08-11-2008 09:10 PM
I have read many docs regarding Criteria selection which try to explain how the various settings affect the mode used but I am not getting the real-world results that I would like. My lock times are still slow as compared with BB maps and I am loosing accuracy.
I would like to use the AGPS modes with fast lock time and accuracy on the order of 0 to 30 meters(ish). Currently my lock times are very high (30 seconds) as compared with BB maps.
Should I set an accuracy for H/V? How does setAlt, SetSpeed affect results? What have other people used and what should I expect from the different combinations?
Here is my Criteria object:
08-12-2008 12:37 AM
My understanding is that cell site and AGPS are only available on CDMA networks (GSM uses a different technology for implemeting e911 functionality, which is where this stuff is from). My testing has shown that Sprint supports it, but others do not (at least not by default).
If others have different experiences, I would also like to hear about it.
08-12-2008 03:39 PM
The following article explains the fix types based on criteria combinations for GSM BlackBerry handhelds. A new article should be posted soon that provides further detail for CDMA devices. When posted, it will appear here: http://www.blackberry.com/knowledgecenterpublic/li
How To - Define criteria to retrieve a GPS fix
Article Number: DB-00461
08-12-2008 04:53 PM
Thanks, I have seen variations of this document (however this one is more clear).
As a follow up. Does anybody know what criteria BB maps is using. A client of mine is complaining that BB maps has a much quicker lock time than my application yet I am using Assisted/Autonomous mode. Without using simple cellcite mode I'm not sure what else I can do.
08-13-2008 10:47 AM
The Criteria that BB Maps uses depends on the device and the carrier. For GSM devices, they use Criteria for defining an autonomous GPS fix, setting costAllowed to false. For CDMA devices, they'll be defining Criteria for MS Based fixes.
Once you've acquired first fix, to ensure that subsequent fixes come in quickly, define your interval to less than or equal to 10 seconds, keeping the chip hot.
08-18-2008 07:44 PM
Thanks. According to the LocationProvider documents provided previously CellSite mode is not supported. Is that a carrier specific or blackberry specific limitation?
costAllowed = TRUE
horizontalAccuracy > 0
powerUsage = LOW
As explained in "JSR179 Criteria -> gpsOne Mode mapping for CDMA devices" (shaque), I understand the CDMA will support other modes that GSM. I am using Rogers (GSM).