GB2282937A

GB2282937A - Method and apparatus for implementing hunt groups

Info

Publication number: GB2282937A
Application number: GB9420588A
Authority: GB
Inventors: Deborah L Pinard
Original assignee: Mitel Corp
Current assignee: Microsemi Semiconductor ULC
Priority date: 1993-10-12
Filing date: 1994-10-12
Publication date: 1995-04-19
Anticipated expiration: 2014-10-12
Also published as: DE4430344A1; CA2108224A1; GB2282937B; CA2108224C; GB9420588D0; DE4430344C2

Description

1 2282937 METHOD AND APPARATUS FOR IMPLEMENTING HUNT GROUPS This invention

relates to telephone systems, and in particular a structure and method for allowing single telephone line to participate in different hunt groups.

When a person is away from his telephone but wishes incoming calls to be answered, usually one of two techniques is used to provide this result: call forwarding, and hunt group implementation.

In call forwarding, a destination line number is registered against a single telephone line, which is used by the telephone switching system to which to route incoming calls.

Using hunt groups, a group of telephone lines are listed against a single telephone line, and when implemented, each of the listed telephone lines in the group is rung for incoming calls to that single telephone line. Plural lines can designate the same hunt group, so that, for example, in night service all telephone calls to any of many telephones will ring all telephone lines of the group, so that a person such as maintenance staff working late within hearing range of one of the telephone lines of the group could take the call. When hunt groups are designated in a central office, a telephone line can only be a member of a single hunt group, for at least billing considerations.

Some telephone lines have plural telephone numbers. For example, a telephone line can be rung with one ringing cadence when an incoming call is to one number associated with that line, and with a different cadence when an incoming call is to a different number associated with that line. It has not been possible to include such lines in hunt groups.

1 2 is The present invention provides for each of plural station numbers associated with one telephone line to be members of plural hunt groups. Thus, for example, if one station number (e.g. telephone directory number) is the master number of a home, and a secondary station number is associated with a teen-ager living in the same home, when the teen-ager wishes to receive calls at any of plural homes of friends the teen-ager can invoke a hunt group which is headed by the secondary number. All incoming calls to the secondary number will ring the telephone lines in that hunt group.

In accordance with one embodiment, all of the lines of the hunt group will ring using a distinctive ringing cadence for the secondary number. With the teen-ager being at the home of a friend who has a telephone number that is in the hunt group, he and persons at each of the telephones which have numbers in the hunt group can distinguish incoming calls to the teen-ager because of the distinctive cadence, from calls to the master numbers of the various telephones, and the master number of the telephone at the home of the teenager.

In accordance with another embodiment, if the secondary number is listed in a hunt group which is headed by a designator of a different telephone, for example when a hunt group is set up by the friend of the teenager, which contains the (secondary) telephone number of the teenager, with incoming telephone calls to the friend, the telephone lines listed in the hunt group will be rung, but the telephone line of the teenager will be rung using the distinctive cadence of the number of the teenager, allowing the parents of the teenager to ignore the ringing.

1 3 In accordance with another embodiment of the invention, a telephone switching system is comprised of at least one telephone line having multiple station numbers, apparatus for storing a first hunt group list of numbers designating plural stations including a pilot number and a number designating one of the multiple station numbers, and apparatus for receiving the pilot number and in response ringing each of the plural designated stations including the one of the multiple station numbers, whereby a station connected to the one telephone line can be rung.

In accordance with another embodiment, a telephone switching system is comprised of apparatus for storing hunt group lists relating to groups of telephone lines, a single telephone line being contained in more than one hunt group list, and apparatus for ringing each of the telephone lines relating to the separate hunt group lists.

In accordance with another embodiment, a method of ringing a telephone line is comprised of storing different numbers each designating the same telephone line in different hunt group lists, receiving a call to one of the different numbers, ringing each of the telephone lines in the hunt group contained the one number, and ringing the telephone line designated by the one number with a particular ringing cadence.

