Title of Invention

A MODULAR EXPANDABLE PARTY-LINE TELEPHONE SYSTEM

Abstract

The invention concerns a multi-party (also called party-line) telephone system for connecting to copper-loop based public-switch systems. This multi-party system with group sizes from 2 to 12 parties or more carl be used to connect to one single line coming from a telephone exchange. The group size can be easily expanded with no disruption in service. This system gerlerates separate customized telephone usage billing for each member of the multi-party group causing no billing conflicts within a group. The customized member telephone billing is directly related to the calls originated by each member of the group.

Full Text

This invention relates to the technical field of electronic communication and in particular relates to telephone system especially one where a singe telephone line can be used by multi-party (also known as Party line telephones). OBJECTS OF THE INVENTION The primary object of this invention is to develop a very low-cost, modular, easily expandable, apparatus for sharing a single line in basic telephony. A second object of the invention is to make it compatible with existing twisted-pair or wired telephone-switching systems. A third object of the invention is to ensure that the groups attached to a single line coming from the central-office can be easily expanded or shrunk with no disruption in service. A fourth object of the invention and system design is to ensure that there are no billing disputes within members of a group. A fifth object of the invention is to ensure that the system can also operate without additional power-supplies. Telecommunication is one of the prime requisites for economic development and rural upliftment in developing countries. The cost of installation of separate telephone lines and the running cost is beyond the reach of the average rural poor. However access to telecommunication can dramatically change the economic status of the rural poor. The lower rentals and call charges currently charged for rural telephone connections do not reflect the actual cost of the service provided. There is a considerable amount of subsidy. Therefore spread of telecommunication network in rural community is retarded due to shortage of funds not only for providing infrastructure but also for the subsidy. The introduction of multi party telephone system or party line telephone system will reduce the infrastructure cost and make the service affordable to the rural poor, even without subsidy and optimize the use of the rural telecommunication net work which currently is underutilized. STATEMENT OF INVENTION: A Modular, expandable, low-cost, party line telephone system for connecting a single telephone line coming from a telephone exchange to telephone sets in a large group, connected through copper-loop (or wired) public-switch system, wherein the group size can be varied from two to twelve or more, having the facility of separate customized billing for each member of the group based on actual calls originating from the member, and wherein incoming calls are transferred to group members by signaling through either a Star ringing system or Bus ringing system or the alt-ringing architecture party-line system. Now this invention will be discussed in detail with reference to the accompanying diagram. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a configuration in which Private Branch Exchange is connected to a Central-office Switch. FIG. 2 illustrates the basic architecture of party-line telephone system. FIG. 3. describes the prevailing North-American technologies for party-line telephone system ringing, and station identification. FIG. 4 illustrates a "Bus" party-line architecture. FIG. 5 describes the modular ringing system for the "Bus" architecture. FIG. 6 illustrates a "Star" party-line architecture. FIG. 7 describes a Ring signal generator for both the "Star" and "Bus" architectures. The power-supply system with battery charging capability can be used in the "All-Ringing" architecture as well. FIG, 8 describes the "All-Ringing" party-line architecture. FIG. 9 describes Ring Signal Detection and Buzzer Signal Generation for the "All-Ringing" architecture. FIG. 10 describes the "Non-Buzzer" party-line architecture. The invention concerns a multi-party telephone system for connecting to copper-ioop (or wired) public-switch systems. This multi-party system can be deployed in four configurations for group sizes from 2 to 12 or more. The group size is only limited by the telephone traffic patterns and the corresponding quality of service. In all forms of the invention, standard analog telephone-sets are powered directly from the central-office switch with single-pair wires. There are four forms of the invention, one of which does not require any external power supply. Three forms of the invention require an extremely low wattage power-supply that could be from a set of two to four 1.5-volt standard batteries. Even in these three forms of the invention, if this low power battery power-supply were to fail, the system will still operate in a manual mode. In all forms of the invention, separate telephone usage billing for each member of the multi-party system is done at the central-office. The separate telephone billing for each Group Member is directly related to the calls originated from his/her telephone-set. BACKGROUND OF THE INVENTION Figure "I illustrates a basic configuration in which several single parties Pi, P2, P3, and one Private Branch Exchange PBX is connected to a Central-office Telephone Switch CO. Each of the single-party