Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
  • H04L12/40—Bus networks
  • H04L12/407—Bus networks with decentralised control
  • H04L12/417—Bus networks with decentralised control with deterministic access, e.g. token passing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W28/00—Network traffic management; Network resource management
  • H04W28/16—Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
  • H04L12/40—Bus networks
  • H04L12/40143—Bus networks involving priority mechanisms
  • H04L12/40156—Bus networks involving priority mechanisms by using dedicated slots associated with a priority level
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
  • H04L12/40—Bus networks
  • H04L2012/40208—Bus networks characterized by the use of a particular bus standard
  • H04L2012/40241—Flexray
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
  • H04L12/40—Bus networks
  • H04L2012/40267—Bus for use in transportation systems
  • H04L2012/40273—Bus for use in transportation systems the transportation system being a vehicle

Definitions

• a bus system is the unit of transmission medium and the bus controllers connected to it.
• Electronic Control Units (ECUs) are connected to bus systems via bus controllers, enabling them to transfer data to the bus or to listen to data from the bus.
• bus controllers To transfer data, the bus controllers must have exclusive access to the transmission medium. At any one time, only a single bus
• bus systems In order to coordinate the media access of the bus controllers, bus systems usually realize different media access methods (Medium Access Control, in short:
• the standardized FlexRay bus system uses a media access method that establishes a fixed, cyclic time frame on the transmission medium and assigns individual time slices to individual communication users. These can use their allocated and cyclically recurring time slice to send their messages or leave the allocated time slot unused.
• the likewise standardized bus system CAN uses a media access method, which assigns fixed priorities to individual message types. In competitive situations each one receives Communication party Transmission right, whose message has the highest priority of all competing messages.
• a bus system is a special case of a communication system. These are generally devices for supporting the transmission of information.
• QoS Quality of Service
• Resources unused by communication parties during runtime of the communication system are usually not otherwise used and remain unused.
• EP 1 061 671 A2 discloses an allocation of transmission resources in a message transmission system. A control center is informed by a communication partner that he only a reduced
• Time slots in the time frame are allocated to the communication participants, unused time slots are shortened in duration, which additional time slots can be accommodated in the time frame, the communication participants dynamically in particular
• Spontaneously unused resources at runtime can be assigned to other connections and thus the usage intensity of the communication system can be increased. Likewise, connections may be necessarily restricted in their resource consumption.
• the central entity is not dependent on it receiving a communication from a communication subscriber about a reduced resource requirement. She decides when and to whom she allocates extra time slots.
• the resource allocation or allocation of the time slots can be adapted to the different communication needs.
• the allocation of time slots within the time frame can be done depending on the priority. This ensures that high-priority communication needs are always taken into account.
• the time slot assignments are advantageously sent via control messages to the communication participants.
• a reallocation takes place only after a following control message. This reduces the control and data exchange overhead.
• each class can be assigned its own quality parameter set. As a result, a separate parameter set does not have to be evaluated for each connection. This facilitates the evaluation and calculation in the central instance.
• the time slots are formed advantageously identifiable. This is the
• the method according to the invention can be advantageously integrated into a FlexRay bus system, whereby existing architectures and agreements can continue unchanged.
• FIG. 1 shows a FlexRay network
• FIG. 2 shows a time frame structure for the communication.
• a communication system which can be used for the invention has the following properties:
• the communication system establishes a communication cycle of at least temporary fixed duration
• the established cycle is divided into any number of time slots
• the timeslots are identifiable, i. they carry unique identifiers. Ideally, this is a consecutive numbering
• Unused time slots are advantageously shortened automatically in terms of their duration, whereby a communication cycle can include a variable number of time slots, since it is of fixed duration.
• a shortening by a central authority can alternatively be made.
• the resource manager which from time to time gives the software applications of the communication participants transmission permissions for messages and thus manages communication system resources.
• the allocation of communication system resources to software applications takes place through the exclusive allocation of time slots.
• the software applications can use the time slots assigned to them for the transmission of each message or even leave time slots unused.
• control messages In order to give the software applications of the communication participants knowledge of which timeslots they have send permissions for, the resource manager sends control messages to them as needed.
• control messages advantageously consist of a list of software
• the interpretation of the control message can then take place according to the following scheme: the nth entry in the list assigns the time slot n of the software application with the identifier specified at this nth list position.
• the control message contains a list with a total of 5 software application identifiers and looks like this: R, K, U, E, K.
• Application R receives a transmission authorization for time slot 1
• Application K receives send permissions for time slots 2 and 5 Application U receives a transmission authorization for time slot 3
• Application E receives a transmission authorization for time slot 4
• the first n entries contain the consecutive numbers or number ranges of the time slots for the first software application, the next m entries accordingly for the second software application, etc.
• the resource manager can additionally change the duration of the communication cycle and thereby change the number of time slots in a cycle.
• the communication system can be adapted even more efficiently to changing communication needs.
• time slots persists until the resource manager makes a new allocation. With each new communication cycle, the time slots are again redone, are cyclic transmit permissions that persist until a subsequent control message indicates a reassignment of the time slots.
