Patent EP0813346A1 successfully refreshed from Google Patents.
EP0813346A1
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Dynamic assigment of signalling virtual channels for wireless ATM systems
Assignee: Ascom Tech AG
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Filing: 1997-03-07
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Granted: —
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Expires: 2017-03-07
Abstract
Abstract A wireless communication system for asynchronous transfer mode includes the dynamic assignment of signalling virtual channels and/or virtual paths for communications between a mobile terminal and a controller or control function. An access point (AP) associated with the wireless mobile terminal (MT) is transparent for transmitted data and control information. The dynamic assignment of the signalling virtual channel (SVC) takes place in the event of new registration to the system and handover from one access point to another. The protocol uses finite state machines and timers at the mobile terminal and at the control function. For new registrations, an assignment channel is used on a broadcast uplink from the mobile terminal to the control function to request the SVC, while the response from the control function is transmitted on the downlink broadcast channel. The response contains the unique signalling virtual channel identifier (SVCI) to be used by the mobile terminal and the control function for further signalling between them. A loss of carrier connection is detected by exchanging alive messages. If there is no response to the alive messages, pending connections are released and assigned SVCs are freed. Handover from one access point to another is initiated by the mobile terminal. A new SVCI is assigned by the control function as part of the messages exchanged during the handover protocol.
Inventors
- 👤 Thomas Kühnel
- 👤 Yung-Shain Wu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 05:48
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04W; H04W36/00; H04W36/08; H04L; H04L12/00; H04L12/54; H04L12/56; H04L12/5601; H04L2012/5603; H04L2012/5604; H04L2012/5607; H04L2012/5629; H04L2012/563; H04W60/00; H04W72/00; H04W72/04; H04W76/00; H04W76/20
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
87 words
A digital radio communication system providing wireless access to an ATM environment, comprising: a controller for controlling communications within a geographical area; a mobile terminal having a wireless communication interface; at least one access point operatively connected to said controller, for facilitating communication between said controller and the wireless communication interface of said at least one mobile terminal when said mobile terminal is located within the geographical area, wherein information communicated between said mobile terminal and said controller identifies a signalling virtual channel of the ATM environment.
Claim 2
Dependent Claim
57 words
The digital radio communications system of claim 1, further comprising: a signalling virtual channel engine in said at least one mobile terminal, for controlling the wireless communication interface to transmit a request for a signalling virtual channel, the signalling virtual channel to be used in subsequent communications for control purposes from said mobile terminal to said controller.
Claim 3
Dependent Claim
34 words
The digital radio communications system of claim 2, wherein said signalling virtual channel assignment engine transmits the request immediately after establishing an initial wireless link with one of said at least one access points.
Claim 4
Dependent Claim
37 words
The digital radio communications system of claim 3, wherein the controller assigns, in response to the request, a signalling virtual channel identifier for future use by said mobile terminal and transmits the identifier to the mobile terminal.
Claim 5
Dependent Claim
48 words
The digital radio communications system of claim 2, wherein said signalling virtual channel engine controls said wireless communication interface to transmit the request on a predetermined assignment channel, the assignment channel being identified in the request by a predetermined virtual channel identifier and a predetermined virtual path identifier.
Claim 6
Dependent Claim
30 words
The digital radio communications system of claim 5, wherein the predetermined virtual channel identifier and the predetermined virtual path identifier are identical for all mobile terminals used in the system.
Claim 7
Dependent Claim
43 words
The digital radio communications system of claim 1, further comprising: a signalling virtual channel engine in said at least one mobile terminal, for controlling the wireless communication interface to transmit information including the identity of a signalling virtual channel assigned by said controller.
Claim 8
Dependent Claim
92 words
The digital radio communications system of claim 7, wherein said signalling virtual channel engine in said at least one mobile terminal controls the wireless communication interface to transmit a request for a signalling virtual channel, the request being received by said controller, and wherein said system further comprises: a signalling virtual channel assignment engine in said controller, for assigning a virtual channel to said mobile terminal in response to the request, the identity of the virtual channel being transmitted to said mobile terminal through one of said at least one access points.
Claim 9
Dependent Claim
35 words
The digital radio communications system of claim 7, wherein the transmitted information includes a single ATM header followed immediately by a plurality of ATM cells, the header including the identity of the assigned virtual channel.
