When a person cannot get to Mass through no fault of his own, the Sunday/holy day obligation is dispensed. That said, this presumes that the person has made every reasonable effort to overcome the hurdles of getting to Mass. For example, most people who cannot themselves drive can arrange for carpooling or for public transportation.
Of course, if a person is homebound due to illness or physical incapacity, even though the obligation is dispensed he may wish to call (or have a caretaker call) the local parish to have the sacraments of confession and the Eucharist brought to his home. And, although a televised Mass does not fulfill the Sunday/holy day obligation, a homebound person may wish to watch Mass on television on those days so as to participate in the Mass in some way.
