I can save the Government some of the £200,000.
The chances of working through technical issues, permissions and protocols for attaching any sort of equipment to the Overhead Line Equipment structures is naff all.
As part of the 25 Kv AC overhead line system the structures are also part of the traction 'Earth Return' path. Active electronics attached to them will require considerable protection from the high currents and impulse noise in the contact wire while trains pass through drawing potentially 200 odd amps.
Any power supply, for the BTS, will require considerable filtering and will itself have to be protected by, externally, becoming part of the return current system to prevent dangerous touch potentials. What about battery support? where will that be located? There is often little room in the railway corridor for more infrastructure. In many cases there are no general power supplies (as in domestic types) in the vicinity of the track anyway, providing those will add to costs. Tapping the OLE power could be an option - but at high cost and unreliability, as sections of OLE can be isolated for railway maintenance activities. (as a side note I don't think the Railways supply agreements for the use of OLE power allow them to use it for non operational purposes anyway) Solar cells and the like is even more infrastructure to go wrong (and be stolen).
Providing telecoms links to the units will offer similar complexities.
Then you have the matter of BTS maintenance. The Railway Electrical Engineers will most likely refuse access to the structures, to maintain the BTS equipment, unless under an isolation i.e. the OLE disconnected and earthed. You can't have some random Telco tech climbing ladders up the gantry to attend to a broken BTS. The permissions and protocols for work on OLE are onerous, and take time to arrange, but they need to as 25 Kv is unforgiving.
When there is a derailment the OLE tends to suffer significantly so any BTS will be wiped out.
Ask yourself why the Railways signal engineers do not save money and attach signals to the OLE? It is just far too problematic, even passive signs (speed limits, restricted clearances etc.) are, in most cases, considered a no no.
Then ask why Network Rail spent millions building new towers/rooms for the the GSM-R equipment if they could have just stuck it on the OLE gantry.
This has been talked about in many railways over many years and large scale implementations, to my knowledge, have never materialised. I'm aware of some limited implementation on some European lines for GSM-R but am not aware of any public BTS kit attached to OLE structures.
The report is thus simple;
No option for using existing railway operational infrastructure exists. Improvement of public wireless coverage in the railway corridor can only be effectively achieved by Telcos developing stand alone masts and infrastructure, preferably a safe distance from the railway safety zones. Some opportunity exists for sharing of existing railway buildings and apparatus rooms but it is not considered that this opportunity helps in many areas where existing coverage is poor. Improvements in wireless distribution, inside trains, can be made but these will only be successful if Telcos provide the necessary improvement in coverage and capacity to the areas along the rail corridors - much as they do for the motorway corridors.
(please remit £199,999.99)