JP2911392B2 - Communication service conflict detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication service contention detection device, and more particularly, to a communication service contention detection device for automatically detecting a conflicting rule among a plurality of rules applied to a plurality of terminals. .

[0002]

2. Description of the Related Art Communication systems are growing and becoming more complex as the number and sophistication of communication services increases. The introduction of advanced communication services requires rapid development of communication software, especially the detection and resolution of service interactions caused when new services are added to existing services. The main reason that this is difficult is that it is not possible with conventional methods to understand and predict all the situations that may arise when new services are combined with existing services.

A typical conflict that occurs when combining services is, for example, a conflict between a busy call (CW) and a call forwarding (CFV).

(1) Busy incoming call (CW) If subscriber A has the ability to execute a busy incoming call and is on a call with B, and C dials A, A receives a busy incoming call ringing tone. Receive (if A triggers a flash hook event, A is connected to C and B waits).

(2) Call Forwarding (CFV) If the subscriber A has preset call forwarding to D,
When C dials A while is in the idle state, the dialed destination is transferred to D, and C is in a state to call D.

A communication system that provides these two services simultaneously will be considered. Assume that A with both execution capabilities is on a call with B and has preset call forwarding to D. In this situation, if C dials A,
It is not possible to decide which rule to apply.

[0007] Conventional service description methods (SDL, LOTO
S and Estelle), a service description is a set of procedural descriptions or sequences of actions. If the above two services are specified using a procedure description, the description of the operation of the dialed terminal is the sum of the following procedures. That is, the procedure for a busy call receives a test of the description of the busy call. On the other hand, the procedure for call diversion undergoes a test of the call diversion description. If these two procedures are combined into one, the operation depends on the order of the two test statements. If the procedures are executed in the wrong order, there is no way to detect conflicts mechanically.

Here, the STR for the communication service is used.
(State transition rule) Description is assumed. An STR description is a set of declarative state transition rules, where each rule is a current state description,
It consists of an event description and a next state description. Assuming a set of declarative service rules, the problem of detecting non-deterministic behavior in service descriptions is introduced. For example, if an event occurs and the current state description of two rules is satisfied simultaneously, this raises the problem that the two rules specify two different next states. This is called non-deterministic operation of the communication service description.

In order to detect all such conflicts,
A conflict detection method including the following steps has been proposed (Japanese Patent Laid-Open No. 5-236527).

Step 1. Acquire all possible terminal states of one terminal. Step 2. If two rules have the same event description, build a situation from the current state descriptions of the two rules. The situation sometimes consists of multiple terminal states. These situations are called “competition candidates”.

Step 3. By comparing the state of each terminal in the situation with the terminal state acquired in step 1 above, it is determined whether each situation exists. If neither of these situations exists, the two rules are determined not to conflict and are excluded from consideration.
The remaining situations are considered competitive candidates.

[0012]

However, in the above-described conventional contention detection system, it is only necessary to assume the state of another terminal without judging the synchronization between many terminal states.
Applying the rules to the state of one terminal can result in erroneous transitions that do not appear in many actual terminals.
Erroneous transitions often lead to erroneous terminal states, which are not visible to the actual large number of terminals. If the rules are applied to the acquired false state, more false states of the terminal will be acquired. As a result, there has been a problem that the accuracy of conflict detection is reduced.

An object of the present invention is to provide a communication service contention detection device which obtains a terminal state accurately reflecting a service description (rule) by determining the synchronization between the states of a large number of terminals. It is to propose.

[0014]

SUMMARY OF THE INVENTION A communication service contention detection device according to the present invention comprises: a current state that is currently being taken by one or a plurality of terminals; an event that occurs in the current state of the terminal; Communication service conflict detection device that is used when a terminal applies a plurality of state transition rules having a next state to be taken next, and automatically detects a conflict among the plurality of state transition rules A rule storage means for storing a plurality of state transition rules, a real state storage means, and a real state storage means for storing a predetermined initial state.
And initial setting means for storing the stage Zhou from in rule storage means
Select state transition rule, already the simultaneous presence determining means determines whether or not stored in the current state of real state storage means in the selected state transition rule, the current state by the simultaneous presence determining means when already determined stored in the real state storage means, to generate the next state by applying the selected state transition rules to the current state, the product of
Must be stored in the actual state storage means.
If the generated next state is an independent one of the terminals,
Device or multiple devices synchronized with each other can actually take
And rule applying means for newly added memory to the actual state storage means as an actual state, a contention candidate extracting means for extracting at least two state transition rule having the same event from within rule storage means as a competitive candidates, the simultaneous presence determination after treatment with manual stages Contact and rule applying means, with reference to the actual state storage means, a plurality of current state in the state transition rule extracted by competing candidate extraction unit determines whether or not the terminal can take the same time, Toridoku If it is determined that there is no competition transition candidate, the extracted state transition rule is deleted from the competition candidates.

In this communication service conflict detection device, it is determined whether or not the current state in the rule can actually exist in one terminal, that is, whether or not the state can exist in a plurality of terminals simultaneously. You. If it is determined that the states can exist at the same time, the next state is obtained by applying the rule. On the other hand, two rules having the same event are extracted as competition candidates, and if the current state in the extracted rule is not included in the acquired state, the rule is deleted from the competition candidates. Thereby, the competition candidates are further narrowed down.

