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hcso1510
(@hcso1510)
Active Member

I was informed earlier when sending a preservation request if you are requesting cell site data you should also ask for PCMD or per call measurement data and evolution data optimized information.

The information I am referring to applies to the Verizon network and can apparently narrow down the location of the handset within the towers radius. I have not seen these records before, but I think they will narrow things down from miles to feet and give a more exact location. Apparently this information rolls off after about 14 days.

The individual I spoke with was a bit frustrated he didn’t know that Verizon had the capability to provide that type of data. I’m sort of happy because I now know. I don’t know that this is any big secret, but I assume there may be other capabilities the service providers have, but they don’t openly talk about?

Does anyone know if other cellular service providers maintain PCMD or EDOI? I saw the word “evolution” and started thinking about Verizon specifically, but it would be nice to know if AT&T, Sprint or T-Mobile capture this as well.

How accurate is it?

Thanks!

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Posted : 26/01/2011 2:55 am
hcso1510
(@hcso1510)
Active Member

I did a little homework this week and wanted to give an update on PCMD.

Sprint I spoke to a Manager in Subpoena Compliance that advised me they do retain PCMD (Per Call Measurement Data). He stated it is only a tool, but it can be an effective tool along with the accompanying cell site data. He stressed that it is NOT Historical GPS. He also stated PCMD accuracy can be affected by the handsets range to the tower, attenuation, geography and the lack of other towers in the area. They retain the data from 5 to 7 days and it rolls off.

Verizon My contact in their LERT was much more optimistic. He stated it will normally narrow down the position of the handset within a tenth of a mile. I asked if there were any variable that might affect the reliability of the data and he stated he has never heard of the data being affected. They also keep the data from 5 to 7 days. The PCMD report with Verizon is called a RTT and this data can be provided if only an SMS was sent. I asked if Verizon could provide an expert witness to testify as to the accuracy of PCMD and I was told Verizon does not provide expert witnesses, but they could provide listings of expert witnesses if necessary.
I just got off the phone with another Verizon analyst. She expressed the same concerns as the guy from Sprint. I had a feeling he was overstating things a bit

Cricket Nothing, but that was not a surprise.

AT&T One of their LERT analysts told me they didn’t have the capability to obtain PCMD. I’m not saying they are wrong, but I find this surprising and would like to speak with another contact at AT&T. AT&T has timing advance.

T-Mobile I’m working on it. 8) T-Mobile does not support PCMD. PCMD is specific to the CDMA service providers, but T-Mobile does have additional ranging data called timing advance. I understand it is difficult to obtain this data. I believe it would be a safe assumption that this data would also only be retained several days before rolling off.

ReplyQuote
Posted : 29/01/2011 2:48 am
armresl
(@armresl)
Community Legend

Ed,

I wanted to bump this great post you made, dare I say SIX years ago.
Wow, has it been that long on the forum.

Any new info on the ATT part, or changing info on others?

ReplyQuote
Posted : 23/03/2017 9:48 pm
Billsimp
(@billsimp)
New Member

Ask for NELOS from ATT. Much better accuracy than with Verizon Real Time Tool or Sprint PCMD. NELOS will give LAT Long and accuracy in meters.

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Posted : 04/04/2017 7:16 am
armresl
(@armresl)
Community Legend

It gives it in approximate meters with a caveat/disclaimer on accuracy of data and measurements.

Ask for NELOS from ATT. Much better accuracy than with Verizon Real Time Tool or Sprint PCMD. NELOS will give LAT Long and accuracy in meters.

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Posted : 06/04/2017 4:23 am
Nick.Barker1011
(@nick-barker1011)
New Member

T-Mobile also has come out with their own PCMD records called "TrueCall". It's a report that is very new to them and not a lot of examiners know to even ask for it. When you are submitting papers to their compliance center make sure you ask for "TDOA or Timing Advanced Information". If you don't specifically ask for either of those they will not give you the data. Also, they only retain the records for 90 days so be sure to get a preservation letter off immediately to save the records.

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Posted : 05/07/2018 7:42 pm
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