KR0123105B1 - Method for connecting cellular phone - Google Patents

Abstract

A method of connecting a termianl to a base station is disclosed. The method of connecting the termianl to the base station comprises the steps of: receiving signals from a plurality of base stations and connecting the terminal to a first base station having a strongest signal level; connecting the terminal to a base station having a second strongest signal level of more than a reference signal level and an avaliable time slot when the avaliable time slot is not in the first base station; connecting the terminal to a third base station having a third strongest signal level of more than a reference signal level and an avaliable time slot when the avaliable time slot is not in the second base station. Thereby, the method of connecting a termianl to a base station may increase the probability capable of connecting a DECT terminal to the base station for many users.

Description

How to connect a terminal to a fixed station

1 is a block diagram showing an embodiment of a general 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 method for connecting a terminal to a fixed station, and more particularly, to a portable terminal of a DECT (Digital European Cordless Telecommunications) system. In particular, a terminal suitable for connecting a terminal to a fixed station (also called a base station) is connected to the fixed station. It is about how to.

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 overall operation control of the terminal, A power supply unit 4 controlled by the central processing unit 2 to indicate the current power state of the terminal, 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 voice signal into an electric analog voice signal, an analog-digital converter 10 for converting an analog voice signal of the microphone 8 into a digital signal, The digital voice signal of the analog-to-digital converter 10 is converted into ADPCM (Adaptive Differential Pulse Code Modulation) data and input to the digital signal processing (DSP) processor 14. A digital signal processing processor 14 which communicates with an ADPCM-PCM (Pulse Code Modulation) converter 12 and the central processing unit 2 to digitally process digital signals according to a speech coding method used in the DECT standard. A PCM-ADPCM converter 16 for converting ADPEM data of the digital signal processing 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 for a modulation carrier ( 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. Propagate the signal to the atmosphere An antenna 26 for receiving a high frequency signal in the air, a low noise amplifier 28 that receives a high frequency signal from a fixed station received through the antenna 26 during a reception period, and low-weights it; An intermediate frequency converter 30 which converts the received high frequency signal of the low noise amplifier 28 into an intermediate frequency, and extracts the original signal transmitted from the intermediate frequency of the intermediate frequency converter 30, ), A key input unit 34 for inputting a call to the central processing unit 2, and a screen display unit 36 for displaying a longitudinal state by receiving a signal from the central processing unit 2; ), A buzzer 38 for generating a special sound generated for use of a terminal such as a key input and a beep by receiving a signal from the central processing unit 2, and control of the central processing unit 2 Record initial status and various phone numbers This pirom (Electrically Erasable Programm able Road Only Memory leave; EEPROM) 40, a ROM 42 storing data for operation of the entire processor by the central processing unit 2, and a longitudinal operation by the central processing unit 2; And RAM 44 which temporarily stores the parameters.

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

First, the central processing unit 2 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. By using light emitting elements such as diodes), the user can know the current state of 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 processing processor 14, and the digital signal processing 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 DEC T standard.

In addition, the PCM-ADPCM converter 16 converts ADPCM data of the digital signal processing processor 14 into PCM data, and the digital-analog converter 18 converts the PCM data of the PCM-ADPCM converter 16 into analog. The signal is converted to a signal, and the speaker 20 outputs a 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 is a signal synthesizing unit 24. The modulated signal 22 is amplified to a level defined by DECT, and the antenna 26 propagates the amplified signal of the signal amplifier 24 in the air and receives the high frequency signal in the air.

Accordingly, the low noise amplifier 28 receives the 1.8 GHz signal of the fixed station received through the antenna 26 during the reception period of the terminal and performs low noise amplification, and the intermediate frequency converter 30 of the low noise amplifier 28 The received frequency of 1.8 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. do.

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 (Liquid Crystal Display). A bell state 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 beep so that the user can listen to it. ) Records the initial state of the volume and various telephone numbers by the central processing unit 2, and 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 longitudinal operation by the central processing unit 2.

FIG. 2 is a flowchart showing one 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 of the hardware is read from the ROM 42 or EPI rom 40 to initialize the respective hardware, and the RAM 44 is inspected and cleared. After operating a diagnostic program or the like to check the basic abnormality of the hardware, the radio base station (also referred to as a fixed station) receives signals from the radio channels 0 to 9 over 10 times (100, 102, 104, 106, 108, 110, 112).

Next, the received electric field strengths for all 10 radio channels are examined to determine the connection to the radio base station which emits the strongest radio signal, and based on the signals sent from the radio base station, Motivate to be the reference (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 a registration procedure is performed (116).

At this time, the terminal enters the standby state after completing the registration procedure, the operation of the terminal proceeding in the standby state can be divided into four.

First, the terminal checks for the presence of 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 the wireless channel. The connection of the DLC (Data Link Control) layer and the network (Network) layer are sequentially performed to form a call path and then proceed with the call (118, 120, 122, 124, 126).