lines Pi, P2, P3 is usually connected to a single residence or a business. The PBX, which is used by both large and small organizations, allows multiple extensions to share a few incoming lines from the central-office switch. The PBX also facilitates private calls within the organization without paying any toll to the public switch operator. These private calls do not go through the central-office and hence no charges need to be paid to the public-switch operator. The PBX is typically designed for extension connections within a building, or a campus, and requires a reliable power-supply that can withstand disruptions from the Electric Utility. Thus the cost of a typical PBX with all these fail-safe features makes it less affordable for residential users willing to share a single line coming from the central-office switch. Figure 2 describes a party-line system where a group of people consisting of A, B, C, and D, share one single line coming from the Central-office. A typical party-line system that was used in North America, and continues to be used in some parts of Europe, required no separate power-supply system. According to the Washington DC, National Academy of Engineering, in 1950,75 percent of all phone lines in USA were party-lines. Figure 3 describes the technology used in North America to identify the station for calls originating from the party lines, and also the ringing system for routing calls going into the party-tine. The resistors R1, R2, .. etc, had unique connections for the line circuit in the central-office to distinguish the calls originating from a particular party. This ability to distinguish calls allowed the central-office to prepare separate telephone bills based on usage. In one technique, each of the telephone-sets had a tuned ringer with frequencies that varied from 15 Hz to 70 Hz. For calls going into the party-line, the central-office could route the call by selecting the frequency of the ring signal. But this meant that one needed to have specialized telephone-sets that had the varying uniquely connected resistors and tuning frequencies. In yet another scheme, the ringing pattern was varied as shown at the bottom of Figure 3. The individual members of the group had to listen to the ringing pattern and then decide whether to pick up the phone or not. In both these systems, the number of parties in a group could not be increased to more than four. The need for creating specialized telephone-sets, and line-circuits at the central-office increased the complexity and costs. In yet another system, a technique called polarity switching was used to switch the last digit. But this could be don© with only two phones per party. DESCRIPTION OF THE INVENTION The "Bus" Architecture Party-Line System Figure 4 describes one form of the invention in which a group of different sizes can share a single phone line. For large groups, the typical central-office switch would not have enough ring signal strength to turn-on the ringer in more than three or four phone extensions simultaneously. If the user is located more than 3 or 4 kilometers away from the exchange, then perhaps only a single phone-set system or two phone-set extension system would operate with the ringing. The apparatus in Figure 4 solves the problem by being able to operate several extensions even when the telephone-sets are at furthest distance allowed by the central-office loop resistance specification. In this architecture, except for one member"s telephone-set Ti, all other member telephone-sets will have their ringers disconnected. This would ensure that a system with 10 or 20 members could still share one line, as long as only one telephone-set had the ringer circuit connected. The group member located at Station-0 who has the phone-set with the ringer working is referred to as the "Designated Operator". He will answer the incoming calls and route the phone call to the correct member by using the separate ringing system. As shown in the Figure 4, the ringing system consists of a ring-generator RG located at Station-0, and buzzers BZ1, BZ2,... BZn, and a common set of "n+1" number of wires W, that go to all stations. This ringing system is completely separated from the central-office wiring. The single pair of wires TR coming from the central-office goes to all the Stations. TR runs in parallel to the ringing wires W. Modular Connection-Panels CP1, CP2, .. CPn are used for connecting the buzzer system wires W to the respective buzzers at Stations 1 through n. Other than Station-0, each of the other Group Member"s Station would have a telephone-set and an accompanying low-power buzzer. Operating the System for Incoming Calls The "Designated Operator" of the party-line group receives all incoming calls, because only his/her telephone-set has a functioning ringer that responds to the central-office ring signal. Upon receiving an incoming call, he routes the call to the appropriate Group Member by activating the appropriate switch in the Ring Generator RG. Refer to Figure 5 for details on Ring Generator RG and the corresponding buzzer system. After transferring the call over to the appropriate Group Member, he hangs up his phone. Outgoing Calls For Group Members to originate a phone call, they do not have to go to through the designated operator. Each telephone-set will receive a dial tone, and can be operated independently. Ring Generator and Buzzer System for the Bus-Architecture Figure 5 describes the apparatus for generating a ring signal and routing it to the appropriate buzzer. This apparatus in Figure 5 is required for the operation of the