A better understanding of the invention will be obtained by referring to the detailed description below, with reference to the following drawings, in which:

Figure 1 is a block diagram of a system which contains an embodiment of the invention, and Figure 2 is a detail of the memory of the system of Figure 1.

4 Figure 1 is a block diagram illustrating a telephone switching system, of the type described in U.S. patents 4,615,028 issued September 30th, 1986, invented by Conrad Lewis and Gino Totti and 4,616,360 issued October 7, 1986, invented by Conrad Lewis. It should be understood that other telephone switching systems could be used in place thereof.

In the system of Figure 1, station sets I such as telephone sets are interconnected with each other and with trunks 2 via at least one circuit switch 3, telephone lines 4 connected to the station set being switched to circuit switch links via peripheral controls 5 which interface the telephone lines and trunks via peripheral interface circuits (PICs) 6. Ringing generators 7 are connected to the peripheral controls 5 in order to provide ringing signals to the telephone lines. Random access memories (RAMs) 8 are also connected to the peripheral controls 5, which store control signals for operation of the peripheral controls.

A processor (main control) 10 is connected via a main bus 12 to the circuit switch 3, to control it's operation. A message switch 13 is also connected to bus 12 and to peripheral controls 5, to receive control messages from processor 10 and to route them to peripheral control 5, for storage in memories 8 or for transmission to telephone lines 4, destined for the station sets 1. A system memory 14, connected to bus 12, contains control programs and data used by the processor for controlling the operation of the system. An operator console 16 is connected to the main bus 12, which is used to configure and test the system when required.

A i is In accordance with the present invention, a hunt group memory 17 is connected to bus 12, for read and write access by processor 10. This memory is used to store hunt group tables.

With reference to Figure 2, the details of an the present invention will be described.

Using the operator console 17, for example, an operator who has been asked to prepare a hunt group prepares a hunt group such as hunt group list 18 with members designated by the subscriber (e.g. the teenager). The hunt group is headed by a pilot number, which can be either a special number stored in a table and associated with the subscriber number, or can be the subscriber number itself. The hunt group list should also contain the subscriber numbers of the other members of the hunt group, as shown. This list is converted, if necessary, to a hunt group table 20, which is headed by the pilot number of the subscriber, and lists information designating each of the stations (telephone lines and numbers associated therewith) of the other members of the hunt group.

Contained within system memory 14 are station tables 22. Each station table retains information used by the switching system about the characteristics of each station number, for example the classes of service allocated to each station number. one of the characteristics stored in station tables 22 is the ringing cadence of each station number.

Each of the station identifiers stored in the hunt group tales 20 contains a pointer to a particular station table 22.

The system memory 14 contains a table 24 which is looked up as a result of an incoming call, referred to herein as a digit tree table. This table contains reference to the station associated with each incoming 6 is telephone number, and in particular a pointer to the station table 22 containing the station characteristics so that the processor can avail itself of the information stored in the station table for a particular incoming call and properly process the call. For example, incoming dialed digits 5110103 has an entry in digit tree table 24, and a cross-reference to station y. This cross-reference is a pointer to the station table carrying the characteristics of station y.

In the present invention, when a hunt group is set up the digit tree replaces the cross-reference to a particular station table of a particular subscriber for which the hunt group is set up, with reference to a corresponding hunt group table 20. Each of the members of the hunt group also has its own pointer to a particular station table 22.

In the case that a particular telephone line has two different station numbers, each appears on a separate station table. Each of those station tables can contain data causing different ringing cadences to be used.

Thus for an incoming call to a number which is the pilot number, or which designates the pilot number of one hunt group table, a station designated in that hunt group will be only one of the numbers of the multinumber station. That one number will point from the hunt group to a particular station table. The data relating to that station number is retrieved by the processor, and is transmitted to the peripheral control for controlling the ringing of that station in the hunt group in accordance with the particular ringing cadence stored in the pointed-to station table.

