IEEE 802.11s terms and definitions July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 IEEE 802.11s terms and definitions Date: 2008-07-16 Authors: Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Abstract IEEE 802.11s faces many new problems that require interaction with other 802 groups. From the initial PAR until the most recent draft, TGs has significantly changed its terms and definitions several times. Often the terms chosen did not base on solid research. Thus, imprecise definitions were mistaken and members developed contradicting understandings. This document resolves the issue and provides a framework of terms that fits into the 802 family of standards. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

IEEE 802 definitions July 2008 July 2008 doc.: IEEE 802.11-08/xxxxr0 Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Definitions according to 802-2001 July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Definitions according to 802-2001 We refer to [1] On two pages with column notation Left hand column has original text Highlighted text provides key definitions Right hand column holds explanatory notes Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.1.1 Access Domain A set of LAN or MAN stations together with interconnecting data transmission media and related equipment (e.g., connectors, repeaters), in which the LAN or MAN stations use the same MAC protocol to establish the sequence of stations that are in temporary control of the shared transmission media. The definition comes close to what a BSS in 802.11 is A can connect with B-F Inside A’s access domain A cannot connect with G-J Outside A’s access domain Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.1.5 End station A device attached to a LAN or MAN, which acts as a source of, and/or destination for, data traffic carried on the LAN or MAN. The definition of an end station is clear and simple Use it in 802.11s whenever traffic will not be relayed Path selection information Security related messages Traffic forwarded to final destination Etc. We do not need to invent another term for 802.11s Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.1.3 Bridge MAC bridge: A functional unit that interconnects two or more LANs or MANs that use the same Data Link layer protocols above the MAC sublayer, but can use different MAC protocols. A bridge connects similar and dissimilar 802 networks A bridge is a superior term to the 802.11 definition of a portal The portal connects dissimilar 802 networks 802.11 and 802.XY When several Meshes interconnect, a bridge relays traffic between the different LANs Even between two 802.11 Meshes Definition is simple and clear Use it in 802.11s! Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

3.1.23 Station An end station or bridge. July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.1.23 Station An end station or bridge. The 802-2001 standard provides a superset of terms to all other 802 standards The station definition is broad The 802.11 definition of a station is more specific than the 802-2001 standard However, 802.11 has no definition for a bridge between 802.11 networks This might be covered the Distribution System concept Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.1.14 Interconnection The provision of data communication paths between LAN or MAN stations. This is truly what 802.11s does Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

6.3 Interconnection and interworking July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 6.3 Interconnection and interworking In some cases, the end systems on a LAN or MAN have no need to communicate with end systems on other networks (other LANs, WANs, etc.). However, this is not expected to be the norm; there are many cases in which end stations on a LAN or MAN will need to communicate with end systems on other networks and so devices that interconnect the LAN or MAN with other kinds of networks are required. In addition, several standard methods have been developed that permit a variety of interconnection devices to operate transparently to end stations on a LAN or MAN in order to extend the LAN/MAN capabilities available to end stations, particularly in terms of the geographical extent and/or total number of end stations that can be supported. [to be continued on next page] This is exactly the use case for Wireless Mesh Networks A solution within the technology to achieve interconnection Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

6.3 Interconnection and interworking July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 6.3 Interconnection and interworking [continued from previous page] See also Clause 11 of this standard, for an outline of the optional methods by which ISLANs and MANs may support isochronous interworking with WANs and with remote ISLANs and MANs. Standard methods of interworking fall into the following three general categories, depending on the layer at which the corresponding interconnection devices operate: Physical-layer interconnection, using devices usually termed repeaters or hubs (6.3.1) MAC-sublayer interconnection, using devices termed bridges (6.3.2) Network-layer interconnection, using devices usually termed routers (6.3.3) 802.11s provides wireless multi-hop connectivity at MAC layer level Mesh devices mutually forward frames  Mesh devices mutually serve as bridge Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

