CA2106342C - Alert method for cordless telephones - Google Patents
Alert method for cordless telephonesInfo
- Publication number
- CA2106342C CA2106342C CA 2106342 CA2106342A CA2106342C CA 2106342 C CA2106342 C CA 2106342C CA 2106342 CA2106342 CA 2106342 CA 2106342 A CA2106342 A CA 2106342A CA 2106342 C CA2106342 C CA 2106342C
- Authority
- CA
- Canada
- Prior art keywords
- alert
- base unit
- handset
- unit
- ring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Abstract
The method of the present invention controls the alert generation of a cordless telephone, thus synchronizing all cordless telephones at a particular number. The base unit of the cordless telephone sends a ring start message in the sub-audible message stream to the handset unit. The handset then monitors the audible portion of the channel for a tone.
Upon reception of the tone, the alert is generated until the handset receives the sub-audible ring stop message from the base unit.
Upon reception of the tone, the alert is generated until the handset receives the sub-audible ring stop message from the base unit.
Description
- . 210~3~2 ALERT METHOD FOR CORDLESS TELEPHONES
Eq~dofl~ vention The present invention relates generally to the field of commlmic~t;ons and particularly to cordless telephones.
B~ound of 1 he I~.~lion l 0 An obvious requirement of any telephone is that it must ring or generate some form of alert tone. ~;n~inE in a l~n~lline telephone is initiated by a ring voltage that is turned on and offby the telephone company. A typical ring is a cycle of two seconds on and four seconds off. Some telephone 1 5 systems support- distinctive ringing. A distinctive ring is defined as one short-long-short ring cycle every six seconds as specified in the Bellcore document CL~ASSsM Feature Distinctive Ringing/Call Waiting, TR-TSY-000219 Issue 2, Revision 1. The two short rings are 200 to 500 ms in length 2 0 and the one long ring is 800 to 1000 ms. The off periods between the long and short Iings are 200 to 500 ms in duration. An off period after the last short ring is for the rem~in~ler of the six second cycle.
It is typically desirable that the ringing of all phones at 2 5 a particular number be synchronized. Unsynchronized ringing sounds strange to the end user. In a cordless telephone, ringing must be initiated by an RF signal from the cordless telephone's base unit.
In order to synchronize ringing in a cordless telephone, 3 0 a mes,s~e could be sent to start or stop the ring. This solution would not work in a system that transmits data sub-audibly at a low speed since a meSsAEe could take appro~im~tely 700 ms to transmit. The ring duration is much shorter than the time to transmit a meSs~e.
~- - 3 5 Another solution would be to dedicate several bits in the message for a ring indication. These ring indication bits would be evenly distributed throughout the message. After ~ ' -2- 21063~2 seeing a predetermined number of these bits in the ringer ON
state, the h~ntlset would begin ringing. A predetermined nllmher of these bits in the ringer OFF state would indicate to the handset that it should termin~te ringing.
In this case, the h~n~cet needs to sample several bits prior to rh~nging the ring state to avoid f~lRing Lf the h~n~l~et neerle~l to receive two bits in the ringer ON state prior to turning on the ringer, and if the ringer must be turned on within 100 ms of the land line indication, then the base would 1 0 need to transmit at least two ring indication bits every 100 ms.
Ring infiic~tion bits, the~efo~e, would consume 20 percent of the message stream in a cordless system that transmits 100 I\/r~nrhester bits per second. Dedicating 20 percent of the message stream to the ring indication severely tiiminishes the throughput of the communications channel for other operations. There is a resulting need for an alert control method that does not require dedication of a signific~nt portion of the message stream.
2 0 ~ of l he I~. ~Lion The process of the present invention encomr~sses a method for controlling an alert tone in a cordless telephone.
The cordless telephone is comprised of a base unit, a h~n~et 2 5 unit, and an alert generator. The method begins by the base unit detecting a ring signal. If the ring signal is detected, the base unit transmits an alert start message and a tone signal to the handset unit. If the handset unit receives the tone signal and the alert start message, the alert generator is 3 0 activated.
