: Public <<Protocol>> Class
Created: |
16.04.2018 11:56:53 |
Modified: |
16.04.2018 11:57:33 |
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Project: |
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Author: |
deniz |
Version: |
1.0 |
Phase: |
1.0 |
Status: |
Proposed |
Complexity: |
Easy |
Difficulty: |
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Priority: |
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Multiplicity: |
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Advanced: |
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UUID: |
{0F294185-3124-430f-A031-F4D4E6B5A050} |
Appears In: |
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Intelligent Transport Systems (ITS); Decentralized Congestion Control Mechanisms for Intelligent Transport Systems operating in the 5 GHz range; Access layer part<br/><br/>Description: DCC is a cross layer function, i.e. it has functions located on several layers of the ITS station reference architecture.<br/>Therefore the present document defines which DCC components are located on which layer of the ITS station communication architecture [5]. Furthermore the present document specifies the DCC mechanisms on the access layer (DCC_access) including transmit power control (TPC) per packet, transmit rate control (TRC) and transmit datarate control (TDC). The latter two control functions modify the average transmit power by modifying the duty cycle of the ITS station, i.e. the fraction of time that the ITS station is in "transmit" state. Additionally, DCC sensitivity control (DSC) adapts the clear channel assessment to resolve local channel congestion. Packets with higher priority are handled less restrictive introducing a transmit queueing concept and transmit access control (TAC).<br/>The DCC mechanisms rely on knowledge about the channel. The channel state information is gained using channel<br/>probing. Channel probing measures are defined that enable the DCC methods TPC, TRC and TDC. The measures are on receive signal level thresholds or preamble information of detected packets.<br/>The present document does not define the mechanisms at other layers than the access layer nor defines management aspects. These other mechanisms and the management aspects are necessary in order to make DCC work properly. The present document is primarily intended for trial use and may need to be updated after validation in field trials and/or other projects.<br/><br/>