System and method for restricting mobility of subscribers assigned to fixed subscription areas in a cellular telecommunications network

Claim 2

A cellular telecommunication system having a plurality of cells and a plurality of subscribers utilizing cellular telephones of approximately equal radio frequency transmitter power to access said cellular system, said plurality of subscribers including at least one fixed subscriber assigned to a fixed subscription area (FSA) engaged in an ongoing call in a serving cell, said system comprising: a mobile switching center (MSC) which includes a database defining which of said plurality of cells are included in said FSA; a home location register (HLR) that stores a subscriber profile for each of said plurality of subscribers, each subscriber profile identifying whether an associated subscriber is a fixed subscriber; means for sending an inquiry from said MSC to said HLR to determine whether a subscriber is a normal subscriber or a fixed subscriber; a plurality of base stations electronically connected to said MSC, each of said base stations transmitting radio frequency signals over a coverage area defining one of said cells, and receiving radio frequency signals from said cellular telephones of approximately equal radio frequency transmitter power; and a restricted mobility function for restricting said on-going call of said fixed subscriber to said FSA.

Claim 3

The cellular telecommunication system of claim 1 wherein said restricted mobility friction includes means for detecting when said fixed subscriber is crossing a cell border between said serving cell and a neighbor cell.

Claim 4

The cellular telecommunication system of claim 2 wherein said restricted mobility function includes means for dropping said on-going call of said fixed subscriber when said fixed subscriber is detected crossing a cell border between said serving cell and a neighbor cell which is located outside said FSA.

Claim 5

The cellular telecommunication system of claim 3 further comprising means for determining whether handoffs are allowed from said serving cell to said neighbor cell when said neighbor cell is located in said FSA.

Claim 6

The cellular telecommunication system of claim 4 further comprising means for allowing handoff of said fixed subscriber from said serving cell to said neighbor cell when said neighbor cell is located in said FSA, and up on determining that handoffs are allowed from said serving cell to said neighbor cell when said neighbor cell is located in said FSA.

Claim 7

The cellular telecommunication system of claim 5 wherein said means for dropping said on-going call of said fixed subscriber includes: means for determining whether a threshold has been exceeded; and means for generating a release order upon determining that said threshold has been exceeded.

Claim 8

The cellular telecommunication system of claim 6 wherein said means for determining whether a threshold has been exceeded includes: a secure timer for defining a secure time period during which said means for dropping said on-going call is prohibited from dropping said call; means for recording the number of intercell handoff requests received during said secure time period; and means for determining whether the number of intercell handoff requests received during said secure time period is greater than or equal to a predetermined secure threshold.

Claim 9

The cellular telecommunication system of claim 7 wherein said means for determining whether a threshold has been exceeded further comprises: a drop timer for defining a drop time period; means for starting said drop timer upon determining that the number of intercell handoff requests received during said secure time period is greater than or equal to said predetermined secure threshold; means for recording the number of intercell handoff requests received during said drop time period; and means for determining whether the number of intercell handoff requests received during said drop time period is greater than or equal to a predetermined drop threshold.

Claim 10

The cellular telecommunication system of claim 1 further comprising means for allowing handoffs of each of said plurality of subscribers that are not assigned to a FSA to any neighbor cell.

Claim 11

In a cellular telecommunication system having a serving mobile switching center (MSC), a home location register (HLR), a plurality of cells and a fixed subscription area (FSA), a method of restricting an on-going call of a fixed subscriber to said FSA, said method comprising the steps of: receiving radio frequency transmissions from a plurality of subscribers utilizing cellular telephones of approximately equal radio frequency transmitter power to access said cellular system, said plurality of subscribers including said fixed subscriber assigned to said FSA; defining, in a subscriber profile stored in said HLR, whether each of said plurality of subscribers is a fixed subscriber assigned to said FSA; detecting when one of said plurality of subscribers is crossing a cell border between a serving cell and a neighbor cell; sending an inquiry from said serving MSC to said HLR to determine whether said subscriber crossing the cell border is a fixed subscriber assigned to said FSA; determining, from a database in said MSC, whether said neighbor cell is located in said FSA; and dropping said on-going call of said fixed subscriber upon determining that said subscriber crossing the cell border is a fixed subscriber assigned to said FSA and said neighbor cell is located outside said FSA.

