With the caveat that the situation changes quickly in the U.S. high speed access market, recent speed tests conducted by DSL Reports suggest that, in many countries, under some conditions, users might experience faster speeds using a Long Term Evolution 4G mobile connection, rather than an all-copper digital subscriber line service.
Of course, all things are not equal. DSL cost per bit is far lower than mobile data cost per bit, so the typical application set for any single user will determine whether mobile data is a functional substitute for DSL.
The DSL Reports tests suggest an average DSL speed of about 13.7 Mbps, and an average 4G speed of about 12.3 Mbps. There is not so much functional difference there, for a single user account.
The cost decision of course hinges on how much data any single user consumes in an average billing period. The economics shift dramatically for multi-user households.
The tests show that in some countries, such as Canada and Australia, 4G speeds actually are faster than DSL.
In another year or so, cable speeds are likely to climb fast, as Comcast and other providers roll out ubiquitous gigabit access, and fiber providers upgrade many lines to 1 Gbps as well.
Out another five to 10 years, matters could change again, as mobile 5G speeds potentially reach a gigabit per device, initially, then potentially extend to 5 Gbps or 10 Gbps.