The choice is yours with TV on demand

PVRs, DVRs, programmes on broadband... Television is undergoing a revolution in advance of the digital switchover. Esther Shaw looks at what's available – and how to find the best value package

The way we watch television is changing: not only can you record programmes, you can now also pause and rewind live TV. This is thanks to a box, known as a personal video recorder (PVR) or digital video recorder (DVR). The box is not unlike a traditional video recorder, but the crucial difference is that it makes use of a built-in hard disk to store shows – eliminating the need for video tapes.

For starters, this means improved picture, sound and reliability, but the fact that a hard disk can read and write at the same time means you can start watching a programme before it finishes recording, and press the pause button to freeze playback. Furthermore, most PVRs store the last few minutes of whatever you've been watching, enabling you to "rewind" live TV too.

Which?, the consumer body, points out a number of features to look out for when buying a PVR: these include easy programming, capacity, number of tuners, and editing facilities.

A good PVR, it says, will record at least 20 programmes from the electronic programming guide (EPG), while a typical hard disk gives around 80 hours of standard recording time. Also, look at the number of tuners, as a PVR with two tuners will let you record one programme while watching another.

PVRs work only with digital TV and are a crucial part of part of the revolution set to sweep across the nation over the next few years, in the run-up to the digital switchover. As a result, the television market is getting increasingly competitive, and providers are jostling to press their boxes on the TV viewer.

For some time now, Sky and Virgin have been locked in a bitter pricing row – with customers defecting from Virgin back in February when a contract dispute over charges led to Sky withdrawing its package of channels from Virgin's services, including shows such as Lost and 24. But both Sky and Virgin now face heightened competition, not only from one another, but from new entrants to the market, such as BT Vision.

PVRs can essentially be divided into two types: those that are tied to a subscription service, such as Sky, or Virgin Media, and Freeview PVRs that can be bought for a one-off payment. Sky was the first significant entrant to the market some five years ago, and with Sky+, you have a dedicated box next to the television.

This is a PVR which has "good functionality" according to Jason Lloyd from price comparison service Moneysupermarket.com. "You can watch a programme from the beginning while recording the rest of it," he says. "The PVR also has two tuners." One useful feature of this PVR is remote record, adds Dave Holes, spokesman for Which?, enabling you to phone, text, or go online to request that the box records a programme for you.

The box costs £99 but there's a £60 installation fee. There's also a £10 monthly charge unless you subscribe to two or more premium channels such as Sky Sports and Movies – on top of the cost of a Sky Channel package. Opt for the HD version, and this will cost you £299 for the special HD box. Virgin Media has gone down a similar route with the new Virgin V+ box. "It receives both normal and HDTV and is versatile," says Holes. "And, like the Sky boxes, has 'series link' to record a whole series with one button. It also has three tuners, which means you can record two channels and watch a third live programme."

That said, Holes says the fan is noisy, and that while the EPG is fast to navigate, you go to a different menu to make recordings.

The V+ is available only from Virgin. The box itself is free, but you pay £10-£15 a month subscription, depending on your TV package. Installation costs £25 for new customers, and £75 for existing digital TV subscribers.

BT is one of the more recent entrants to the television business, and has pumped a lot of money into promoting its new BT Vision V-box – a hybrid which combines the Freeview digital TV service with a PVR which can record up to 80 hours of programming. It is offering customers the ability to download "on-demand" from a library of films, football and TV shows. Viewers can subscribe to blocks of programmes or pay per view for films and, later this summer, Premiership football – through a deal with Setanta Sports.

There is no separate monthly subscriber fee, but users have to be BT Total Broadband customers with a Home Hub to use the BT V-box, says Lloyd.

The alternative to these services is one of the Freeview PVRs which can be bought for a one-off payment of between £100 and £300. You may not get the same choice of channels, but this could save you money in the long term.

In a recent survey by Which?, its top-scoring PVR was the Logic LPV2250 which lets you record 125 hours, has twin tuners and a "decent eight-day EPG that's well laid out and simple to use." Which? also picks out the Humax PVR9200T which can record two channels and play back a third.

"Its remote is clearly labelled, the basic functions are easy to use and the EPG is well laid out," it says. A further recommendation is the Topfield TF5800 PVR.

Elsewhere in the market, Tiscali, the internet service provider, has also moved into TV after last year's acquisition of HomeChoice, and is now offering video-on-demand (VOD) over broadband. Tiscali offers a catch-up service, allowing customers to re-watch TV shows up to seven days after transmission.

"It has a greater storage capacity and access to more 'on-demand' content than anyone else in its library," says Lloyd.

It has limited availability at the moment, as its service is only available in the London area, but it will be rolled out across the UK over the coming year.

Elsewhere, Orange, the mobile company, also has plans to offer TV over broadband – and VOD – as its sister company already does in France. "We could see this launch later this summer – and this could be a pretty good proposition," says Lloyd.

There have already been some big developments in this arena – such as 4 on Demand, where people can watch Channel 4 content from the past seven days for free, or pay a small fee for older programmes and films.

And now that both ITV.com and BBC iPlayer are developing plans to provide "on-demand" and "catch-up" TV services, we are going to see some very big changes ahead.