Thus, conflicts between multiple service characteristics with the same event can be detected not only on a single terminal with multiple service execution capabilities, but also on multiple terminals with multiple service execution capabilities.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of a communication service conflict detection device according to an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

1. FIG. 1 is a block diagram showing the overall configuration of a communication service conflict detection device according to an embodiment of the present invention. Referring to FIG. 1, the apparatus includes a rule storage unit 10, a simultaneous existence determination unit 12, a rule application unit 14, a real state storage unit 16,
A competition candidate extraction unit 18 for extracting a competition candidate 20;
Candidate narrowing unit 22 for narrowing down the competition candidates 20 to the competition candidates 24
And

The rule storage unit 10 stores a plurality of rules described by the STR (state transition rule) method. The coexistence determining unit 12 sequentially reads one rule from the rule storage unit 10 and determines whether or not the current state described in the read rule is stored in the real state storage unit 16. When the current state is stored in the real state storage unit 16, the rule applying unit 14 acquires the next state based on the current state by applying the read rule. The obtained state is written in the real state storage unit 16. As described above, only the rule that allows the current state to exist at a plurality of terminals at the same time is applied, and the state is acquired thereby.
6 stores only a state that an arbitrary terminal can actually take in consideration of a relationship with another terminal.

The competition candidate extraction unit 18 sequentially extracts two rules having the same event from the rule storage unit 10,
Thereby, a competition candidate 20 is created. Candidate narrowing unit 22
Determines whether the current state described in the rule listed as the competition candidate 20 is stored in the real state storage unit 16, and if not, deletes the rule from the competition candidate 20. A competition candidate 24 is created.

Here, the point that the competition candidate 20 is extracted and the competition candidate is narrowed down with reference to the real state storage unit 16 is similar to the competition detection method disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-236527. It is. Therefore, a feature of the present invention is that it is determined whether or not the current state described in the rule can actually exist at the same time, and the state is obtained by applying the rule only when it can exist. .

2. STR (State Transition Rule) Method In the STR method, a service operation that does not depend on a target system operation is described from a user's viewpoint (FIG. 2).
In the STR method, service characteristics are described as a set of rules. The following definitions are based on the rule description using the STR method,
This is a rule application definition of the R method.

Definition 2.1 (Rule Description) A rule Ri is described as a set of expressions.

Ri: = ISi Ei: NSi Here, ISi indicates a current state of the rule Ri, Ei indicates an event of the rule Ri, and NSi indicates a next state of the rule Ri, respectively.
ISi and NSi are described as a set of state description elements of the following formula.

ISi, NSi: = {SE0,..., SEn} Here, SEi is a state description element, and includes state identification and terminal variables. The first parameter of the state description element indicates the terminal that holds the state description element. For example, S
Ei (A, B) indicates that terminal A is in SEi state with terminal B.

Definition 2.2 (Rule application) The rule is applied when the condition part (current state and event) is satisfied, when an actual event occurs in the actual state in which many terminals operate there. You. Thereafter, the actual state description element equivalent to the current state of the rule is changed to the next state of the rule by the act of applying the rule. The condition of rule application is that the current state of the rule is equivalent to or included in the actual state, and that the event of the rule is equivalent to the actual event. Therefore, the determination of the conditions for rule application is described in the formula as follows:

(ISi⊆G) ∧ (GE = Ei) where ISi is the current state of the rule Ri, G is an actual state constructed from the actual terminal state, GE is an event occurring in the state G, and Ei is Each event of rule Ri is shown.

The actual state description element that is equivalent to the current state of the rule (ISi) is changed to the next state of the rule (NSi) by the act of applying the rule.

For example, using the STR method, FIG. 3 shows a busy reception service operation and a call transfer service operation. Here, “m-cw (A)”, “path (A, B)”, “dial-ton
e (C) ”,“ cw-ringing (A, C) ”,“ ringback
(C, A) "," m-cfv (A, D) "," idle (D) "
And "ringing (D, C)" are called state description elements. “Dial (C, A)” is called an event. The current state and the next state are described as a set of state description elements.
The rule “cw-1) in FIG. 3 indicates that the terminal A has the busy call execution capability (“ m-cw (A) ”) and is in a call with the terminal B (“ path
(A, B) "), and when terminal C dials terminal A while terminal C is listening to a dial tone (" dial-tone (C) "), terminal A receives" m-cw (A), path
(A, B) ”without receiving a busy ringing tone from terminal C (“ cw-ringing (A, C) ”), and terminal C calls terminal A (“ ringback (C, A) ) ").

In the rule “cfv-1) in FIG. 3, the terminal A sets in advance the call transfer operation to the terminal D (“ m-cfv
(A, D) "), the terminal B is in a call, the terminal D is in an idle state (" idle (D) "), and the terminal C is listening to a dial tone (" dial-tone ( C) "),
Terminal C dials terminal A, then the call is transferred to terminal D, and terminal C is ringing terminal D ("ringback
(C, D) ”) and the terminal D is“ m-cfv (A, D), pa
th (A, B) "without being changed (" ringing (D, C) ").

3. Overview of conflict detection The following is a summary of the approach used to detect all conflicts.

Step 1. By applying the rules,
Get all possible terminal states of the terminal.

Step 2. If two rules have the same event description, build a situation from the current state descriptions of the two rules. The situation sometimes consists of a number of terminal states. These situations are called “competition candidates”.

Step 3. By comparing the state of each terminal in the situation with the terminal state acquired in step 1 above, it is determined whether each situation exists. If neither of the situations exist, the two rules are determined not to conflict and are excluded from consideration. The remaining situations are considered competitive candidates.

