EP0222308A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Radio communication system having means for avoiding signal collision
Assignee: NEC Corp
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Filing: 1986-11-04
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Granted: —
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Expires: 2006-11-04
Abstract
Abstract The radio communication system comprising a plurality of communication groups (A,B) each including a master station (1A, 1B) and at least a slave station (2A, 2B). The communication groups (A, B) are adapted to use a single common frequency, wherein the master station has means for sensing a carrier wave of the common frequency. The master station transmits a data when the master station does not detect the carrier wave for a first predetermined time period, and the slave station transmits an acknowledging signal, upon a reception of the data, within a second predetermined time period shorter than the first predetermined time period. This radio communication system avoids the signal collision problem.
Inventors
- 👤 Yoshio Ichikawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 17:17
CPC Classifications
H; H04; H04W; H04W16/00; H04W16/14; H04W84/00; H04W84/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
98 words
A radio communication system comprising a plurality of communication groups each including a master station and at least a slave station, said communication groups being adapted to use a single common frequency, wherein said master station has means for sensing a carrier wave of said common frequency, wherein said master station transmits a data when said master station does not detect said carrier wave for a first predetermined time period, and wherein said slave station transmits an acknowledging signal, upon a reception of said data, within a second predetermined time period shorter than said first predetermined time period.
Claim 2
Dependent Claim
98 words
A radio communication system comprising a plurality of communication groups each including a master station and at least a slave station, said communication groups being adapted to use a single common frequency, wherein said master station has means for sensing a carrier wave of said common frequency, wherein said master station transmits a data when said master station does not detect said carrier wave for a first predetermined time period, and wherein said slave station transmits an acknowledging signal, upon a reception of said data, within a second predetermined time period shorter than said first predetermined time period.
Claim 3
Dependent Claim
25 words
A radio communication system as claimed in claim 1, wherein service areas of at least two of said communication groups are overlapped partially each other.
Claim 4
Dependent Claim
24 words
A radio communication system as claimed in claim 1 or 2, wherein said means for sensing said carrier wave comprises a carrier squelch circuit.
Claim 5
Dependent Claim
66 words
A radio communication system as claimed in any of claims 1 to 3, wherein said data transmitted from said master station includes an identification number of said slave station, and wherein said slave station compares said identification number included in said data received thereby with an identification number stored therein and transmits said acknowledging signal when both of said identification numbers are coincident with each other.
Claim 6
Independent Claim
110 words
A method of avoiding signal collisions in a radio communication system including a plurality of communication groups each including a master station and at least a slave station and using a single frequency, comprising the steps of: monitoring a carrier wave of said frequency in said master station; transmitting a data from said master station when there is no carrier wave ,detected for a first predetermined time period; receiving said data at said slave station; and transmitting an acknowledging signal from said slave station within a second predetermined time period from a reception of said data thereby, said second predetermined time period being shorter than said first predetermined time period.
Claim 7
Independent Claim
110 words
A method of avoiding signal collisions in a radio communication system including a plurality of communication groups each including a master station and at least a slave station and using a single frequency, comprising the steps of: monitoring a carrier wave of said frequency in said master station; transmitting a data from said master station when there is no carrier wave ,detected for a first predetermined time period; receiving said data at said slave station; and transmitting an acknowledging signal from said slave station within a second predetermined time period from a reception of said data thereby, said second predetermined time period being shorter than said first predetermined time period.
Claim 8
Dependent Claim
23 words
A method as claimed in claim 5, wherein service areas of at least two of said communication groups are overlapped partially each other.
Claim 9
Dependent Claim
21 words
A method as claimed in claim 5 or 6, wherein the step of monitoring is performed by using a squelch information.
Claim 10
Independent Claim
72 words
A method as claimed in any of claims 5 to 7, further comprising the steps of: inserting a first identification number of said slave station into said data; storing a second identification number in said slave station; comparing said first identification number inserted into said data and received by said slave station with said second identification number stored therein; and transmitting said acknowledging signal when both of said identification numbers are coincident.
References Cited (Backward Citations)
No citation records indexed.
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