Claim 10
Dependent Claim
42 words
The digital radio communications system of claim 1, further comprising: a detector in said mobile terminal for detecting disconnection of communication from said controller, the detector including a timer which is reset by the receipt of a predetermined signal from said controller.
Claim 11
Dependent Claim
55 words
The digital radio communications system of claim 1, further comprising: a circuit in said at least one access point for mapping ATM cells from the controller into radio cells for transmission to the wireless communication interface, and for mapping radio cells from said wireless communication interface for transmission over a hardwired link to said controller.
Claim 12
Dependent Claim
45 words
The digital radio communications system of claim 1, wherein the controller assigns a new virtual channel to said mobile terminal when said mobile terminal approaches a portion of the geographical area not covered by the access point with which said mobile terminal is currently communicating.
Claim 13
Dependent Claim
35 words
The digital radio communications system of claim 12, wherein said controller transfers the identity of the new virtual channel to the mobile terminal through the access point with which said mobile terminal is currently communicating.
Claim 14
Dependent Claim
81 words
The digital radio communications system of claim 13, wherein said mobile terminal initiates the transfer of the new virtual channel identifier by transmitting a handover request to said controller, and further wherein said mobile terminal, after receiving the identity of the new virtual channel, controls the wireless communication interface to transmit a hello message such that a new access point receives the hello message and transfers the hello message to the controller, thereby identifying to the controller the new access point.
Claim 15
Dependent Claim
56 words
The digital radio communications system of claim 1, further comprising: a signalling virtual channel assignment engine in said controller, for receiving a request for a signalling virtual channel from said mobile terminal, and for assigning a virtual channel to the requesting mobile terminal, the virtual channel already being used by another mobile terminal in said system.
Claim 16
Dependent Claim
70 words
The digital radio communications system of claim 1, further comprising: a processor in said controller for controlling the handover of said mobile terminal to a second access point, the processor receiving a handover request from said mobile terminal and for awaiting a hello message from said mobile terminal through said second access point such that the identity of said second access point is determined after the hello message is received.
Claim 17
Dependent Claim
67 words
The digital radio communications system of claim 1, further comprising: a memory in said mobile terminal preprogrammed to contain the identifier for the signalling virtual channel; and a database containing the identities of a plurality of virtual paths, from which said controller chooses a first virtual path to be assigned the mobile terminal, the first virtual path being transmitted to said mobile terminal through said access point.
Claim 18
Dependent Claim
66 words
The digital radio communications system of claim 3, further comprising: a signalling virtual channel assignment engine in said controller, for assigning, in response to the request, a signalling virtual path identifier for future use by said mobile terminal, wherein the signalling virtual channel identified in the information communicated between said mobile terminal and said controller is a predefined signalling virtual channel known to said mobile terminal.
Claim 19
Dependent Claim
33 words
The digital radio communications system of claim 18, wherein said mobile terminal includes additional data connections to said controller, said data connections being transmitted using respective virtual channels within the assigned virtual path.
Claim 20
Dependent Claim
62 words
A process for the dynamic assignment of signalling virtual channels for wireless ATM systems, comprising the steps of: (a) providing at least one mobile terminal having wireless ATM communication capabilities; (b) controlling a wireless ATM system within a geographical area; and (c) dynamically assigning signalling virtual channels to the mobile terminal when the mobile terminal is connected to the wireless ATM system.
Claim 21
Dependent Claim
43 words
The process of claim 20, wherein the mobile terminal includes a plurality of data connections to a controller of the wireless ATM system, the dynamically assigned virtual channel of the step (c) being for use by one of the plurality of data connections.
Claim 22
Dependent Claim
55 words
The process of claim 20, further comprising the step of: (d) transmitting information between the mobile terminal and the controller, the information identifying the assigned virtual channel of the ATM environment and including a single ATM header followed immediately by a plurality of ATM cells, the header including the identity of the assigned virtual channel.
Claim 23
Dependent Claim
30 words
The process of claim 20, further comprising the step of: (d) controlling a signalling virtual channel engine of the mobile terminal to transmit a request for a signalling virtual channel.
Claim 24
Dependent Claim
26 words
The process of claim 23, wherein the request of the step (d) is transmitted immediately upon establishing a wireless communication link to the wireless ATM system.