Step 1 described above is performed by the simultaneous existence determining unit 12 and the rule applying unit 14 in FIG. That is, here, terminal states that can actually exist are acquired based on the rule storage unit 10 and stored in the real state storage unit 16.

Step 2 is performed in the competition candidate extracting section 18 in FIG. That is, in this case, a rule that may conflict among a plurality of rules is given as the conflict candidate 20.

Step 3 is a candidate narrowing unit 22 shown in FIG.
It is performed in. That is, here, the competition candidate 2
If the current state of the rule listed as 0 cannot actually exist, the rule is excluded from the conflict candidates 20 to create a conflict candidate 24.

An outline of conflict detection will be described using the rules of CW and CFV shown in FIG. This is a situation in which the above two rules conflict when the terminal C dials the terminal A. This is because the current state of the two rules is satisfied at the same time, and it is not clear which specification is activated.

Terminal A: path (A, B), m-cfv (A,
D), m-cw (A) Terminal C: dial-tone (C) Terminal D: idle (D) The competition candidate is constructed from the current state and event of the two rules. Here, an outline of determination of a competition candidate by combining terminal variables will be described. For illustration purposes, the rule "cw
-1) "1" is added to the terminal variable, and "2" is added to the terminal variable of the rule "cfv-1)". Then, the current state and event of the two rules are as follows.

Cw-1) path (A1, B1), m-cw (A
1), dial-tone (C1) dial (C1, A1): cfv-1) path (A2, B2), m-cfv (A2, D2),
dial-tone (C2), idle (D2) dial (C2, A
2): [Addition of event constraint] Terminal variables "A1" and "A"
2 "are determined to be the same, and" C1 "and" C2 "
Is determined to be the same for both rules. This is because a conflict occurs when the same event of two rules occurs. Therefore, the terminal variables used in the two rules are as follows.

Cw-1) A1, B1, C1 cfv-1) A1 (= A2), B2, C1 (= C2), D2 [Addition of state description element constraint] "path (A1, B1)" and "path (A1, B2) "is considered to be the same, so that the terminal variable" B1 "of" cw-1) "is determined to be" B2 "of" cfv-1). Therefore, the terminal variables used in the two rules are as follows.

Cw-1) A1, B1, C1 cfv-1) A1 (= A2), B2, C1 (= C2), D2 [Addition of Rule Constraints] In one rule description, different terminal variables correspond to different terminals. Point. Therefore, "cfv-1)"
Are "A1", "B1" and "C2".
It is determined to be other than 1 ".

The first parameter of the state description element indicates a terminal holding the state description element. Therefore, a competition candidate composed of the terminal status is constructed as follows.

Terminal A1: path (A1, B1), m-cfv
(A1, D2), m-cw (A1) Terminal C1: dial-tone (C1) Terminal D2: idle (D2) Next, in the candidate narrowing unit 22, if all terminal states are present in the real state storage unit 16, If so, the competition candidates are determined to be in competition. If no conflict candidate exists, the two rules are determined not to conflict and are excluded from consideration. Thus, the detected conflict situation between the two rules of FIG. 3 is shown in FIG.

4. Problem of State Acquisition When acquiring a state by applying a rule defining an operation between a plurality of terminal states, a method of determining synchronization between a plurality of terminal states is required. However, for designers,
It is difficult to specify whether a large number of terminal states are synchronized or not, especially when a new service is added to an existing service. This is because the designer must keep track of all service interactions to determine synchronization.

In the following, the classification of the current state of the rule will be described. Here, the state of an arbitrary terminal is PS, the state of another terminal (not an arbitrary terminal) is OT, and a rule Rj
Is the current state of ISj, and the event of rule Rj is Ej.

[Case 1] All current states of a rule are included in the state of an arbitrary terminal (ISj⊆PS).

If all the current states of the rule are included in any terminal state (ISj⊆PS), event E
It is believed that j can occur in that state. Thus, rule Rj can be correctly applied to any terminal state. This is because the conditions for rule application have been met (see Definition 2.2).

[Case 2] Some of the current state description elements of the rule are included in the state of an arbitrary terminal ((ISj
{PS) ≠ φ).

If the subset “(ISj∩PS) ≠
If φ ″ is common to the state of any terminal PS and the current state ISj, the state PS of any terminal and
A determination must be made of the synchronization with the state Oti of the other terminals (OTi = (ISj- (ISj @ PS)), for example, if the rule "Rj" is applicable to any terminal shown in FIG. No is determined by determining the synchronization between the states of terminals P and Q as shown in FIG.

Simply assuming that the state of the other terminal is satisfied before applying the rules may cause erroneous transitions and states. This problem will be described as an example. For example, typical correct transitions when the rules shown in FIG. 7 are applied are shown in FIG. 8, and typical incorrect transitions and states are shown in FIG.

Example 1: In the transition "T0" in FIG. 8, the arbitrary terminal state is "idle (P)", and the other terminal is applied to apply the rule "r-1)" shown in FIG. No state is required and the event "offhook (P)" can occur in any terminal state "idle (P)". Therefore, the transition “T0”
Is correct and the acquired state of the terminal P "dial-tone
(P) "is correct.

Example 2: In the transition "T1" in FIG. 8, when any terminal P is in "dial-tone (P)", other terminals Q can be in the idle state "idle (Q)" at the same time. Therefore, the transition “T1” caused by the application of the rule “r-2)” is correct and the acquired state “ringback” of the terminal P
(P, Q) "is correct.