Bus-Architecture in Figure 4. In Figure 5, the Ring Generator RG consists of a 3-volt to 6-volt battery-based power-supply with push button switches SWi, SW2,.. SWn. When the Designated Operator pushes a push-button switch SW„, the buzzer BZn operates. Each of the buzzers is connected to the Bus wires W through a modular Connection Panels CP1, CP2, .. CPn. A simple jumper on each of the Connection Panels is all that is required to associate the buzzer with the specific Station identification. Operating without the Buzzer System The buzzer system is not an absolute requirement for the Bus-Architecture based party-fine system to operate. Without the buzzer-system, the Designated-Operator will have to manually notify Group Members about incoming phone calls. So even if the batteries were to expire, the party-line system will not collapse. Separate Billing for each Group Member Each Group Member in the party-line system is given a unique password consisting of a few digits. This password is programmed at the central-office and is used for identifying the Group Member"s station number. When originating a phone call, after picking up the receiver and hearing the dial-tone, the Group Member first enters the password, and then dials the telephone number. The central-office is programmed to first, only allow the authorized users to make phone calls, and second, to keep track of each Group Member"s call duration and destination. As a result of the programming and password-based Station identification, customized telephone usage bills can be generated for each Group Member. This eliminates billing problems amongst Group Members. Back-up Operator The Designated-Operator at times might leave his/her Station-0 (which could be at his/her residence) unattended. A Back-up Operator say at Station-2 could be activated when the Designated Operator is absent. In such a case, the Designated Operator would be required to transfer his/her Operator functions to Station-2. This process of transferring the operator control can be done by simply disabling the ringing of telephone set T0 at Station-0, and by activating the ringer in Station-2"s tetephone-set T2. Rotating the Designated Operator The Group Members in a party-line system may wish to rotate the "Designated Operator" function amongst their members after an agreed to period of time. All that is required for transferring the Designated Operator is for Station-0 to transfer his/her Ring Generator RG apparatus over to the "Next-Operator". Group Member at Station-0 would de-activate his ringer on his telephone-set T0, and install a buzzer from the Next-Operator. The Next-Operator would activate the ringer in his/her telephone-set, and install the modular Ring Generator RG. The "Star" Architecture Party-Line System Figure 6 describes a second form of the invention in which a group of different sizes can share a single phone line. For large groups, the typical central-office switch would not have enough ring signal strength to turn-on the ringer in more than three or four phones simultaneously. If the user is located more than 3 or 4 kilometers away from the exchange, then perhaps only a single-party system or two phone extension system would operate with the ringing. The apparatus in Figure 6 solves the problem by being able to operate several extensions even If the telephone-sets are at furthest distance allowed by the central-office loop resistance specification. In this architecture, except for one member"s telephone-set at Station-O, all other member telephone-sets will have their ringers disconnected. This would ensure that a system with 10 or 20 members could still operate, as long as only one telephone-set had the ringer circuit connected. The apparatus in Figure 6 is similar to the apparatus in Figure 4 except for the difference in the Buzzer Ring Signaling System. There is one permanent Operator at "Station-O". From Station-0, a separate single pair of wire is used to connect the Ring-Generator RG to each of the Buzzers BZt, BZ2, BZn. The Operator at "Station-O" will answer the incoming calls and route the phone call to the correct member by using the separate ringing system. This ringing system is completely separated from the central-office wiring. The single pair of wires TR coming from the central-office goes to all the Stations. Each of the other Group Members Stations would have a telephone-set and an accompanying low-power consumption buzzer. The Star-Architecture buzzer ringing wire system in Figure 6 might have lower length for the total of ail the copper wires in the system, and possibly a lower cost when compared Bus Architecture in Figure 4. However, the Star-Architecture is more suited for a permanent wiring system. So if the Operator in the party-line Group changes, then the ringing system has to be re-wired. Operating the System for Incoming Calls The "Operator" at Station-O receives all incoming calls, because only his/her telephone-set has a functioning ringer that responds to the central-office ring signal. Upon receiving an incoming call, he routes the call to the appropriate Group Member by activating the appropriate buzzer through the parallel buzzer system. After the transferring the call over to the Group Member, he hangs up his/her the phone. Outgoing Calls For Group Members to originate a phone call, they do not have to go to through the designated operator. Each telephone-set will receive a dial tone, and can be operated independently. Operating without the Buzzer System The buzzer system is not an absolute requirement for the Star-Architecture based party-line system. Without the