KR910004402B1 - Method of connecting a cordless telephone by radio - Google Patents

Abstract

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Description

How to connect a cordless phone

1 is a block diagram showing a fixture of a cordless phone in accordance with the present invention.

FIG. 2 is a block diagram showing a portable device associated with the securing device of FIG.

3 is a flow chart showing special processing occurring in response to an indoor call.

4 is a flowchart showing special processing that occurs in response to a call origination request.

5 shows how the fixing device finds the voice channel.

6 illustrates how a portable device finds a voice channel.

7 is a block diagram showing the configuration of an idle channel sensing circuit.

* Explanation of symbols for main parts of the drawings

10: switch 12: 2-4 converter

16, 44: transmitter 14, 42: amplifier

18, 46: duplexer 20: 48: antenna

22: beacon detector 24: controller or central processing unit

26, 56: identification ROM 28, 58: synthesizer

30, 60: receiver 32, 54: data modulator

34, 62: data demodulator 40: microphone

50: key switch

The present invention relates to a method of wirelessly connecting a wireless telephone, and more particularly, to a method of connecting a wireless telephone of a type not using a control channel.

Cordless telephones consist of fixed-device portable devices that act as base stations and mobile stations, respectively. The portable device may be connected to the fixed device via a wireless link. The two devices each include a transmitter and a receiver to allow full duplex communication. In order to advance the effective use of electromagnetic waves, multiple wireless telephones share multiple wireless channels. Each phone searches for an idle radio channel and connects its fixed and portable devices to each other via an idle radio channel. For this reason, the stationary and portable devices are individually configured by the frequency synthesizer system to tune the transmit and receive frequencies on any radio channel. Each telephone has a specific identification number (ID No.), so that the fixed device and the portable device may check the electromagnetic waves transmitted from each other.

Radio access systems for cordless telephones can generally be classified into two types: systems using control channels and systems without control channel systems.

In a control channel type connection system, fixed and portable devices are each waiting on a control channel. The fixed device from which the incoming call was received and the portable device from which the call originated sends a call signal and a call origination signal holding an identification number and channel information to be used. The stationary and portable device then regulates the transmission of the signal and receives frequencies on the same radio channel. The control channel is divided by the wireless telephone based on time-division.

On the other hand, previous access systems that do not use control channels allow each fixed and portable device to continuously adjust the transmit and receive frequencies in standby conditions, thereby periodically monitoring the available wireless channels. The fixed device on which the call signal has been received or the portable device for the inserted call origination request fixes the transmit and receive frequencies to one of the idle radio channels, and then transmits the call origination signal or the identification number on such a channel. Send a call signal that contains Since the other device periodically monitors the radio channel, such a unit receives the call signal containing the call origination signal or an identification number of its own station, and fixes the transmit and receive frequencies on the radio channel. Let's do it. Thereafter, the call, receive flow, or call origination flow is executed over a particular wireless channel. For a connection system without a control channel, it is possible to allocate the entire radio frequency band available to the radio channel for communication, thus making effective use of electromagnetic waves.

However, a wireless access system without a control channel has the following disadvantages that are not solved. When a fixed device sends a call signal to more portable devices than any wireless channel, the portable device results in an off-hook cond-ition before receiving the call signal. The portable device then determines that the call is made and sends a call origination signal to more fixed devices than other wireless channels. When the fixed device and the portable device are tuned to different radio channels as if they are stationary, the radio connection for the reception of the call as well as the radio connection for the origination of the call are also prone to weakening.

It is therefore an object of the present invention to provide a radio access method for a wireless telephone of the type which does not use a control channel to ensure the radio connection for indoor calls even when call origination occurs before the radio connection is completed for an indoor call.

Another object of the present invention is to provide an improved method of connecting wireless telephones generally wirelessly.

