JP2000125331A - Phs (registered trademark)system, its phs terminal and selection method of base station by the phs system awaiting its call - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a PHS system or the like in which a call loss due to concentration of a communication load onto a specific base station is reduced. SOLUTION: This PHS system consists of a prescribed PHS terminal (PS) and plural base stations (CS1-CS4) that can communicate with the PS, and the PS selects at random a base station from the call of which the PS awaits among base stations whose reception electric field strength is more than a specified strength and the control cannel of which the PS can acquire. Furthermore, plural kinds of different electric field strength values are set in advance for the specified value of the reception electric field strength and any of them is automatically selected, based on the distribution of the electric field strength of the base stations at a current point of time. Through the configuration above, number of call losses due to the concentration of communication load onto a specific base station is decreased, and the generation of call loss can easily suppressed by extending a new base station in an area of the base station that is highly selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a PHS system and a method for selecting a standby base station in a PHS system.

[0002]

2. Description of the Related Art Conventionally, PHS terminals (hereinafter referred to as PS)
Is a new base station when a power supply is turned on or when a base station that has steadily received a control channel (hereinafter, referred to as an LCCH) cannot obtain a control channel having a reception electric field strength specified by the system. Is selected as a standby base station. In this case, as shown in FIG. 3, for example, a base station having the highest received electric field strength is selected as a standby base station from a plurality of LCCHs that can be received within a certain time. In the case of this example, the reception electric field strength of each base station is 60 dBμV /
CS1, 55dBμV / CS2, 40dBμV / CS
3, 35 dBμV / CS4. Therefore, the base station CS1 having the maximum received electric field strength is selected as the standby base station.

[0003]

However, in the case of the above-mentioned conventional PHS system and the method of selecting a standby base station of the PHS system, in a place where a route to which a person travels is fixed, such as an office, or a PS user, In a place where there is a concentration in a polar region, there is a problem that all the PSs wait for a specific base station and call loss increases.

[0004] To elucidate the mechanism that causes the above problems,
This will be described below with reference to FIGS. FIG. 3 is a specific example for explaining the problem, and FIG. 4 is a specific example of the communication mode in FIG. FIG. 5 shows the PBX (Pr
ivate Branch Exchange / private branch exchange), base station (C
S) is a communication flow diagram between the terminal devices (PS1 to PSn).

[0005] The PS turned on at the point A selects CS1 having the strongest electric field strength as a standby base station.
At this time, the standby zone holding level (P
S switches receiving base station Received field strength / example 2
0 dBμV). The PS moves from the point A to the point B through the corridor.

[0006] At the point B, the received electric field strength of the LCCH received from the predetermined first base station CS1 of the PS is 20
dB μV. Therefore, the PS selects a new base station. At this time, the LCCHs of CS3, CS4, and CS5 can be captured, and the PS selects CS3 having the highest received electric field strength as a standby base station. As a result, P passing through the same route
All of S will select CS3 as a standby base station.

[0007] In the above situation, when the PSs waiting for a specific base station are concentrated, if incoming calls occur simultaneously, the specific base station (for example, CS3) responds to the incoming call of the PS by the incoming call. PBX than speed of
The speed of receiving calls from is faster. FIG. 5 shows an example of a state in which a call loss occurs due to such load concentration. In FIG. 5, when the CS receives an incoming call exceeding the number of incoming call holding buffers (for example, n), the excess incoming call is discarded. Here, the call holding capacity is represented by the following relational expression.

[0008] Incoming call holdable number = number of incoming calls / received calls-number of incoming call responses When CS receives an incoming call exceeding the number of incoming call holding buffers, the incoming call holding buffer of the base station becomes full and the number of incoming calls is received. Incoming calls exceeding the limit are discarded, causing a problem that a call loss occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a PHS system and a method for selecting a standby base station of a PHS system in which call loss due to concentration of communication load on a specific base station is reduced. Aim.

[0010] More specifically, the present invention provides a method of randomly selecting a base station that waits for an incoming call from base stations having sufficiently high reception electric field strength when the LCCHs of a plurality of base stations can be captured. The purpose of the present invention is to reduce call loss caused by concentration of communication load on a specific base station.

[0011]

The present invention adopts the following constitution in order to solve the above problems.

[0012] The PHS system according to the first aspect of the present invention comprises:
A base station that waits for an incoming call is randomly selected from base stations having sufficiently strong reception electric field strength. As a result, it is possible to prevent a communication load from being concentrated on a specific base station, and to reduce call loss.

[0013]

An embodiment of the present invention relates to a PHS system comprising a predetermined PS and a plurality of base stations capable of communicating with the PS, wherein the PS captures a control channel. Of multiple possible base stations,
From among the base stations that can be captured with a predetermined received electric field strength or higher,
A configuration is adopted in which a base station that waits for an incoming call is selected.