buzzer-system, the Designated-Operator will have to manually notify Group Members about incoming phone cads. So even if the battery-based power-supply in the Ring Generator RG in Figure 6 were to expire, the party-line system will not collapse. Separate Billing for each Group Member The billing system for the Star Architecture is the same as the Bus Architecture as described earlier. Back-up Operator The Operator at times might leave his/her Station-0 (refer to Figure 6) unattended. A Back-up Operator say at Station-2 must be activated when the Operator is absent In such a case, the Operator would be required to deactivate the ringer in his/her telephone-set To, and activate the ringer in Station-2"s telephone-set T2. The Back-up Operator at Station-2 wiii have to manually notify other members of incoming calls. Rotating the Designated Operator Rotating the Operator function to another member requires the entire ringing wiring to be re-done. The Low-Power Ring Generator Figure 7 shows the apparatus for low-power battery-based power-supply. The apparatus consists of a battery system B (which consists of two to four standard 1.5 volt batteries), a protection diode D1, a step-down transformer T, a diode bridge rectifier OB, a capacitor C1, buzzers BZ,, BZ2, .. BZn, and Push-button switches SW,, SW2, .. SWn. The Push-button switches SW1, SW2, .. SWn are used for activating the respective buzzers. The batteries could be re-charged through resistor R, with a slow current from a 110 or 220 Vac power system. This power-supply apparatus would operate with the 110/220 Vac power source whenever that source is available, and automatically switch to the batteries B, when the AC source is not available. The "All-Ringing" Architecture Party-Line System Figure 8 describes a third form of the invention in which a group of different sizes can share a single phone line. When the central-office is far away from the subscriber, and/or for large groups, the typical central-office switch would not have enough ring signal strength to turn-on the ringer in more than one or two phones simultaneously. If the user is located more than 3 or 4 kilometers away from the exchange, then perhaps only a single-party system with no extensions would operate with the ringing. The apparatus in Figure 8 solves the problem by being able to operate several extensions even if the telephone-sets are even at the furthest distance allowed by the central-office loop resistance specification. In this architecture, except for one member"s telephone-set at Station-0, all other member telephone-sets will have their ringers disconnected. This would ensure that a system with 10 or 20 members could still operate, as long as only one telephone-set had the ringer circuit connected. In Figure 8, the device marked "RDG" at Station-0, denotes the "Ring Detection and buzzer signal Generator". This device detects the incoming ring-signal, and at the time of the central-office ringing, turns-on all the buzzers BZi, BZ2, .. BZnfrom Station 1 through "n". The advantage of this system is that it requires no member in the group to act as an Operator. The Ring signal is automatically routed to everyone in the group, and the members who pick up the phone have to determine for the whom the incoming call is meant for. The buzzer ringing system is completely separated from the central-office wiring. The single parr of wires TR coming from the central-office goes to all the Stations. Even at the device marked "RDF", the two wiring systems are electrically isolated through an optical coupler, which is described in Figure 9. Each of the other Group Members Stations would have a telephone-set and an accompanying tow-power consumption buzzer. Operating the System for Incoming Calls There is no "Operator" required for incoming calls. The buzzer will ring in Stations 1 through "n", and at Station-O, the in-built ringer in the telephone-set will ring. In essence, all stations will get the ring signal at the same time. When members in the group pick up the phone, they decide amongst themselves for whom the call is meant for. Outgoing Calls Each telephone-set will receive a dial tone, and can be operated independently. Operating without the Buzzer System The buzzer system is not an absolute requirement for the "All-Ringing" party-line architecture. If the buzzer-system were to fail for lack of battery power, the person at Station-O, will have to play the role of an "Operator" and will have to manually notify Group Members about incoming phone calls. Separate Billing for each Group Member The billing system for the Star Architecture is the same as the Bus Architecture as described earlier. Ring-Detection and Buzzer Signal Generator for the All-Ringing Architecture Figure 9 shows the apparatus for a low-power ring-signal detection, and buzzer signal generation. The apparatus consists of a battery system B (which consists of four or more standard 1.5 volt batteries), threshold-sensing resistors and diode bridge rectifier DB, a current-regulator and LED (tight Emitting Diode) Driver, an opticaf-coupler with a high gain output, and buzzers BZi, BZ2,.. BZ* Although not shown in Figure 9, the battery system B, can use parts of the apparatus in Figure 7 for re-charging from an external 110/220 Vac power source whenever that source is available. The threshold-sensing resistors and diode bridge rectifier DB are set up for detecting the appropriate AC (alternating current) Ringing signal coming from the central-office. Once detected, the current-regulator and LED-Driver circuit is activated to turn-on the LED in the Optocoupler. The