KR20000027438A - Mobile phone used as city phone as well as pcs phone - Google Patents

Abstract

PURPOSE: A mobile phone used as a city phone as well as a PCS phone is disclosed to save fees for a call by using a city phone in CT-2 allowable region. CONSTITUTION: A mobile phone used both as a city phone and a PCS phone includes a logic circuit(10) having a single-chip baseband processor, an RF module(12) for PCS, and an antenna(16). To use as a city phone, an RF module(13) operated in a city phone frequency band is further provided. The antennal(16) is coupled to the RF module(12) for the PCS and the RF module(13) operated in the city phone by an RF switch(14). When the mobile phone is for a PCS mode, all of the required values are set in the PCS mode, and when it is operated in a city phone mode, all of the required values are set in the city-2 mode.

Description

Citiphone combined PS handset

The present invention relates to a city phone combined PS terminal, and more particularly, to a terminal operated as a city phone in a city phone service area and a PCS terminal in an area where city phone service is not available.

The City Phone Service (CT-2: Second Generation Cordless Telephone), which has developed a home wireless phone into a public wireless phone, has been commercialized in Korea since spring 1997.

This city phone system is a digital wireless communication device classified into public, business, and home according to the application field, and for public service, it is a call-only mobile phone (CT-2) called telepoint. It is possible to receive outgoing service by connecting to public telephone network (PSTN) through public base station in home office, and home and business service is connected to public telephone network through base station installed in home or office base station or building. It's a free service.

For public use, only the outgoing function is provided and it is a pedestrian-oriented communication service that can make calls within 200 meters from the base station and has a low power micro-cell method, which has high frequency utilization and can accommodate about 5,000 people / sq km of subscriber per unit area. There is a number. However, since there is no handoff and roaming functions, the call is disconnected when the service radius is exceeded, and the call is dropped when the walking speed exceeds 30 km / H. The frequency used is 910-914 MHz, the channel spacing is 100 KHz, the multiple access method is FDMA / TDD, and the voice coding method uses ADPCM.

PCS (personal communications service) communication is a system for the provision of personal number and mobility, and can use the unique number assigned to individual subscribers to communicate with the mobile terminal anytime, anywhere with anyone in the service area, and consider personal mobility. Rather than assigning numbers by maids, it is a system that assigns a unique number for each individual and enables individual identification by this number in any area.

Therefore, subscribers with PCS mobile phones can be provided with various services, and subscribers of all classes can use them for a long time because they have convenient terminals. The frequency bands used are 1,841.25-1,868.75 MHz for transmission and 1,751.25-1,778.75 MHz for reception. The multiple access scheme is CDMA / FDMA, the voice encoding scheme is ADPCM, and the transmit / receive scheme uses FDD. It is a system that started to be used in Korea in October 1, 1997.

PCS terminals and city phone terminals are currently sold in the market, but they cannot be used in common, so you need to purchase city phones and PCS separately to use PCS and city phone services. However, PCS calls are very expensive while CitiPhone service is very cheap, so users are more likely to call CitiPhone and have limited Citi Phone service areas. do.

The purpose of the present invention is to combine the city phone terminal and the PCS terminal in order to meet the needs of the telephone users, the city phone combined PCS terminal to enable the call to the city phone in the city phone enabled area and other PCS ( It will be referred to as a composite device hereinafter). PCS terminal using CDMA method and Citiphone terminal using FDMA method are designed to be compatible with the exception of some parts that have similar basic operation, and other parts with low specification are provided with low cost composite device. I can do it.

The terminal of the present invention is an RF module operating in a frequency band for a city phone in a commonly used PCS terminal having a logic circuit having a baseband processor, an RF module for PCS and an antenna, and the antenna for the PCS RF module or a city phone. An additional RF switch is connected to the module.When operating in PCS mode, all setting values are set to PCS mode to enable PCS communication by software. It is a city phone combined PCS terminal that sets all the settings to CT-2 mode.

In addition, as a method of setting the operation mode in the city phone combined PCS terminal, when the power is applied, first set all the setting values of the baseband processor to the PCS mode to make a call when there is a PCS call request, and determine whether it is in the automatic mode or the manual mode. In the automatic mode, all settings are made with CT-2 to make a Citiphone call, and in an area where a Citiphone call is not possible, all the settings are set to PCS to allow PCS calls.

1 is a schematic block diagram of a terminal of the present invention.

2 to 4 are flow charts for explaining the operation of the terminal of the present invention.

1 is a block diagram illustrating a composite device of the present invention, and FIGS. 2 to 4 are flowcharts for explaining the operation of the composite device of the present invention.

As shown in FIG. 1, the composite device of the present invention includes a logic circuit 10 having a single-chip baseband processor, and an RF module 12 for a PCS that receives data and control signals from the logic circuit. ) And a switch RF-SW (14) for connecting the signal of the antenna to the CT-2 module (13), the antenna (15), the PCS module or the CT-2 module, and the logic circuit to convert the battery signal into sound waves Speaker SP 20, microphone Mic 22 for converting sound waves into electrical signals, LCD display 24, keypad 26, and the like.

The LCD indicator 24 serves to display the setting state and operation state of the handset.