Example 3: In the transition “T2” in FIG. 9, any terminal P has the CW service execution capability “m-cw
(P) ", and is in the CW mode" cw (P) ", and the terminal Q is kept waiting without hanging up.
(P, Q) "and" ri "listening to the ringing tone from terminal Q.
nging (P, Q) ". This situation is caused when the terminal P hangs up and" onhook (P) ", while the terminal P waits for the terminal Q without hanging up. In this situation, if terminal Q is in the state of "ringback (Q, P)" listening to the return sound from terminal P, transition "T2" is correct because rule "r-3" in FIG.
)) Is satisfied, because in this situation the event "offhook (P)" may occur. However, the transition "T2" is incorrect because terminal Q is This is because when P is in the above-mentioned state, it is impossible to listen to the return sound from the terminal P. This erroneous transition is caused when the terminal P is in a call with the terminal Q and “path (P, Q)”. On the other hand, terminal P is the same terminal Q
Waits without hanging up the phone "path-passive (P,
Q) ", which leads to an incorrect state of the terminal P.

Example 4: In the transition "T3" in FIG. 9, any terminal P has a three-party call execution capability "m-3wc
(P) ”, in the three-way call mode“ 3wc (P) ”, and waiting for the terminal Q without hanging up the call“ path-passive ”
(P, Q) ", and indicates that the terminal Q is in the idle state when the terminal P is in the above-mentioned state in the state of listening to the dial tone. It will never be "idle (Q)", as a result the transition "T3" is wrong because the current state of the rule "r-2)" in Fig. 7 is not satisfied. Puts terminal P in a state "path-passive (P, Q)" in which terminal Q waits without hanging up, while terminal P listens to the return sound from the same terminal "ri"
ngback (P, Q) ", which leads to an incorrect state of the terminal P.

Therefore, when determining whether a rule is applicable to multiple terminal states, it is necessary to determine whether the multiple terminal states can be the same at any given time. is there.

5. Approach to State Acquisition To obtain the correct state by applying rules, it is necessary to evaluate the synchronization between the state of any terminal and the state of other terminals.

There are the following two types of terminal states. (1) Terminal state independent of the state of other terminals, eg, “idle-tone (A)”; and (2) Terminal state synchronized with each other, eg, “ringback
(A, B), ringing (B, A) ".

The former indicates that the terminal A is in a state of listening to a dial tone after going off-hook. The latter indicates that terminal A calls terminal B after dialing terminal B. In the STR method, a first terminal in a state description element indicates a terminal holding the state description element, and a second terminal in the state description element indicates a terminal related to the first terminal. For example, “ringback (A, B)” indicates that terminal A is listening to the call back sound from terminal B, and “ringing (B, A)” indicates that terminal B is calling from terminal A. Indicates that you are listening to sound.

Assume the state description elements "SE1 (A1, B1)" and "SE2 (B1, A1)". In the STR method, the state description element “SE1 (A1, B1)” of the terminal A1
Is the second terminal "B1" and the second terminal is the terminal A
If it has a state description element pointing to 1, terminals A1 and B1 are treated as synchronized terminals. In the case of a three-way call service, the three-way controller can establish a three-way call with the other two terminals. In this case, the states of these three terminals are considered as synchronized terminals. Because the three-way controller has a state description element whose second terminal points to the other two terminals, and each terminal connected to the three-way controller has its second terminal pointing to the three-way controller This is because it has a state description element. Therefore, the states of the three terminals are considered to have been synchronized by the three-way controller.

If the state of the independent terminal and the state of the terminal synchronized with each other are known, the applicability of the current state of the rule is determined by the simultaneous existence determining unit 12 in FIG. 1 according to the following criteria. obtain.

Cr-1. The independent terminal state is a state that can occur in other terminals. If the state of the independent terminal is included in the current state of the rule, the state of the independent terminal can be determined as a possible state. If the terminals are different, independent terminal (s) state combinations may exist simultaneously.

Cr-2. A synchronized terminal state is a state that can be taken by another, different synchronized terminal. It can be determined that a combination of the state of the synchronized terminal and other synchronized terminals can exist if they are included in the current state of the rule.

Cr-3. Combinations of terminal states synchronized with independent terminal states may be determined to be possible if they are included in the current state of the rule.

Cr-4. The current state of the rule consists of the state of the independent terminal and the state of the terminal synchronized. If it is determined that either the independent terminal state or the synchronized terminal state does not exist, the rule applying unit 14 cannot apply the rule.

For example, the erroneous transition “T” shown in FIG.
Consider the PS, OT and "ISj @ PS" in "2".

PS = ｛ringing (P, Q), path-passi
ve (P, Q), cw (P), m-cw (P)｝ OT = ｛ringback (Q, P)｝ “(ISj∩PS)” = ｛ringing (P, Q)｝ The PS is the terminal P And the state of “ringing (P,
The second terminal Q of "Q)" and "path-passive (P, Q)" indicates a synchronized terminal. If the terminal Q has the state description element "ringback (Q, P)", the rule The current state is satisfied, but the current state of the rule is not included in the state set of the synchronized terminals P and Q. As a result, this rule uses the above "cr-4)" Therefore, no erroneous transition occurs, and conversely, consider PS, OT and “(ISj∩PS)” at the correct transition “T1” in FIG.