The other station number can be contained in a different hunt group. when an incoming call is placed to a station designating the pilot number (which can be 7 7 that other station number), the hunt group table points to the station table relating to that other station number. The ringing cadence is retrieved, which ringing cadence will typically be different from that of the cadence associated with the first station number.

In this case, all station numbers in a hunt group are rung with the particular cadence stored in association with it in its station table. With the pilot station number designating as part of the hunt group it's own station number, its own station number will be rung using its own particular ringing cadence.

However, instead of using the cadences stored in each of the station tables associated with each station listed in the hunt group tables, the processor can look up the station table of the pilot station, retrieve the ringing cadence, ignore the ringing cadences of the station tables for each of the stations in the hunt group table, and cause each of the stations in the hunt group to ring with the distinctive cadence of the hunt group pilot. Thus the subscriber located at any of the stations will recognize his own ringing cadence, and know that the call is for him, while others at those stations will not recognize the cadence and know that the call is not for them.

A person understanding this invention may now design variations and improvements, using the principles described herein, and falling within the scope of the claims appended hereto. All such structures are considered to be part of the present invention.

8

Claims

1. A telephone switching system including:a) at least one telephone line having multiple station numbers, b) means for storing a first hunt group list of numbers designating plural stations including a pilot number and a number designating one of the multiple station numbers, and c) means for receiving the pilot number and in response ringing each of the plural designated stations including the one of the multiple station numbers, whereby a station connected to the one telephone line can be rung.

2. A system as defined in claim 1 including means for storing plural hunt group lists each having a hunt group list of numbers designating plural stations, including a different pilot number and a number designating a different one of said multiple station numbers, and means for receiving said different pilot number and in response ringing each of said plural designated stations in a different hunt group including said different one of said multiple station numbers, whereby said station connected to said one telephone line can be rung.

3. A system as defined in claim 2 including means for ringing said station connected to said one telephone line using different cadences when rung resulting from different hunt groups designating said one and said different numbers.

4. A system as defined in claim 2 in which said means for storing is comprised of a memory containing said hunt group lists in separate tables, and a station table for storing station characteristics, each station listed in each i 9 hunt group list having a pointer to a station table entry, the station characteristics being used by a switching system processor to ring stations pointed to by a hunt group according to characteristics stored therein.

5. A system as defined in claim 4 in which one of the characteristics stored in the station tables is ringing cadence, which cadence is different for different station numbers relating to a single station.

6. A telephone switching system comprising means for storing hunt group lists relating to groups of telephone lines, a single telephone line being contained in more than one hunt group list, and means for ringing separately each of the telephone lines relating to the separate hunt group lists.

7. A system as defined in claim 6 in which groups of numbers stored in each of said more that one hunt group list designating a single telephone line, are different from each other.

8. A method of ringing a telephone line comprised of storing different numbers each designating the same telephone line in different hunt group lists, receiving a call to one of the different numbers, ringing each of the telephone lines in the hunt group containing the one number, and ringing the telephone line designated by the one number with a particular ringing cadence.

9. A method as defined in claim 8 including receiving a call to another one of said different numbers, ringing each of the telephone lines in the hunt group containing said another number, and ringing said same telephone line with a ringing cadence different from said particular ringing cadence.

10. A method as defined in claim 9 including looking up said ringing cadences in a station characteristic table prior to the ringing step.

11. A method as defined in claim 8 in which a hunt group contains a pilot number designating one of said different telephone numbers relating to said same telephone line, and including ringing each telephone line designated by the hunt group using a particular ringing cadence related to said one of said different telephone numbers.

12. A method as defined in claim 10 in which a hunt group contains a pilot number designating one of said different telephone numbers relating to said same telephone line, and including ringing each telephone line designated by the hunt group using a particular ringing cadence related to said one of said different telephone numbers.

13. A telephone switching system as claimed in claim 1 substantially as described herein with reference to the accompanying drawings.

14. A method of ringing a telephone line as claimed in claim 8 substantially as described herein with reference to the accompanying drawings.

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