The logic circuit 10 is configured based on a single chip baseband processor. The analog signal generated from the microphone 24 is digitally converted, and the digital signal is compressed again by a voice compression algorithm of PCS or CT-2 standard, respectively. The audio signal that is sent to the RF module through the channel coding process and digitally encoded by the PCS or CT-2 standard signals received and converted by the RF module is recovered by the algorithm by using the common channel coded data. Restore it again, convert it to an analog signal, amplify it, send it to the speaker to make a call, and this repetition is very fast. In addition, the terminal control commands and various data sent from the base station continues to communicate in real time even in the call waiting state to operate the setting of the strength of the radio wave from the terminal to the optimal state, in addition to the user dialog keypad 26 and information display It monitors the control of LCD indicators and the condition of the battery to ensure proper operation and use of the user.

RF module is used for CT-2 or PCS miniaturized, and this module amplifies weak signal, transmits and receives only necessary frequency, converts received RF signal to low frequency, and baseband. It takes power control commands and automatic gain control commands from the processor to ensure that the signal is optimal.

The RF switch 14 converts signals from the antenna or signals to and from the antenna into respective RF modules. The RF switch 14 is used to remove unnecessary obstacles from each other and uses an electronic switch rather than a mechanical switch in consideration of miniaturization and characteristics. It is convenient to do

The antenna is calculated and used based on the minimum frequency band transmitted or received from the terminal.

The operation of the device thus configured is as follows.

As shown in FIG. 2, when the power switch of the multifunction device is turned on, a control operation is started (step 100).

When the operation is started, the baseband processor first reads the data stored in the memory to initialize the system (110), and controls to set the PCS reception mode are executed. Set to operate (120).

Next, data is transmitted to the base station, data is received from the base station to adjust the transmission power, and the clock and the like receive information 130 to display the information on the LCD display (135).

Subsequently, it checks whether there is a call request from the keypad (SEND button is pressed) and a call request signal is received. If there is no call request or a call request signal, the operation of step 130 is repeated, and there is no call request. If there is a signal reception, go to node ⓑ to make a call, and if there is a call request, branch to node ⓒ of FIG. 3 (step 140).

If there is a call request in step 140, it checks whether it is automatic mode setting or manual mode setting. If it is set to automatic mode, it goes to step 170, and if it is in manual mode, it is connected to 160 steps (150 steps). If it is checked and set to CT-2, the baseband processor is set to CT-2 mode and the RF switch is connected to the CT-2 module to operate as a CT-2 terminal (step 170). In this way, the user confirmation and communication status are checked (step 180). If the user is recognized as a normal user and communication is possible, CT-2 mode is displayed on the LCD display (step 190), and the baseband processor voice codes G721, Full32, ADPCM are displayed. Set (200) and call the phone number (210). When the call is connected, the baseband processor restores the voice data from the received signal, makes the call through the speaker and the microphone, and stops the call (END key) while continuing to store the message in the internal memory. If the call stop signal is generated (step 230), go to node ⓐ and perform step 120.

In step 160, if it is manually set to CDMA, or in step 180, if the user identification and communication status are not normal as CT-2 mode, branch to node ⓓ of FIG. 4, baseband processor is set to PCS mode and RF switch is set to RF module. After the connection (step 250), it checks whether the user is a legitimate user (260), and if the user is not a legitimate user, branches to the node ⓐ.If the user is identified as the legitimate user (terminal), the LCD display shows PCS mode (270) Call the number (280). When the call is connected, the baseband processor restores the voice data from the received signal, makes the call through the speaker and the microphone, and stores the message in the internal memory device, and stops the call while continuing the operation (END key). If call stop signal is generated by checking whether is pressed (step 300), go to node ⓐ and perform step 120.

In step 140, if there is no call request from the terminal and the call request signal is received from the base station, the call goes to node ⓑ of FIG. That is, the baseband processor restores the voice data from the received signal, makes a call through the speaker and the microphone, and stores the message in the internal memory device while the call stop button is pressed. If the call stop signal is generated (step 300), go to node ⓐ in Fig. 2 and perform step 120.

As described above, using the city phone light PCS terminal of the present invention can operate by using a city phone in a CT-2 capable area and reduce the cost by operating as a PCS terminal in other areas, and the RF module only takes about double In addition, other parts can be used in common, which saves resources, and the city phone does not have royalties, thus saving royalties.

Claims (3)

In the terminal for selectively using the city phone and PCS services, In addition to logic circuits with baseband processors and commonly used PCS terminals with RF modules and antennas for PCS, RF module operating in the frequency band for the city phone, An RF switch for connecting the antenna to the RF module for PCS or the RF module for city phone, When operating in PCS mode, set all the settings to PCS mode so that PCS communication can be done in software. Citiphone combined PCS terminal that sets all the settings to CT-2 mode for CT-2 communication by software when operating as a city phone. The method according to claim 1, If the terminal is set to automatic mode, the city phone mode is set first, and the city phone call is attempted first. If the city phone is impossible, the city phone light PCS terminal is characterized in that the PCS mode is set. An RF module operating in a frequency band for a city phone, and an antenna for a commonly used PCS terminal having a logic circuit having a baseband processor and an RF module and antenna for a PCS to selectively use a city phone and a PCS service, and the antenna A method of setting an operation mode in a city phone combined PCS terminal further comprising an RF switch for connecting to an RF module or a city phone RF module, When the power is applied, all the settings of the baseband processor are first set to PCS mode to make a call when there is a PCS call request. Determines whether it is in auto mode or manual mode. In auto mode, all settings are made with CT-2 to make a city phone call. How to set the operation mode of the city phone combined PCS terminal that allows PCS calls by setting all the settings to PCS in the area where the city phone call is impossible.