A method of dividing a plurality of radio channels into other radio telephones without using the control channel of the present invention, and wirelessly connecting a radio telephone having a base apparatus and a portable apparatus, and in particular having an identification number, may be performed by (a) a radio channel. Selecting a preferred radio channel from and assigning each preferred radio channel to each one of the wireless telephones, and (b) monitoring the preferred wireless channel assigned to the wireless telephone associated with the base device when a call signal is received. (C) if the wireless channel is idle first, causing the base device to first send a call signal to the mobile device over the wireless channel, and (d) the mobile device is assigned to the wireless telephone when the call origination signal is sent. First monitoring the wireless channel; and (e) the portable device when the call signaling means for the wireless telephone is first received over the wireless channel. Sending a response signal to the base device; and (f) when the call signaling means for the wireless telephone is not received over the first radio channel and if the first wireless signal is idle, the mobile device first calls to the base device over the wireless channel. And sending an outgoing signal.

One embodiment of the method according to the invention will be described in detail with reference to the accompanying drawings.

According to the present invention, a wireless telephone is composed of a stationary device and a portable device for use as a base station and a mobile station. The portable device may connect to the fixed device by a wireless link. In general, a fixed device consists of a power supply portion for providing power of a predetermined voltage and frequency, a transmitting and receiving portion allowing sufficient duplex communication, and a logic circuit controlling the entire apparatus. On the other hand, a portable device generally includes, for example, a power supply portion of a predetermined Ni-Cd battery, an operation portion including a dial key pad and a function key, a transmission and reception portion, and It consists of logic circuits suitable to control the whole device. Specific configurations of the stationary and portable devices except for the power supply portion will be described with reference to FIGS. 1 and 2, respectively.

Referring to FIG. 1, the fixing device FU includes a switch 10 connected to a telephone line and a 2-4 converter 12. The 2-4 converter 12 is connected to the transmitter 16 via an amplifier 14, while the transmitter 16 is connected to an antenna 20 through a duplexer 18. The controller 24 is also connected to an identification read only memory (ID-ROM) 26 and a synthesizer 28. Synthesizer 28 is connected to transmitter 16 and receiver 30. The data modulator 32 is located between the controller 24 and the transmitter 16. The receiver 30 is connected to the antenna 20 via the duplexer 18. The receiver 30 is directly connected to the controller 24 via the data demodulator 34. The amplifier 36 is located between the receiver 30 and the 2-4 converter 12.

As shown in FIG. 2, the portable device PU includes a microphone 40 that is connected to the transmitter 44 via an amplifier 42. Transmitter 44 is connected to antenna 48 via duplexer 46. The key switch 50 is connected to the controller 52. The data modulator 54 is located between the controller 52 and the transmitter 44. The controller 52 is also connected to the ID-ROM 56 and the synthesizer 58 which are connected to the transmitter 44 and the receiver 50. The receiver 60 is connected to the antenna 48 via the handset switch 46 and directly to the controller 52 through the data demodulator 62. Speaker 64 is connected to the receiver via amplifier 66.

3 is a flow chart showing the special operation of the fixation device that occurs in response to a call. 4 is a flowchart showing the special operation of a portable device for which a call start request is performed.

The radio channel is first selected from radio channels that are divided by independent radio telephones and individually assigned to the radio telephones. It is assumed that ID numbers are contiguous and consecutive numbers starting at zero are assigned to individual radio channels. If each radiotelephone having an ID number is then provided with a preferred radio channel having a number corresponding to a residual number generated by dividing the ID number by the number of radio channels, then the radio channel is first evenly assigned. If a consecutive number starting at 1 is assigned to an individual radio channel, then the radio channel is first a radio channel having a number corresponding to the sum of the residual number generated by dividing the ID number by the radio channel and 1. 40 radio channels are available and the ID number is denoted by N, where N is given by 40 x A + B (B = 1, 2, 3, 39). In this case, the 40 radio channels for ID number or N are represented as (B + 1) channels. For example, when the ID number or N is 100012, the 40 priority radio channel assigned to it is channel 13 because B is 12 from 100012 = 40 × 2500 + 12 and therefore (B + 1) = 13.

