La Sperimentazione White Spacesin PiemonteApplicazioni per Reti Veicolari                                  Claudio Casetti...
Goals¤  ITS (Intelligent Transportation Systems) environment¤  Design a roadside downloading application for vehicles   ...
Starting Point¤  VICSUM project  ¤  funded by Regione Piemonte in 2007-09  ¤  partners: Politecnico di Torino, CSP, CRF...
Network Architecture¤  Infrastructure   ¤  Central Controller (CC)   ¤  Roadside Units (RSU)   ¤  Long-Range Unit (LRU...
Network Architecture¤  Control Plane  ¤  Common channel shared by CC (though LRU) and Vehicle      OBUs      (700 MHz)  ...
The LFT Protocol¤  We designed and implemented a communication    protocol called Locate-Fetch-Transfer (LFT)¤  LFT oper...
LFT Protocol Overview (1)¤  Vehicle notifies to CC over    700 MHz link:   ¤  own position   ¤  content requests¤  CC ...
LFT Protocol Overview (2)¤  When moving out of RSU    coverage, the download stops¤  RSU reports the outcome of    the d...
The Test¤  The OBU requests the download of a 200-MB file¤  The download is completed over several “contacts”    with RS...
The Test¤  Preliminary tests at Villa Gualino (Torino)   ¤  Signalling traffic on a 2.4-GHz (802.11b) channel   ¤  Data...
Val di Viù Testbed
Results                                         20 km/h                                                                   ...
Comparison with simple transfer            Our protocol: 7 contacts needed to transfer content      Access Point       AP1...
Conclusions¤  LFT is not a Cognitive Radio application but could work    with any CR system¤  Sustained throughput compa...
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La Sperimentazione White Spaces in Piemonte Applicazioni per Reti Veicolari

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Giornata di studio sui White Spaces, che si è tenuta lunedì 24 ottobre 2011, 9.30 - 17.00 – Sala Agorà, Incubatore d’Imprese Innovative del Politecnico di Torino (I3P).

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La Sperimentazione White Spaces in Piemonte Applicazioni per Reti Veicolari

  1. 1. La Sperimentazione White Spacesin PiemonteApplicazioni per Reti Veicolari Claudio Casetti Dipartimento di Elettronica Politecnico di Torino
  2. 2. Goals¤  ITS (Intelligent Transportation Systems) environment¤  Design a roadside downloading application for vehicles with prefetching of content¤  Exploit long-range UHF coverage for signalling traffic (vehicle position, content requests)¤  Exploit short-range, high-bandwidth 5GHz links for content downloading
  3. 3. Starting Point¤  VICSUM project ¤  funded by Regione Piemonte in 2007-09 ¤  partners: Politecnico di Torino, CSP, CRF¤  The VICSUM legacy ¤  Hand-on expertise in VANETs ¤  Designing mobile applications ¤  Living testbeds (Villa Gualino) ¤  The “VICSUM cars”
  4. 4. Network Architecture¤  Infrastructure ¤  Central Controller (CC) ¤  Roadside Units (RSU) ¤  Long-Range Unit (LRU) ¤  Vehicle On-Board Units (OBU) RSU1 RSU2
  5. 5. Network Architecture¤  Control Plane ¤  Common channel shared by CC (though LRU) and Vehicle OBUs (700 MHz) ¤  High-bit rate communication on point-to-point link between CC and RSU¤  User Plane ¤  RSU to vehicles OBU communication (5 GHz)
  6. 6. The LFT Protocol¤  We designed and implemented a communication protocol called Locate-Fetch-Transfer (LFT)¤  LFT operates among RSUs, CC and OBUs¤  LFT incorporates control and user plane
  7. 7. LFT Protocol Overview (1)¤  Vehicle notifies to CC over 700 MHz link: ¤  own position ¤  content requests¤  CC fetches requested content and dispatches it to the nearest RSU RSU1 RSU2¤  Vehicle associates to RSU and downloads as much as possible
  8. 8. LFT Protocol Overview (2)¤  When moving out of RSU coverage, the download stops¤  RSU reports the outcome of the download¤  If incomplete, the CC schedules the download to continue at the next RSU RSU1 RSU2¤  Remaining file is dispatched to the next RSU
  9. 9. The Test¤  The OBU requests the download of a 200-MB file¤  The download is completed over several “contacts” with RSUs¤  We measured ¤  the number of contacts to complete the transfer ¤  the coverage time ¤  the achieved throughput
  10. 10. The Test¤  Preliminary tests at Villa Gualino (Torino) ¤  Signalling traffic on a 2.4-GHz (802.11b) channel ¤  Data channel on a 5-GHz (802.11a) channel¤  Final tests in Val di Viù
  11. 11. Val di Viù Testbed
  12. 12. Results 20 km/h 40 km/h 25 25 vehicle request and vehicle configuration vehicle request and vehicle configuration vehicle configuration vehicle configuration 20 20 Throughput [Mbps]Throughput [Mbps] 15 15 10 10 5 5 0 0 0 100 200 300 400 500 600 700 0 200 400 600 800 1000 1200 Time [s] Time [s]
  13. 13. Comparison with simple transfer Our protocol: 7 contacts needed to transfer content Access Point AP1 AP2 AP2 AP1 AP1 AP2 AP2# of downloaded chunks from the CC 35000 35000 35000 35000 35000 35000 18494# of downloaded chunks 32850 30430 24750 18686 12650 28950 18494 Coverage time [s] 39 32 41 48 33 31 20 Throughput [Mb/s] 8.33 9.4 5.97 3.85 3.79 9.23 9.14 Simple transfer: 10 contacts needed to transfer content Access Point AP1 AP2 AP2 AP1 AP1 AP2 AP2 AP1 AP1 AP2# of downloaded chunks from the CC 35000 35000 35000 35000 35000 35000 35000 35000 35000 17379# of downloaded chunks 17890 22887 26080 21261 29190 19903 32574 27438 26555 17379 Coverage time [s] 38 40 48 46 35 36 40 38 39 21 Throughput [Mb/s] 3.68 3.77 5.37 3.75 6.41 3.45 7.81 5.8 5.39 4.52
  14. 14. Conclusions¤  LFT is not a Cognitive Radio application but could work with any CR system¤  Sustained throughput comparable to ADSL speeds to mobile users¤  Use of today’s technology¤  Future work: lots of optimization to do!

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