PS = {dial-tone (P)} OT = {idle (Q)} “(ISj∩PS)” = {dial-tone (P)} The above PS indicates the state of the terminal P, and OT indicates The state of the terminal Q is shown, and both states are independent terminal states. If the dial-tone (P) and “idle (Q)” are included in the real-state storage unit 16, these are “cr-
1) ", it is determined that they exist at the same time. Therefore, the rule is determined to be applied in the rule application unit 14.

The theory for introducing the above-mentioned criteria "cr-1)" to "cr-3)" is shown below. First, the relationship between the service specification and the application of the service specification to an actual system including many terminals is considered. In general, the following theory is applicable.

[Theory 1] The provided service specification can be applied in parallel to an actual distributed system. This is because the distributed terminals operate in parallel. Assuming there is an infinite number of terminals in a real environment, if there is no relationship between any terminals in a given state, the states are independent of each other and can occur simultaneously.

[Proof of Theory 1] The number of terminals required to define the service specification is “n” (1 ≦ n). The given service specification is implemented in the "n" terminal. Here, another number “m” of terminals that is larger than n is assumed (n ≦ m). The provided service specification is also realized in the “m” terminal. Thus, the provided service specifications can be implemented independently between the "n" and "m" terminals.
There is no relationship between the "n" terminal sets and the "m" terminal sets. Thus, the state of the service specification provided in the set of “n” terminals is not related to the state in the set of “m” terminals, and these two sets of terminals are independent of each other; Any combination of states from these two sets of terminals can occur simultaneously.

For example, given service specifications are shown in FIG.
Assume that it is as shown at 0. This is PO
It is representative of the TS (conventional basic telephone service) specification. Terminals X and Y are considered variables. The actual terminals are P, Q, R and S, and the provided specifications are terminal P
And the actual system applied between terminals R and S and between Q and Q (FIG. 11). The situation (A) in FIG. 11 indicates that all terminals are in an idle state. Terminal P can initiate an off-hook event, terminal R can also asynchronously initiate an off-hook event, and then dial terminal S while listening to a dial tone. Next, terminal R
Calls the terminal S, and then the terminals R and S enter the talking state after the terminal S answers [FIG. 11B]. FIG.
From the situation (B), the terminal P can dial the terminal Q, the terminal S can hang up asynchronously, and the situation of FIG. 11C appears. “Dial-tone
(P) ”and“ path (R, S), path (S, R) ”state pairs, and“ ringback (P, Q), ringing (Q,
P) ”and“ path (R, S), path (S, R) ”states can occur simultaneously.

The following is a process for determining synchronization between a number of terminals. Step 1. Classify the current state description of the rule as an independent terminal state or a synchronized terminal state.

Step 2. It is determined whether the state of the independent terminal or the state of the synchronized terminal exists in the acquired positive knowledge. If so, proceed to step 3 or determine that the rule does not apply.

Step 3. Using the criteria introduced from Theory 1, it can be determined whether a combination of states from different terminals occurs simultaneously. Therefore, the rules are applied and the transition is correct.

[Proof] The states required to apply the rules can be categorized as independent terminal or synchronized terminal states. If all states are present in the acquired states, using Theory 1, it is determined that their combination occurs simultaneously. Therefore, the characteristics of the proposed process were proved.

The method for obtaining a state while determining the current state of a rule is described in detail in the following sections.

6. Acquiring a state while determining the current state of a rule The following is a list of steps required to acquire a state. The terminals used are “X1”, “X2”, “X3”
... (and so on, as needed), which are treated as variables. The set of acquired states is represented by S (real state storage unit 1).
6, the initial state of S is S0, the state of S is Si, and the current state of the rule Rj is ISj.

Step 1. The initial state S0 is set up in the real state storage unit 16. Initial state "SE0 (X1)" which is actually idle state "idle (X1)"
Is set to S0. This state is also obtained as an independent terminal state.

Step 2. Acquire state. (1) The simultaneous existence determining unit determines synchronization between the set of states and the current state of the rule.

If the current state ISj of the rule Rj is the state S
i or equal to state Si (I
Sj⊆Si), ISj is determined to be satisfied, and the rule R
j is applied correctly.

When a transition occurs, it is not necessary to determine the occurrence of a rule event if the current state of the rule is satisfied. This is because the event is assumed to occur in that state. Therefore, the transition that has occurred is correct. In this case, synchronization between the states of multiple terminals is not required. Because the current state of the rule is satisfied.

When there is no common state description element between the current state ISj and the state Si of the rule ((ISj∩Si) =
φ), the rule cannot be applied to Si. Because the current state of the rule is not satisfied.

When there is some state description element common between the current state ISj and the state Si of the rule ((ISj
{Si) ≠ φ) and if any terminal used in the common state description element is used in the current state of the rule, except for the common state description element (ISj- (ISj
∩Si)), rule Rj does not apply. This is because the current state ISj of the rule is not satisfied with the state Si. For example, assume the following state Si and the current state ISj of rule Rj.

SI: ringing (X1, X2), path-pas
sive (X1, X2), cw (X1), m-cw (X1), pat
h (X2, X1) ISj: ringback (A, B), ringing (B, A) Between Si and ISj, terminal “A” is the same as “X2” and terminal “B” is “X1”. And that the current state ISj of the rule has another state description element "ringing (A, B)" for terminal A (= X2), the common state element " ringing (B, A) "can be found. However, the state (Si) does not have the description element “ringback (X2, X1)” corresponding to the terminals A (= X2) and B (= X1) of the current state ISj of the rule. Therefore, the current state ISj of the rule is not satisfied with the state Si.

