EP0260763A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Radio system
Assignee: Philips Electronics UK Ltd
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Filing: 1987-09-17
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Granted: —
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Expires: 2007-09-17
Abstract
Abstract A mobile radio transmission system comprises a plurality of base stations (BS) with corresponding service areas (SA) which together cover a geographical area through which mobile stations (M) can roam. Each base station is connected to a central station (CS) by means of a respective two-way communication link (CL). In order that it can be contacted without all the base stations having to put out a call, each mobile station registers in known manner with the base station in whose service area it is situated, and this is recorded by the control station. When it roams into a new service area this process is repeated. However, in order to preclude frequent re-registrations when the mobile station repeatedly crosses the boundary between two service areas, when it registers with a new base station and hence a new service area it retains its registration with at least one service area with which it is already registered, thereby creating its own customised enlarged registration area. Thus the transmission overhead created by the registration procedure is reduced.
Inventors
- 👤 Geoffrey Richard Selby
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 19:55
CPC Classifications
H; H04; H04W; H04W60/00; H04W60/04; H04W88/00; H04W88/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
304 words
A mobile radio transmission system comprising a plurality of base stations which are situated at respective geographical locations to thereby define a plurality of service areas and a plurality of mobile stations capable of communicating by two-way radio with each base station when in communication range of that base station, the system being provided with control means which includes a location record corresponding to each mobile station, which location record is capable of storing a service area identity, characterised in that each location record is capable of storing at least two service area identities, in that each mobile station also includes a location record capable of storing at least two service area identities and is arranged when operative to respond to it not being within communication range of any base station serving a service area the identity of which is currently stored in the location record included therein by communicating with a base station of which it is within such range (if any) and storing the identity of the service area served by that base station in said location record in such manner that said identity replaces the identity of another service area already present in said location record if the resulting number of stored identities would otherwise exceed a given value n greater than one, and in that said control means is arranged to respond to each such communication by updating the contents of that location record included therein which corresponds to the communicating mobile station so that the mobile station is recorded as being currently located in the service area served by the base station with which the communication takes place while retaining in said location record the identity or identities (if present) of at least (n-1) other service area(s) in which the relevant mobile station was previously recorded as being located.
Claim 2
Dependent Claim
304 words
A mobile radio transmission system comprising a plurality of base stations which are situated at respective geographical locations to thereby define a plurality of service areas and a plurality of mobile stations capable of communicating by two-way radio with each base station when in communication range of that base station, the system being provided with control means which includes a location record corresponding to each mobile station, which location record is capable of storing a service area identity, characterised in that each location record is capable of storing at least two service area identities, in that each mobile station also includes a location record capable of storing at least two service area identities and is arranged when operative to respond to it not being within communication range of any base station serving a service area the identity of which is currently stored in the location record included therein by communicating with a base station of which it is within such range (if any) and storing the identity of the service area served by that base station in said location record in such manner that said identity replaces the identity of another service area already present in said location record if the resulting number of stored identities would otherwise exceed a given value n greater than one, and in that said control means is arranged to respond to each such communication by updating the contents of that location record included therein which corresponds to the communicating mobile station so that the mobile station is recorded as being currently located in the service area served by the base station with which the communication takes place while retaining in said location record the identity or identities (if present) of at least (n-1) other service area(s) in which the relevant mobile station was previously recorded as being located.
Claim 3
Dependent Claim
208 words
A system as claimed in Claim 1, wherein each mobile station is arranged, when it responds to it not being within communication range by storing a service area identity, and when it communicates with a base station serving a service area the identity of which is currently present in the location record included therein, to maintain an indication that the relevant identity now takes precedence over any other identities which are present and, when the mobile station subsequently responds to it not being within communication range, to retain in said location record that already present identity which is indicated as currently taking precedence, and wherein the control means is arranged, when it carries out a said updating, and when a mobile station communicates with a base station serving a service area the identity of which is currently present in that location record included in the control means which corresponds to the relevant mobile station, to maintain an indication that the relevant identity now takes precedence over any other identities present in the relevant location record, and, when the control means subsequently carries out a said updating of the relevant location record, to retain in said location record that already present identity which is indicated as currently taking precedence.
