KR100248419B1 - A terminating call procedure of ct2 system in public network and private network - Google Patents

Abstract

According to the present invention, a call of a Citi 2 system for a public network and a private network, which performs an incoming call procedure after tracking a location of a terminal in a Citi 2 (Codeless Telephone 2) system for a public network and a private network supporting incoming calls The present invention relates to a method for processing a location of a terminal by using a cell in a CIS (CT2 fixed part Information and Status) message, grouping a plurality of cells together, and performing an incoming call to the terminal from an exchange in an incoming call procedure. When the called exchange / base station controller informs the base stations belonging to the area where the called terminal is located and requests the unique identifier of the called terminal and confirms its location, each base station polls the terminal for ID OK for location tracking. The terminal monitoring the channel detects that polling is in progress and receives a response from the terminal. The base station reports the location confirmation of the terminal to the exchange / base station controller, and finally performs the incoming procedure defined in the CT2 specification only to the base station to which the exchange / base station controller reported the terminal location. By reducing the failure of incoming call due to the load of the image and the wrong location information, the system performance and wireless efficiency can be improved.

Description

Method of processing incoming call of Citi2 system for public and private network

The present invention relates to an incoming call processing method of a CET2 system for public and private networks supporting incoming calls. In particular, the present invention relates to a location tracking procedure before performing an incoming call procedure during incoming call processing. The present invention relates to a call processing method of a public network and a private network Citi2 system for reducing a failure of an incoming call due to incorrect location information by checking a location of a terminal.

In the Citi2 system for public and private networks, an incoming call procedure consists of a call connection with a terminal by a pole following the occupation of a wired channel and acquisition of radio resources. At this time, since the network needs to know the location of the terminal to perform the incoming call, the terminal reports its location to the network in various ways, and when the incoming call is made, the incoming call is attempted only in a specific area.

Initiation of Citi2 uses one radio channel to process one incoming call. Conventionally, when there are N base stations in one location area, the incoming call procedure is performed using one channel for each base station. In N, N additional channels are used. However, the successful incoming procedure is performed only at the base station where the actual terminal is located, and the N-1 base stations terminate the incoming procedure by timeout and so on, resulting in N-1 channels being wasted during the timeout period. In addition, when there are M calls at the same time, an incoming procedure must be performed using M * N separate channels, resulting in more waste of channels.

On the other hand, in order to avoid such waste, when the terminal updates its location information in units of cells in registering its location information with the network, the load on the wireless channel for information update is increased, resulting in performance and performance of the Citi2 network. There is a problem that the wireless efficiency is lowered.

In order to solve the above problem, the present invention performs the location registration of the terminal by using the information of the CIS message by binding a few cells in the area unit, and when there is an incoming call, using a location tracking mechanism in the base stations in the location area By initiating an incoming call after confirming the cell where the terminal is actually located, the purpose is to improve the performance and wireless efficiency of the system by reducing the failure of the incoming call due to the load on the wireless channel for updating the location information and the incorrect location information. .

1 is a network diagram of the Citi 2 system according to the present invention;

2 is an incoming signal processing diagram of the Citi 2 system of FIG. 1;

3 is an operation flowchart of a Citi2 base station according to the present invention;

4 is a polling process of a base station and a terminal according to the present invention;

<Explanation of symbols for main parts of drawing>

10: Citi 2 exchange 20: Exchange / base station controller

30: base station 40: terminal

50: subscriber location information database

The present invention relates to an incoming call processing method of a public and private network C2 system for supporting incoming calls, and in particular, by checking a location of a terminal through a location tracking procedure before performing an incoming call procedure during incoming call processing. The present invention relates to a call processing method of a Citi2 system for public and private networks which reduces failure of an incoming call due to incorrect location information.

The Citi 2 wireless standard defines the location registration by the terminal using the information of the CIS (CT2 fixed part Information and Status) message and the location tracking mechanism by the network as the following three.

First, a network periodically transmits a CIS message. The CIS message expresses location area information of a base station transmitting the information, information for network identification, and information related to a resource of the base station. The terminal may determine the current location by observing the CIS message, and if the current terminal location is different from the location registered in the network, the terminal acquires a radio channel and performs a procedure for requesting the location information update of the network.

Second, the terminal that does not support the CIS message can inform the network of its location according to an operation such as using a timer or pressing a specific button, regardless of whether the subscriber's actual location changes. At this time, the quality of the incoming service depends on the timer interval and the user's operation frequency, but it has the advantage that it can be implemented simply.

Third, while location registration by CIS is active update of location information by a terminal, location tracking is an update procedure for location information of a terminal by a network. CT2 provides two types of location tracking mechanisms: polling using the LT POLLING LID value and polling using the LR POLL LID value on the channel where the CIS is transmitting. In both schemes, the base station transmits a poll message (ID OK) carrying the identifier (PID) of the terminal over the air, and the terminal that detects it responds to the poll (ID OK) to check whether the base station exists in the terminal area. In the form of However, if the base station does not have information about the identifier of the terminal in the area, location tracking is impossible. Therefore, location tracking can only be used as a complement to location registration. When using the LR POLL LID, the ID OK message is alternately transmitted with the CIS message, and the ID OK message using the LT POLL LID is transmitted on any channel. In addition, both methods can simultaneously poll for multiple terminals. That is, the polls for multiple terminals are successively transmitted in one channel.