~_ , -3- 21063~2 B~iefDescriptionof the Dra~vi~gs FIG. 1 shows a flowchart of the process of the present invention.
FIG. 2 shows the Ri~n~l~ generated in accordance with the process of the present invention.
FIG. 3 shows a simple block diagra_ of a cordless telephone in accordance with the present invention.
1 0 DetailedDescriptionofthe P~ed Emho~ment A cordless telephone base unit, using the process of the present invention, transmits a sub-audible alert or ring start and stop mess~ge to the h~n~l~et unit. After the ring start is l 5 transmitted, a tone is transmitted to signal the ring to start.
As a result, after a slight delay to receive the initial message, the handset rings in cadence with other extension telephones at the particular number being called.
The process of the present invention, illustrated in FIG.
2 0 1, begins when the h~ntlset locks to the base unit (201). This locking operation occurs when the base unit transmits a nallowband pattern to the handset so that the handset locks to the channels assigned to cordless telephones. The handset's alert generator is also turned off in case it was previously 2 5 turned on (203). A RING_TOTAL value is initialized to zero at this point. RING_TOTAL contains a rlmning total of the energy detected on the çh~nnel. The energy level is high when the tone is turned on and is low when the tone is turned off.
3 0 The process then continuously checks the sub-audible data mess~Ee stream for a ring start message (205) sent by the base unit. This message is one of many mess~Ees that the base can transmit to the handset unit. After receiving this m~ss~ge, the h~nflset monitors the audible portion of the _ ~ - 3 5 rhs~nnel (206). The handset next determines if the ring stop message was received (207). If the ring stop mess~ge was 4- 210G3~2 received, the h~n-l~et turns off the ringer and resets RING_TOTAL (203).
If the ring stop mess~Ee was not ~eceived, the most recent low speed data bit feceived from the base unit is eY~minell to dete~ine if it is in error (209). This error check avoids f~l.einE under poor ~ign~llinE conditions. Ideally, it also avoids f~lRinE on voice in the event of co-rh~nnel intelrele~ce. The process of the present invention provides Ly~lelesis to ~lev~llt f~l~inE and bit error determin~tion to detect erroneous samples. In an alternate embo-liment, a severe shift in the received signal strength indicator (RSSI) could also be utilized to detect erroneous samples.
If the BER indicates that the most recent bit is in error (211), the process br~nçhes to (207). The audible portion of the l 5 ch~nn~l is not sampled if the bit is in error. This is done since an error in sub-audible data indicates that the sample of the audible band is probably in error.
If the sub-~ lihle data bit is not in error (211), the audible portion of the rh~nnel is measured to detect for the 2 0 presence of a tone (213). This measurement is done via an expander A/D conversion. This sample is combined into RING_TOTAL (215) by the equation:
RING-ToT = RING_TOT * 2 TO
This method of updating RING_TOT provides the hysteresis to prevent fiqlsinE.
RING_TOT is now compared to a RING_T~Rh' (217). RING_THRESH is picked so that it is as high as 3 0 possible to avoid f~l~in~ on noise but also low enough so that a small number of samples will cause the threshold to be exceeded. In the ~iefelled embo(liment RING_THRESH is 104. In this embodiment, the e~p~n~ler A/D samples are al,~lo~hllately 40 when the base is transmitting the tone.
3 5 If RING_TOT meets or exceeds RING_THR~,~qH, then the ringer is turned on (221). In an alternate embo~iment, the ~5~ 21063~2 ringer is cherke~l before it is turned on to avoid a strange solm~1inE alert. If RING_TOT is less than RING_THRESH, then the ringer is turned off (219).
Whether the ringer is turned on or off, the process S continues by checking for a ring stop mess~sEe (207). A
meSsa~e that indicates that ringing should be terminated is sent sub-audibly by the base once the call is answered or the land-line ringing stops for ten continuous seconds. Once this meSss~e is ,eceived, the ringer is turned off and RING_TOT
l 0 reset (203).
