KR970001871B1 - Method for connecting cellular phone to station - Google Patents

Abstract

The method of connecting a terminal to a fixed station includes: the steps (200, 202 and 204) of starting a handover process, if a signal level of the fixed station is under a regulated value during communication; the steps (206, 208, 210, 212, 214 and 216) of searching the fixed station, and receiving all of the channels; the steps (218, 220, 222 and 224) of displaying handover impossibility, if the fixed station is not searched, and trying the connection to the searched fixed station, if it is searched; the steps (226, 228, 230, 232, 234, 236 and 238) of selecting the fixed station having more stronger signal level in two fixed station, if two fixed station are searched and the signal levels thereof are not identical to each other, and checking a transfer record to connect the terminal to the fixed station having more stronger value of "signal+longitude", if the signal levels of two fixed station are identical to each other.

Description

How to connect a terminal to a fixed station

1 is a block diagram generally showing one embodiment of a DECT terminal.

FIG. 2 is a flow chart showing step by step an embodiment of general DECT terminal processing of FIG. 1 according to the DECT standard. FIG.

3 is a flowchart showing step by step an embodiment of a method for connecting a terminal to a fixed station according to the present invention;

The present invention relates to a portable terminal of the DECT (Digital European Cordless Telecomm-unications) method, and more particularly, to a method for connecting a terminal suitable for maintaining a continuous call during handover processing to a fixed station.

In this regard, FIG. 1 is a block diagram illustrating an embodiment of a general DECT terminal, including a central processing unit (CPU) 2 having a baseband processing function for controlling overall operation of the terminal, A power supply unit 4 controlled by the central processing unit 2 to indicate the current power state of the terminal and a power supply unit 6 controlled by the central processing unit 2 to supply power for operating the terminal to the terminal system; A microphone 8 for converting a signal into an electrical analog voice signal, an analog-digital converter 10 for converting an analog voice signal of the microphone 8 into a digital signal, and an analog The digital voice signal of the digital converter 10 is converted into ADPCM (Adaptive Differential Pulse Code Modulation) data and applied to a digital signal processing (DSP) processor 14. The digital signal processing processor 14 which communicates with the ADPCM-PCM (Pulse Code Modulation) converting unit 12 and the central processing unit 2 and processes the digital signal according to a voice encoding method using the digital signal in the DECT standard; A PCM-ADPCM converter 16 for converting ADPCM data of the digital signal processor 14 into PCM data, and a digital-analog converter for converting PCM data of the PCM-ADPCM converter 16 into an analog signal ( 18), a speaker 20 which is driven by an analog signal of the digital-to-analog converter 18 to output voice, and voice data encoded by ADPCM from the central processing unit 2 to a carrier for modulation. A signal synthesizer 22 for carrying and modulating the signal, a signal amplifier 24 for amplifying the modulated signal of the signal synthesizer 22 to a level defined by DECT, and amplified signal 24. Spreads the signal in the air An antenna 26 for receiving a call, a low noise amplifier 28 for low noise amplifying a high frequency signal of a fixed station received through the antenna 26 during a reception period, and a low noise amplifier 28 The intermediate frequency converter 30 converts the received high frequency signal into an intermediate frequency, and the original signal transmitted from the intermediate frequency of the intermediate frequency converter 30 is extracted and applied to the central processing unit 2. A key input unit 34 for making a call input to the roughing unit 32, the central processing unit 2, a screen display unit 36 for receiving a signal from the central processing unit 2 to display the bell state, and a central processing unit. A buzzer 38 for generating a special sound generated for use of a terminal such as a key input and a bell by receiving the signal of the device 2, and the initial state and various numbers of the volume under the control of the central processing unit 2 Electrically erasable programmab le Read Only Memory; EEPRON) 40, a read only memory (ROM) 42 storing data for the operation of the entire processor by the central processing unit 2, and a longitudinal operation by the central processing unit 2; And a read access memory (RAM) 44 which temporarily stores the parameters.

Referring to FIG. 2, a general DECT terminal made in this way is as follows.

First, it is controlled by the central processing unit 2 and has a baseband processing function for controlling the overall operation of the terminal, and the power display unit 4 is controlled by the central processing unit 2 to indicate the current power state of the terminal LED (Light Displayed using a light emitting element such as an Emitting Diode, so that the user can know the current state of the power on / off of the terminal.

