16 HH22 HH23 JJ52 JJ54 JJ57 JJ66

Claims (4)

[Claims] 1. A wireless communication terminal receives control information transmitted from each base station over a certain period of time, records the number of receptions for each base station, and records the average received electric field strength. A position registration method for a wireless communication terminal, wherein a base station having the highest average received electric field strength among base stations that have reached the number of times is selected as a first position candidate for position registration. 2. As the position registration candidate ranking, a group of base stations whose number of receptions has reached the reference number is ranked higher, and a group of base stations whose number of receptions has not reached the reference number is ranked lower. 2. The method according to claim 1, wherein a base station having a higher average received electric field strength in each group is positioned higher. 3. The radio according to claim 1, wherein the number of receivable times at which control information can be normally received from one base station within the predetermined period is set as the reference number of times. Communication terminal location registration method. 4. When the fixed period is a (ms) and the transmission period of control information of the base station is b (ms), (a-1)
4. The method of claim 3, wherein a value obtained by truncating a decimal point of 0) / b is used as the reference number. 5.