FIG. 2 illustrates the audible (401) and sub-audible (402) portions of the communication channel. The ring start signal (403) is present on the sub-audible (402) band and the tone (404) is present on the audible (401). In the preferred embodiment, l 5 the ring stop signal (405) occurs ten seconds after the last tone.
In an alternate embodiment, the ring start signal (403) can occur mulitple times before the ring stop signal (405). Also in this embodiment, the ring stop signal (405) may be transmitted multiple times after the last tone (404).
2 0 FIG. 3 illustrates a simple block diagr~m of a typical cordless telephone using the process of the present invention.
The base unit (301) is connected to the land-line telephone system from which it receives the ring siEn~l The handset (302) is comprised of a transceiver (303) to transmit and 2 5 receive si~n~l~. The transceiver (303) is connected to audio circuits (305) that contain the A/D converter and the ring generation circuits. An interface circuit (311) performs the .~iEn~llin~ for the h~ntl~et. A microprocessor (307), in conjunction with the memory (309), controls the operation of 3 0 the handset and uses the process of the present invention.
~_ ,
Eq~dofl~ vention The present invention relates generally to the field of commlmic~t;ons and particularly to cordless telephones.
B~ound of 1 he I~.~lion l 0 An obvious requirement of any telephone is that it must ring or generate some form of alert tone. ~;n~inE in a l~n~lline telephone is initiated by a ring voltage that is turned on and offby the telephone company. A typical ring is a cycle of two seconds on and four seconds off. Some telephone 1 5 systems support- distinctive ringing. A distinctive ring is defined as one short-long-short ring cycle every six seconds as specified in the Bellcore document CL~ASSsM Feature Distinctive Ringing/Call Waiting, TR-TSY-000219 Issue 2, Revision 1. The two short rings are 200 to 500 ms in length 2 0 and the one long ring is 800 to 1000 ms. The off periods between the long and short Iings are 200 to 500 ms in duration. An off period after the last short ring is for the rem~in~ler of the six second cycle.
It is typically desirable that the ringing of all phones at 2 5 a particular number be synchronized. Unsynchronized ringing sounds strange to the end user. In a cordless telephone, ringing must be initiated by an RF signal from the cordless telephone's base unit.
In order to synchronize ringing in a cordless telephone, 3 0 a mes,s~e could be sent to start or stop the ring. This solution would not work in a system that transmits data sub-audibly at a low speed since a meSsAEe could take appro~im~tely 700 ms to transmit. The ring duration is much shorter than the time to transmit a meSs~e.
~- - 3 5 Another solution would be to dedicate several bits in the message for a ring indication. These ring indication bits would be evenly distributed throughout the message. After ~ ' -2- 21063~2 seeing a predetermined number of these bits in the ringer ON
state, the h~ntlset would begin ringing. A predetermined nllmher of these bits in the ringer OFF state would indicate to the handset that it should termin~te ringing.
In this case, the h~n~cet needs to sample several bits prior to rh~nging the ring state to avoid f~lRing Lf the h~n~l~et neerle~l to receive two bits in the ringer ON state prior to turning on the ringer, and if the ringer must be turned on within 100 ms of the land line indication, then the base would 1 0 need to transmit at least two ring indication bits every 100 ms.
Ring infiic~tion bits, the~efo~e, would consume 20 percent of the message stream in a cordless system that transmits 100 I\/r~nrhester bits per second. Dedicating 20 percent of the message stream to the ring indication severely tiiminishes the throughput of the communications channel for other operations. There is a resulting need for an alert control method that does not require dedication of a signific~nt portion of the message stream.
2 0 ~ of l he I~. ~Lion The process of the present invention encomr~sses a method for controlling an alert tone in a cordless telephone.
The cordless telephone is comprised of a base unit, a h~n~et 2 5 unit, and an alert generator. The method begins by the base unit detecting a ring signal. If the ring signal is detected, the base unit transmits an alert start message and a tone signal to the handset unit. If the handset unit receives the tone signal and the alert start message, the alert generator is 3 0 activated.