In the present invention, when the terminal registers its own location information in the network, a plurality of cells are bundled and performed in area units by using the information of the CIS message, and in the destination processing method of the Citi2 system, the destination side exchange A unique identifier of a called terminal to a base station belonging to an area in which a called station / base station controller is located in an area in which a base station controller is requested to receive a terminal from a switch, and according to the incoming request of the first step. And a second step of requesting the location confirmation and a third step of performing the ID OK polling procedure for location tracking by each base station that is requested for the location confirmation in the second step, and the terminal monitoring the channel. A fourth step of detecting and responding to the polling of the terminal by the third step and a response of the terminal in the fourth step A fifth step of reporting that the base station receiving the answer has confirmed the location of the terminal to the switch / base station controller; and the base station reporting the terminal location check in the fifth step to the incoming procedure defined in the CT2 standard. Is processed through a sixth step performed.

Hereinafter, with reference to the accompanying drawings will be described in detail the incoming call processing method of the Citi 2 system for public and private networks according to the present invention.

FIG. 1 is a network configuration diagram of a Citi 2 system according to the present invention. The Citi 2 switch 10 receives a voice information signal transmitted to a public network and a private network, and transmits the received voice information signal to a corresponding terminal. Interconnect and control with the base station, and receives the voice information signal from the Citi2 switch 10 under the control of the switch / base station controller 20 and the switch / base station controller 20 to manage each base station And a subscriber station information database 50 for storing the location of the terminal 40 and a terminal 40 for communicating by relay of the base station 30.

Here, in the case of the actual network configuration, the Citi2 switch 10, the switch / base station controller 20, and the subscriber location information database 50 may be implemented as one physical entity or may be implemented as separate physical entities. .

FIG. 2 is an incoming signal processing diagram of FIG. 1.

First, the Citi 2 exchange 10 receives voice information signals transmitted to public and private networks, and requests the exchange / base station controller 20 for incoming calls for the corresponding terminals. (1) Then, the exchange / base station controller ( 20) informs the base stations 30 belonging to the area where the called terminal is located to inform the unique identifier of the called terminal stored in the subscriber location information database 50 and to confirm the location thereof. The location information database 50 stores information on the identifier of the terminal.

The base station 30 receiving the position request of the exchange / base station controller 20 polls using an ID OK message (3), and the terminal 40 monitoring the channel detects that polling is in progress. (4) The base station 30 reports to the exchange / base station controller 20 that the terminal has been located according to the response of the terminal 40. (5) Then, the exchange finally (6) The base station controller 20 performs the incoming procedure defined in the CT2 standard only to the base station 30 which has reported the terminal location check so that the terminal 40 can communicate.

Here, there are three cases of polling using the ID OK message of the base station 30.

First, when there is a channel transmitting CIS message, ID OK polling using LR POLLING LID, and second, when there is no channel transmitting CIS message, ID OK polling using LT POLLING LID. do. And, third, if a location confirmation procedure is already performed on a wireless terminal by the first or second ID OK polling when a location confirmation request is received, a poll message for a new terminal is added to the current procedure.

3 is a flowchart illustrating an operation of a Citi2 base station according to the present invention, (a) is a flowchart illustrating a process of polling by using an ID OK from a base station to a terminal, and (b) shows the operation of the base station when a response is received from the terminal. (C) is a flowchart illustrating the operation of the base station when no response is received from the terminal.

(a) is the operation of the base station receiving the incoming call request for the terminal from the exchange / base station controller, and includes the following steps.

In S1, the base station receives a location request for an arbitrary terminal i from the exchange / base station controller, in S2 adds the terminal i to a target to be polled by the base station, and in S3, polls for the terminal i. Set a timer for its duration. In S4, it is determined whether there is a channel transmitting a CIS message to the base station, and if there is a channel being transmitted, the process goes to S5. In S5, an ID OK message for target terminals to be polled is alternately transmitted with the CIS message being transmitted. In S6, it is determined whether the polling for the other terminal j is in progress. If the polling for the other terminal is in progress, the process goes to S7, and if not, the process goes to S8. In S7, only an ID OK message for a new target terminal is added and transmitted in a channel in which polling is performed without acquiring a new wireless channel.

In S8, a new radio channel for a polling procedure is obtained, and in S7, an ID OK message for polling targets is wirelessly transmitted.

(b) is an operation after the base station receives the response from the terminal and includes the following steps.

