MATRIX & REALITY, What equipment can link the two things? Options

[Luca]

1) From "neuromancer" I remembered Casey being in the Matrix and watching Molly's adventures in the real world through a kind of "window" in his visual.
How can this be possible in Shadowrun?
What equipment/utility/deck hardware do you use to make your decker follow the adventures of his chummers?
Do you use any alternative method? (radio, etc...)
i am not exactly a Shadowrun-virgin but I do not play the game so often (...3 games per year? due to my group addiction to d20...) so, things that might be obvious for others are not obvious for me. SO, please, state exactly what objects and techniques you use.

2)Another stuff. I've noticed the existence of the "Null operation": does it make boring the game of a decker? Furthermore if the decker is watching the chummers from the Matrix (and so often waiting), how often you do those tests?

3) A last question: can Matrix initiative be compared to normal initiative (for example in a real combat which is contemporary with a matrix one) (I think that it is possible).

If you have to answer only one question: PLEASE ANSWER TO THE FIRST!!!!