A method includes generating, by a first software process of the data processing system, a source partition descriptor for a DMA job which requires access to a first partition of a memory which is assigned to a second software process of the data processing system and not assigned to the first software process. The invention proposes to form the expansible anchor with a locking connection which locks the expander body on the expansible anchor in a position in which the expander body is drawn in between the expansion tongues and holds the expansion tongues in a spread-open position. Optionally, the controller may designate certain access points to remain active so as to monitor for clients attempting to access the WLAN.