Subsequently, due to any one call disconnection situation, network layer disconnection, DLC layer disconnection, and MAC layer disconnection are performed 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 examines 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. If the time slot is not empty, wait until the time slot is not exceeded the set value until the end of the use of another user's time slot. When another user's use of the 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 right of the wireless channel, and access to the DLC layer and network layer are sequentially performed to form a call path and then proceed with the call (138, 140, and 142).

Subsequently, due to any 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 (144, 146, 148).

At this time, after there is no paging signal and the user's request for transmission or the processing (step 132 or 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 to display a message such as, for example, a need for charging. It informs the state of the need for charging and receives a signal from the fixed station to check whether it maintains 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 signal level is more than -83dBm, the signal state of the currently registered station is maintained as it is.If the signal level drops below a certain value and a mobile connection to the previous station is required, the radio channel is changed from 0 to 9. Accepted across dogs (160,162,164,166,168,170,172).

Therefore, the received electric field strengths for all ten radio channels are examined to determine the connection to the wireless base station which emits the strongest wireless signal, and the various timings within the terminal are determined based on the signal sent from the wireless base station. Motivate to be the reference (174,176).

After that, the time slot usage state of the radio base station is examined to determine whether there is an empty time slot, and then handover is newly performed.

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 processed 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.

This conventional technique is intended to connect to a fixed station defined in the DECT standard, after receiving all signals of all fixed stations, and attempting to connect to the strongest fixed station.

In addition, there is an area in which two or three signals of a fixed station are received to support a handover function in a cell configuration of the DECT scheme and to eliminate an out of service state between cells.

When attempting to connect only to the strongest fixed station in such an area, the time slots of the strongest fixed station are all used, and the time slot of the adjacent fixed station may remain available although the signal level is not the strongest.

Thus, if a connection is attempted only to a fixed station that exhibits the strongest signal level in any area, it must wait until one of the users of the time slot finishes the call if all of the fixed station's time slots are in use.

In addition, if there are a lot of call waiting after the end of the call, it is impossible to connect immediately, and further delay may occur due to a problem such as a collision of access attempts.

Therefore, in this case, even if the fixed station does not exhibit the strongest signal level, it checks whether there are available time slots of the fixed station for the call. You can save.

The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to provide a method for connecting a terminal to a fixed station that can increase the connection efficiency when attempting to register or call at an arbitrary location.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention for achieving the above object is as follows.

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

At this time, the algorithm according to the present invention is mounted in the Ypyrom 40 or the ROM 42 and is operated by the central processing unit 2. In addition, communication between terminals can be made by a switching action of the exchange via a base station (also referred to as a fixed station) having one cell, a base station controller communicating with a plurality of base stations, and an exchange communicating with a plurality of base station controllers. In general, the terminal and the base station communicate wirelessly in a cell of the base station, and the base station, the base station controller, and the exchange between the wired communication.

The basic operation of each part according to FIG. 1 showing the hardware of the terminal according to the present invention will be described above.

First, each signal of neighboring fixed stations is received, that is, all channels from channel 0 to channel 9 are received, and the fixed station representing the strongest signal among them is selected and connected to the selected fixed station (200, 202, 204, 206, 208, 210, 212).

Next, if there is no available time slot in the selected fixed station, it is determined whether the signal level of the next fixed station is greater than or equal to the prescribed value, and if the signal level of the fixed station is greater than or equal to the prescribed value and there is an available time slot, access and register with the fixed station. Receive standby state (214, 216, 218, 220, 228).

Then, if all the time slots of the next fixed station are in use, the signal of the third fixed station is checked, and if the signal level of the third fixed station is equal to or higher than the prescribed value and there is an available time slot, access and register the third fixed station and wait for reception. Maintain state (222, 224, 226, 228).

If there is no available time slot in the third fixed station, the process from checking the time slot of the fixed station having the strongest signal level again is repeated.

Of course, the connection attempt with the fixed station is not limited to the third time, but may be further set in consideration of the received field strength of the fixed station.

Especially. This method is very effective when a connection request is made at a point where two fixed stations meet or when a connection attempt is made in an area where signals of two fixed stations overlap.

As described above, according to the present invention, the fixed stations are sequentially examined according to the signal level, and the connection attempt can be made much higher than the case where only one station having the strongest signal level is irradiated. .

Claims (1)

Receiving each signal of the surrounding fixed stations and connecting to the fixed station representing the strongest level signal among them (200, 202, 204, 206, 208, 210, 212); If there is no available time slot in the fixed station, the signal level of the fixed station indicating the next strongest level signal is higher than the prescribed value and there is a time slot available. 214,216,218,220,228); If all the time slots of the next fixed station are in use, if the signal level of the fixed station indicating the third strongest level signal is higher than the prescribed value and there are available time slots, the station receives the reception state after accessing and registering the third fixed station. And (222, 224, 226, 228) the terminal.