If the current state ISj and the state Si of the rule have a common state description element ((ISj {Si)})
φ) and some terminals used in the common state description element share a common state description element (ISj− (ISj∩Si))
If the terminal is not used in the current state of the rule except for the above, it is necessary to determine the synchronization between the state Si and other terminal states (I
Sj- (ISj @ Si)). For example, the state Si
And the current state ISj of the rule Rj.

SI: dial-tone (X1) ISj: dial-tone (A), idle (B) A common state between Si and ISj if it is shown that terminal “A” is the same as “X1” The element "dial-tone (A)" is found, and the state of another terminal (ISj- (ISj-
By specifying (∩Si)), another state description element “idle (B)” can be found. Here, the terminal variable B is X
2 indicates a terminal other than X1. Therefore, in order to apply rule Rj, “dial-tone (X1)”
(S1) and the state of the other terminal "idle (X2) (ISj-
It is necessary to determine the synchronization with (ISj∩Si). The state “idle (X1)” has already been obtained as an independent terminal state when setting the initial state. The terminal “X2” Indicates that “idle (X2)” is equivalent to “idle (X1).” Therefore, dial-tone (X1), id
The rule Rj can be applied in the state of le (X2) ", since this state can be proved by the criterion" cr-1) ".

Generally speaking, other terminal states (ISj-
(ISj∩Si)) are classified into several groups such as independent terminal states and synchronized terminal states.
If these states are present in the set of acquired states and there is no relationship between any of the terminals in these states, then according to theory 1 mentioned in section 6, the states (Si) and Other terminal states (ISj- (IS
j∩Si)) can be determined to occur simultaneously. Therefore, it is determined that the current state ISj of the rule is satisfied.
Groups that are not in the acquired state set may be acquired in other cases. Therefore, the case is suspended and waits until a state is satisfied that fills the group. If this is not achieved,
The case is abandoned.

(2) The rule application section 14 applies a rule, thereby acquiring a state.

If it is determined that the current state ISj of the rule Rj is satisfied, an event Ej of the rule Rj can occur. Therefore, rule Rj is determined to be applicable, and a state is generated by application of the rule.

Step 3. The acquired state is given to the real state storage unit 16. If the state acquired in step 2 is not included in the real state storage unit 16, it is given to the real state storage unit 16. Steps 2 and 3 described above are repeated until the next state to be assigned to the real state storage unit 16 disappears.

Step 4. Get the status of any terminal.
The first parameter of the state description element indicates the terminal holding the state description element, and the state of the terminal will consist of the state description element with the same first parameter. Therefore, the state of the terminal is extracted from each acquired state.

The following is control for avoiding explosion of the state. (1) Check if the state description element for the terminal is duplicated. Because this leads to an infinite process loop.

(2) It is confirmed whether or not the number of terminals included in Si has reached the limit previously set by the designer. This is because Si may increase indefinitely.

The checked state no longer obeys the application of the rules, and this should be pointed out to the designer to encourage the designer to analyze the problem. FIG. 13 shows a data flow for acquiring a set of states S (stored in the real state storage unit 16) using the rule of FIG. The acquired state of the terminal is shown in FIG.

Step 1 The initial state "idle (X1)" (s-1) is given to S0.

Step 2: First time For the state "idle (X1)" (s-1), the rule indicating that the terminal "A" is the same as "X1" without considering the state of the other terminals r-1) is applied, and thus the next state "dial-tone (X1)" (s-2) is obtained.

Step 3: First time The next state "dial-tone (X1)" is given to S (set of states). This is because it is not yet included in S.

Step 2: Second Time For the state "dial-tone (X1)" (s-2), the candidate to be applied is rule r-2). This is because terminal "A" is the same as "X1" and terminal "B" is "X1".
2 ”, the common state description element (“ ISj @ Si ”)) becomes“ dial-tone (X
1) ”and other terminal states (“ IS
j- (ISj @ Si) ") is" idle (X2) "(s-3)
Because it is found that The other terminal state “idle (X2)” is the state of the independent terminal, and is equivalent to the acquired state “idle (X1)” by indicating that the terminal “X2” is the same as “X1”. Something is found. Therefore, "dial-tone (X1)"
And “idle (X2)” can be determined to be in the same state at the same time. After application of the rules, state s-4) is obtained.

Step 3: Second Time State s-4) is given to S (set of states). This is because it is not yet included in S.

Steps 2 and 3 are repeated until the next state to be assigned to S (set of states) disappears.

Step 4 An arbitrary terminal is set to Y1, and other terminals are set to terminals Y2, Y3, etc. (if necessary). Extract the state of the terminal and change the terminal. The acquired state of the terminal is shown in FIG.

The state "dial-tone (X1), idle (X
For 2) ", rule r-2) is a candidate to be applied because it has a state description element in common with state" idle (X1) ". In the second application, "dial-tone (X1)
Until assigned to (acquired state set), the state "dial-tone (X2)" of the other terminal is not found. Therefore, this case is temporarily put on hold and "dial-tone (X
1) "is assigned to S and then synchronization is determined. As a result, rule r-2) is applied and the next state" ringing (X
1, X2), ringback (X2, X1) "are obtained.

After all the states that can actually exist are obtained and written into the real state storage unit 16,
Competition candidates are detected as in the conventional case. Here, detection of a competition candidate will be described using a simple example.

First, the rule storage unit 10 stores the following rule r-
Assume that 1) to r-7) are stored.