In S1, while the polling from the base station to the terminal is performed wirelessly, an ID OK message is received from the terminal i as a response to the poll, and in S2, the terminal i is confirmed to exist in the current base station area. Deletes the terminal i so that no ID OK message for polling the terminal i is transmitted over the air. In S3, the timer for the terminal i is released, and in S4, a message indicating that the location of the terminal is confirmed is transmitted to the exchange or the base station controller that has transmitted the incoming call request for the terminal i.

(c) includes the following steps in the operation of the base station when it does not receive a response from the terminal.

In S1 to end the polling duration for the terminal (i) by the expiration of the timer,

In S2, the terminal i is deleted from the polling target of the base station so that the ID OK message for polling is no longer transmitted wirelessly.

FIG. 4 is a polling process diagram between a base station and a terminal according to the present invention, (a) is a polling process diagram in a channel transmitting CIS, and (b) is a polling process diagram in a channel not transmitting CIS. In (a), it can be seen that the CIS message and the ID OK message are alternately transmitted, and in (b), the ID OK message is transmitted in an arbitrary channel.

The incoming call processing method reduces the number of channels used in the incoming call procedure, reduces the failure rate of the incoming call due to incorrect location information, and improves the performance and wireless efficiency of the system. Since the location information update can be performed, the frequency of location information update can be reduced compared to the cell-based location information update, thereby reducing the consumption of the wireless channel and reducing the load on the system for updating the subscriber location information database.

In the present invention, the location registration of the terminal is performed by uniting several cells by using the information of the CIS message in the area unit, and in the incoming call procedure, the destination side exchange / base station controller, which is requested to receive the terminal from the exchange, is the destination terminal. When the base stations belonging to the location are informed of the unique identifier of the called terminal and the location confirmation is requested, each base station performs ID OK polling to the terminal for location tracking, and the terminal monitoring the channel is polled for itself. In response to this, the base station receiving the response of the terminal reports the position confirmation of the terminal to the exchange / base station controller, and finally the base station to which the exchange / base station controller reported the terminal position is defined in the CT2 standard. By performing the incoming procedure, load and wrong positioning on the wireless channel for updating the location information Reducing the incoming call fails to be also due to the effect of improving the performance of the system and the radio efficiency.

Claims (4)

In the incoming procedure of the Citi2 system to the terminal in the Citi2 system for public and private networks supporting the incoming call, A first step of updating location information in units of location areas, which are a bundle of cells, wherein a called-side exchange / base station controller is requested to receive a terminal from a switch; A second step of the called exchange / base station controller informing the base stations belonging to the area where the called terminal is located according to the incoming call request of the first step and requesting identification of the called terminal; A third step of performing ID OK polling by each of the base stations that are requested for location checking in the second step to the terminal for location tracking; A fourth step of the terminal monitoring the channel detecting and responding to polling of the terminal by the third step; A fifth step of, by the base station receiving the response of the terminal in the fourth step, reporting the location confirmation of the terminal to the exchange / base station controller; And a sixth step of performing, by the exchange / base station controller, an incoming procedure defined in the CT2 standard only to the base station that has reported the terminal location in the fifth step. Way. The method of claim 1, The third step includes: a first substep of the base station receiving a location request for an arbitrary terminal from an exchange / base station controller; A second sub-step of adding a terminal to a target to be polled by a base station that has received a location request for an arbitrary terminal in the first sub-step; A third substep of setting a timer for a duration of polling for the terminal added in the second substep; It is determined whether there is a channel transmitting the CIS message at the current base station. If there is a channel being transmitted, the process goes to the polling step. 4 substeps; A fifth sub-step of alternately transmitting an ID OK message for the target terminals to be polled when there is a channel transmitting the CIS message in the fourth sub-step; In the fourth sub-step, if there is no channel currently transmitting the CIS message to the base station, it is determined whether polling for another terminal is in progress, and if the polling is in progress for another terminal, go to the polling step; A sixth substep leading to the step; In the sixth sub-step, when the polling for another terminal is in progress, a seventh sub-step of transmitting and adding only an ID OK message for the new target terminal in the polling channel without acquiring a new radio channel; When there is no polling for another terminal in the sixth sub-step, the eighth part acquires a new radio channel for the polling procedure, and goes to the seventh sub-step to wirelessly transmit ID OK messages for polling targets. Method for processing the incoming call of the Citi 2 system for public and private networks, comprising the step. The method of claim 1, The fifth step includes: a first substep of receiving an ID OK message as a response to the poll from the terminal while the polling from the base station to the terminal is wireless; A second sub-step of deleting the terminal whose location is identified in the first sub-step from a polling target; A third substep of releasing a timer for a terminal whose location is identified; And a fourth substep of transmitting a message informing that the location of the terminal has been confirmed to the exchange / base station controller that has transmitted the incoming call request to the terminal. The method according to claim 1 or 3, The fifth step may include: a first substep of terminating a polling duration for the terminal upon expiration of a timer when the base station does not receive a response to the poll from the terminal while the polling is performed wirelessly; And a second sub-step of deleting the terminal from the polling target of the base station.

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