Claim 12

In a cellular telecommunication system having a serving mobile switching center (MSC), a home location register (HLR), a plurality of cells and a fixed subscription area (FSA), a method of restricting an on-going call of a fixed subscriber to said FSA, said method comprising the steps of: receiving radio frequency transmissions from a plurality of subscribers utilizing cellular telephones of approximately equal radio frequency transmitter power to access said cellular system, said plurality of subscribers including said fixed subscriber assigned to said FSA; defining, in a subscriber profile stored in said HLR, whether each of said plurality of subscribers is a fixed subscriber assigned to said FSA; detecting when one of said plurality of subscribers is crossing a cell border between a serving cell and a neighbor cell; sending an inquiry from said serving MSC to said HLR to determine whether said subscriber crossing the cell border is a fixed subscriber assigned to said FSA; determining, from a database in said MSC, whether said neighbor cell is located in said FSA; and dropping said on-going call of said fixed subscriber upon determining that said subscriber crossing the cell border is a fixed subscriber assigned to said FSA and said neighbor cell is located outside said FSA.

Claim 13

The method of restricting said on-going call of said fixed subscriber to said FSA of claim 10 further comprising the step of determining whether handoffs are allowed from said serving cell to said neighbor cell when said neighbor cell is located in said FSA.

Claim 14

The method of restricting said on-going call of said fixed subscriber to said FSA of claim 11 further comprising the step of allowing handoff of said fixed subscriber from said serving cell to said neighbor cell upon determining that said neighbor cell is located in said FSA, and upon determining that handoffs are allowed from said serving cell to said neighbor cell when said neighbor cell is located in said FSA.

Claim 15

The method of restricting said on-going call of said fixed subscriber to said FSA of claim 12 wherein said step of dropping said ongoing call of said fixed subscriber includes the steps of: determining whether a threshold has been exceeded; and generating a release order upon determining that said threshold has been exceeded.

Claim 16

The method of restricting said on-going call of said fixed subscriber to said FSA of claim 13 wherein said step of determining whether a threshold has been exceeded includes the steps of: defining a secure time period during which said means for dropping said on-going call is prohibited from dropping said call; recording the number of intercell handoff requests received during said secure time period; and determining whether the number of intercell handoff requests received during said secure time period is greater than or equal to a predetermined secure threshold.

Claim 17

The method of restricting said on-going call of said fixed subscriber to said FSA of claim 14 wherein said step of determining whether a threshold has been exceeded further comprises: defining a drop time period; staring said drop time period upon determining that the number of intercell handoff requests received during said secure time period is greater than or equal to said predetermined secure threshold; recording the number of intercell handoff requests received during said drop time period; and determining whether the number of intercell handoff requests received during said drop time period is greater than or equal to a predetermined drop threshold.

Claim 18

The method of restricting said on-going call of said fixed subscriber to said FSA of claim 10 further comprising the step of allowing handoffs of each of said plurality of subscribers to any neighbor cell upon determining that each of said plurality of subscribers is not assigned to a FSA.

Claim 19

A cellular telecommunication system having a plurality of cells and a plurality of subscribers, said plurality of subscribers including at least one fixed subscriber assigned to a fixed subscription area (FSA) engaged in an on-going call in a serving cell, said system comprising: a mobile switching center (MSC) which includes a database defining which of said plurality of cells are included in said FSA; a home location register (HLR) that stores a subscriber profile for each of said plurality of subscribers, each subscriber profile identifying whether an associated subscriber is a fixed subscriber; means for sending an inquiry from said MSC to said HLR to determine whether a subscriber is a normal subscriber or a fixed subscriber; a plurality of base stations electronically connected to said MSC, each of said base stations transmitting radio frequency signals over a coverage area defining one of said cells; and a restricted mobility function for restricting said on-going call of said fixed subscriber to said FSA.

