I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. Document editors and WG chairs should treat these comments just like any other last call comments As you might guess from the draft name, this is an informational document describing a number of use cases for low-power wireless personal area networks. The security considerations section, reasonably enough, briefly indicates why different use cases may have considerably different security requirements and what some types of such security requirements could be. The thing that I think is lacking is some hint as to where to look to find possible mechanisms to meet those requirements. For this type of document, no detailed analysis of mechanisms is needed. But I would feel better if a sentence could be added such as follow (with some alternative wording in square brackets): "These varied security requirement [can commonly][are expected to] be met by the use of mechanisms such as IPsec and IKE, TLS, or 802.15.4 link security.". If there is an appropriate security mechanism survey document that would be fine. I did look at RFC 4919 as something that could be referenced and it seems too preliminary and tentative. RFC 4944 is only a little better. Perhaps there should be a reference to draft-qiu-6lowpan-secure-router at least as an example of work in progress in this area. Thanks, Donald =============================  Donald E. Eastlake 3rd   +1-508-333-2270 (cell)  155 Beaver Street  Milford, MA 01757 USA  d3e3e3 at gmail.com