Method and communication system for data exchanging data between users of a bus system
First Claim
1. A method for exchanging data between at least two user units connected by a bus system, comprising:
- assigning a priority to each message containing data sought to be transmitted by the user units;
dynamically modifying, during the operation of the bus system, the priority assigned to each message;
categorizing each message into one of a plurality of equivalence classes;
assigning a priority to each equivalence class, the assigned priority corresponding to a highest priority of any message in that equivalence class; and
dynamically modifying, during the operation of the bus system, the priority of at least one particular equivalence class after a message transmission, wherein;
the priority is reduced if at least one of;
any message of the particular class was the message transmitted, or any message of the particular class could have been the message transmitted;
the priority is maintained if no message of the particular class could have been transmitted, independent of the priority of the particular class; and
the priority is raised if no message of the particular class could have been transmitted, but at least one message of the particular class could have been transmitted if the particular class had had a higher priority.
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Accused Products
Abstract
The present invention provides a method and a communications system for the exchange of data between at least two users who are in contact with one another using a bus system. The data are included in messages which are transmitted by users over the bus system. A specifiable priority is assigned to each message. In order to achieve, in the normal case, a high probability of a short latency period (t) of a message to be transmitted, and to be able to guarantee, in the worst case, a maximum latency period (tmax), it is provided that the priorities assigned to the messages be dynamically modified during the operation of bus system. Preferably, the set of all messages is subdivided into equivalence classes, and a priority is assigned to each equivalence class. During the operation of the bus system, the priorities of the messages are dynamically modified within an equivalence class, and the priorities of the equivalence classes are dynamically modified.
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Citations
18 Claims
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1. A method for exchanging data between at least two user units connected by a bus system, comprising:
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assigning a priority to each message containing data sought to be transmitted by the user units; dynamically modifying, during the operation of the bus system, the priority assigned to each message; categorizing each message into one of a plurality of equivalence classes; assigning a priority to each equivalence class, the assigned priority corresponding to a highest priority of any message in that equivalence class; and dynamically modifying, during the operation of the bus system, the priority of at least one particular equivalence class after a message transmission, wherein; the priority is reduced if at least one of;
any message of the particular class was the message transmitted, or any message of the particular class could have been the message transmitted;the priority is maintained if no message of the particular class could have been transmitted, independent of the priority of the particular class; and the priority is raised if no message of the particular class could have been transmitted, but at least one message of the particular class could have been transmitted if the particular class had had a higher priority. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A communications system, comprising:
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a bus system; at least two user units connected by the bus system for exchanging messages containing data; a means for assigning a priority to each message and dynamically modifying, during the operation of the bus system, the priority assigned to each message; means for categorizing each message into one of a plurality of equivalence classes; means for assigning a priority to each equivalence class, the assigned priority corresponding to a highest priority of any message in that equivalence class; and means for dynamically modifying, during the operation of the bus system, the priority of at least one particular equivalence class after a message transmission, wherein; the priority is reduced if at least one of;
any message of the particular class was the message transmitted, or any message of the particular class could have been the message transmitted;the priority is maintained if no message of the particular class could have been transmitted, independent of the priority of the particular class; and the priority is raised if no message of the particular class could have been transmitted, but at least one message of the particular class could have been transmitted if the particular class had had a higher priority. - View Dependent Claims (13)
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14. A bus system, comprising:
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a bus; and at least two user units connected to the bus, the bus facilitating exchange of messages containing data between the two user units; wherein a priority is assigned to each message, the assigned priority being dynamically modified during the operation of the bus; wherein each message is categorized into one of a plurality of equivalence classes; wherein a priority is assigned to each equivalence class, the assigned priority corresponding to a highest priority of any message in that equivalence class; and wherein, during the operation of the bus system, the priority of at least one particular equivalence class is dynamically modified after a message transmission, wherein; the priority is reduced if at least one of;
any message of the particular class was the message transmitted, or any message of the particular class could have been the message transmitted;the priority is maintained if no message of the particular class could have been transmitted, independent of the priority of the particular class; and the priority is raised if no message of the particular class could have been transmitted, but at least one message of the particular class could have been transmitted if the particular class had had a higher priority.
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15. A computer-readable storage element for a first user unit of a communications system exchanging data via a bus system with at least one additional user unit, contents of the computer-readable storage element causing a computing element of the first user unit to perform the following steps:
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assigning a priority to each message containing data sought to be transmitted by the user units; dynamically modifying, during the operation of the bus system, the priority assigned to each message; categorizing each message into one of a plurality of equivalence classes; assigning a priority to each equivalence class, the assigned priority corresponding to a highest priority of any message in that equivalence class; and dynamically modifying, during the operation of the bus system, the priority of at least one particular equivalence class after a message transmission, wherein; the priority is reduced if at least one of;
any message of the particular class was the message transmitted, or any message of the particular class could have been the message transmitted;the priority is maintained if no message of the particular class could have been transmitted, independent of the priority of the particular class; and the priority is raised if no message of the particular class could have been transmitted, but at least one message of the particular class could have been transmitted if the particular class had had a higher priority. - View Dependent Claims (16)
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17. A computer program for execution by a computing element of a first user unit of a communications system exchanging data via a bus system with at least one additional user unit, the computer program performing the following steps:
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assigning a priority to each message containing data sought to be transmitted by the user units; dynamically modifying, during the operation of the bus system, the priority assigned to each message; categorizing each message into one of a plurality of equivalence classes; assigning a priority to each equivalence class, the assigned priority corresponding to a highest priority of any message in that equivalence class; and dynamically modifying, during the operation of the bus system, the priority of at least one particular equivalence class after a message transmission, wherein; the priority is reduced if at least one of;
any message of the particular class was the message transmitted, or any message of the particular class could have been the message transmitted;the priority is maintained if no message of the particular class could have been transmitted, independent of the priority of the particular class; and the priority is raised if no message of the particular class could have been transmitted, but at least one message of the particular class could have been transmitted if the particular class had had a higher priority. - View Dependent Claims (18)
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Specification