R-1) idle (A) offhook (A): di
al-tone (A). r-2) dial-tone (A), idle (B) dial (A,
B): ringback (A, B), ringing (B, A). r-3) dial-tone (A), not [idle (B)] dial
(A, B): busy (A). r-4) ringback (A, B), ringing (B, A) of
fhook (B): path (A, B), path (B, A). r-5) path (A, B), path (B, A) onhook
(A): idle (A), busy (B). r-6) busy (A) onhook (A): idle (A). r-7) dial-tone (A), path (B, C) dial
(A, B): busy (A), path (B, C). It is also assumed that the following states are written in the real state storage unit 16 according to the above-described method.

Idle (A), dial-tone (A), ringback
(A, B), ringing (A, B), path (A, B), bu
sy (A) In such a state, the competition candidate extraction unit 18 extracts two rules having the same event, and creates a competition candidate 20. Here, r-1) and r-
4), r-2) and r-3), r-2) and r-7), r-
3) and r-7), and r-5) and r-8) are extracted. The situations in which these rules may conflict are as follows:

R-1) and r-4): idle (A), r
inging (A, B), ringback (B, A) r-2) and r-3): dial-tone (A), id
le (B), not [idle (B)] r-2) and r-7): dial-tone (A), id
le (B), path (B, C) r-3) and r-7): dial-tone (A), no
t [idle (B)], path (B) r-5) and r-8): path (A, B), busy
(A), path (B, A) Next, in the candidate narrowing unit 22, it is determined whether or not the above-described situation of possible conflict is stored in the real state storage unit 16. The results are as follows.

In r-1) and r-4), ｛idle (A),
ringing (A, B)} does not exist as a real state of the terminal.

In r-2) and r-3), ｛idle (B),
not [idle (B)]｝ does not exist as the actual state of the terminal.

In r-2) and r-7), ｛idle (B),
path (B, C)} does not exist as the actual state of the terminal.

In r-5) and r-8), ｛path (A,
B), busy (A)} does not exist as the actual state of the terminal.

As a result, it becomes clear that the above four rules do not conflict. On the other hand, r-3) and r-7) are
｛Dial-tone (A), not [idle (B)], path
(B) It becomes clear that they can be applied simultaneously in the situation (1). In this case, r-7 is unnecessary because the two rules specify exactly the same behavior. Therefore, among the combinations of the five rules described above, the combinations of the four rules are deleted from the competition candidates 20. Therefore, one remaining combination of rules {r-3) and r-7)} is presented to the designer as a competition candidate 24.

As described above, generally distributed terminals operate in parallel according to a given service specification. Thus, if there is no relationship between any terminals in a given state, the states are independent of each other and can occur simultaneously (theory 1). The current state of the rule is a candidate to be applied if any state description element is common to the current state ISj and the state Si of the rule Rj ((ISj) {Si) ≠ φ). Other terminal states (ISj- (IS
j∩Si)) is classified as synchronous or asynchronous. If these states are in a set of states and are not relevant between any terminals in a given state,
According to theory 1, state (Si) in a real system
And the state of another terminal (ISj- (ISj∩Si)) can be determined to occur simultaneously. Thus, the properties that determine whether the current state of the rule is satisfied are clearly shown.

Recent moves in knowledge acquisition have turned to “problem solving models”. However, how to solve specific problems by applying knowledge is still awaiting clarification. While traditional expert systems are useful for a narrow range of problems, their architecture cannot be scaled well for larger applications. Although several Knowledge Acquisition (KA) support tools have been studied, it is a difficult task to extract knowledge from experts and solve the problems that arise when designing large and complex system applications. . This is because even a professional designer does not seem to be able to predict all problems, such as service interaction problems in communication service design. Several knowledge-based systems for software design have been proposed, but in the design of communication service specification level, synchronization between a large number of terminals is determined, and conflicts are detected using the acquired states. A state acquisition method has not been proposed yet.

At present, detection and resolution of service interaction caused when a new service is added to an existing service is an urgent issue. The main reason this is difficult is that it is not possible to grasp and predict all possible situations that would occur if new services were combined with existing services using conventional methods. is there.

The present invention has proposed how to automatically acquire states and detect conflicts. To solve the difficulty of determining synchronization, a method has been described for automatically acquiring states and determining synchronization between multiple terminal states using the acquired states. With the present invention, conflicts between communication service descriptions having the same event can be detected satisfactorily.

Communication systems are large, complex, and distributed. In general, applications involving distributed computing systems require a determination of subject synchronization. Therefore, the determination of the synchronization of the conditions of the specification is not limited to this approach, but is common to distributed computing systems.

The communication service specification is handled as an FSM (finite state machine) based on a state transition model. There are many applications based on the state transition model, such as applications for elevators and refrigerators. If such actions can be described as a set of rules, the proposed basic model can be used to detect conflicts between specifications. In this way, it is possible to extend this approach.

[0120]

【Example】

(A) Experimental Results (A-1) According to the present invention, whether false transitions are satisfactorily excluded for POTS (conventional basic telephone service), CW (busy call) and TWC (three-way call) An experiment was performed for Two methods for acquiring the state of the terminal were compared. The first method is to apply a rule to the state of a certain terminal without judging the synchronization between the states of a large number of terminals in the current state description of the rule, and the second method is to describe the current state of the rule. In this invention, the synchronization between the states of a large number of terminals is determined according to the present invention. The results of the first scheme are shown in Table 1, where the number of transitions refers to the total number of transitions that should not have been generated, and the percentage indicates the number of incorrect transitions relative to the total number of transitions.
“POTS + CW” indicates a combination of POTS and CW, and “POTS + TWC” indicates a combination of POTS and TWC. From experiments, it was found that the transition accuracy was about 1 in this invention.
Is found to increase by 7% ((3 + 23 + 1
4) / (28 + 104 + 109) × 100) and PO
It was found that erroneous transitions as shown in FIG. 9 for TS, CW and TWC were completely eliminated in the service specification design stage.