6.3.2.4 Transparent bridging and source routing July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 6.3.2.4 Transparent bridging and source routing ISO/IEC 15802-3 specifies transparent bridging operation, so called because the MAC bridging function does not require the MAC user frames transmitted and received to carry any additional information relating to the operation of the bridging functions; end-station operation is unchanged by the presence of bridges. […] This description describes the desired behavior of an 802.11 network from an 802.11 station’s point of view  Mesh devices shall be transparent to outside Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

6.3.1 Physical-layer interconnection: repeaters and hubs July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 6.3.1 Physical-layer interconnection: repeaters and hubs The original IEEE 802 LAN specifications were for end stations attached to a shared communication medium. This basic LAN configuration is referred to as a single access domain; the domain consists of the set of LAN stations such that at most one can be transmitting at a given time, with all other stations acting as (potential) receivers. to be continued on next page] With 802.11, the access domain would relate to the set of 802.11 stations that an 802.11 station has an 802.11 link with For 802.11s, the access domain is the Mesh neighborhood Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

6.3.1 Physical-layer interconnection: repeaters and hubs July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 6.3.1 Physical-layer interconnection: repeaters and hubs [continued from previous page] A repeater is a device used to interconnect segments of the physical communications media, for example, to extend the range of a LAN when the physical specifications of the technology would otherwise be exceeded, while providing a single access domain for the attached LAN stations. Repeaters used in support of multiple end stations attached by star-wired network topologies are frequently referred to as hubs. Although 802.11s extends the range of the wireless network, it does not rely on simple repeaters 802.11s uses MAC based relaying Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

6.3.2.1 Bridges and bridged LANs July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 6.3.2.1 Bridges and bridged LANs Bridges (see 3.1.3) are devices that interconnect multiple access domains. ISO/IEC 15802-3 provides the basic specification for bridge interworking among IEEE 802 networks. A bridged LAN (see 3.1 of ISO/IEC 15802-3) consists of one or more bridges together with the complete set of access domains that they interconnect. A bridged LAN provides end stations belonging to any of its access domains with the appearance of a LAN that contains the whole set of attached end stations. A bridged LAN can provide for the following: Communication between stations attached to LANs of different MAC types An increase in the total throughput of a LAN An increase in the physical extent of, or number of permissible attachments to, a LAN Partitioning of the physical LAN for administrative or maintenance reasons If “access domain” is the generic 802 term for the 802.11s “radio neighborhood”  “bridged LAN” is the 802 generic term for an 802.11s network Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

6.3.2.2 Relaying and filtering by bridges July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 6.3.2.2 Relaying and filtering by bridges A bridge processes protocols in the MAC sublayer and is functionally transparent to LLC and higher layer protocols. MAC frames are forwarded between access domains, or filtered (i.e., not forwarded to certain access domains), on the basis primarily of MAC addressing information. [to be continued on next page] In 802.11s, the path selection protocol provides filtering, the Mesh devices provide forwarding between different radio neighborhoods (=“access domain”) Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

6.3.2.2 Relaying and filtering by bridges July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 6.3.2.2 Relaying and filtering by bridges [continued from previous page] Figure 4 shows the position of the bridging functions within the MAC sublayer; note particularly that the relaying and filtering functions are considered to belong entirely within the MAC sublayer. Filtering by bridges tends to confine traffic to only those parts of the bridged LAN that lie between transmitting end stations and the intended receivers. This permits a bridged LAN to support several transmitting end stations at any given time (up to the total number of access domains present). The wireless is a broadcast medium 802.11s cannot achieve this degree of filtering However, 802.11s does not apply pure flooding The directed forwarding of 802.11s provides similar functionality Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Internal organization of the MAC sublayer with bridging July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Internal organization of the MAC sublayer with bridging From 802-2001 point of view, an 802.11 portal is “just another” bridge Another example for bridging in 802.11 is a Mesh device that is collocated with an AP Due to minor implementation details, 802.11 chose not to use the bridge term in 802.11 See Backup – B slides Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Conclusions on IEEE 802 definitions July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Conclusions on IEEE 802 definitions 802-2001 describes the general framework 802.11 concepts fit into the framework However, some terms are different The radio environment is different than a wired network There are legacies on both sides that sometimes lead to confusion AP, PC, HC and Portal are relaying entities They operate as filtering bridges Often, the 802.11 term “station” is understood as 802 “end station” Important to consider the difference Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

