EP0708571A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and system for distributed control in wireless cellular and personal communication systems
Assignee: AT&T Inc
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Filing: 1995-10-03
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Granted: —
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Expires: 2015-10-03
Abstract
Abstract A system for distributed control in wireless cellular and personal communication systems includes separate servers (120,130) for performing call control and connection control functions, thereby obviating the need for a mobile switching or other switch (140) to be anchored for the duration of a call. During a registration procedure, visitor location servers (190) track only roaming mobiles, rather than tracking both roaming mobiles as well as mobiles located in their home network (101). Direct signalling links between servers and base stations (150-159), or other servers, located in different networks (102,103) allow roaming mobiles to contact their home networks for service at all times, thereby obviating the need for passing signalling information for mobiles when they are not involved in a call. The use of multicast signalling with asynchronous transfer mode switches, permits specified channel control functions to take place concurrently in channel servers associated with base station and switches that form a segment of the route for a call. Similarly, specified call control functions are performed concurrently with mobile location functions, thereby decreasing the delays in setting up a call.
Inventors
- 👤 Thomas F. La Porta
- 👤 Malathi Veeraraghavan
- 👤 Ramachandran Ramjee
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 02:49
CPC Classifications
H; H04; H04W; H04W64/00; H04W8/00; H04W8/02; H04W8/04; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04W36/00; H04W36/0005; H04W36/0055; H04W36/12; H04W36/14; H04W36/144; H04W40/00; H04W40/02; H04W76/00; H04W76/10; H04W76/30; H04W88/00; H04W88/08; H04W88/14; H04W88/16; H04W88/18; H04L; H04L12/00; H04L12/54; H04L12/56; H04L12/5601; H04L2012/5629; H04W8/08; Y; Y02; Y02D; Y02D30/00; Y02D30/70
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
122 words
A telecommunication system at least a portion of which comprises: a plurality of networks each of which comprises: (a) a home location server; (b) a visitor location server; (c) a roamer call server; and (d) a plurality of clusters each of which comprises: (1) a call server; (2) a connection server; (3) a plurality of base stations each having a channel server associated with it; (4) a plurality of switches where each of said plurality of switches has a channel server associated with it; and (5) a plurality of signalling transfer points; and a plurality of end systems, including a plurality of mobiles, where each of said plurality of mobiles has a home network which is one of said plurality of networks.
Claim 2
Dependent Claim
17 words
The system of claim 1 wherein said plurality of switches include the capability of broadcasting multicast messages.
Claim 3
Dependent Claim
19 words
The system of claim 1 wherein said plurality of switches comprises a plurality of asynchronous transfer mode (ATM) switches.
Claim 4
Dependent Claim
29 words
The system of claim 3 wherein at least some of said plurality of asynchronous transfer mode (ATM) switches are used to establish connections along a route in said system.
Claim 5
Dependent Claim
50 words
The system of claim 3 wherein at least some of said plurality of asynchronous transfer mode (ATM) switches are used to establish direct signalling links between a base station in one of said plurality of networks and a roamer call server in a different one of said plurality of networks.
Claim 6
Dependent Claim
50 words
The system of claim 3 wherein at least some of said plurality of asynchronous transfer mode (ATM) switches are used to establish direct signalling links between a roamer call server in one of said plurality of networks and a connection server in a different one of said plurality of networks.
Claim 7
Dependent Claim
30 words
The system of claim 1 wherein said home location server tracks the location of mobiles for which it is the home location server according to a mobile location tracking routine.
Claim 8
Dependent Claim
26 words
The system of claim 1 wherein said visitor location server tracks the location of mobiles roaming in its domain according to a mobile location tracking routine.
Claim 9
Dependent Claim
43 words
The system of claim 1 wherein said call server performs call control functions in response to a call origination message from a mobile, located in its home network and located within the domain of said call server, according to a call control routine.
Claim 10
Dependent Claim
32 words
The system of claim 1 wherein said call server performs call control functions in response to a setup call message for a call to a mobile according to a call control routine.
