Telephone system for mobile wireless telephone services

• US 5,734,984 A
• Filed: 01/22/1996
• Issued: 03/31/1998
• Est. Priority Date: 11/30/1993
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Reece, Christopher Sean, Sandler, Howard Martin, Newman, William John, O'Neill, Keith Daniel, Priest, David Michael, Row, Paul Murray, Del Rio, Jorge Alberto, Jawanda, Jastinder Singh
• Primary Examiner(s): Stoll, Thomas L.
• Application Number:
  US08/589,573
• Time in Patent Office: 799 Days
• Field of Search: 379/60, 379/62, 379/58, 379/59, 455/33.1, 455/33.2, 455/33.4, 455/56.1, 455/458, 455/436, 455/437, 455/31.2
• US Class Current: 455/458
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like

Abstract

A wireless telephone system is adapted for serving portable telephone sets of itinerant users. The wireless telephone system is provided with a plurality of radio base stations being organized in at least two groups or paging areas. Each group has a boundary, a portion of each boundary being overlapped by at least one other boundary, and at least two of the at least two groups having at least two radio base stations, one of which is in common with the other group. From time to time in relation to each group, a beacon signal is radio transmitted from a radio base station exclusive to the group for soliciting a recordation response from a portable telephone set of an itinerant user within a beacon zone. When the presence of a respondent portable set is recorded as being within a service area of one of the groups, the portable set is instructed not to respond to subsequent occurrences of the same beacon signal for some hours to avoid cluttering the wireless spectrum with undue supervisory signalling. A call request wherein the itinerant user is a called party, results in the recorded portable set being paged via at least an idle one of the radio base stations of the group within which the portable set is recorded as being present, whereby the itinerant user may be called via the wireless telephone system without any requirement for the user to have prior knowledge of or to have taken any action in relation to the wireless telephone service.

Claims

1. A digital telephone system for providing communication paths between station sets of calling and called parties, wherein the station sets may include portable telephone sets, whose presence are of record within the digital telephone system and may include an itinerant portable telephone set, whose presence may not normally be of record within the digital telephone system, and wherein a communication path associated with any portable telephone set includes a radio link between the portable telephone set and any one of a plurality of radio base stations, each of which is connected by a communications conduit to the digital telephone system, the digital telephone system comprising:

a port circuit for interfacing an operating signal format of the communications conduit with an operating signal format of the digital telephone system, the operating signal format of the communications conduit including a bidirectional message channel and at least one bidirectional communication channel, and the operating signal format of the digital telephone system including frame organized channels;

a service controller for receiving and transmitting message signals via the frame organized channels; and

a switch being responsive to the service controller for transferring communication signals from a frame organized channel of any one port to a frame organized channel of any other port;

wherein the service controller includes

a plurality of cell managers each being responsive to message signals received from any of the radio base stations for causing one of the radio base stations to maintain a radio link with a portable telephone set of record of a calling or called party,

a plurality of zone lists, each zone list defining a beacon zone and having stored therein an identity of at least one radio base station having been selected from the plurality of radio base stations, the beacon zones defined by the zone lists being separated by a buffer zone having at least one radio base station,

a plurality of paging lists, each paging list having stored therein a corresponding one of the zone lists, and in addition thereto an identity of the at least one radio base station from the buffer zone, and

means for causing a beacon zone signal to be radio transmitted from time to time via at least one of the radio base stations, for soliciting a radio transmitted response, including an identity, from any itinerant portable telephone set,

whereby an itinerant user of wireless telephone service may be unaware of an available low power wireless telephone service and may yet be a recipient of a telephone call routed via the digital telephone system.