LED once activated, turns on the photo-diode and the high-gain output stage, which then activates the buzzers. The buzzers are activated for the duration of the AC ringing coming from the central office. The "Non-Buzzer" Party-Lina Architecture Figure 10 describes the fourth form of the invention in which a group of different sizes can share a single phone line. When the central-office is far away from the subscriber, and/or for large groups, the typical central-office switch would not have enough ring signal strength to turn-on the ringer in more than three or four phones simultaneously. If the user is located more than 3 or 4 kilometers away from the exchange, then perhaps only a single-party system or two-phone extension system would operate with the ringing. The apparatus in Figure 10 solves the problem by being able to operate several extensions even if the telephone-sets are at the furthest distance allowed by the central-office loop resistance specification. In this architecture, except for one member"s telephone-set at Station-0, all other member telephone-sets will have their ringers disconnected. This would ensure that a system with 10 or 20 members could still operate, as long as only one telephone-set had the ringer circuit connected. The person at Station-0 is the designated operator and he manually notifies the appropriate group member for incoming calls. Note that all of the three previously described architectures in Figures 4,6, and 8 would resort to this architecture, if their respective buzzer system were to fail to operate in the event of a power-supply failure. Operating the System for Incoming Calls There is a manual "Operator" required for incoming calls at Station-O. Only the telephone-set at Station-0 will ring (all other stations have their phone-set ringer off). No buzzer is used in this architecture, and the designated "Operator" at Station-0 will manually notify the call recipient. Outgoing Calls Each tetephone-set will receive a dial tone, and can be operated independently. Separate Billing for each Group Member The billing system for this Architecture is the same as the Bus Architecture as described earlier. We claim: 1. A Modular, expandable, low-cost, party line telephone system for connecting a single telephone line coming from a telephone exchange to telephone sets in a large group, connected through copper-loop (or wired) public-switch system, wherein the group size can be varied from two to twelve or more, having the facility of separate customized billing for each member of the group based on actual calls originating from the member, and wherein incoming calls are transferred to group members by signaling through either a Star ringing system or Bus ringing system or manually as in the case of the all-ringing architecture party-line system. 2. The Bus ringing system as claimed in Claim 1 which consists of a Bus-wiring system (Figure 5) connecting all members of the group, a ring signal generator, and a buzzer, through which a designated operator receiving all incoming calls transfers calls to the concerned member of the group by signaling through the ring signal generator, in which the designated operator can be easily changed/rotated without changing the wiring. 3. A Star-ringing system as claimed in Claim 1 which consists of a star-wiring system (Figure 6) separate from the central office wiring, which has a reduced wiring length, connecting all members of the group, a ring signal generator, and a buzzer, through which a designated operator receiving all incoming calls transfers calls to the concerned member of the group by signaling through the ring signal generator, in which the designated operator can be changed/rotated. 4. A Modular, tow-cost, multi party telephone system as claimed in Claim 1 wherein the number of telephones that can be connected to the multi-party system is flexible, and can be varied from two members, all the way up to several dozen members by disabling the ringer in all the phone-sets except for one or two. 5. A Modular, low-cost, multi party telephone system as claimed in Claim 1 wherein separate billing for each member of a party-line group can be generated based on actual calls originating fro 6. m the member. 7. A low-cost battery-based ring signal generator as described in Figure 7 and claimed in Claim 1 which contains: standard 1.5 volt batteries, ring- selector switch, buzzer, an alternative AC power-supply and battery charger. 8. A Modular, low-cost, multi party telephone system as claimed in Claim 1 wherein the central-office based software contains: a password-based recognition system to identify a Group Member, and track his/her telephone usage. 9. A Modular, low-cost, multi party telephone system as claimed in Claim 1 and as described in Figure 10 wherein where no external power-supply is required. 10. An All-Ringing system as described in Figure 8 and Figure 9 which does not require an operator and wherein the ringing is automatically extended to a number of telephone-sets connected as extensions to a single line from the central-office. 11. A Modular, low-cost, expandable, multi party telephone system as substantially described herein, the figures 4 to 10.

Documents:

381-mas-2001 abstract-duplicate.pdf

381-mas-2001 abstract.pdf

381-mas-2001 claims-duplicate.pdf

381-mas-2001 claims.pdf

381-mas-2001 correspondence-others.pdf

381-mas-2001 correspondence-po.pdf

381-mas-2001 description (complete)-duplicate.pdf

381-mas-2001 description (complete).pdf

381-mas-2001 drawings.pdf

381-mas-2001 form-1.pdf

381-mas-2001 form-19.pdf

381-mas-2001 form-26.pdf