Claim 11
Dependent Claim
23 words
The system of claim 1 wherein said call server performs call-release functions in response to a release-call message according to a release-call routine.
Claim 12
Dependent Claim
49 words
The system of claim 1 wherein said roamer call server performs call control functions in response to a call origination message from a mobile, located in a network other than its home network and located within the domain of said roamer call server, according to a call control routine.
Claim 13
Dependent Claim
33 words
The system of claim 1 wherein said roamer call server performs call control functions in response to a setup call message for a call to a mobile according to a call control routine.
Claim 14
Dependent Claim
33 words
The system of claim 1 wherein said connection server performs connection control functions in response to a setup connections message for a call originating in its domain according to a connection establishment routine.
Claim 15
Dependent Claim
24 words
The system of claim 1 wherein said connection server performs connections control functions in response to a release-connections message according to a release-connection routine.
Claim 16
Dependent Claim
26 words
The system of claim 1 wherein said plurality of channel servers perform channel control functions in response to a hanfoff-order message according to a handoff routine.
Claim 17
Dependent Claim
15 words
The system of claim 1 wherein said communication system is a wireless cellular communication system.
Claim 18
Dependent Claim
14 words
The system of claim 1 wherein said communication system provides personal communications services (PCS).
Claim 19
Independent Claim
162 words
A method of tracking the location of a mobile having a home network, said method comprising the steps of: generating a registration message; performing the following steps if said mobile is located in its home network: (a) forwarding registration information to a home location server for said mobile; and (b) storing a mobile-to-cluster mapping for said mobile in said home location server; and performing the following steps if said mobile is not located in its home network: (a) forwarding said registration information to a visitor location server tracking said mobile; (b) storing a mobile-to-cluster mapping for said mobile in said visitor location server if said registration message indicates a cluster change; (c) forwarding said registration information to said home location server for said mobile if said registration message indicates that said mobile is powering up or powering down; and (d) storing in said home location server a network identifier and visitor location server identifier corresponding to the location of said calling mobile.
Claim 20
Independent Claim
176 words
A method of setting up a call from a calling end system to a called end system, where at least either said calling end system or said called end system is a mobile, said method comprising the steps of: generating a call origination message; performing a call control routine for said call; and performing a connection establishment routine for said call, wherein said connection establishment routine comprises the steps of: (a) receiving a setup connections message; (b) finding a route from said calling end system to said called end system for said call; (c) performing a connection admission routine with respect to each segment of said route; and (d) performing a connection setup routine with respect to each segment of said route; wherein said connection admission routine comprises the step of performing channel reservation functions concurrently in a plurality of channel servers associated with base stations and switches which form a segment of said route and wherein said connection setup routine comprises the step of performing setup translation functions concurrently in said plurality of channel servers.
Claim 21
Dependent Claim
27 words
The method of claim 20 wherein said connection admission routine further comprises the step of sending a multicast reserve channel message to said plurality of channel servers.
Claim 22
Dependent Claim
27 words
The method of claim 20 wherein said connection setup routine further comprises the step of sending a multicast setup translation message to said plurality of channel servers.
Claim 23
Independent Claim
202 words
A method of setting up a call from a calling end system to a called end system, where at least either said calling end system or said called end system is a mobile, said method comprising the steps of: generating a call origination message; performing a call control routine for said call; and performing a connection establishment routine for said call; wherein said call control routine comprises the steps of: (a) sending a setup call message to a call server serving said calling end system; (b) creating a state machine for said call; (c) invoking implicit services for said calling end system; (d) creating a record for mapping connections for said call; (e) identifying a call server serving said called end system, a connection server for said called end system and a gateway switch for said called end system; (f) communicating with said call server for said called end system to invoke implicit services for said called end system; and (g) sending a setup connections message to a connection server for said calling end system; and wherein the steps (b), (c) and (d) of said call control routine are performed concurrently with the steps (e) and (f) of said call control routine.