2. A telephone system for providing wireless telephone services for itinerant users of wireless portable telephone sets via a plurality of ports, each port transferring communications signals between one of a plurality of radio base stations and one of a plurality of channels in an operating signal format of the telephone system, comprising:

(a) a plurality of cells, each cell having one or more radio base stations, said plurality of cells being partitioned into a plurality of beacon zones, each of said beacon zones comprising at least one cell, and a buffer zone which separate said beacon zones from one another, said buffer zone comprising at least one cell;

(b1) a service controller for causing radio base stations which are idle and located within one of said beacon zones to radio transmit a zone beacon signal including a repetitive recordation solicitation from time to time,

(b2) the service controller being responsive to signalling received in response to the recordation solicitations, recording an identity of a responding portable telephone set, and radio transmitting a zone confirmation of said recordation via a radio base station from which the signalling was received,

(b3) the service controller being responsive to a request for service in which said responding portable telephone set is identified as being a called party by causing paging signals to be transmitted from radio base stations which are idle and located within the same beacon zone as said base station from which the signalling was received and from at least one more radio base station which is idle and located within said buffer zone,

(b4) the service controller thereafter selecting one of the radio base stations at which an answer to the paging signals was received for establishing a radio link with said responding portable telephone set,

(b5) the service controller restricting only one radio base station in each cell to radio transmit the zone beacon signal from time to time; and

(c) switch means responsive to the service controller for providing a communication path via a port channel associated with said radio link;

(d) whereby an itinerant user of wireless telephone service may be unaware of an area of low power wireless telephone service and yet be availed of a low power wireless radio link.

3. A telephone system as defined in claim 2 wherein the service controller includes a plurality of cell managers each for controlling functions within a cell.

4. A telephone system as defined in claim 2, wherein a reception characteristic of the radio base stations defines geographical operating limits of said beacon zones and said paging area.

5. A telephone system as defined in claim 3 wherein each cell manager includes means responsive to signal strengths as received from time to time at any of its radio base stations for transferring a radio link to another of its radio base stations if said another of the radio base stations has received a greater signal strength from a portable telephone set than a radio base station which is radio linked with said portable telephone set.

6. A telephone system as defined in claim 3 wherein each cell manager includes means responsive to signal strengths as received from time to time at any of its radio base stations for acting in concert with another cell manager to effect a handoff of a radio link with a portable telephone set to one of the plurality of radio base stations in a neighboring cell.

7. A telephone system for providing wireless telephone service for portable telephone sets including portable telephone sets of itinerant users who from time to time may enter, linger, traverse, and depart an area of operation of the wireless telephone system, the wireless telephone system comprising:

a plurality of radio base stations, each station being capable of supporting a radio link for communications with a portable telephone set;

at least two groups organized from some of the plurality of radio base stations, each group having a beacon zone and a buffer zone, the buffer zone consisting of at least one radio base station in common with at least one other group and separating the beacon zones of the respective groups;

switch means for completing paths of communication with any of the radio base stations, and

a service controller including

means for soliciting a recordation response from time to time via radio base stations inside the beacon zones,

means for recording a presence of a responding portable telephone set of an itinerant user as being within a service area of one of the groups, and

means responsive to a call request to the itinerant user, for paging the responding portable telephone set via the radio base stations of a group within which the responding portable telephone set is present, whereby the portable telephone set of the itinerant user may be called via the telephone system even though the itinerant user may be unaware of an available low power wireless telephone service.

8. In a wireless telephone system having first and second groups of cells separated by a buffer group of cells for wireless communication with portable telephone sets each having a preassigned identity, wherein each of the cells includes a plurality of radio base stations, any one of which is operable to initiate provision of a radio link with a portable telephone set over any one of a plurality of radio frequency channels, by first broadcasting a paging signal for identifying the portable telephone set, from at least one of the radio base stations on at least one vacant radio frequency channel, wherein a portable telephone set which has been identified is operable to complete the radio link by responding to the paging signal, a method by which the wireless telephone system may provide service to an itinerant portable telephone set having entered an area wherein wireless telephone service is available via the wireless telephone system, the method comprising the steps of:

i) from time to time radio transmitting a plurality of interrogation signals from a radio base station in each cell of the first and second groups, whereby an unrecorded portable telephone set is invited to transmit its identity to the wireless telephone system;

ii) in response to having received a signal from said unrecorded portable telephone set at one of the radio base stations, recording the unrecorded portable telephone set as being availed of telephone service and broadcasting a confirmation signal from the radio base station, the confirmation signal identifying the wireless telephone system,

iii) in response to the wireless telephone system receiving a request for a call completion to a portable telephone set, broadcasting a paging signal from an idle one of the radio base stations in each cell of the first, second and buffer groups; and

iv) in the event of a radio signal broadcast response from the portable telephone set has been received at one of the radio base stations, initiating a radio link with the portable telephone set via said one of the radio base stations, and in the event of a failure to receive a response from the portable telephone set, deleting the identity of the portable telephone set from the wireless telephone system.