Claim 4
Dependent Claim
146 words
A system as claimed in Claim 2, wherein each mobile station is arranged to maintain an indication of the current order of precedence, taken on a historical basis, of all the identities currently present in the location record included therein and, when the mobile station responds to it not being within communication range by replacing an identity already present in said location record, to replace that identity which is indicated as currently being lowest in said order of precedence, and wherein the control means is arranged, for each location record included therein, to maintain an indication of the current order of precedence, taken on a historical basis, of all the identities currently present in that location record and, when it carries out a said updating, to retain in the relevant location record those (n-1) already present identities which are indicated as currently taking the most precedence.
Claim 5
Dependent Claim
39 words
A system as claimed in Claim 3, wherein each indication of the current order of precedence takes the form of a record of the absolute time which has elapsed since respective ones of the relevant identities last took precedence.
Claim 6
Dependent Claim
63 words
A system as claimed in Claim 4, wherein each mobile station and the control means is arranged to delete any service area identity stored in a said location record should the corresponding absolute time which has elapsed exceed a predetermined value, at least if at least one service area identity will continue to be present in the relevant location record after the deletion.
Claim 7
Dependent Claim
55 words
A system as claimed in Claim 5, wherein each mobile station and the control means is arranged, if one service area identity is present in said location record, to also delete that identity should the corresponding absolute time which has elapsed exceed a further predetermined value greater than the corresponding value specified in Claim 5.
Claim 8
Independent Claim
24 words
A system as claimed in any preceding claim, wherein the base stations are arranged to transmit said given number n to each mobile station.
Claim 9
Dependent Claim
130 words
A mobile station for use in a system as claimed in any preceding claim, which station includes a location record capable of storing at least two service area identities and is arranged when operative to respond to it not being within communication range of a base station serving a service area the identity of which is currently stored in said location record by communicating with a base station of which it is within such range (if any) and storing the identity of the service area served by that base station in said location record in such manner that said identity replaces the identity of another service area already present in said location record if the resulting number of stored identities would otherwise exceed a given value n greater than one.
Claim 10
Dependent Claim
254 words
In a mobile radio transmission system comprising a plurality of base stations which are situated at respective geographical locations to thereby define a plurality of service areas and a plurality of mobile stations capable of communicating by two-way radio with each base station when in communication range of that base station, a method by which the location of a mobile station is recorded, in which method the mobile station responds to it not being within communication range of any base station serving a service area the identity of which is currently stored in a location record included therein by communicating with a base station of which it is within such range (if any) and storing the identity of the service area served by that base station in said location record in such manner that said identity replaces the identity of another service area already present in said location record if the resulting number of stored identities would otherwise exceed a given value n greater than one, and a control means with which the system is provided responds to each such communication by updating the contents of a location record included therein which corresponds to the communicating mobile station so that the mobile station is recorded as being currently located in the service area served by the base station with which the communication takes places while retaining in said location record the identity or identities (if present) of at least (n-1) other service area(s) in which the mobile station was previously recorded as being located.
Claim 11
Dependent Claim
254 words
In a mobile radio transmission system comprising a plurality of base stations which are situated at respective geographical locations to thereby define a plurality of service areas and a plurality of mobile stations capable of communicating by two-way radio with each base station when in communication range of that base station, a method by which the location of a mobile station is recorded, in which method the mobile station responds to it not being within communication range of any base station serving a service area the identity of which is currently stored in a location record included therein by communicating with a base station of which it is within such range (if any) and storing the identity of the service area served by that base station in said location record in such manner that said identity replaces the identity of another service area already present in said location record if the resulting number of stored identities would otherwise exceed a given value n greater than one, and a control means with which the system is provided responds to each such communication by updating the contents of a location record included therein which corresponds to the communicating mobile station so that the mobile station is recorded as being currently located in the service area served by the base station with which the communication takes places while retaining in said location record the identity or identities (if present) of at least (n-1) other service area(s) in which the mobile station was previously recorded as being located.
References Cited (Backward Citations)
No citation records indexed.
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