• the Resource Manager has system-wide knowledge of the communication requirements of the individual software applications and can change the allocation of time slots to the software applications at any time, thus meeting the time-varying requirements of individual software applications.
• Additional data rate requirements can be met, for example, by allocating additional time slots, and by reducing the frequency of individual time slots.
• the resource manager is realized with extended functionality. In its expanded form, it does not identify the participants alone
• connection quality QoS For each individual connection, he manages information regarding them to be provided connection quality QoS. This can be specified by a fixed parameter set. Possible parameters are:
• the resource manager can now carry out calculations for the optimal allocation of communication system resources to software applications and the calculation results are transmitted to the software components.
• the resource manager points within the communication
• a communication cycle i. a timeframe that takes 500 milliseconds. unused
• Time slots take exactly 2 milliseconds, time slots used for data transmissions exactly 10 milliseconds. If all time slots remain unused, the cycle thus comprises 250 time slots. If, on the other hand, all time slots are used for data transmissions, the cycle comprises only 50 time slots. Each cycle thus comprises at least 50 and a maximum of 250 timeslots. The assignment of time slots 51 to 250 to software
• Range of time slots to provide those connections which in terms of their QoS parameters the least demands on the communication system.
• Assignment be made. This can replace the prioritized assignment at least at predetermined time intervals, so that low-priority connections are not completely excluded from a communication.
• the resource manager has an evaluation and control device that can detect idle capacities in a timeframe and that can provide these idle capacities in the form of additional time slots to communication users with increased communication needs.
• Procedures of dynamic resource allocation by a central RM can not be realized, can be reliably integrated by means of a supplementary extension of the method.
• the provided by the communication system Time slots divided into two groups. While for the one group of time slots, the assignment to software applications as described above at runtime by the resource manager is made, the time slots of the other group are already committed at the time of development to those software applications that do not realize the method described here , At runtime, the resource manager has knowledge of which timeslots he can dynamically allocate and which are out of his control because they were already statically assigned at the time of development.
• ECU 200 carries the software applications 500 and 501, ECU 201 the software application 502, and ECU 202 the software applications 503 and 504 as well
• the software application "Resource Manager" 600 the software application "Resource Manager" 600.
• Software application 502 is an application that does not implement the method described here and only wants to use the FlexRay bus system for processing data exchange in a conventional manner.
• the communication cycle of the FlexRay bus system is divided into a static and a dynamic segment.
• the method described here should be applied to the dynamic segment. It should be noted at this point that the static segment of the FlexRay communication cycle does not correspond to the characteristics of the communication system set out above.
• the dynamic segment of the FlexRay communication cycle is now configured at design time to take i milliseconds.
• An unused and thus shortened time slot takes i / 6 milliseconds, a used time slot takes i / 2 milliseconds.
• Software application 502 already receives an arbitrary, but in this example the first timeslot fixed and exclusively assigned at the time of development.
• the Resource manager 600 has the task of assigning the remaining 6 -1 time slots to the software applications at runtime.
• the resource manager 600 after powering up the system, sends a control message with the contents: 500, 501, 501, 503, 504.
• the ECUs 200 and 202 receive and evaluate this control message.
• the following assignment of time slots to software applications results:
• FIG. 2 schematically shows the length of the time slots used by the applications and the length of the unused time slots.
• the first time frame is marked N and the next time frame is N + 1.
• the resource manager 600 has made the assignment of the time slots exactly so that exactly those messages could be transmitted whose transmission has generated the greatest benefit, while exactly those messages were not transmitted whose contribution to the overall benefit would have been less.
• Example 3 The resource manager recognizes that only software application 504
• the resource manager recognizes the current (and previously specified) assignment of time slots to software applications as unfavorable and calculates a better allocation.
• the result of the calculation is communicated to the software applications in the form of a control message.
• the control message is: 504, 504, 504, 504, 504.
• time slot 1 which is beyond the control of the resource manager, all available time slots are assigned to the software application 504, which can handle their extensive data transfers therein. All other
• the resource manager according to the invention has an evaluation and control device which is able to detect idle capacities selectively or reactively in a time frame and to make these unused capacities available to selected communication users by allocating additional time slots.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Quality & Reliability (AREA)
• Small-Scale Networks (AREA)
• Time-Division Multiplex Systems (AREA)
• Mobile Radio Communication Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=37999326

Family Applications (1)

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Citations (1)

Family Cites Families (8)

• 2006
  • 2006-01-20 DE DE102006003067A patent/DE102006003067A1/de not_active Withdrawn
• 2007
  • 2007-01-03 US US12/087,802 patent/US20090304021A1/en not_active Abandoned
  • 2007-01-03 KR KR1020087017631A patent/KR20080093998A/ko active Search and Examination
  • 2007-01-03 AU AU2007209418A patent/AU2007209418A1/en not_active Abandoned
  • 2007-01-03 JP JP2008550706A patent/JP2009524308A/ja active Pending
  • 2007-01-03 BR BRPI0707879-0A patent/BRPI0707879A2/pt not_active IP Right Cessation
  • 2007-01-03 WO PCT/EP2007/050032 patent/WO2007085508A1/de active Application Filing
  • 2007-01-03 CN CNA2007800026438A patent/CN101370691A/zh active Pending
  • 2007-01-03 EP EP07703605A patent/EP1979198A1/de not_active Withdrawn

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