9. A method as defined in claim 8 wherein the signal broadcast in step ii) includes an indication of a limited period for recordation, and after the limited period expires, an identity of the unrecorded portable telephone set is not recorded in the wireless telephone system.

10. In a telephone system having a plurality of cells for wireless communication with portable sets each having a preassigned identity, wherein each cell includes a plurality of radio base stations, any one of which is operable to provide a radio link with a portable set of either a calling party and a called party over any one of a plurality of radio frequency channels, a method of establishing a call between a radio base station and a portable set within an operating area of one of the cells, wherein an originating radio link may be established, from a radio base station, with a portable set of an itinerant called party, said method comprising the steps of:

i) positioning at least one of the radio base stations between two zones, each of said zones including at least one cell with at least one radio base station such that the two zones have mutually exclusive boundaries of effective operation and an overlapping boundary of effective operation including said at least one of the radio base stations;

ii) in each of the zones, from time to time broadcasting distinct interrogation signals, whereby an unrecorded portable set of an itinerant party is invited to transmit an identity signal to the telephone system;

iii) responsive to an identity signal which is acceptable to the telephone system, making record of a presence of the portable set of the itinerant party and the zone within which the itinerant party is present; and

thereafter

a) receiving an incoming call request wherein the itinerant party is a called party;

b) selecting radio base stations having vacant radio frequency channels in the zone within which the itinerant party is present and in said overlapping boundary of effective operation of said zone;

c) broadcasting a radio signal including a coded message corresponding to the preassigned identity of the called portable set in at least one vacant radio frequency channel of each selected radio base station;

d) after each radio signal broadcast, monitoring said at least one radio frequency channel for a portable set response broadcast which includes an identity of the called portable set;

e) receiving the portable set response broadcast at a first radio base station, and if the portable set response broadcast is of a receive signal strength indication (RSSI) level greater than a switch originating link setup (SOLS) threshold level, broadcasting a radio signal indicative of the channel and the RSSI level of the radio link with the called portable set to a first cell manager associated with said first radio base station; and

f) establishing a radio link between the first base station and the called portable set on said indicated channel.

11. A method for providing wireless telephone service for portable telephone sets including portable telephone sets of itinerant users who from time to time may enter, linger, traverse, and depart an area of operation of the wireless telephone system, the method comprising the steps of:

providing a plurality of radio base stations organized into first and second groups of cells separated by a buffer group of cells, said first, second and buffer groups each having at least one radio base station, each radio base station being capable of supporting a radio link for communications with a portable telephone set;

at the first and second groups, from time to time soliciting a recordation response via at least one of the radio base stations in each of said first and second groups,

recording a presence of a responding portable set of an itinerant user within a service area of one of the first and second groups, and

responsive to a call request to the itinerant user, paging the responding portable telephone set via at least an idle one of the radio base stations of the buffer group and the group within which the portable telephone set is present, whereby the portable set of the itinerant user may be called via the telephone system even though the itinerant user may be unaware of and have taken no action in relation to the wireless telephone service.

12. A digital telephone system which includes portable telephone sets whose presence are of record and an itinerant portable telephone set whose presence may not normally be of record, comprising:

a plurality of radio base stations which provide the portable telephone sets communication paths with the digital telephone system; and

a service controller managing a plurality of zone lists and a plurality of paging lists, each zone list defining a beacon zone and having stored therein an identity of at least one radio base station having been selected from the plurality of radio base stations, the beacon zones defined by the zone lists being separated by a buffer zone having at least one radio base station, each paging list having stored therein a corresponding one of the zone lists, and in addition thereto an identity of the at least one radio base station from the buffer zone.

13. A digital telephone system as defined in claim 12 wherein the service controller includes a plurality of cell managers each being responsive to message signals received from any of the radio base stations for causing one of the radio base stations to maintain a radio link with a portable telephone set of record.