~_ , -3- 21063~2 B~iefDescriptionof the Dra~vi~gs FIG. 1 shows a flowchart of the process of the present invention.
FIG. 2 shows the Ri~n~l~ generated in accordance with the process of the present invention.
FIG. 3 shows a simple block diagra_ of a cordless telephone in accordance with the present invention.
1 0 DetailedDescriptionofthe P~ed Emho~ment A cordless telephone base unit, using the process of the present invention, transmits a sub-audible alert or ring start and stop mess~ge to the h~n~l~et unit. After the ring start is l 5 transmitted, a tone is transmitted to signal the ring to start.
As a result, after a slight delay to receive the initial message, the handset rings in cadence with other extension telephones at the particular number being called.
The process of the present invention, illustrated in FIG.
2 0 1, begins when the h~ntlset locks to the base unit (201). This locking operation occurs when the base unit transmits a nallowband pattern to the handset so that the handset locks to the channels assigned to cordless telephones. The handset's alert generator is also turned off in case it was previously 2 5 turned on (203). A RING_TOTAL value is initialized to zero at this point. RING_TOTAL contains a rlmning total of the energy detected on the çh~nnel. The energy level is high when the tone is turned on and is low when the tone is turned off.
3 0 The process then continuously checks the sub-audible data mess~Ee stream for a ring start message (205) sent by the base unit. This message is one of many mess~Ees that the base can transmit to the handset unit. After receiving this m~ss~ge, the h~nflset monitors the audible portion of the _ ~ - 3 5 rhs~nnel (206). The handset next determines if the ring stop message was received (207). If the ring stop mess~ge was 4- 210G3~2 received, the h~n-l~et turns off the ringer and resets RING_TOTAL (203).
If the ring stop mess~Ee was not ~eceived, the most recent low speed data bit feceived from the base unit is eY~minell to dete~ine if it is in error (209). This error check avoids f~l.einE under poor ~ign~llinE conditions. Ideally, it also avoids f~lRinE on voice in the event of co-rh~nnel intelrele~ce. The process of the present invention provides Ly~lelesis to ~lev~llt f~l~inE and bit error determin~tion to detect erroneous samples. In an alternate embo-liment, a severe shift in the received signal strength indicator (RSSI) could also be utilized to detect erroneous samples.
If the BER indicates that the most recent bit is in error (211), the process br~nçhes to (207). The audible portion of the l 5 ch~nn~l is not sampled if the bit is in error. This is done since an error in sub-audible data indicates that the sample of the audible band is probably in error.
If the sub-~ lihle data bit is not in error (211), the audible portion of the rh~nnel is measured to detect for the 2 0 presence of a tone (213). This measurement is done via an expander A/D conversion. This sample is combined into RING_TOTAL (215) by the equation:
RING-ToT = RING_TOT * 2 TO
This method of updating RING_TOT provides the hysteresis to prevent fiqlsinE.
RING_TOT is now compared to a RING_T~Rh' (217). RING_THRESH is picked so that it is as high as 3 0 possible to avoid f~l~in~ on noise but also low enough so that a small number of samples will cause the threshold to be exceeded. In the ~iefelled embo(liment RING_THRESH is 104. In this embodiment, the e~p~n~ler A/D samples are al,~lo~hllately 40 when the base is transmitting the tone.
3 5 If RING_TOT meets or exceeds RING_THR~,~qH, then the ringer is turned on (221). In an alternate embo~iment, the ~5~ 21063~2 ringer is cherke~l before it is turned on to avoid a strange solm~1inE alert. If RING_TOT is less than RING_THRESH, then the ringer is turned off (219).
Whether the ringer is turned on or off, the process S continues by checking for a ring stop mess~sEe (207). A
meSsa~e that indicates that ringing should be terminated is sent sub-audibly by the base once the call is answered or the land-line ringing stops for ten continuous seconds. Once this meSss~e is ,eceived, the ringer is turned off and RING_TOT
l 0 reset (203).