With this configuration, the LCCHs of a plurality of base stations are
Can be captured, it is possible to reduce occurrence of call loss due to concentration of communication load on the fixed base station.

According to a second aspect of the present invention, the PHS system according to the first aspect adopts a configuration in which a base station that waits for an incoming call is randomly selected from among base stations that can be captured with a predetermined received electric field strength or more. .

According to the third aspect of the present invention, the predetermined reception electric field strength according to the first or second aspect is provided in advance with a plurality of types having different electrolytic intensities, and is based on the electric field intensity distribution of the base station at the present time. , A configuration that enables switching selection is adopted. According to this configuration, it is possible to make a selection in view of the balance between the communication load concentration and the securing of the electric field strength.

According to a fourth aspect of the present invention, there is provided a configuration in which the switching selection of a plurality of different types of electrolytic strengths is automatically performed.

According to the fifth aspect of the present invention, the first to fourth aspects are provided.
The PHS system according to any of the above, by adding a new base station in the area of the base station with a high selection frequency,
A configuration is adopted in which the occurrence of a call loss can be easily suppressed.

According to a sixth aspect of the present invention, there is provided a PHS system having a PH configured to communicate with a plurality of base stations.
This is a PS of the S system, and adopts a configuration in which a base station that waits for an incoming call is selected from among base stations that can be captured with a predetermined reception electric field strength or higher among a plurality of base stations that can capture a control channel.

With this configuration, it is possible to reduce the probability of occurrence of communication failure due to concentration of communication load on the fixed base station.

According to the invention of claim 7, the PS of the PHS system according to claim 6 randomly selects a base station that waits for an incoming call from among base stations that can be captured with a predetermined received electric field strength or more. Take the configuration.

[0022] According to a eighth aspect of the present invention, there is provided a method for selecting a standby base station in a PHS system, comprising the steps of:
A standby base station selection method for a PHS system constituted by a plurality of base stations capable of communicating with the PS.
A configuration is adopted in which S selects a base station that waits for an incoming call from among a plurality of base stations that can capture a control channel and that can capture at a predetermined reception electric field strength or higher.

With this configuration, the LCCHs of a plurality of base stations
Can be captured, it is possible to reduce occurrence of call loss due to concentration of communication load on the fixed base station.

According to a ninth aspect of the present invention, there is provided a method for selecting a standby base station for a PHS system according to the eighth aspect, wherein the base station which randomly waits for an incoming call from among base stations which can be captured with a predetermined received electric field strength or more. A configuration for selecting a station is adopted.

According to the tenth aspect of the present invention, the predetermined reception electric field strength according to the eighth or ninth aspect is provided in advance with a plurality of types having different electrolytic strengths, and is based on the distribution of the electric field strength of the base station at the present time. , A configuration that enables switching selection is adopted.

According to the eleventh aspect of the present invention, the switching selection of a plurality of different types of electrolytic strengths according to the tenth aspect is performed by:
It adopts a configuration that performs it automatically.

According to a twelfth aspect of the present invention, in the method of selecting a standby base station for a PHS system according to any one of the eighth to eleventh aspects, a new base station is added in an area of a base station having a high selection frequency. Thus, a configuration in which the occurrence of a call loss can be easily suppressed is adopted.

Next, a PHS system and a method of selecting a standby base station in the PHS system according to an embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2
Is a PHS system and P according to an embodiment of the present invention.
FIG. 3 is a diagram for explaining a configuration of a standby base station selection method of the HS system.

FIG. 1 shows the PHS system and the PH of the PS.
3 shows a method of selecting a standby base station in the S system. In FIG. 1, PS is the LC of four base stations (CS1 to CS4).
The receiving field strength of the LCCH received from each base station is 60 dBμV, 55 d
BμV, 40 dBμV, and 35 dBμV. Also, P
Threshold at which S randomly selects a base station (hereinafter also referred to as "random selection threshold" or "specified value")
Is 40 dBμV.

In this case, the PS randomly selects a base station from the LCCH having a reception electric field strength of 40 dBμV or more. For this reason, it is possible to freely select a standby base station from the base stations CS1 to CS3 having the reception electric field strength equal to or higher than the specified value, except for the base station CS4 having the reception electric field strength equal to or lower than 40 dBμV. An operation example in the case where the PS actually moves will be described below with reference to FIG. 2 which makes this assumption more concrete.

At the point A, the power-on PSx
Is the “random selection threshold / 40” assumed above.
base station CS1 or C having an electric field strength of “dBμV” or more
S2 is selected as a standby base station. At this time, the system sets the standby zone holding level (receiving electric field strength at which the PS switches the standby base station / for example, 20 dBμ).
V).

The above PSx moves from point A to point B through a corridor, for example. PSx after moving is point B
, The received field strength of the LCCH received from CS1 is 20 dBμV. For this reason, PSx selects a new base station. At this time, CS3, CS4, CS5
Can be captured.

