I have had a few requests to put some detail around the topic, and as I am currently in the middle of a power cut, and have a back-up light/laptop battery, I will.
I need to preface this, to say, I dont actually trade horses any more, either remotely or on-course, but, still know enough,(I think), to have a decent go.
The current situation :
Trading rooms do exist on many racecourses in the country - but, they are not called such. Normally, a pro-trader will have secured a Box, for the whole season,paying .. £300-£1000 per raceday, depending on size/meetng etc. Some tracks have allowed many boxes, others, just 1 or maybe 2, in return for 'sponsorship'.
This Box normally has v good internet fitted, and tables are brought in, so, traders have decent workplaces. (You pay the internet bills etc)
Normally, there would be 4-8 people to a box, but, sometimes, it can be more, and recently, it can be less, as supply has outstripped demand.
What typically happens, is that the Box has 4 regulars, who share lots of boxes. Each trader, goes to the course, armed with 1 or maybe 2 laptops, a portableTV screen, various connection cables, and ancilliary splitters, to share the TV signal/internet.
This sounds extreme, but, u get used to it.
The cost, for the day, would be £100-£200, which normally includes entry to the course.
For this, u get the live TV picture. Its anywhere between 1 sec and 3 secs ahead of home users .. so, maybe its worth it. (The laptop u bring to the course, normally has your prefered one-click betting software on it) - so, maybe the 1 sec advantage, is worth the money .. a lot depends on your style of trading.
The problem is, by going to the course, u are just working 7 races a day, where as , if u stayed at home, u might work 40 - and the days of laying fallers etc, are largely in the past.
Video feeds on the internet are getting better and better, especially as internet capability improves. Hopefully, video will be available within a few yrs, which is only slightly behind live, and its an equal playing field, which may help improve the 'in-play' liquidity, which seems to have been dropping.
Because Box leasing has become important to a racecourse from a monetary standpoint, traders who have not paid a daily fee, are not allowed to work from the stands, and security will normally give 'freeloaders' grief .. not always, a lot depends on the track.
Phone callers are still permitted, and, often u will see people with ladders, at the furlong, or even 2 furlong pole, as, its a great place to get a side on view, no-one else has, and call it back to someone .. maybe auto-traded.
Some tracks police this activity, some dont .. they can argue it affects their public liability etc, to have people wandering down the course, miles from the grandstand.
Mobile 4g, has meant internet speeds at a lot of course has become v good, and for a while, people tried to 'steal' the pictures, having facetime cameras, pointed at the big screen, and having it sent back to a distribution point. This is illegal .. as u are infringing copyright etc .. but, it may still exist, in some form.
Its all a question of balance, and what u can get away with. The daily costs, together with Prem Charge, has made the proposition marginal, for average traders. Good traders, will still find ways to win .. some v good ways.
Off-course trading Rooms
One of the first, if not the absolute first, was Cardiff, run by John Lovell, who tragically got killed, driving home from the shop.
It had racetech feeds, obtained via a motorised satelite dish, which in the v early days, were not scrambled. These feeds were gold .. the value of sitting in a high-spec shop, watching a picture, that was at most, 1 sec behind live, was just too big of an edge, and almost anyone could make money. The daily charge, of £50 or whatever, was cheap. (some days, I would commute by TAXI, from cardiff to Birmingham, as the late train, went at 7pm or whatever, and a taxi got me 2-4 extra races. As the e-v per race, was probably £500, it was a no brainer.
As on-course rooms became more widely known/used, the edges left, for the people off-site, became less, and people who found they could win, were now, failing. Some people still prefer to work off-course, but, certainly, the off-site exchanges are diminishing (especially as Betfair no longer encourage them - they used to give comm rakebacks (I think)) and the racetech feeds, are largely gone, but, its still possible someone has the encryption codes .....
Year 1, was thought to be the Wolverhampton Hotel, but, I was trading via hand-helds, at least 6 mths before that (from memory - its a long time ago).
In those days, 2g was often the best signal u could get a course - so, phone traders often called back to someone at home, who would execute the instructions.
Being one of the first, if not, the absolute first people to work on track, with mobile devices, was obviously, pretty lucrative. There are many stories .. but, they are in my book (not published - yet). If I get a chance, I will maybe start a storytime thread.