{"action":"created","issue":{"url":"https://api.github.com/repos/cyoung/stratux/issues/216","labels_url":"https://api.github.com/repos/cyoung/stratux/issues/216/labels{/name}","comments_url":"https://api.github.com/repos/cyoung/stratux/issues/216/comments","events_url":"https://api.github.com/repos/cyoung/stratux/issues/216/events","html_url":"https://github.com/cyoung/stratux/issues/216","id":128028433,"number":216,"title":"Is there a “switch” to disable UAT Dongle Power Saving?","user":{"login":"Axtel4","id":15059010,"avatar_url":"https://avatars.githubusercontent.com/u/15059010?v=3","gravatar_id":"","url":"https://api.github.com/users/Axtel4","html_url":"https://github.com/Axtel4","followers_url":"https://api.github.com/users/Axtel4/followers","following_url":"https://api.github.com/users/Axtel4/following{/other_user}","gists_url":"https://api.github.com/users/Axtel4/gists{/gist_id}","starred_url":"https://api.github.com/users/Axtel4/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Axtel4/subscriptions","organizations_url":"https://api.github.com/users/Axtel4/orgs","repos_url":"https://api.github.com/users/Axtel4/repos","events_url":"https://api.github.com/users/Axtel4/events{/privacy}","received_events_url":"https://api.github.com/users/Axtel4/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":9,"created_at":"2016-01-21T21:54:02Z","updated_at":"2016-01-22T18:41:18Z","closed_at":null,"body":"1. Stratux version: 0.5b5\r\n2. Stratux config: single/**dual** SDR, GPS **yes**/no (type?), AHRS **yes**/no, battery, battery cable.\r\n3a. EFB app and version: DroidEFB / Avare \r\n3b. EFB platform: Android KitKat / Lollipop \r\n3c. EFB hardware: ASUS Tablet / LG G3\r\n4. Description of your issue. \r\nI have been analyzing the performance of Stratux (see issue 203).  The 1090ES analysis has gone well, but I have observed some anomalies with 978UAT.  While observing the performance I have noticed that the reception of UAT has decreased since the release of 0.5b3.  With 0.5b3 Stratux appears to take longer to acquire tower and display the data.  A switch for the “power save” feature would aid in analyzing Stratux performance. \r\n\r\nBackground:\r\nAt my location I have an antenna mounted outside for UAT reception.   I am also on the edge of the reception range for the closest tower so this allows for the observation of low signal performance.  Based on the data I have examined, I appear to have less than 6 dB of Link Margin at my location.  With this margin it doesn’t take much to vary between having tower reception and no tower reception.  At L-Band frequencies reception can be affected by following losses: the amount of moisture in the air, tropospheric ducting, or Freznel Path Loss in addition to the natural path loss.  Each of these losses can push the received signal level below the MSD (Minimum Discernible Signal) threshold for the subject receiver.  \r\n\r\nBased in what I glean from the code and the Stratux log the new power settings cycle the 978 UAT dongle in 100 second cycles with 50 second “sleep” intervals and 50 second “parse” intervals.  If it doesn't parse data during the 50 second “wake” cycle it goes back to sleep until the next wake cycle.  If it receives a signal it “stays awake” until the signal is lost and reverts back to the power saving cycles.\r\n\r\nMy observation is, when receiving signals close to the SDR noise floor (MDS) there doesn't appear to be enough data to achieve a valid parse to keep the SDR awake. I have seen it take up to 45 minutes before it sees a signal that persists long enough for it to process and display the data.  I have also observed it acquire the tower data faster (a matter of minutes) if stronger UAT traffic happens to fly by my location.\r\n\r\nWorking Theory:\r\nIt may be that when receiving a stronger UAT signal the “channel is left open” thus allowing Stratux to see the weaker Tower Signal without the sleep interruptions.  However, with a signal at the MSD level, there is not enough data decided to keep the UAT dongle “awake.”\r\n\r\nIf Stratux is in an area of high UAT traffic the sleep mode may not be that much of an issue. However, if in the western parts of the US or other areas where UAT traffic is sparse, it may take a long time for Stratux to decode and display UAT traffic or tower data. This may appear to some users as, “my UAT dongle is operating poorly.”\r\n"},"comment":{"url":"https://api.github.com/repos/cyoung/stratux/issues/comments/174005416","html_url":"https://github.com/cyoung/stratux/issues/216#issuecomment-174005416","issue_url":"https://api.github.com/repos/cyoung/stratux/issues/216","id":174005416,"user":{"login":"Ergonomicmike","id":15025888,"avatar_url":"https://avatars.githubusercontent.com/u/15025888?v=3","gravatar_id":"","url":"https://api.github.com/users/Ergonomicmike","html_url":"https://github.com/Ergonomicmike","followers_url":"https://api.github.com/users/Ergonomicmike/followers","following_url":"https://api.github.com/users/Ergonomicmike/following{/other_user}","gists_url":"https://api.github.com/users/Ergonomicmike/gists{/gist_id}","starred_url":"https://api.github.com/users/Ergonomicmike/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Ergonomicmike/subscriptions","organizations_url":"https://api.github.com/users/Ergonomicmike/orgs","repos_url":"https://api.github.com/users/Ergonomicmike/repos","events_url":"https://api.github.com/users/Ergonomicmike/events{/privacy}","received_events_url":"https://api.github.com/users/Ergonomicmike/received_events","type":"User","site_admin":false},"created_at":"2016-01-22T18:41:18Z","updated_at":"2016-01-22T18:41:18Z","body":"A switch in the next beta, accessible via the WebUI, would allow me to A/B in flight over remote parts of the desert SW and gather empirical data. Perhaps the log files should also be modified to know when power saving is on/off. That way, a smart guy looking at the logs could see if there's any night/day difference in receive rates when power saving is on/off."}}