First, to answer your question, you can seek cancellation of a registration for a mark that has been abandoned. Be advised, however, that showing abandonment can be difficult. If the mark has been out of use for five years, abandonment may be presumed, which would help your case significantly.
Second, you state:
There are other possible names for the technology, but this is the best and most descriptive one.
That's not something you want to say publicly. Merely descriptive words or phrases cannot function as trademarks and are neither registerable nor protectable as trademarks.
Ultimately, my advice to you is to seek the services of a qualified TM attorney.