FIG. 2 illustrates the audible (401) and sub-audible (402) portions of the communication channel. The ring start signal (403) is present on the sub-audible (402) band and the tone (404) is present on the audible (401). In the preferred embodiment, l 5 the ring stop signal (405) occurs ten seconds after the last tone.
In an alternate embodiment, the ring start signal (403) can occur mulitple times before the ring stop signal (405). Also in this embodiment, the ring stop signal (405) may be transmitted multiple times after the last tone (404).
2 0 FIG. 3 illustrates a simple block diagr~m of a typical cordless telephone using the process of the present invention.
The base unit (301) is connected to the land-line telephone system from which it receives the ring siEn~l The handset (302) is comprised of a transceiver (303) to transmit and 2 5 receive si~n~l~. The transceiver (303) is connected to audio circuits (305) that contain the A/D converter and the ring generation circuits. An interface circuit (311) performs the .~iEn~llin~ for the h~ntl~et. A microprocessor (307), in conjunction with the memory (309), controls the operation of 3 0 the handset and uses the process of the present invention.
~_ ,
Claims (4)
1. A method for controlling an alert tone in a cordless telephone having a base unit, a handset unit, and an alert generator, the method comprising the steps of:
the base unit detecting a ring signal;
if the ring signal is detected, the base unit transmitting an alert start message to the handset unit;
if the ring signal is detected, the base unit transmitting a tone signal to the handset unit; and if the handset unit receives both the tone signal and the alert start message, activating the alert generator.
the base unit detecting a ring signal;
if the ring signal is detected, the base unit transmitting an alert start message to the handset unit;
if the ring signal is detected, the base unit transmitting a tone signal to the handset unit; and if the handset unit receives both the tone signal and the alert start message, activating the alert generator.
2. The method of claim 1 and further including the step of if an alert stop message is received by the handset unit, deactivating the alert generator.
3. A method for controlling an alert tone in a cordless telephone having a base unit, a handset unit, and an alert generator, the base unit communicating with the handset unit via an audible voice band and a sub-audible data band, the method comprising the steps of:
the base unit detecting a ring signal;
if the ring signal is detected, the base unit transmitting an alert start message in the sub-audible data band to the handset unit;
if the ring signal is detected, the base unit transmitting a tone signal in the audible voice band to the handset unit;
if the handset unit receives the tone signal and the alert start message, activating the alert generator; and if the handset unit receives an alert stop message, deactivating the alert generator.
the base unit detecting a ring signal;
if the ring signal is detected, the base unit transmitting an alert start message in the sub-audible data band to the handset unit;
if the ring signal is detected, the base unit transmitting a tone signal in the audible voice band to the handset unit;
if the handset unit receives the tone signal and the alert start message, activating the alert generator; and if the handset unit receives an alert stop message, deactivating the alert generator.
4. A method for controlling an alert tone in a cordless telephone having a base unit, a handset unit, and an alert generator, the base unit communicating with the handset via an audible voice band and a sub-audible data band, the method comprising the steps of:
the base unit detecting a ring signal;
if the ring signal is detected, the base unit transmitting an alert start message in the sub-audible data band to the handset unit;
if the ring signal is detected, the base unit transmitting a tone signal in the audible voice band to the handset unit;
updating an energy total in response to the alert start message and the tone signal;
if the energy total is greater than or equal to a predetermined threshold, activating the alert generator; and if the handset unit receives an alert stop message, deactivating the alert generator.
6. A cordless radiotelephone for communicating with a land-line telephone system, the radiotelephone comprising:
alert generation means;
a base unit coupled to the land-line telephone system and receiving a ring signal from the land-line telephone system;
a handset unit for communicating with the base unit over sub-audible and audible portions of a communication channel, the handset unit having processing means for performing a method for alert control in response to the ring signal, the method comprising the steps of:
the base unit detecting the ring signal;
if the ring signal is detected, the base unit transmitting an alert start message to the handset unit;
if the ring signal is detected, the base unit transmitting a tone signal to the handset unit; and if the handset unit receives the tone signal and the alert start message, activating the alert generator.
the base unit detecting a ring signal;
if the ring signal is detected, the base unit transmitting an alert start message in the sub-audible data band to the handset unit;
if the ring signal is detected, the base unit transmitting a tone signal in the audible voice band to the handset unit;
updating an energy total in response to the alert start message and the tone signal;
if the energy total is greater than or equal to a predetermined threshold, activating the alert generator; and if the handset unit receives an alert stop message, deactivating the alert generator.