IEEE 802.11 definitions July 2008 July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 IEEE 802.11 definitions Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Definitions according to 802.11-2007 July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Definitions according to 802.11-2007 We refer to [2] On two pages with column notation Left hand column has original text Highlighted text provides key definitions Right hand column holds explanatory notes Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.40 Distribution System A system used to interconnect a set of basic service sets (BSSs) and integrated local area networks (LANs) to create an extended service set (ESS). A system is a set of entities, devices & services It’s more than a single entity/device Here The term is specific to 802.11 The term LAN is broad Any 802 network To integrate a non-802.11 LAN, however, a portal is mandatory The portal unifies the DS & non-802.11 LANs Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.8 Association The service used to establish access point/station (AP/STA) mapping and enable STA invocation of the distribution system services (DSSs). To “associate” in 802.11 is a process similar to connecting a station with a wired 802 network In an 802.3 network, the bridge learns about the station and forwards frames on the according port 802.1X (Port-Based Network Access Control) provides security related features in the wired network Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.39 Distribution Service The service that, by using association information, delivers medium access control (MAC) service data units (MSDUs) within the distribution system (DS). The 802.11 association process is used as similar information as an 802.3 bridge would learn addresses of its attached stations 802.11s uses the information of membership in a Mesh to forward frames Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

3.42 Distribution System Service (DSS) July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.42 Distribution System Service (DSS) The set of services provided by the distribution system (DS) that enable the medium access control (MAC) to transport MAC service data units (MSDUs) between stations that are not in direct communication with each other over a single instance of the wireless medium (WM). These services include transport of MSDUs between the access points (APs) of basic service sets (BSSs) within an extended service set (ESS), transport of MSDUs between portals and BSSs within an ESS, and transport of MSDUs between stations in the same BSS in cases where the MSDU has a multicast or broadcast destination address or where the destination is an individual address and the station is associated with an AP. DSSs are provided between pairs of IEEE 802.11 MACs. An 802.11s Mesh could be seen as one implementation of a DS as it transports MSDUs between stations that are not in direct communication range Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

3.41 Distribution System Medium (DSM) July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.41 Distribution System Medium (DSM) The medium or set of media used by a distribution system (DS) for communications between access points (APs) and portals of an extended service set (ESS). The DSM can use a wireless or wired medium Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Access Point (AP) Any entity that has station functionality and provides access to the distribution services, via the wireless medium (WM) for associated stations. In 802.11 it is not mandatory for an AP to be collocated with a portal! Huge difference to what Wi-Fi Alliance & “ordinary users” think about an AP The distribution service delivers MSDUs within the distribution system The distribution system can be a logical “thing” inside the AP Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.71 Infrastructure The infrastructure includes the distribution system medium (DSM), access point (AP), and portal entities. It is also the logical location of distribution and integration service functions of an extended service set (ESS). An infrastructure contains one or more APs and zero or more portals in addition to the distribution system (DS). In 802.3, the infrastructure consists of wires, patch panels, outlets, bridges, hubs etc. The Mesh could be one element of the infrastructure Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.72 Integration Service The service that enables delivery of medium access control (MAC) service data units (MSDUs) between the distribution system (DS) and a non-IEEE 802.11 local area network (LAN) (via a portal). The 802.11s Mesh is not part of the integration service 802.11s delivers MSDUs within the 802.11 network Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.110 Portal The logical point at which the integration service is provided. The term portal is specific for 802.11 A portal is a non-802.11-to-802.11 bridge Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

3.16 Basic Service Set (BSS) July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.16 Basic Service Set (BSS) A set of stations that have successfully synchronized using the JOIN service primitives and one station that has used the START primitive. Membership in a BSS does not imply that wireless communication with all other members of the BSS is possible. The BSS definition is broad BSS = A bunch of stations In a BSS, stations may be able to communicate with each other Via AP Directly BSS description in accordance with 802.11s “Wireless communication” is possible  A link exist between two stations “Wireless communication” is not possible  No link between two stations In 802.11s, Multi-hop enables communication if no link exists Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

