Telewest was the second cable supplier to launch digital TV services in the UK, and was largely based off the same infrastructure as Cable & Wireless, employing the same middleware and set top box hardware. After Cable & Wireless merger with ntl: telewest evolved their services by adding interactive TV, Blueyonder broadband, Teleport – Their own video on demand service and had launched their own PVR, TV Drive.
Set Top Boxes
The Pace Di1000 was the first cable box that was available for active digital customers, and featured dual smart cards with the second intended for use with a Mondex card, similar to the interactive card slot on Sky digibox’s. This unit also featured a 4 digit display that displayed the channel number and any error messages, but not the time. In standby the display has left blank with just the power LED lit. The remote control used a non-standard protocol based on IrDA, that was developed by Two-Way TV. The intention of this was to allow for multiple remote controls, keyboard and gamepads to be used for interactive games and activities. This mean that regular universal remotes had issues working with these boxes, unless the remote supported IrDA.
On the real panel the Di1000 featured dual scart outputs for connection to a TV and VCR, with RGB support for the TV scart. A RF antenna loop through was featured that allows an older non-scart TV to be used, along with separate audio output jacks for connection to a Hi-Fi system. An ethernet port allows for a computer to be connected to provide internet access through the internal modem. Lastly there were also RS232 and IEEE1284 connections, also known as serial/COM and printer ports respectively. These were intended to be used to connect to external devices that could interact with the cable box, such as a printer or an external remote control. This was never fully utilized.
Internally the Di1000 was powered by an Hitachi SH3 processor, along with 8Mb of RAM, 4Mb of dedicated RAM for the C-CUBE MPEG2 decoder, and a Broadcom chipset for the internal DOCSIS modem.
The Di1010 was the follow-up model that was released in 2000, and saw a change in the memory management, the Flash was reduced to 4Mb in favour of having 16Mb of system RAM, which the firmware would decompress the flash into, and run from as RAM as like some sort of Ram drive. The ethernet socket was changed, no longer requiring a cross over adaptor.
The Di2000, released late 2000 saw a reduction of components in order to reduce cost and complexity of the unit, however the feature set of the previous boxes remained in this model. This was considered to be the preferred box of boxes for Telewest.
The Di4000 was released in 2001 and saw a substantial change both internally and externally. Whilst the front panel looked the same as the previous models, the real panel had major changed. The audio outputs were removed which caused issues with customers who wanted to connected their digital boxes to their Hi-Fi or AV receiver, instead they needed to use a scart breakout cable to extract the audio, or use the audio output on their TV. The RS232 and IEEE1284 ports were also removed in favour of a single USB port, since none of these ports were used by customers, this made little to no difference for the end user.
Internally the hardware was resigned, with the CPU and MPEG2 decoder now being built onto a single chip, which was also much faster than the SH3 CPU for the previous models. Because of the reduction in components, the box now runs much cooler and uses less electricity. There were two revisions of the Di4000, with a later version called the Di4000TC. The main difference was a slightly redesigned front panel that only ha a single card slot.
Scientific Atlanta was introduced as a supplier in 2002 with its first model, the Explorer 4000DVB. This was similar to the Pace Di4000, however it featured dedicated audio out that the previous Pace models had. The front panel mirrors the ntl Pace Di4001 design.
The 4200DVB looked similar to the Explorer 4250 and featured a significantly faster processor, single card slot and optical audio out.
Telewest launched its active digital service in 1999, and was based heavily on Cable&Wireless implementation of their digital TV service. This was deliberate as it was expected for both companies to merge in the near future, so it made sense for the platforms to be built off identical technology
The first generation of software utilised a property EPG system written by Pace and was known as ’At a glance’, and shipped with an interactive browser by Liberate. This all ran on a custom VXWorks operating system. Since this was loaded as an additional application, this meant the interactive was not always on, for example pressing the interactive button, the user had to wait for the Liberate browser to load before they could access interactive services. This also prevented red button and digital text services. There were issues with the audio DAC which prevented the user from being able to adjust the volume using the STB remote control, attempting to do so yielded a message onscreen informing the user to use their TV remote control to adjust the volume.
The second generation of the software was introduced in early 2002 and was known as the Liberate 1.2 update, and saw a complete rewrite of the EPG guide. The Liberate middleware browser was loaded on STB boot up, and allowed the user to instantly open interactive services without having to wait for the browser to initialize. This came with a disadvantage, as due to Ram limitations the TV guide listings had to be reduced, and the guide data was reduced from 7 days to 3 days in order for the Liberate browser to be loaded resident into the STB memory. Telewest wanted customers to have easier access to interactive services, since e-commerce services were being launched on the service. Red button services were also now possible for the first time, and debuted with the Big Brother live feed. During this time Telewest launched the Pace Di4000 box, and had introduced Scientific Atlanta as a second box supplier with the 4000DVB.
The third generation of software was introduced in 2004, and saw a complete redesign bringing it inline with the new corporate Telewest Broadband branding. The menu layout was changed to a 9×9 grid and the background colour used an electric blue colour scheme. Teleport VOD service was later added in 2005 and replaced Front Row for box office events. This software was the basis for the TV Drive, and following the ntl:telewest merger, was introduced to ntl customers in 2006 and would eventually be the basis for the Virgin Media UK1 guide that would be launched a year later. Sadly, this guide would reduce the EPG data to just 24 hours, whilst the TVDrive supported 8 days.