[0121]

[Table 1]

(A-2) Contention Detection The contention detection device according to the present invention detects when some service characteristics can be applied to an actual situation. ST
Using the R-method, when an event occurs and the current state description of the two rules is satisfied simultaneously, a non-deterministic problem arises that it is not clear which of the two rules to apply. Thus, by selecting the two rules whose events are the same by combination, and then constructing a situation from the current state descriptions of the two rules, compare the state of each terminal in that situation with the acquired terminal state By doing so, it is possible to determine whether each situation exists. Thus, in the present invention, conflicts between multiple service characteristics with the same event are detected not only on a single terminal with multiple service capabilities, but also on multiple terminals with multiple service capabilities. obtain. For example, CFV (call transfer operation), CW (busy call), CFV and TCS (call screening), CW and TWC (three-way call) on a single terminal are successfully detected.

CFV + CW: The conflict between CFV and CW is described in Section 1, and this conflict situation is shown in FIG.

CFV + TCS: The TCS blocks connections from terminals whose terminal numbers are included in the screening list. The CFV transfers the call to a preset terminal. If terminal A activates the TCS and CFV, it cannot determine whether to forward or block calls from terminals on the screening list.

CW + TWC: In TWC, when terminal A raises a flash hook and enters the three-party mode while terminal A is talking with terminal B, terminal A waits without turning off terminal B while listening to the dial tone. I will keep it. On the other hand, in the CW, if the terminal C is in a call with the terminal B and the terminal C dials the terminal A, the incoming call ringing tone is given to the terminal A. Thereafter, if terminal A raises a flash hook, terminals A and C are connected, and terminal B is put in a waiting state by terminal A.

If terminal A raises a flash hook while terminal A has both execution capabilities, is on a call with terminal B, and is listening to the incoming call ringing tone from terminal C, Does not apply.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a communication service conflict detection device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a communication service network including a plurality of terminals.

FIG. 3 is a diagram showing an example of a rule described by the STR method.

FIG. 4 is a diagram showing an example in which rules compete with each other.

FIG. 5 is a diagram for explaining how a simultaneous presence determination unit in FIG. 1 determines whether a rule is applicable to an arbitrary terminal.

FIG. 6 is a diagram showing a terminal P in a simultaneous existence determining unit 12 in FIG.
FIG. 9 is a diagram for explaining how synchronization between Q and Q is determined.

FIG. 7 is a diagram showing another example of a rule described by the STR method.

FIG. 8 illustrates a typical correct transition when the rules shown in FIG. 7 are applied.

FIG. 9 illustrates a typical erroneous transition when the rule shown in FIG. 7 is applied.

FIG. 10 is a flowchart illustrating an example of a service specification.

FIG. 11 is a flowchart showing an example of a POTS service operation between actual terminals.

FIG. 12 is a diagram showing still another example of a rule described by the STR method.

FIG. 13 is a flowchart for obtaining a state that can actually exist based on the rule shown in FIG. 12;

FIG. 14 is a diagram showing a state of a terminal obtained according to the flowchart of FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Rule storage part 12 Simultaneous existence judgment part 14 Rule application part 16 Real state storage part 18 Competition candidate extraction part 20, 24 Competition candidate 22 Candidate narrowing part

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Nobuyoshi Terashima 5 Sanraya, Daiya, Seika-cho, Soraku-gun, Kyoto Pref. (JP, A) JP-A-7-95634 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04Q 3/545 H04M 3/42

Claims (1)

(57) [Claims] 1. Each of the current state that one or more terminals are currently taking, the events that occur in the current state of the terminal, and the next state that the terminal should take next when the event occurs. A communication service conflict detection device that is used when applying a plurality of state transition rules having, and automatically detects a conflicting state among the plurality of state transition rules. The stored rule storage means, the real state storage means, and the initial state for storing a predetermined initial state in the real state storage means.
Determining setting means selects a state transition rule from among said rule storage means, already whether stored in the current state wherein the actual state storage means at the selected <br/>-option has been state transition rule and simultaneous presence of <br/> determining means, when said is determined that the present state is already stored in the real state storage means by the simultaneous presence determination means, the selected state transition wherein the current state The next state is generated by applying the rule, and the generated next state is the previous state.
If it is not already stored in the actual state storage means, the generated next state is stored in one of the terminals.
Or the actual state that multiple terminals that are synchronized with each other can actually take
Wherein the rule applying means for newly added memory to the actual state storage means, and competing candidate extracting means for extracting at least two state transition rule having the same event as competitor candidates in the rule storage means, the simultaneous presence of a by the determination hand stage and the rule applying means
After treatment, before referring to you state storage means, said terminal plurality of the current state of the extracted state transition rule by the competition candidate extracting means is operable to determine whether possible simultaneously,
A communication service conflict candidate detecting device comprising: a conflict candidate narrowing means for deleting the extracted state transition rule from the conflict candidates when it is determined that the rule cannot be taken.