3.69 Independent Basic Service Set (IBSS) July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.69 Independent Basic Service Set (IBSS) A basis service set (BSS) that forms a self-contained network, and in which no access to a distribution system (DS) is available. Has a common identifier Stations join an IBSS based on the SSID Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Infrastructure BSS In 802.11-2007, the term does not exist July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Infrastructure BSS In 802.11-2007, the term does not exist It’s the combination of the definitions for Infrastructure BSS Has unique identifier SSID = AP’s MAC address A BSS where all frames are exchanged via the AP AP operates as relay for all associated stations Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

3.54 Extended Service Set (ESS) July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.54 Extended Service Set (ESS) A set of one or more interconnected basic service sets (BSSs) that appears as a single BSS to the logical link control (LLC) layer at any station associated with one of those BSSs. An ESS is the union of the BSSs connected by a DS. The ESS does not include the DS. ESS = {BSS0  BSS1  …  BSSn} Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

3.53 Extended Service Area (ESA) July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 3.53 Extended Service Area (ESA) The area within which members of an extended service set (ESS) may communicate. An ESA is larger than or equal to a basic service area (BSA) and may involve several basic service sets (BSSs) in overlapping, disjointed, or both configurations. In an ESA, connectivity to a specific 802.11 is available Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Annex M.4, Integration service versus bridging July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Annex M.4, Integration service versus bridging There are a number of differences between the 802.11 Integration Service and the service provided by an 802.1 bridge. In the 802.11 architecture, a Portal provides the minimum connectivity between an 802.11 WLAN system and a non-802.11 LAN. Requiring an 802.1D bridge in order to be compliant with 802.11 would unnecessarily render some implementations non-compliant. The most important distinction is that a Portal has only one "port" (in the sense of 802.1D, for example) through which it accesses the DS. This renders it unnecessary to update bridging tables inside a Portal each time a STA changes its association-status. That is, the details of distributing MSDUs inside the 802.11 WLAN need not be exposed to the Portal. The decision to distinguish between an 802 bridge and an 802.11 portal is due to historic reasons “… unnecessarily render some implementations non-compliant” The portal does not know about the DS Details about DS are hidden to portal DS works transparently to portal Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Annex M.4, Integration service versus bridging July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Annex M.4, Integration service versus bridging Another difference is that the DS is not an IEEE 802 LAN (although it carries IEEE 802 LLC SDUs). Requiring that the DS implements all behaviors of an 802 LAN places an undue burden on the architecture. Finally, it is an explicit intent of this standard to permit transparent integration of an 802.11 WLAN into another non-802.11 LAN, including passing Bridge Protocol Data Units through a Portal. While an implementer may wish to attach an 802.1D bridge to the Portal (note that the non-802.11 LAN interface on the bridge need not be any particular type of LAN), it is not an architectural requirement of this standard to do so. The DS remains unspecific A logical concept May be filled by 802.11s? Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Conclusions on IEEE 802.11 definitions July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Conclusions on IEEE 802.11 definitions Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Generic terms In 802.11, everything is an STA July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Generic terms In 802.11, everything is an STA “Any device that contains an IEEE 802.11-conformant MAC and PHY interface to the WM.”  Way too broad for 802.11s Fun in 802.11, fun for 802.11s? non-AP STA non-HC STA non-MP STA non-Portal STA non-Portal MP non-AP MP non-QoS STA … Do we really want to define all these categories? Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Transparent operation July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Transparent operation 5.1.1.4 Interaction with other IEEE 802 layers IEEE 802.11 is required to appear to higher layers [logical link control (LLC)] as a wired IEEE 802 LAN. Ok … No problem for 802.11 How about 802.11s? Tough goal In accordance: IEEE 802.11s is required to appear to higher layers (LLC) as a wired IEEE 802 LAN Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Basic building block 5.2 Components of the IEEE 802.11 architecture July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Basic building block 5.2 Components of the IEEE 802.11 architecture […] The basic service set (BSS) is the basic building block of an IEEE 802.11 LAN. 802.11 knows different types of BSSs IBSS, infrastructure BSS, QBSS etc. We can extend the BSS concept Introduce the Mesh BSS Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Implications for 802.11s July 2008 July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Implications for 802.11s Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Issues with current definitions July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Issues with current definitions What is a WLAN? 802.11 defines the WLAN system Broad term, includes almost anything Too generic What is a Mesh? Not a well defined term What’s a WLAN Mesh? Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 One example … The default values used by non-AP STAs and MPs for the parameters in the EDCA Parameter Set element are defined in Table 7-37. The text indicates that two categories exist: non-AP STAs non-AP MPs Here, both categorizes shall have the same behavior. However, one might ask if that is a general assumption? Is any description for the non-AP STA mandatory for the non-AP MP too? Is it necessary to explicitly state “non-AP STA and MP”? If not, what applies to the MP? Do we need to check all occurences of non-AP STA in 802.11-2007? Do we need to add non-AP MP in this places too? Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Where do we fit in? Notice the terms! Relay Intra BSS July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Where do we fit in? Notice the terms! Relay Intra BSS Figure taken from 802.11-2007 Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Simple modifications for 802.11s July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Simple modifications for 802.11s Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Mesh STA & Mesh BSS Replace the term “Mesh Point” with “Mesh Station” July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Mesh STA & Mesh BSS Replace the term “Mesh Point” with “Mesh Station” Derive definition for a set of Mesh STAs  Mesh BSS The term “station” is well defined  802.11s should build on it A set of Mesh stations communicates in a Mesh BSS Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Mesh Point or Mesh Station? July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Mesh Point or Mesh Station? Mesh Point Defines its own device category class Unique and new In mathematics, an n-tuple defines a point No two points are equal In a BSS, the AP is unique STAs are not unique A BSS may have multiple STAs but only one AP Mesh STA In accordance with other STA definitions Mesh devices do not provide access service Prevent confusion with AP definition Mesh has no unique devices All devices are equal No “singularity”  Mesh device closer to station than to access point specification Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Mesh BSS Can be easily extended Introduce a new term July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Mesh BSS Introduce a new term Mesh BSS Either you are in the Mesh BSS or you’re not Only mesh devices can be in the Mesh BSS No need to hassle with non-MP, non-AP, non-XYZ terminology Can be easily extended HT mesh station (802.11n & 802.11s compliant entity) Consistent with 802.11n definitions 802.11y & 802.11s Dependent mesh STA Etc. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Why Mesh BSS? In an Independent BSS there are Stations only July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Why Mesh BSS? In an Independent BSS there are Stations only See 802.11 definitions In an Infrastructure BSS there is only one AP & one or more Stations In an ESS there are APs & Portals only In an 802.11s network there are MPs only No integration of non-Mesh STAs into Mesh BSS Consistent terminology: Mesh BSS Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Why Mesh BSS (continued)? July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Why Mesh BSS (continued)? What’s a BSS? See previous pages  BSS is a well defined term in 802.11 Make terminology consistent with 802.11 language Let’s use the right term! Let’s define a definition that fits! Let’s define the Mesh BSS! Straight forward thinking! Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Straightforward … Independent BSS (IBSS) Mesh BSS (MBSS) Only STAs July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Straightforward … Independent BSS (IBSS) Only STAs No APs, Portals etc. Mesh BSS (MBSS) Only Mesh Stations No APs, Portals etc. Mesh MP1 MS MP2 MBSS Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Proposed Definitions July 2008 July 2008 doc.: IEEE 802.11-08/xxxxr0 Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Proposed definitions in tight accordance with 802.11-2007 July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Proposed definitions in tight accordance with 802.11-2007 We refer to [2] that will become 802.11-2007 On pages with two column notation Left hand column has original text Highlighted text provides original version Right hand column holds proposed definitions Highlighted text indicates changes Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Proposed Terminology July 2008 Single-hop Multi-hop doc.: IEEE 802.11-08/xxxxr0 July 2008 Proposed Terminology Single-hop Multi-hop Centrally controlled Infrastructure BSS (AP for authentication, power save support; HC for QoS guarantee etc.) Relay BSS (RBSS) (yet not defined by 802.11; could be devices that operate on behalf of an AP) Decentrally controlled Independent BSS (IBSS) (Shared responsibility for beaconing, power saving, common denominator etc.) Mesh BSS (MBSS) (Mesh Stations according to 802.11s, autonomous forwarding, independent medium access etc.) Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Proposed terms Mesh station (Mesh STA) If needed Mesh BSS July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Proposed terms Mesh station (Mesh STA) Operates in an Mesh BSS Forwards frames Participates in mesh formation If needed Multilink station (Multilink STA) Operates in a Mesh BSS Does not forward frames Mesh BSS A set of mesh stations (Mesh STAs) and/or multilink stations (Multilink STAs) Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

