Tr@Ins4 Onboard Communication Frederik Vermeulen

  • 616 views
Uploaded on

 

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
616
On Slideshare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
3
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Onboard communication Frederik Vermeulen (f.vermeulen@televic.com) Televic NV
  • 2. Mobility scenarios Mobility scenarios Legend: E D D F B B B B A A C C C Legend A: personal WiFi device D: vehicle wireless connection point B: on-board WiFi hotspot E: way-side wireless connection point C: on-board services switch F: station WiFi hotspot
  • 3. Mobility scenarios (1) Mobility scenarios (1)  User moving inside train E D B B2 B3 1 A C C C E D B B2 B 1 3 A C C C
  • 4. Mobility scenarios (2)  Train moving -> handover E D D F B1 B2 B3 B A A C C C
  • 5. Mobility scenarios (3)  User leaving the train D F D F B B A A
  • 6. Tr@ins architecture Train management Internet AAA NAT Mobility DHCP Management Mobility Management Local content 6
  • 7. Onboard network components Train Train Switch Switch WiFi WiFi WiFi WiFi WiFi WiFi BS BS BS BS BS BS Mobility On-board server: Management - voice/video communication, passenger information, entertainment - content server - web, mail cache - TCP accelerator Wayside - crew authentication, gateway link - train management (TCMS) interface technologie s
  • 8. Onboard use cases Seamless connectivity and Quality of Service for - crew moving through the train - passengers moving through the train I. Moerman, B. Jooris, A. Schoutteet, F.Vermeulen 8
  • 9. Applications on train Applications Passengers + Crew • on-board content • e-ticketing (web/MM) • maintenance, man • email • CCTV • internet • video/audio streaming • VoIP
  • 10. Two layer 2 handovers  Vertical handovers when a crew terminal switches between the wired and the wireless connection WLAN Satellite G PR S AP x A P- A P- A P- MAR A P- A P- BS A P- BS BS A PP-- A x OSS OSS OSS content WL AN Satellite GP RS AP x A P- A P- A P- MAR A P- A P- BS A P- BS BS A PP-- A x OSS OSS OSS content
  • 11. Two layer 2 handovers  Horizontal handover when a user is moving inside the train WLAN Satellite G PR S AP x A P- A P- A P- MAR A P- A P- BS A P- BS BS AAPP-- x OSS OSS OSS content WL AN Satellite GP RS A P- AP x A P- A P- MAR A P- A P- BS A P- BS BS AAPP-- x OSS OSS OSS content
  • 12. Connectivity requirements Requirements  bandwidth  latency (< 50 ms for voice)  continuous connectivity (=guaranteed <50ms latency at handover) available solutions 500 ms  compatible with standards 802.3, 802.11
  • 13. Vertical handover: wired-wireless Convergence layer: 1 Device Operating principle HS1 HS2 OK1 OK2 PS COL- 1 2 3 4 5 6 7 8 910 12 11 Switch CONSOLE  One virtual interface ACT- STA- Gratuitous ARP  One MAC and one IP address ETH WLAN MAC MAC CL-MAC Decision module CL-IP 1 Interface
  • 14. Horizontal handover  Visualization of the horizontal handover  MAP.html
  • 15. Horizontal handover  BS = AP + extra functionality  Extra WLAN NIC (passive)  listens to neighbor channel  info per received Terminal  the MAC address  a flag passive/active  list with the last received RSSIs  time of the last received packet  IP address  IP address of the BS  RSSI per neighbor  Inter BS protocol  Terminal info protocol p. 15
  • 16. Details: horizontal handover  Vendor independent software package Channel of the RSSI of terminal terminal measured on the serving BS RSSI of terminal measured on the neighbor BSs, with their Sends beacons to the access channels network every X ms
  • 17. Demo setup P BS X A Asterisk Terminal Switch P P A A BS Z BS Y
  • 18. Evaluation • Sending 20Mb/s UDP with iPerf from server to terminal • Simulate motion → handoff every 15 seconds • Average of 15 lost packets per handoff • Lost packets ranged from 10 to 50 packets • 30 of the 37 handoffs → less 14 lost packets • Results in < 10ms disconnection time Content SB ATT 4:1 2:1 Attenuation BS A 1 Terminal ATT 1-2 X 2 in SB ATT 3-4 P ATT 5-6 BS A 3 Time Y P 4 BS A 5 Z Switch P 6
  • 19. Quality of Service onboard the train BS OSS Provide QoS for Crew and Passenger applications
  • 20. QoS AP with dynamic mapping of 5 Access Classes to 4 Access Queues AP / Crew node Public node Access Queues: Access Access Queues: • AQ_VO Classes: • AQ_VI • Alarm • AQ_VO • AQ_BE • Voice • AQ_VI • AQ_BK • Video • AQ_BE • AQ_BK • Best Effort • EDCA parameters provided by QAP: Background CWmin[A CWmax[A AIFS[AC TXOP[A AC C] C] ] C] Alarm 1 2 1 2048 ms Voice 2 3 1 1504 ms Video 3 4 2 3008 ms Best 4 10 3 2048 ms Effort Backgrou 4 10 7 0 nd
  • 21. QoS results: Public and Crew Video, Downlink Two Public video streams One Public and one Crew video stream 100 100 90 90 80 80 % of Maximal Throughput AC_VI % of Maximal Throughput 70 70 60 60 AC_VI 50 50 40 40 30 30 20 AC_VI AC_VI AC_VI 20 AC_VI AC_BE AC_VI 10 10 0 0 1 11 21 31 41 51 61 71 81 91 101 111 121 131 141 151 161 171 1 11 21 31 41 51 61 71 81 91 101 111 121 131 141 151 161 171 181 Time (s) time (s) Public Video Traffic Stream 1 Public Video Traffic Stream 2 Public Video Traffic Stream Crew Video Traffic Stream
  • 22. Conclusions  Onboard voice communication and multimedia have strict requirements  Fast handover: new mechanisms developed  QoS: dynamic class mappings  Layer 2 solutions for onboard network  scope of onboard communication provider  compatible with standard terminals
  • 23. Q&A & Demo