Base stations CS3 and CS capable of capturing LCCH
4, among CS5, a random selection threshold [40 dBμ
V] are two base stations CS3 and CS5.
For this reason, PSx selects CS3 or CS5 as a standby base station.

As described above, even when the predetermined PSx passes through the same route, the base stations that are actually selected as the standby base stations are dispersed. Therefore, the concentration of the communication load on the specific base station is dispersed. Thereby, the call loss can be reduced. Further, at points where a large number of PS users gather, the load can be more dispersed by increasing the number of base stations installed so as to exceed the random selection threshold. For this reason, it is possible to greatly reduce the call blocking rate.

As described above, in the present embodiment, when a new base station is selected as a standby base station, a base station that waits for an incoming call is randomly selected from base stations having a sufficiently strong reception electric field strength. As a result, it is possible to reduce the call loss due to the concentration of the communication load on the specific base station.

The above embodiment is an example of a preferred embodiment of the present invention. However, it is not limited to this.
Various modifications can be made without departing from the spirit of the present invention. For example, the prescribed value of the electric field strength is not limited to one, and a plurality of types having different electric field strengths are provided. When the number of base stations selected as a standby base station is equal to or more than a predetermined number or equal to or less than a predetermined value in the specified values of the plurality of types of strengths, it is selectively switched to any specified value. This switching is performed automatically by the PHS terminal device, for example.

[0037]

As is apparent from the above description, according to the present invention, when a new base station is selected as a standby base station, a base station which waits for an incoming call from base stations having a sufficiently strong reception electric field strength. Select a station. As a result, it is possible to reduce call loss due to concentration of communication load on a specific base station.

[Brief description of the drawings]

FIG. 1 is a block diagram of a PHS system according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining an operation example of the embodiment;

FIG. 3 is a block diagram of a conventional PHS system.

FIG. 4 is a conceptual diagram for explaining a mechanism of occurrence of a call loss due to load concentration in a conventional PHS system.

FIG. 5 is a flowchart showing an example of the conventional procedure of FIG. 4;

[Explanation of symbols]

 CS1 to CS4 Base station PS PHS terminal Point A Point B

Claims (12)

[Claims] 1. A PHS system comprising a predetermined PHS terminal and a plurality of base stations capable of communicating with the PHS terminal, wherein the PHS terminal includes a predetermined one of a plurality of base stations capable of acquiring a control channel. A PHS system, wherein a base station that waits for an incoming call is selected from among base stations that can be captured with a received electric field strength equal to or higher than the received electric field strength. 2. The PHS system according to claim 1, wherein a base station that waits for an incoming call is randomly selected from base stations that can be captured with a predetermined reception electric field strength or higher. 3. A method according to claim 1, wherein a plurality of predetermined reception electric field intensities having different electrolysis intensities are provided in advance, and switching can be selected based on the distribution of the electric field intensity of the base station at the present time. 3. The PHS system according to 1 or 2. 4. The PHS system according to claim 3, wherein the switching selection of a plurality of different types of electrolytic strength is automatically performed. 5. The method according to claim 1, wherein a new base station is added in an area of a base station having a high selection frequency, so that occurrence of a call loss can be easily suppressed. The PHS system as described. 6. A P configured to communicate with a plurality of base stations.
A PHS terminal for an HS system, wherein a PHS terminal for waiting for an incoming call is selected from among a plurality of base stations capable of capturing a control channel at a predetermined reception electric field strength or higher. PHS terminal of the system. 7. The PHS terminal of the PHS system according to claim 6, wherein a base station that waits for an incoming call is randomly selected from base stations that can be captured with a predetermined reception electric field strength or higher. 8. A method for selecting a standby base station in a PHS system including a predetermined PHS terminal and a plurality of base stations capable of communicating with the PHS terminal, wherein a plurality of base stations capable of acquiring a control channel are provided. A method for selecting a standby base station in a PHS system, wherein the base station selects a base station that waits for an incoming call from base stations that can be captured by a base station at a predetermined reception electric field strength or higher. 9. The PHS system according to claim 8, wherein a base station that waits for an incoming call is selected at random from base stations that can be captured with a predetermined reception electric field strength or higher. Method. 10. A predetermined reception electric field strength, wherein a plurality of types having different electric field strengths are provided in advance, and switching can be selected based on the distribution of the electric field strength of the base station at the present time. 10. The method for selecting a standby base station of the PHS system according to 8 or 9. 11. The method for selecting a standby base station in a PHS system according to claim 10, wherein switching selection of a plurality of different types of electrolytic strengths is performed automatically. 12. The method according to claim 8, wherein the occurrence of a call loss can be easily suppressed by adding a new base station in an area of a base station having a high selection frequency. A method of selecting a standby base station in a PHS system.