Claim 25
Dependent Claim
28 words
The process of claim 24, wherein the dynamic assignment of the virtual channel in the step (c) in done in response to the request of the step (d).
Claim 26
Dependent Claim
31 words
The process of claim 20, wherein the virtual channel assigned to the mobile terminal in the step (c) is common to a plurality of mobile terminal connected to the ATM system.
Claim 27
Dependent Claim
26 words
The process of claim 20, further comprising the step of: (d) transmitting the assigned virtual channel identifier to the mobile terminal using a predetermined assignment channel.
Claim 28
Dependent Claim
40 words
The process of claim 20, further comprising the step of: (d) detecting disconnection of the mobile terminal from the wireless ATM system by providing a timer in the mobile terminal, and resetting the timer upon receipt of a predetermined signal.
Claim 29
Dependent Claim
48 words
The process of claim 20, further comprising the steps of: (d) mapping ATM cells from the controller of the wireless ATM system into radio cells for transmission to the mobile terminal, and mapping radio cells from the mobile terminal for transmission over a hardwired link to the controller.
Claim 30
Dependent Claim
42 words
The process of claim 20, further comprising the step of: (d) providing a plurality of access points serving respective geographic areas for the wireless ATM system, to facilitate ATM communication between the mobile terminal and a controller of the wireless ATM system.
Claim 31
Dependent Claim
43 words
The process of claim 30, further comprising the step of: (e) assigning a new virtual channel to the mobile terminal when the mobile terminal approaches a new geographical area not covered by the access point with which the mobile terminal is currently communicating.
Claim 32
Dependent Claim
32 words
The process of claim 31, wherein said controller transfers the identity of the new virtual channel to the mobile terminal through the access point with which said mobile terminal is currently communicating.
Claim 33
Dependent Claim
70 words
The process of claim 32, further comprising the step of: (f) controlling the mobile terminal to initiate the transfer of the new virtual channel identifier by transmitting a handover request to the controller; and (g) transmitting a hello message from the mobile terminal such that a new access point receives the hello message and transfers the hello message to the controller, thereby identifying the new access point to the controller.
Claim 34
Dependent Claim
55 words
A process for wireless digital radio communication to an ATM system, comprising the steps of: (a) providing at least one mobile terminal having wireless ATM communication capabilities; (b) controlling a wireless ATM system within a geographical area; and (c) transmitting a virtual channel identifier between the mobile terminal and a controller of the ATM system.
Claim 35
Dependent Claim
34 words
The process of claim 34, further comprising the step of: (d) storing in the mobile terminal a predetermined virtual channel identifier, the identifier transmitted in the step (c) being the predetermined virtual channel identifier.
Claim 36
Dependent Claim
30 words
The process of claim 34, further comprising the step of: (d) transmitting a request for a virtual channel identifier from the mobile terminal to the controller of the ATM system.
Claim 37
Dependent Claim
66 words
The process of claim 36, further comprising the steps of: (e) storing in the mobile terminal a predetermined virtual channel identifier, the identifier transmitted in the step (c) being the predetermined virtual channel identifier; and (f) transmitting, in response to the request of the step (d), a virtual path identifier to the mobile terminal for future use in communications between the mobile terminal and the controller.
Claim 38
Dependent Claim
40 words
The process of claim 36, wherein the request is transmitted by the mobile terminal using a predetermined assignment channel, the predetermined assignment channel being identified in the request by a predetermined virtual channel identifier and a predetermined virtual path identifier.
Claim 39
Dependent Claim
27 words
The process of claim 38, wherein the predetermined virtual channel identifier and the predetermined virtual path identifier are identical for all mobile terminals used in the system.
Claim 40
Dependent Claim
28 words
The process of claim 34, wherein the virtual channel identifier assigned in the step (c) is already being used by another mobile terminal in the wireless ATM system.
Claim 41
Dependent Claim
48 words
The process of claim 34, further comprising the step of: (d) assigning a signalling virtual path identifier for future use by the mobile terminal, the virtual channel identified in communication between the mobile terminal and the controller being a predefined signalling virtual channel known to the mobile terminal.
Claim 42
Dependent Claim
41 words
The process of claim 41, wherein the mobile terminal includes a plurality of data connections to the controller, each of the plurality of data connections being transmitted using respective virtual channel identifiers within the assigned virtual path of the step (d).
References Cited (Backward Citations)
EP0637185A2
Cited
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