Then, the power supply unit 6 is controlled by the central processing unit 2 to supply power for terminal operation, and the microphone 8 converts a voice signal by the user into an electrical analog voice signal, and converts the analog-digital conversion. The unit 10 converts the analog audio signal of the microphone 8 into a digital signal.

The ADPCM-PCM converter 12 converts the digital voice signal of the analog-digital converter 10 into ADPCM data and applies it to the digital signal processor 14, and the digital signal processor 14 performs central processing. It communicates with the device 2 and processes the digital signal according to the speech coding method used in the DECT standard.

In addition, the PCM-ADPCM converter 16 converts the ADPCM data of the digital signal processor 14 into a PCM data, and the digital-analog converter 18 converts the PCM data of the PCM-ADPCM converter 16. Is converted into an analog signal, and the speaker 20 outputs the voice by the analog signal of the digital-analog converter 18 so that the user can hear the voice.

Next, the signal synthesizing unit 22 receives the voice data encoded by the ADPCM from the central processing unit 2 and modulates it in a carrier for modulation of 1.8 GHz for wireless transmission, and the signal amplifying unit 24 performs the signal synthesizing unit 24. The modulated signal at 22 is amplified to the level specified in the DECT, and the antenna 26 propagates the amplified signal of the signal amplifier 24 in the air and receives the signal in the air.

Accordingly, the low noise amplifier 28 receives the 1.8 GHz signal of the fixed station received through the antenna 926 during the reception period of the terminal to low noise amplification, and the intermediate frequency converter 30 is 1.8 of the low noise amplifier 28. The received frequency of GHz is converted into an intermediate frequency of 110 MHz, and the demodulator 32 extracts the original signal transmitted from the intermediate frequency of 110 MHz of the intermediate frequency converter 30 and applies it to the central processing unit 2. .

In addition, the key input unit 34 inputs a call to the central processing unit 2, and the screen display unit 36 receives a signal from the central processing unit 2 and uses a display element such as an LCD (Lequid Crystal Display). The bell state 38 is displayed, and the buzzer 38 receives a signal from the central processing unit 2 to generate a special sound generated for use of a terminal such as a key input and a bell so that the user can hear it. ) Records the initial state of the volume and various telephone numbers by the central processing unit 2, the ROM 42 stores the non-volatile data for the operation of the entire terminal by the central processing unit 2, 44 temporarily stores the parameters for the longitudinal operation by the central processing unit 2. FIG. 2 is a flow chart showing, by group, an embodiment of the general DECT terminal processing of FIG. 1 according to the DECT standard, that is, an algorithm of the central processing unit 2.

First, when the power is turned on, the initial value for the hardware (Hardware) is read from the ROM 42 or EPI rom 40 to initialize each hardware, and the RAM 44 is inspected and cleared. After checking the hardware for basic abnormality by operating a self-diagnosis program, the radio base station receives signals from the radio base stations 10 through 10 (100, 102, 104, 106, 110, 112).

Next, the received electric field strengths of all 10 channels are examined to determine the connection to the wireless base station which emits the strongest signal among them, and based on the signal sent from the wireless base station, to be a reference for various timings in the terminal. Motivate (114).

After that, by checking the time slot usage state of the radio base station, it is checked whether there is an empty time slot, and then performs a registration procedure (116).

At this time, the two terminals that have completed the registration procedure enter a standby state, and operations of the terminal proceeding in the standby state can be largely divided into four.

First, the terminal checks whether there is a paging signal from the fixed station, and if there is a paging signal, first accesses a medium access control (MAC) layer to secure a time slot use right of a wireless channel. Then, the DLC (Data Link Control) layer connection and the network (Network) layer proceeds in order to form a call path to proceed with the call (118, 120, 122, 124, 126).

Subsequently, due to one call disconnection situation, the network layer is disconnected, the DLC layer is disconnected, and then the MAC layer is disconnected to release the radio channel and enter the standby state again (128, 130, 132).

On the contrary, if there is no paging signal, the terminal user checks a connection request to a specific subscriber, and if a request occurs, if there is an empty time slot by checking the existence of an empty time slot to secure use of the time slot. Immediately requests the use of the time slot to the station, and if the time slot is not empty, waits until the time delay does not exceed the value set until another user's use of the time slot ends. When the use of another user's time slot ends, an attempt is made to access the MAC layer using the time slot (134, 136).

