Title is wrong, you mean "ULP":<p><pre><code> U ltra
L ow
P ower
</code></pre>
You have "UPL in the title.<p>Apart from that, this seems to be a useful article, listing lots of issues in a single place. While it is light on detail, and seems to contain nothing new, it is an interesting summary, and possibly a good starting point for people to research further the many, many issues.