Ashin Walpola
d107534eb2
obu-firmware builds against the vanetza-idf C-ITS library, which until now came from the colleague's microbu-esp32c5 tree beside the repository and was not tracked here, so a clone of this repository could not build the firmware it ships. The library alone is now part of obu-firmware, as obu-firmware/external/vanetza-idf: their external/vanetza-idf at commit cf4b99f, unchanged (9775 files; see its PROVENANCE.md). CMake takes it from there by default; -DVANETZA_IDF_DIR still points the build elsewhere. The rest of the colleague's tree (their own VAM firmware, PKI tooling, station-link Python tools, the V2X2MAP bridge) stays out of this repository and gitignored; nothing is pushed to their repository. NOTES.md, docs/06, TODO.md and the pcap verifier's usage line point at the new location.
34 lines
950 B
C++
34 lines
950 B
C++
#include "transmission.hpp"
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#include <chrono>
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namespace vanetza
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{
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namespace dcc
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{
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Clock::duration Transmission::channel_occupancy() const
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{
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using namespace std::chrono;
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// assume 6 Mbps as default data rate
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const access::DataRateG5* rate = data_rate() ? data_rate() : &access::G5_6Mbps;
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// PHY
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static const auto phy_preamble = microseconds(32);
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static const auto phy_signal = microseconds(8);
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// MAC
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static const std::size_t bytes_epd = 2; // EtherType Protocol Discrimination (no LLC!)
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static const std::size_t bytes_mac = 34; // 802.11 MAC header
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const std::size_t bytes = rate->data_length(body_length() + bytes_epd + bytes_mac);
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const double seconds_per_byte = 1.0 / (rate->bytes_per_second());
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const duration<double> data_duration { bytes * seconds_per_byte };
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return phy_preamble + phy_signal + duration_cast<microseconds>(data_duration);
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}
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} // namespace dcc
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} // namespace vanetza
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