Subsequently, access to the MAC layer is secured to secure the time slot use rights of the wireless channel, and the DLC layer and the network layer are sequentially accessed to form a call path and then proceed with the call (138, 140, and 142).

Subsequently, due to any one call disconnection, the network layer is disconnected, the DLC layer is disconnected, and then the MAC layer is disconnected to release the radio channel and enter the standby state again (144, 146, 148).

At this time, after there is no paging signal and user's request for transmission or the processing (step 132, step 148) is completed, the state check in the terminal is performed.

A typical internal condition check is the voltage level check of the supply battery.

First, the battery voltage is input through a circuit for converting an analog signal into a digital signal to check whether it is at an appropriate level. If the battery is below an appropriate level, a battery charge warning signal is generated and a message such as, for example, charging is required to the user. It informs the charging condition and checks whether the signal from the fixed station is maintained to maintain an appropriate signal level or whether the signal level is too low to attempt to connect to an adjacent fixed station (150, 152, 154, 156, 158).

If the fixed station's signal level is -83dBm or more, it maintains the signal status of the currently registered station as it is, and if the signal level drops below a certain value and a mobile connection to the previous station is required, the wireless channel can be switched from 0 to 9. First, a process of deregistration of releasing a state registered in the current fixed station is performed (160).

Subsequently, signals from the wireless base station are received again over 10 of the radio channels 0 through 9 (162, 164, 166, 168, 170, 172).

Therefore, the received electric field strengths of all 20 radio channels are examined to determine the connection to the radio base station which emits a strong radio signal, and based on the signals sent from the radio base station, various timing criteria in the terminal are determined. Be as motivated as possible (174,176).

After that, the time slot usage state of the wireless base station is examined to determine whether there is an empty time slot, and then a new registration procedure is performed (116).

That is, in the standby state, as described above, it is determined whether or not there is a paging signal from the fixed station, and the processing thereof is performed, the transmission request of the user is examined, and the processing thereof is performed, and it is checked whether the battery voltage is at an appropriate level. The basic form of the entire DECT terminal processing is to perform a process for it, inspect the signal level of the fixed station, proceed with it, and perform various timer processing of other terminals.

In the conventional technology as described above, there may be an area in which only one signal of the radio base station is received, an area in which two signals of the radio base station are received, and an area in which three signals of the radio base station are received in the conventional cell structure.

In the handover in the area where three signals of the wireless base station are received, if two fixed stations exist besides the station already in talk and the signals are at the same level, the number of radio channels uniformly processed by the program is low or high. To make a handover.

In this case, if the mobile station's moving path is directed to the third station that is not selected after the connection to either station is performed, another additional handover should occur immediately after the handover occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for connecting a terminal to a fixed station in which three signals of the fixed station signal can reasonably proceed handover progress at the same place.

Hereinafter, described in detail by the accompanying drawings an embodiment of the present invention as follows.

Referring to FIG. 3, FIG. 3 is a flowchart showing step by step an embodiment of a method for connecting a terminal to a fixed station according to the present invention.

First, the signal level of the fixed station during the call is checked, and if the signal level is less than the prescribed value, the handover process is started (200, 202, 204).

Next, the fixed station is found and the channels are incremented by one and all ten channels are accepted while recording the signal strengths (206, 208, 210, 212, 214, 216).

Subsequently, if no fixed station is found at all, a handover indication is indicated. If one fixed station is found, an attempt is made to connect to the found fixed station (218, 220, 222, 224).

If two fixed stations are found and the signal levels of the two fixed stations are not the same, a fixed station having the strongest signal level is selected among the two fixed stations. Connect to the fixed station to continue the call (226.228, 230, 234, 238).

As described above, the present invention can add an effective determination function to which fixed station is more efficient when two fixed station signals are input at the same level during handover.

Claims (1)

Starting handover processing (200, 202, 204) if the signal level of the fixed station during the call is less than or equal to the prescribed value; Finding a fixed station and accepting all of the channels (206, 208, 210, 212, 214, 216); If no fixed station is found, indicating no handover; if one fixed station is found, attempting to connect to the found fixed station (218, 220, 222, 224); if two fixed stations are found and the signal levels of the two fixed stations are not equal, the two Selecting a station having a strong signal level among the stationary stations, and if the signal levels of the two stationary stations are the same, checking the movement record to connect to the station having a strong signal & hardness " and continuing the call (226,228,230,232,234,236,238) How to connect to a fixed station.