Claim 24
Dependent Claim
96 words
The method of claim 23 wherein the step of sending a setup call message to a call server serving said calling end system comprises the steps of: sending a setup call message to a call server located in the same cluster as said calling end system if said calling end system is a mobile located in its home network; and sending a setup call message to a roamer call server located in the home network of said calling end system if said calling end system is a mobile which is not located in its home network.
Claim 25
Dependent Claim
85 words
The method of claim 23 wherein the step of identifying comprises the following steps if said called end system is a mobile located in its home network: sending a find request to a home location server for said called end system; and sending a find response to the call server serving said calling end system, wherein said find response specifies the call server serving said called end system, the connection server for said called end system and the gateway switch for said called end system.
Claim 26
Dependent Claim
96 words
The method of claim 23 wherein the step of identifying comprises the following steps if said called end system is a mobile not located in its home network: sending a find request to a home location server for said called end system; sending a find request from said home location server to a visitor location server tracking said called end system; sending a find response from said visitor location server to said home location server; and sending at least one find response from said home location server to the call server serving said calling end system.
Claim 27
Dependent Claim
66 words
The method of claim 26 wherein the step of sending at least one find response to said call server serving said calling end system comprises the steps of: sending a first find response specifying the call server serving said called end system; and sending a second find response specifying the connection server for said called end system and the gateway switch for said called end system.
Claim 28
Dependent Claim
37 words
The method of claim 23 further including the step of performing a base station location routine if said called end system is a mobile, where said base station location routine is performed in parallel with step (f).
Claim 29
Dependent Claim
74 words
The method of claim 28 wherein said base station location routine comprises the following steps if said called end system is located in its home network: sending a page request from a home location server for said called end system to all base stations located in the same cluster as said called end system; generating a page order from each of said base stations; and sending a page response to said home location server.
Claim 30
Dependent Claim
75 words
The method of claim 28 wherein the base station location routine comprises the following steps if said called end system is not located in its home network: sending a page request from a visitor location server for said called end system to all base stations located in the same cluster as said called end system; generating a page order from each of said base stations; and sending a page response to said visitor location server.
Claim 31
Dependent Claim
21 words
The method of claim 29 or 30 wherein said step of sending a page request comprises sending a multicast page request.
Claim 32
Independent Claim
95 words
A method of setting up a call from a calling end system to a called end system, where at least either said calling end system or said called end system is a mobile, said method comprising the steps of: generating a call origination message from said calling end system; performing a call control routine for said call; and performing a connection establishment routine for said call wherein channel reservation functions are performed concurrently in a plurality of channel servers associated with base stations and switches which form a segment of a route for said call.
Claim 33
Dependent Claim
17 words
The method of claim 32 wherein translation functions are performed concurrently in said plurality of channel servers.
Claim 34
Independent Claim
114 words
A method of releasing a call from a calling end system to a called end system, where at least either said calling end system or said called end system is a mobile, said method comprising the steps of: generating a release-order message; sending a release-call message to call servers involved in said call; sending a release-connection message to a connection server corresponding to the one of said call servers which has a record of connections involved in said call; and performing a release-connection routine wherein resources, which are used in a plurality of channel servers associated with base stations and switches which form a segment of a route for said call, are released concurrently.
Claim 35
Dependent Claim
25 words
The method of claim 34 wherein said release-call routine further comprises the step of sending a multicast drop-channel message to said plurality of channel servers.
Claim 36
Independent Claim
145 words
A method of handing off a call comprising the steps of: generating a handoff-order message identifying a previous base station which comprises a first end of an old segment of an old route for said call; forwarding said handoff-order message to said previous base station; sending a handoff segment message from a channel server associated with said previous base station to a new base station; establishing a new segment of a route for said call from said new base station to a switch identified as a second end of said old segment; setting up a new translation from a channel in said old route to a channel associated with said new segment; identifying to said switch each channel server involved in said new segment; and communicating to a connection server responsible for said old segment the change from said old segment to said new segment.
References Cited (Backward Citations)
No citation records indexed.
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