We can all discuss cell phone pings in this case till we are blue in the face. We cannot compare what was done in other cases because this one is unique.
In most of the links and cases cited, they are discussing when a cell phone is able to communicate. Vallecito Lake is not in the middle of a major city nor is it an area that is flat. We are talking a mountainous area in the middle of nowhere with extremely poor coverage.
The fact is many of us are spoiled when we follow cases, as the information is probably available.
In order for a cell phone to ping either an antenna or tower (please note the word antenna here), the cell phone must be able to communicate with the antenna or the tower.
There are some very fundamental things which must occur in order for a cell phone to talk to an antenna or tower. First the antenna must be pointed in the correct direction.
1. Can anyone tell me what direction these antenna's are facing?
2. Can anyone tell me if there is anything that would block the cell phone signal either man made or natural?
When I drive through the mountains I can tell you exactly where I will lose reception and it is not because there is not an antenna close by. I lose reception because there is a mountain which blocks my cell signal from reaching the antenna which is on the other side of the mountain. As the crow flies this would be about 1 mile.
There are antenna's within a 4 miles radius of MR's home but no towers.
Can anyone here tell me which direction those antenna's face? If they face the wrong direction your cell phone will not be able to communicate with it.
Can anyone tell me if there are any man made or natural things which would block the cell and antenna from talking. If so where are they and what are they?
Can anyone tell me on the night/day in question, if there were any atmospheric disturbances taking place?
Were any masts full? If full, your cell phone signal cannot communicate with it. It then will try to communicate with the next one.
Once these questions are answered then we must look at the type of cell, what the antenna requires, what technology it uses and the list goes on.
LE in this case is facing some unique challenges. What I cannot determine is how unique simply for the fact that the information relies on many variables in this particular case.
I don't believe many are understanding that the problem here is not the fact we have the technology. The problem I see is did this area have the technological abilities many of us are use to.
OK, I was able to get a few hours of sleep, so I think I'll be able to communicate more effectively now. My apologies if I was starting to sound impatient last night/early this morning.
As I stated before, I am NOT a cell phone tech, forensics expert, or anything of the like. I will answer the questions you asked above that I can either explain, or answer, but I'm definitely not going to be able to answer some of the questions you asked as it's just way too technical. Even those with experience in this field have complaints about mistakes made by their own peers (as evidenced in the blog with Forensics in the title that I linked last night).
Here's the thing... A cell phone antenna array is ON a Cell Tower, sometimes they are put on existing towers for radio antenna. Sometimes businesses have antennas on the roof - in which case it's not a "tower" but it works the same as one. EITHER is properly called a "Cell Site" ( [ame="http://en.wikipedia.org/wiki/Cell_site"]Cell site - Wikipedia, the free encyclopedia[/ame] )
Yes, there are many things that can interfere with reception as you stated, mountains and other various geographical features (like going into a canyon) can cause you to lose reception. In fact, sometimes there are anomalies that even cell phone techs and professionals can't figure out.
EXAMPLE: On I-90 in Illinois as it passes Arlington Heights, IL there was a section of highway in which they had coverage overlaps, they put signal boosters on the towers, and STILL there was a section on the highway that was just "dead space". The reason I know this is because they finally had to put up a third tower up IN the "Dead Space" to handle the problem, and that tower was erected on the property of where my husband was working at the time.
You stated that we can't compare Dylan's case to others. I wasn't attempting to do that. I was citing examples of how LE has used saved cell tower ping records to locate a person, a crime scene, to determine if a suspect was in the area of a crime at a given time, etc... This WOULD apply to Dylan's case because these are not things that "change" depending on the case. I was illustrating that the pings are saved whether the phone is in use, or not. That they have records of pings even when the person has not made or received a call, and not made or received a text. Those ping (location ping) records are different from the phone records (when, to whom, and what tower the call connected through, and sometimes what tower was last used in that communication - as explained in previous links). And the tower ping records (when the phone is not in use) can be used to track a person's location historically. (See the Kelsey Smith case, and the case mentioned in the last link I posted last night. Again, these were only examples to illustrate my point.)
I lived in Colorado for about 10 years, so I am personally aware of how bad cell reception can be in the mountains. Heck, I moved back to the mid-west 8 years ago, so when I was there reception was even worse. I remember that the only reception I got on my Sprint phone when we moved to CO in the late 90's was ONLY on the I-70 corridor. So, I remember a time when if you were in the mountains anywhere in the state apart from the I-70 corridor you basically needed a Satellite phone to have any hope of finding service.
I've lived in urban areas (Denver, Chicago Suburbs), and I've lived in more rural areas as well (like Central WI where I live now). The only difference between tracking according to tower pings rural vs. urban is that the radius can be HUGE in rural areas (up to around 700 acres as mentioned in the forensics blog link), or in urban areas sometimes as small as one or two square blocks. Obviously in an urban area they will be able to more accurately pinpoint exact location.
Beyond these basic facts you are correct that we would have to start finding out information we are likely never going to be privy to (service provider, data stream connection speed requirements, specific phone type, did they have a booster antenna on the cell phone as some do if they live in an area with bad reception, does MR have a booster antenna on his roof, what are the specific radii of the cell sites located near MR's house, etc... etc... etc...).
I guess sometimes I just get too wordy and end up confusing people more than helping. The variations in technical terms, knowledge of how radio frequency works, calculating cell site coverage in the presence of geographical features that interfere with reception, etc... undoubtedly contributes to that. I've got a lot of information in this head of mine collected from a variety of sources over the years (I read, a LOT). However, I usually attempt to at least double-check that I'm correct before I start speaking about something. Hence, why I was googling while discussing this last night.
Sorry this post is so long. Again with the wordiness, I know... I'm at the point with explaining this topic that I just don't have the patience, and I'm not going to go further into technicalities that I have only a cursory understanding of as there is too much of a risk of being wrong and confusing people even more (like explaining how radio-frequency signals travel through space, or why a phone only triangulates on 911 calls, or how most phones have GPS chips in them that can be turned "on", whether or not you use a GPS application/software on one's phone, and a TON of other things like you asked about above).
I guess I'll end this post by saying this: Google is your friend. I will answer questions of stuff that I already posted about, but I won't go further than what I can comprehend on technical specifics. I don't even know why people would need to understand EXACTLY how it works in order to understand at least the basics, and how LE uses the historical records to track a phone's location whether in use or not.