Claim 20

A cellular telecommunication system having a plurality of cells and a plurality of subscribers, said plurality of subscribers including at least one fixed subscriber assigned to a fixed subscription area (FSA) engaged in an on-going call in a serving cell, said system comprising: a mobile switching center (MSC) which includes a database defining which of said plurality of cells are included in said FSA; a home location register (HLR) that stores a subscriber profile for each of said plurality of subscribers, each subscriber profile identifying whether an associated subscriber is a fixed subscriber; means for sending an inquiry from said MSC to said HLR to determine whether a subscriber is a normal subscriber or a fixed subscriber; a plurality of base stations electronically connected to said MSC, each of said base stations transmitting radio frequency signals over a coverage area defining one of said cells; and a restricted mobility function for restricting said on-going call of said fixed subscriber to said FSA.

Claim 21

The cellular telecommunication system of claim 17 wherein the coverage areas of the cells within the FSA, and of cells bordering the FSA, are of approximately equal size.

Claim 22

The cellular telecommunication system of claim 18 further comprising means for detecting when one of said plurality of subscribers is crossing a cell border between the serving cell and a neighbor cell.

Claim 23

The cellular telecommunication system of claim 19 wherein the serving cell and the neighbor cell are both macrocells.

Claim 24

In a cellular telecommunication system having a serving mobile switching center (MSC), a home location register (HLR), a plurality of cells and a fixed subscription area (FSA), a method of restricting an on-going call of a fixed subscriber to said FSA, said method comprising the steps of: receiving radio frequency transmissions from a plurality of subscribers utilizing mobile stations to access said cellular system, said plurality of subscribers including said fixed subscriber assigned to said FSA; defining, in a subscriber profile stored in said HLR, whether each of said plurality of subscribers is a fixed subscriber assigned to said FSA; detecting when one of said plurality of subscribers is crossing a cell border between a serving cell and a neighbor cell; sending an inquiry from said serving MSC to said HLR to determine whether said subscriber crossing the cell border is a fixed subscriber assigned to said FSA; determining, from a database in said MSC, whether said neighbor cell is located in said FSA; and dropping said on-going call of said fixed subscriber upon determining that said subscriber crossing the cell border is a fixed subscriber assigned to said FSA and said neighbor cell is located outside said FSA.

Claim 25

In a cellular telecommunication system having a serving mobile switching center (MSC), a home location register (HLR), a plurality of cells and a fixed subscription area (FSA), a method of restricting an on-going call of a fixed subscriber to said FSA, said method comprising the steps of: receiving radio frequency transmissions from a plurality of subscribers utilizing mobile stations to access said cellular system, said plurality of subscribers including said fixed subscriber assigned to said FSA; defining, in a subscriber profile stored in said HLR, whether each of said plurality of subscribers is a fixed subscriber assigned to said FSA; detecting when one of said plurality of subscribers is crossing a cell border between a serving cell and a neighbor cell; sending an inquiry from said serving MSC to said HLR to determine whether said subscriber crossing the cell border is a fixed subscriber assigned to said FSA; determining, from a database in said MSC, whether said neighbor cell is located in said FSA; and dropping said on-going call of said fixed subscriber upon determining that said subscriber crossing the cell border is a fixed subscriber assigned to said FSA and said neighbor cell is located outside said FSA.

Claim 26

The method of restricting an on-going call of a fixed subscriber to a FSA of claim 21 wherein said step of detecting when one of said plurality of subscribers is crossing a cell border between a serving cell and a neighbor cell includes detecting when one of said plurality of subscribers is crossing the cell border when the serving cell and the neighbor cell are of approximately equal size.

Claim 27

The method of restricting an on-going call of a fixed subscriber to a FSA of claim 22 wherein said step of detecting when one of said plurality of subscribers is crossing a cell border between a serving cell and a neighbor cell of approximately equal size includes detecting when one of said plurality of subscribers is crossing the cell border when the serving cell and the neighbor cell are both macrocells.

Claim 28

The method of restricting an on-going call of a fixed subscriber to a FSA of claim 22 wherein said step of detecting when one of said plurality of subscribers is crossing a cell border between a serving cell and a neighbor cell of approximately equal size includes detecting when one of said plurality of subscribers is crossing the cell border when the serving cell and the neighbor cell are both microcells.

Claim 29

The method of restricting an on-going call of a fixed subscriber to a FSA of claim 21 wherein said step of detecting when one of said plurality of subscribers is crossing a cell border between a serving cell and a neighbor cell includes detecting when one of said plurality of subscribers is crossing the cell border when the serving cell is a macrocell, and the neighbor cell is a microcell.