and 20 and 30 and 40 of the bss may maintain communication the area is a so called basic service area bsa when the terminal 10 or 30 escapes from the bsa the terminal may not communicate directly with other terminals that are present in the bsa fig2 is a block diagram illustrating another ieee 802 11 system the wlan system includes at least one basic service set bss the bss is a set of stations stas which are successfully synchronized to communicate with each other the bss may be classified into an independent bss and an infrastructured bss further the bss may form a network component of an extended type which may be independently present or be constituted by a plurality of bsss a component of an architecture used to interconnect the bsss is a distribution system ds the ieee 802 11 standard logically divides the wireless medium wm from a distribution system medium dsm respective logical media are used by different components of the architecture and for different purposes an ieee 802 11 definition does not disable and require a plurality of media to be the same as or different from each other understanding that the plurality of media are different from each other is a core used to understand the mobility of the architecture the ieee 802 11 lan architecture is independently designated from a predetermined detailed implemented physical feature the ds processes an address for destination mapping and provides a logical service required for seamless integration of various bsss to support a mobile device the ap represents a predetermined entity that has the function of the sta and enables the access to the.