doc.: IEEE 802.11-00/xxx Jon Edney, Nokia Month 2000 doc.: IEEE 802.11-00/xxx May 2004 What is an ESS? Jon Edney, Nokia Jon Edney, Nokia John Doe, His Company
Anecdotal Definitions for ESS (I have heard people use) Month 2000 doc.: IEEE 802.11-00/xxx May 2004 Anecdotal Definitions for ESS (I have heard people use) Any group of APs having: the same SSID and connected via a Layer 2 network the same SSID and connected by any network the same SSID Jon Edney, Nokia John Doe, His Company
The Distribution System (DS) May 2004 The Distribution System (DS) Distribution System AP AP AP Jon Edney, Nokia
May 2004 The BSS DS AP STA STA Jon Edney, Nokia
May 2004 ESS Distribution System AP AP AP STA STA Jon Edney, Nokia
NO NON 802.11 terminations allowed May 2004 ESS Distribution System AP AP AP MSDU MSDU STA STA THIS IS ALL 802.11 NO NON 802.11 terminations allowed Jon Edney, Nokia
What does the standard say? May 2004 What does the standard say? 3.25 extended service set (ESS): A set of one or more interconnected basic service sets (BSSs) and integrated local area networks (LANs) that appears as a single BSS to the logical link control layer at any station associated with one of those BSSs. Jon Edney, Nokia
May 2004 More (5.2.2.1) The key concept is that the ESS network appears the same to an LLC layer as an IBSS network. Stations within an ESS may communicate and mobile stations may move from one BSS to another (within the same ESS) transparently to LLC. Jon Edney, Nokia
May 2004 Portal 3.39 portal: The logical point at which medium access control (MAC) service data units (MSDUs) from a non-IEEE 802.11 local area network (LAN) enter the distribution system (DS) of an extended service set (ESS). Jon Edney, Nokia
Portal Distribution System May 2004 HOST Router 802.3 network AP AP AP STA Jon Edney, Nokia
May 2004 SSID 7.3.2.1 “The SSID element indicates the identity of an ESS or IBSS” There is no such thing as “ESSID” Jon Edney, Nokia
Summary SSID does not define ESS May 2004 Summary SSID does not define ESS Any network technology can be used for DS but… The only terminations allowed are APs or portals DS must provide a tunnel for MSDUs – effectively this means layer 2 delivery Connections through portal do not change when you roam within ESS If STA is required to change IP address when it roams then it cannot be intra-ESS roaming. Jon Edney, Nokia