6. A cordless radiotelephone for communicating with a land-line telephone system, the radiotelephone comprising:
alert generation means;
a base unit coupled to the land-line telephone system and receiving a ring signal from the land-line telephone system;
a handset unit for communicating with the base unit over sub-audible and audible portions of a communication channel, the handset unit having processing means for performing a method for alert control in response to the ring signal, the method comprising the steps of:
the base unit detecting the ring signal;
if the ring signal is detected, the base unit transmitting an alert start message to the handset unit;
if the ring signal is detected, the base unit transmitting a tone signal to the handset unit; and if the handset unit receives the tone signal and the alert start message, activating the alert generator.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US95339492A | 1992-09-29 | 1992-09-29 | |
| US953,394 | 1992-09-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2106342A1 CA2106342A1 (en) | 1994-03-30 |
| CA2106342C true CA2106342C (en) | 1997-01-21 |
Family
ID=25493930
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2106342 Expired - Fee Related CA2106342C (en) | 1992-09-29 | 1993-09-16 | Alert method for cordless telephones |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU666764B2 (en) |
| CA (1) | CA2106342C (en) |
| MX (1) | MX9306019A (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2531388A (en) * | 1987-09-24 | 1989-04-18 | Alan Baber | Telephone accessory |
| GB2232325B (en) * | 1989-03-08 | 1993-05-05 | Nec Corp | Radio telephone equipment |
-
1993
- 1993-09-16 CA CA 2106342 patent/CA2106342C/en not_active Expired - Fee Related
- 1993-09-17 AU AU47412/93A patent/AU666764B2/en not_active Ceased
- 1993-09-29 MX MX9306019A patent/MX9306019A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| CA2106342A1 (en) | 1994-03-30 |
| MX9306019A (en) | 1994-08-31 |
| AU4741293A (en) | 1994-04-14 |
| AU666764B2 (en) | 1996-02-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4821312A (en) | Voice/data switch | |
| EP0330384B1 (en) | Hands-free telephone | |
| EP0424508A1 (en) | Dialing features for cellular telephone with standard telephone set | |
| EP0214810B1 (en) | Radio telephone system control apparatus | |
| US5325420A (en) | Cordless phone haaving a plurality of personal stations | |
| US4167653A (en) | Adaptive speech signal detector | |
| CA1177566A (en) | Digital communications terminal as a subscriber and/or exchange station in a digital communications installation, more particularly as a terminal for a telephone installation or telephone private branch exchange | |
| US5625653A (en) | Base station emulator | |
| US4431872A (en) | Telecommunication receivers | |
| US5794152A (en) | Cordless telephone | |
| US4070554A (en) | Digital testing and power control in a digital communication system | |
| KR100557110B1 (en) | Dialing method of wireless subscriber network terminal equipment | |
| CA2106342C (en) | Alert method for cordless telephones | |
| KR910008993A (en) | wireless telephone | |
| US7106819B1 (en) | Plural subscriber system utilizing synchronized timeslots on a single frequency | |
| US5136629A (en) | Radio communication system having control method for shortening call response time | |
| CA2088629A1 (en) | Ringing tone signal detecting circuit | |
| US4626628A (en) | Telephone line circuit having time-shared DTMF receivers | |
| JP2806702B2 (en) | Digital cordless button telephone device | |
| JPS642297B2 (en) | ||
| US3993875A (en) | Tone receiver | |
| JPH09331555A (en) | Transmitter | |
| CA1068021A (en) | Digital testing and power control in a digital communication system | |
| KR950013136A (en) | Extension call device by voice guidance in key phone system and method | |
| KR100341567B1 (en) | Method and Apparatus Caller Identification Detection using DSP |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |