A Markman hearing allows the judge to define key terms in the patent claims before trial...these terms are established by a judge prior to trial rather than argued as fact in front of a jury...
the plaintiff--us-- wants the terms defined as specified in the patent...the defendant--TMobile--wants the terms defined so they don't apply to their infringing device/process/gadget...
a favorable definition of the terms by the judge in a Markman historically weighs the trial results in your favor--thus prompting settlements prior to trial--but it is not a given...
we want our duck defined as a duck---they want their duck defined as a goose, even tho' it walks and quacks like a duck