Referring to FIG. 3, when receiving a call, the fixed device FU tunes the transmit / receive frequency to the preferred radio channel assigned to the owning station (step S1), where the channel is idle. That is, the fixed device determines that the received input electric field is present on the channel (step S2). First, if the radio channel is idle, the program proceeds to step S3 to search for an idle radio channel, and if any radio channel is idle, tunes the transmit / receive frequency to the channel (step S4). This step is followed by a call receiving step which is known in the art and will not be described to avoid duplication.

Referring to FIG. 4, the portable device PU detects a call origination request when it is off-hook. The program starts by tuning the transmit / receive frequency to the preferred radio channel assigned to its station to check whether a call signal with its station ID number has been reached. Once this signal has been reached, the portable device PU enters the call receiving phase by sending a response signal containing the ID number. If the call signal has not been reached, the program proceeds to step S13 to first check whether the radio channel is idle. If idle, the portable device PU enters the call start phase by sending a call start signal including the ID number. If the radio channel is not idle first, step S14 experiments with searching for an idle channel, and if any channel is idle, tunes the transmit / receive frequency to the idle channel (step S15). This step is followed by a call origination step. The call origination step is well known in the art and thus will be omitted here.

Whether the idle channel is retrieved in step S3 of the fixed stationary FU and in step S14 of the portable device PU will be described in detail below. In order to search for idle channels, if the field level on each channel is less than 20 dB for 1 micro v / m, a decision is made for 100 ms in each of the device FU and PU. If the electric field level on any channel remains higher than the threshold for a certain period, the device FU or PU considers the channel to be in a very busy state and checks the preliminary level of the next channel after a delay of 300 ms. If the electric field level on the channel is kept smaller than the predetermined period, the unit FU or PU determines that it is an idle channel.

The voice channel search using the fixed unit FU is described below. Assuming that there are 40 radio channels available, as shown in FIG. 5, the fixture FU continuously and sequentially examines channels 40 through 1, and returns to channel 40 when the survey is complete. If the electric field on any field is less than 20 dB for 1 micro v / m, the device FU checks the next channel. If it is larger than the threshold, the device FU searches for the bit sync pattern for a certain period. If the bit sync pattern is not searched for the period, the unit FU moves to the search of the next channel to the communication channel. If a bit sync pattern is found, the unit FU continuously checks the data to the end. Then, when a matching ID code is detected immediately, the device FU switches to search on the next channel during the voice channel.

If the fixed device FU receives a call while performing an investigation in standby as described above, the fixed device FU returns to the preceding channel, such as channel 30, and then enters the call reception flow of FIG.

As for the voice channel search performed by the portable device PU, it ensures that 40 radio channels are available by searching in the fixed device FU. As shown in FIG. 6, the device PU sequentially scans channels 1 to 40 sequentially and then returns to channel 1. FIG. The second scan cycle starts in channel 2 and ends in channel 2 and the third scan cycle starts in channel 3 and ends in channel 3. Therefore, this injection cycle is repeated. At the end of each scan cycle, the device PU deactivates synthesizer 58 for battery storage purposes. The operation is stored in ID-ROM 56 while this battery storage continues. The procedure following channel switching is the same as that described for the fixed device FU.

When the portable device PU receives a call while performing a search in the standby state as described above, it returns to the preceding channel such as channel 30 and enters the call reception flow of FIG.

7 shows a special structure of a circuit for sensing any fixed device FU and an idle channel applicable to the portable device PU of the present invention. Generally, the circuit 79 lies between the receiver 30 of the fixed device FU or the receiver 60 of the portable device PU and the controller 24 or 52. The circuit 70 includes an amplifier 72 for amplifying the output of the receiver 30 or 60, a band pass filter 74 for blocking noise outside the audio band from the output of the amplifier 72, and a band pass filter ( A detector 76 for detecting the output of 74 and a comparator for comparing the output voltage of the detector 76 with a predetermined threshold Vret and the output voltage of the detector 76 and supplying the output to the controller 24 or 52 ( 78). Idle channel sensing circuits of this kind are known and will not be described in detail.

