Prime time is the daypart (block of a day's programming schedule) with the most viewers and is generally where television networks and local stations reap much of their advertising revenues. - Wikipedia 

With relation to data services Prime Time are services that are mission critical and that need to be up 90% or more as outages within that windows could be disastrous to a business.  An analogy could be loss of power during the world cup finals. 

This requires seamless provision of inter-branch connectivity, remote users, mobile users, B2B, B2C, redundancy, SLAs and security all in a single package.

Providing reliable and flexible solutions to meet the clients needs, the mobile providers are moving into fixed wireless and wired services which require site visits and high level of client interaction as opposed to the mobile services they are used to where you can get away with phone and "carry in" support.

Transitioning from wireless to fixed services is more difficult than the reverse, many of you will soon understand why it too KPTC aka Telkom aka Orange days if not weeks to resolve a faulty landline we are about to go full circle as the messiah mobile provides delve into the world of fixed.

I hope I have been able to justify my use of the term primetime.