I would like to capture the lat/lon coordinates from a GPS-enabled cell phone or PDA. Is this possible? Must I subscribe to this information from the cellphone network provider, or can I capture it without charge? What devices will broadcast the coordinates? Is there a device that will broadcast its position inband that can be captured by Asterisk? Can an SMS message include coordinates? The subject will willingly carry the device and will be aware that his location is being monitored, so privacy rights are not an issue. The subject will make periodic calls to the Asterisk server in order to record his movements. Does anyone have experience in this area? Thanks, Mike -- Michael Welter Telecom Matters Corp. Denver, Colorado US +1.303.414.4980 mike@TelecomMatters.net www.TelecomMatters.net
> I would like to capture the lat/lon coordinates from a GPS-enabled cell > phone or PDA. Is this possible? Must I subscribe to this information > from the cellphone network provider, or can I capture it without charge? > > What devices will broadcast the coordinates? Is there a device that > will broadcast its position inband that can be captured by Asterisk? > Can an SMS message include coordinates? > > The subject will willingly carry the device and will be aware that his > location is being monitored, so privacy rights are not an issue. The > subject will make periodic calls to the Asterisk server in order to > record his movements. > > Does anyone have experience in this area?Its my understanding the cell phone coordinates are sent to the cell phone provider and their equipment reads (and holds) that data. Its not part of any data available to you in any form unless you talk to the cell provider and convience them you have a valid need. Highly unlikely in the US anyway. Even if you could convience them to provide it, they would likely demaand some sort of out-of-band data transmission facility.
In the US, Sprint's CDMA network will do the fancy GPS+AFLT business, but like someone else mentioned, it only sends the location data back to Sprint's network. There is an API that you can use to access this data for your handsets, but you have to pay some amount of money for each location fix. Sprint's iDEN phones (formerly Nextel) contain GPS units that can be accessed from the phone's serial port, and I am pretty sure that the GPS data can be accessed from a J2ME applet running in the phone. Such an applet could then make an appropriate HTTP request to a web/app server you run, in order to upload the data. However, the GPS data received using this method is obtained using _only_ GPS, with no AFLT or other form of assistance from the cellular network. The significance of that, of course, is that you will not be able to get a GPS fix in locations where a "regular" GPS receiver can't get a fix, such as indoors in most cases. -Rusty On 2/23/06, Michael Welter <mike@telecommatters.net> wrote:> I would like to capture the lat/lon coordinates from a GPS-enabled cell > phone or PDA. Is this possible? Must I subscribe to this information > from the cellphone network provider, or can I capture it without charge? > > What devices will broadcast the coordinates? Is there a device that > will broadcast its position inband that can be captured by Asterisk? > Can an SMS message include coordinates? > > The subject will willingly carry the device and will be aware that his > location is being monitored, so privacy rights are not an issue. The > subject will make periodic calls to the Asterisk server in order to > record his movements. > > Does anyone have experience in this area? > > Thanks, > Mike > > > -- > Michael Welter > Telecom Matters Corp. > Denver, Colorado US > +1.303.414.4980 > mike@TelecomMatters.net > www.TelecomMatters.net > _______________________________________________ > --Bandwidth and Colocation provided by Easynews.com -- > > Asterisk-Users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users >
Date: Fri, 24 Feb 2006 14:56:54 +0000 From: Steve Kennedy <steve-asterisk@gbnet.net> Subject: Re: [Asterisk-Users] GPS-enabled cell phone/PDA On Fri, Feb 24, 2006 at 07:17:52AM -0600, Rich Adamson wrote:>> Its my understanding the cell phone coordinates are sent to the cell phone >> provider and their equipment reads (and holds) that data. Its not part >> of any data available to you in any form unless you talk to the cell >> provider and convience them you have a valid need. Highly unlikely in >> the US anyway. Even if you could convience them to provide it, they >> would likely demaand some sort of out-of-band data transmission facility. > >GSM networks have the Cell ID available to the phone, however that's not much use without the location of the cellsite. There are now location based services, whereby you can query the network and they'll give out an approximate location (most cells are sectored [6 sectors per cell) which gives a direction, the cell also knows what power the phone is transmitting with, and the power it's received so can make a good approximation of where the phone is (within 60 degrees angle). However it's likely a phone will be picked up by several cells, so the network can triangulate and make a better aproximation. Making the information available to end-users is problematic due to privacy issues, unless the user explicitly agrees to give the info away. With GPS units, the info is stored in the phone and can send it out using SMS or other means. ------------- It was my impression that only a handful of cellphones have full GPS units in them. Benefon and some Motorola units made for the former Nextel come to mind. The Benefon units do send SMS reports, and in fact, I have written code to control and track these units via SMS using a Nokia 31 GSM terminal. Unfortunately, aside from their unique GPS/SMS capability, the Benefons are not very attractive products, in my opinion. And they are expensive. The Motorola units contain Java machines and a well defined API for accessing the location data. I have not worked with them. There have undoubtedly been changes in the marketplace since I did this work about 2 years ago. As I understand it (but don't have thorough knowledge and could be mistaken), other units generally only receive GPS satellite signals and relay the data to cellular provider networks where the actual location calculation is done. This can be done with assistance of data obtained based on tower proximity, which jumpstarts the iterative process of approximation. I think it is called assisted GPS or some such... -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20060224/323b7f93/attachment.htm