Bus Tracker

Transcript

1. Bus  Tracker   Erik  Brännström   Jakob  Hägg   Julia  Ramstedt   Jens  Björk   Max  Edstam   Jens  Ljungblad  
2. System  description   •  Auckland  Regional  Council   •  Track  public  transportaAon  vehicles   •  Expected  high  performance  and  availability  
3. Architectural  overview   •  Three  subsystems   1.  Vehicle  posiAoning  system   2.  Central  system   3.  Display  system   •  1  and  3:  distributed,  keep  simple   •  2:  centralized,  high  performance,   maintainable  
4. Architectural  approaches   •  Client-­‐server:  Simple  distributed  clients,   advanced  centralized  server   •  Blackboard:  Display  data  processes  consumes   informaAon  produced  by  tracking  system   •  Heartbeat:  Workload  divided  by  two  separate   systems,  one  takes  over  in  case  of  heartbeat   failure   •  COTS:  Database  will  be  bought  off  the  shelf  and   outsourced  for  high  performance;  high  service   and  data  availability  
5. Quality  requirements   •  Performance   –  Client-­‐server  and  auxiliary  computer  systems   •  Availability   –  Heartbeat  between  auxiliary  systems  and  dependable   database  system   •  Security   –  Public-­‐key  cryptography  for  radio  communicaAons   •  Maintainability   –  Client-­‐server,  which  centralizes  most  of  the  workload   to  one  locaAon  
6. Risks   •  Computer  system  breaks  down   – MiAgated  using  redundant  systems   •  Central  system  radio  receivers  become   boWlenecks   – Divide  transmissions  into  a  number  of  frequencies   and  use  mulAple  receivers   •  Bus  routes  change   – Locate  such  data  in  the  central  system