EP0177094A2
Expired / Lapsed
EP
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Multiple access communications system
Assignee: Koninklijke Philips NV
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Filing: 1985-09-20
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Granted: —
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Expires: 2005-09-20
Abstract
Abstract A flexible multiple access communications system which is particularly suitable for mobile radio systems. …<??>The system comprises a base station and a plurality of substations whose mode of access is determined in response to an op-code and parameters transmitted in an Aloha invitation message. The value of the op-code and parameters and thereby the particular one of a plurality of access modes and the dynamic operation in that mode is determined from an estimate of the prevailing traffic conditions. The different modes of access include light traffic mode, dynamic frame-length mode, hybrid mode in which subsets of the population of the substations are formed and polling mode.
Inventors
- 👤 Diana Margaret Ball
- 👤 Peter John Mabey
- 👤 Paul Jonathan Stein
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 19:39
CPC Classifications
H; H04; H04W; H04W84/00; H04W84/02; H04W84/04; H04W84/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
60 words
A multiple access communications system characterised by a base station and a plurality of substations whose mode of operation is determined in response to an op-code transmitted in an Aloha invitation message, the value of the op-code and thereby the particular one of a plurality of operating modes being determined in response to an estimate of the prevailing traffic conditions.
Claim 2
Dependent Claim
60 words
A multiple access communications system characterised by a base station and a plurality of substations whose mode of operation is determined in response to an op-code transmitted in an Aloha invitation message, the value of the op-code and thereby the particular one of a plurality of operating modes being determined in response to an estimate of the prevailing traffic conditions.
Claim 3
Dependent Claim
28 words
A system as claimed in Claim 1, characterised in that parameters are transmitted with the op-code, said parameters serving to determine the dynamic operation for any selected op-code.
Claim 4
Dependent Claim
71 words
A multiple access communications system characterised by a base station and a plurality of substations whose mode of operation is determined in response to an op-code and parameters transmitted in an Aloha invitation message, the value of the op-code and parameters and thereby the particular one of a plurality of operating modes and the dynamic operation in that mode being determined in response to an estimate of the prevailing traffic conditions.
Claim 5
Dependent Claim
71 words
A multiple access communications system characterised by a base station and a plurality of substations whose mode of operation is determined in response to an op-code and parameters transmitted in an Aloha invitation message, the value of the op-code and parameters and thereby the particular one of a plurality of operating modes and the dynamic operation in that mode being determined in response to an estimate of the prevailing traffic conditions.
Claim 6
Dependent Claim
45 words
A system as claimed in Claim 1, 2 or 3, characterised in that one of said modes is a dynamic frame-length mode in which there is a predetermined maximum number of time slots in a frame and retransmissions are not permitted in the same frame.
Claim 7
Dependent Claim
48 words
A system as claimed in Claim 1 2 or 3, characterised in that one of said modes is a hybrid mode in which subsets of a population of substations are formed and in which at least one of said subsets operates on a dynamic frame-length random access protocol.
Claim 8
Dependent Claim
22 words
A system as claimed in Claim 1, 2 or 3, characterised in that one of said modes is polling of the substations.
Claim 9
Dependent Claim
36 words
A system as claimed in Claim 6, characterised in that when the system is operating in the polling mode, a parameter in the polling message is an acknowledgement of a response from a previously polled substation.
Claim 10
Dependent Claim
141 words
A system as claimed in Claim 2 or 3, characterised in that one of said modes is a dynamic frame-length mode in which there is a predetermined maximum number of time slots in a frame and retransmissions are not permitted in the same frame and a second of said modes is a hybrid mode in which subsets of the population of substations are formed and in which at least one of said subsets operates on a dynamic frame-length random access protocol, and in that the parameter in the Aloha message comprises an instruction to each substation of the number of the least significant bits in an address being transmitted in the message which should be compared with the appropriate address or addresses of the substation in order for the substation to determine whether it is allowed to respond to the message.
Claim 11
Dependent Claim
72 words
A system as claimed in Claim 1, 2 or 3, characterised in that one of said modes is a light traffic mode in which a base station transmitter operates on a low duty cycle and in which a substation can transmit a request for access in a prescribed access period (hereinafter termed a frame) and in the case of the request being mutilated the request can be retransmitted in the same frame.
Claim 12
Dependent Claim
39 words
A system as claimed in Claim 9, characterised in that the length of a light traffic mode frame and the retry randomisation period are prescribed in the Aloha invitation message, said frame length and randomisation period being determined adaptively.
Claim 13
Independent Claim
38 words
A system as claimed in any one of Claims 4, 5, 8, 9 and 10, characterised in that a substation may transmit in the time slot immediately following call initiation if said time slot is within a frame.
References Cited (Backward Citations)
No citation records indexed.
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