I don't know whether anyone will be interested in reading this, but as I hate leaving issues unfinished I've written this in an attempt to answer any remaining questions about mobile phone technology. It's long but hopefully covers everything. If anyone remains unconvinced I'm honestly not sure there's more I can say about it.
As ever, I will cover my butt by saying this is all JMO. But for those interested I will also provide these two Wikipedia links which go into much more of the technical scientific detail:
en.wikipedia.org
en.wikipedia.org
Claudia's phone was a Samsung D900 which connected to the 2G GSM network. GSM was first developed in the mid 1980s; early implementations went into use in the early 90s, and it was almost ubiquitous by the early 2000s. The technology was already more than twenty years old by the time Claudia went missing. This is important because it speaks to how much experience the police already had with tracking mobile phones using this technology. It wasn't new or crude technology at all.
It is generally true that the 2G masts used in 2009 covered a much wider area than the 4G/5G masts used today. It's a simple matter of wavelength. The lower frequency of the 2G signal has a longer wavelength than the higher frequency of the 4G/5G signal, therefore the signal can travel a longer distance between masts. Despite there being fewer masts in 2009 than there are today, the much wider range of the 2G masts actually meant you were just as likely to be within range of multiple masts as you are in 2025.
Modern 4G/5G mobile technology uses shorter wavelengths which require closer spacing of the masts to achieve the *exact same* level of coverage. Phone companies wouldn't waste their money installing masts at every street corner if they could get away with installing just two or three in every square mile. Modern masts are more densely packed because they have to be. And yet there were, nonetheless, already close to fifty 2G masts in the centre of York as far back as 2002. At any one time, even in 2009, a phone near the centre of York would probably have been within range of at least half a dozen masts.
In any case, a phone mast with a range of 9 miles--such as the York University mast--would almost certainly be what is called a "macrocell". Those are the largest and most powerful types of phone mast: the type you see mounted on top of tall buildings or on huge pylons in the middle of a field. They are generally used in areas of high traffic or as a "router" for smaller local masts. Which means a phone connected to the University's mast would quite possibly have been connected to another more localised mast as well--whether the police ever choose to divulge that information or not.
Moreover, the purpose of such a powerful mast at a University isn't to provide coverage for a wide area, even if the mast is technically capable of doing that: the purpose is to provide a strong signal for the huge number of calls and texts generated by the mass of humanity at the University campus!
The reality is that it doesn't matter precisely where the masts are located when there are so many of them. In the middle of a major city, the chances of EVER being within range of just one phone mast are slim. If your phone is in range of a mast it WILL ping that mast to check the signal strength. That is how the technology has worked ever since the invention of GSM four decades ago; the technology didn't suddenly change just to make things more difficult for the Claudia Lawrence investigation.
If Claudia's phone connected to the University's mast in preference to numerous others nearby, that already tells the police a lot. It already narrows down the likely location of the phone, and calculations based on the strength and direction of the signal could probably get the location down to perhaps a half-mile square. That is with the data from just the *one* mast we can be certain about.
The idea that the police wouldn't be able to narrow it down beyond the mast's full 9-mile range is simply not how this technology works. It doesn't matter whether the police ever admit it or not, the technology has *never* worked that way. GSM uses the strength and direction of the signal to estimate location; merely by looking at the logged signal between the phone and the mast, the police would most likely know if it was 1 mile away, 9 miles away, stationary or in motion. GSM tracking takes more time and effort than modern GPS tracking, but it is nonetheless remarkably accurate.
In addition, the police could look at Claudia's phone records from the previous days and weeks when she was calling and texting from *known* locations. They could check which phone masts she connected to on those occasions, check the signal strength from those locations, and extrapolate where her phone was likely to be on the day of her disappearance based on her prior location history.
This technology has been in use for decades and it's only in recent years that the police have been willing to openly talk about it. They quite understandably didn't want every random person knowing the exact capabilities they had; they wanted to maintain the integrity of the technology as a valid investigative tool. The reason they can talk about it now is because GSM is largely defunct.
Mobile phone technology has never been complicated. A phone pings numerous masts to find the strongest signal. Once the phone finds the strongest signal it connects to it. Once connected to a mast the phone continues to ping other masts to ensure it always has the best possible connection.
Because a phone pings multiple masts, and because those pings are recorded in the logs of the mast, the police can request that data from the service provider. Using that data they can triangulate/trilaterate the location of the phone. Triangulation relates to the direction/angle of the phone relative to the phone mast; trilateration relates to the distance of the phone from the phone mast which is derived from the strength of the signal. By taking those data points and doing some fancy calculations, you absolutely can locate a phone to within a street or two.
The precise location of each mast is only important to the person who is doing those calculations. Whether a mast is two miles away or ten yards away is totally irrelevant unless you have the phone data required to make the locations mean something. We don't have that. We probably never will.
In the earliest days of the investigation the police team seemed to be fairly convinced that Claudia had remained at home and set off for work as intended. Perhaps that was a bluff. But if her phone had been tracked to within the Heworth/Melrosegate area, it wouldn't have rung any alarm bells initially because that was exactly where Claudia's phone was supposed to be.
Even if Claudia's phone had been tracked right to Heworth Road, that would still mean it could have been at her home, at the Nag's Head, at her friend's home across the street, in a dustbin ready to be compacted and dumped at the local tip, or in any of innumerable other places.
It would still be necessary for the police to investigate and conduct searches before the phone's location would actually mean something. If those searches revealed no solid evidence, the police would be stuck. They might have a pretty good idea where, maybe why, and perhaps even who. But sadly that isn't always enough.
I can't say with certainty that the police did any of this with Claudia's phone data, but if they didn't do it I would want to know why; this technology was already so fundamental to police investigations in 2009 that it would boggle my mind if they really only know what they have announced to the press.
The more likely explanation is that they DID do all of this and simply haven't spoken publicly about it.
The police held back information in just about every case I've ever followed. Why should Claudia's be different? A lot of evidence can become inadmissible if it's mishandled prior to a trial. The withholding of evidence is very rarely some big conspiracy or evil lie, it's simply a matter of playing their cards close to their chest until they can present the evidence in court. Which they have sadly never had the opportunity to do for Claudia.
It's much better if the police keep their powder dry until the day when they can actually use it--or the day when the suspects are beyond earthly justice and revealing everything will no longer matter.