In summary, the method of the present invention hardly permits the fixing and mobile device of the radiotelephone to be tuned to another radio channel even when a call origination request occurs before the indoor connection radio connection is completed. Therefore, the method of the present invention is used to eliminate the need for a control channel and in other cases to minimize the occurrence of disabling the wireless connection for indoor calls due to differences in the wireless channel. The advantages described above select a preferred wireless channel from those channels that are divided and allocated later by an independent wireless telephone, and allow the wireless telephone to use the wireless channel first and the indoor call signal takes precedence unless occupied by another wireless telephone. Obtained by checking the lack on the wireless channel and then letting the portable device enter the call originating flow responding only to the request.

Various modifications will be possible to those skilled in the art after learning the subject matter herein without departing from the scope of the invention.

Claims (9)

A method of wirelessly connecting a base station and a mobile device, in particular a radiotelephone having an identification number and dividing a plurality of radio channels into other radiotelephones without using a control channel, comprising: (a) multiple radios from a radio channel; Tuning a channel and assigning each of the plurality of wireless channels to one of the wireless telephones; and (b) the base apparatus monitors the preferred wireless channel assigned to the wireless telephone associated with the base apparatus when a call signal is received. (C) if the preferred radio channel is idle, causing the base device to transmit a call signal to a mobile device over the preferred radio channel; and (d) when the call originating signal is transmitted. Causing the mobile device to monitor a preferred radio channel assigned to a telephone; (e) the call signaling means for the wireless telephone Causing the mobile device to transmit a response signal to the base device when received over a preferred wireless channel; and (f) the call signal means for the wireless telephone is not received over the preferred wireless channel and the preferred wireless channel is And causing the mobile device to first transmit a call originating signal to the base device over a wireless channel only if it is idle. The method of claim 1, wherein the identification number is any serial number starting at zero, and step (a) distributes the identification signal to a plurality of radio channels, the number having priority for the radio telephone having the identification number as a radio channel. Allocating one of the radio channels corresponding to the other (g). 2. The wireless channel of claim 1, wherein the identification signal is all serial numbers starting at 1, and step (a) distributes the identification number to a plurality of wireless channels, with the number corresponding to the remainder or sum of 1 as the preferred wireless channel. (G) assigning one of the wireless telephone access methods. 2. A radiotelephone according to claim 1, wherein step (b) comprises tuning (g) a handset frequency to an assigned preferred radio channel and determining (h) whether a received input field is present. Connection method. 2. The method of claim 1, wherein the base device monitors the wireless channel first in step (b) and then if the primary wireless channel is busy, causing the base device to search for any of the wireless channels that are idle; And (h) causing the base device to transmit a call signal to the mobile device via the idle channel when an idle channel is detected. 6. The method of claim 5, wherein step (g) determines whether the electric field level is higher than a predetermined threshold for a predetermined time period based on a channel by channel, and the electric field of any of the channels. (I) determining that the channel is busy when the level is above a threshold for a predetermined time period and shifting to another channel when the predetermined time period has elapsed and when the field level on the channel is below the threshold level. (K) determining that it is a wireless telephone connection method. 2. The method of claim 1, wherein step (b) comprises tuning (g) a transmit / receive frequency to an assigned preferred radio channel and determining (h) whether a received input field is present in the preferred radio channel. A wireless telephone connection method characterized by the above-mentioned. 2. The method of claim 1, further comprising: (g) allowing the mobile device to search for one of the wireless channels after the mobile device first monitors the wireless channel and if the preferred wireless channel is busy, the idle channel being detected. And (h) causing the mobile device to transmit a call originating signal to a base station over the idle channel. 9. The method of claim 8, wherein step (g) determines whether the electric field level is higher than a predetermined threshold for a predetermined time period based on the channel by channel, and at which time the electric field level of any of the channels is scheduled. (J) determining if the channel is busy and shifting to another channel over a predetermined period of time if there is anything above the threshold level for the period, and when the field level of the channel is lower than the threshold level, the channel is idle. (K) determining that it is a wireless telephone connection method.

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