EPG guide data anomaly
A common issue during the lifespan of the active digital service was the reduction of the TV guide listings, especially in comparison to Sky Digital and later Freeview, which supported a 7-day TV guide and in the case of Sky supported a large amount of channels. Part of this is down to how the EPG data is implemented and handled by each provider.
Sky Digital works by storing 6 hours of EPG listings within the digiboxes RAM, this is downloaded upon boot up (the Searching for Listings message that appears when you first power on a digibox). New listings for the next 6 hours are broadcast on each transponder albeit at a slower data rate. When the user access the TV guide, the digibox actually changes channels (switches transponder to 11778) to where the EPG listings are being broadcast, along with the EPG background music. This allows the digibox to instantly pull the TV listings for the next 7 days, along with the programme synopsis (displayed by pressing the I button). However, with this design the customer cannot watch TV whilst browsing the TV guide, as the digibox needs to switch to another transponder in order to load the information needed, unless the customer uses the search and scan banner and is limited for the next 6 hours.
Cable went a different approach and opted to store all TV listings in the set top boxes Ram which was loaded upon bootup, since the guide data was loaded into memory the set top box did not need to change frequency in order to load TV listings, and the customer could browse the TV guide without interrupting the viewing, either in the main TV guide or by using the Mini guide/Search and scan banner. Another nice feature is that the customer can press the I button to get the synopsis for any other programme from the Mini guide without having to enter the main guide or changed channel, since this information is also resident in the boxes memory. Sadly since the earliest Pace boxes were limited to 8Mb of ram, despite the later boxes having 16Mb and higher meant sacrifices had to be made in order to have a fair and consistent service for all customers.
Both platforms had a different design approach to handling TV guide listings, where they were constrained by the amount of memory available to the STB. Even though it was desirable to increase the amount of memory in the launch set top boxes, this would have affected the cost, and would have a knock on effect on the cost of subscriptions to the end user. In the case of Telewest I believe they could have utilised the cable modem better to extended the capacity of TV listings, where EPG data after 24 hours would be stored on a local server when would be loaded on request, similar to the Sky approach but using the DOCSIS modem rather than the satellite stream. This would have allowed a 7 day EPG (although slightly slower depending on the server and capacity) whilst abiding by the memory limitations.
Accessories
Remote (Black) – The remote control that Telewest used was unique in its approach that it used the IrDA protocol rather than RC5. The reason for this was to allow multiplayer use with TV games, search remote could be assigned a unique ID, determined by the colour tab at the bottom of the remote. The use of IrDA caused issues when using third party remote such as Philips Pronto or Logitech Harmony since these only supported RC5. Using Tivo remote dongles was also problematic as they required special adapters in order for Tivo to control the STB. Alternatively a device called Red Eye was able to translate IrDA commands to RC5.
Remote (Silver) – The remote was redesigned with a new silver style, and was similar to the Sky remote design. This remote was capable of controlling a supported TV for the volume functions. The main difference was the removal of the individual On Demand and Interactive buttons, in favour of a single home button (large blue button with Telewest logo), this was to reflect the new TV guide design.
Keyboard – a full QWERTY keyboard was made available which made the use of email and interactive use easier. This was similar to the Open/Sky keyboard.
Interactive
Interactive service launched on Telewest in late 2000, using the Liberate middleware. Services could be created using HTML3 and were delivered via the STB’s DOCSIS connection.
The use of HTML meant it was easy to create website that can then run on the Telewest STB directly.
Blueyonder email could also be accessed through the TV service, emails could be sent and received.
Known Software History
| P1.20a.00.CR2 (CA ver 5.3.16 1.3.3) | Aug 2001 |
| P1.80a.00.CR2 | Oct 2001 |
TVDrive
This was Telewest’s answer to Sky+ and Tivo, and was to be their next major iteration of their TV service. Telewest had partnered with Scientific Atlanta for their Explorer 8300DVB recorder, which was designed specifically for Telewest and was based on the Explorer 8300HD, which was a popular DVR using by US cable operations. Telewest already had a relationship with Scientific Atlanta as it had used the 4000DVB and 4200DVB boxes for its digital TV service, and had used their analogue set tops previously.
The TV Drive uses the same Liberate TV Navigator that the regular digital TV boxes has used, allowing full compatibility with interactive service, and a familiar interface to customers that had upgraded. The TV guide data was extended to 8 days compared to the 24 hours offered by the standard digital boxes.
The 8300DVB features 4 tuners, three for digital TV and one data tuner which was for the internal DOCSIS modem. Although the 8300DVB could provide broadband services using its internal cable modem, Telewest never used it in favour of stand alone modems. A new remote control design was introduced with the box also featuring record and playback buttons that could be used with Telewest on demand services. The use of three tuners for TV means the TV Drive could 2 programmes whilst a third could be watched. Recording are stored on 160Gb hard disk.
The TV drive also supported High Definition TV, however it was limited to MPEG2 for its video, rather than MPEG4 that was being used by Sky and Homechoice. This meant HD channels on Telewest consumed a lot of bandwidth since MPEg2 was a less efficient codec for video, and that HD video required more bandwidth than SD video. This however allows Telewest to launch their HD service earlier than Sky, due to the shortage of MPEG 4 AVC decoder processors. Initially the only HD channels broadcast on Telewest was BBC HD and ITV HD, which was later a trial. HD on demand programs were also available.
Documents and Manuals
More Information
Telewest Communications Carry Two Way TV (archive.org)
Liberate Technologies, Customers (archive.org) – Telewest announcement
Drew1440: Blog 