QoS Station  Mesh Station July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 QoS Station  Mesh Station 802.11-2007 Quality of service (QoS) station: A station (STA) that implements the QoS facility. A QoS STA acts as a non-QoS STA when associated in a non-QoS basic service set. 802.11s Mesh station (MSTA): A station (STA) that implements the Mesh facility. An MSTA that operates in the Mesh BSS may provide the distribution services for other MSTAs. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 IBSS  MBSS 802.11-2007 Independent basic service set (IBSS): A basis service set (BSS) that forms a self-contained network, and in which no access to a distribution system (DS) is available. 802.11s Mesh basic service set (MBSS): A basic service set (BSS) that forms a self-contained network of Mesh Stations (MSTAs), and which may be used as a distribution system (DS). Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Distribution system service (DSS) July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Distribution system service (DSS) 802.11-2007 Distribution system service (DSS): The set of services provided by the distribution system (DS) that enable the medium access control (MAC) to transport MAC service data units (MSDUs) between stations that are not in direct communication with each other over a single instance of the wireless medium (WM). These services include transport of MSDUs between the access points (APs) of basic service sets (BSSs) within an extended service set (ESS), transport of MSDUs between portals and BSSs within an ESS, and transport of MSDUs between stations in the same BSS in cases where the MSDU has a multicast or broadcast destination address or where the destination is an individual address and the station is associated with an AP. DSSs are provided between pairs of IEEE 802.11 MACs. 802.11s Distribution system service (DSS): The set of services provided by the distribution system (DS) that enable the medium access control (MAC) to transport MAC service data units (MSDUs) between stations that are not in direct communication with each other over a single instance of the wireless medium (WM). These services include transport of MSDUs between the access points (APs) of basic service sets (BSSs) within an extended service set (ESS), transport of MSDUs between portals and BSSs within an ESS, transport of MSDUs between mesh stations (MSTAs) of mesh basic services sets (MBSSs) and transport of MSDUs between stations in the same BSS in cases where the MSDU has a multicast or broadcast destination address or where the destination is an individual address and the station is associated with an AP. DSSs are provided between pairs of IEEE 802.11 MACs. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 ESA  MBSSA 802.11-2007 Extended service area (ESA): The area within which members of an extended service set (ESS) may communicate. An ESA is larger than or equal to a basic service area (BSA) and may involve several basic service sets (BSSs) in overlapping, disjointed, or both configurations. 802.11s Mesh BSS service area (MBSSA): The area within which members (mesh stations) of a mesh basic service set (MBSS) may communicate. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Wireless distribution system  ? July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Wireless distribution system  ? 802.11-2007 Wireless distribution system (WDS): A mechanism for wireless communication using a four address frame format specified in this standard. This standard describes such a frame format, but does not describe how such a mechanism or frame format would be used. Kill the term, or 802.11s Wireless distribution system (WDS): A mechanism for wireless communication using a four address frame format specified in this standard. This standard describes such a frame format. This standard describes its usage for mesh stations (MSTAs) only. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Additionally, if needed Non-forwarding Mesh Station  Multilink Station 802.11s (proposed) Mesh station (MSTA): A station (STA) that implements the Mesh facility. An MSTA that operates in the Mesh BSS may provide the distribution services for other MSTAs. 802.11s Multilink Station (MLSTA): A station (STA) that implements the Mesh facility. An ML STA that operates in the Mesh BSS but does not provide the distribution services for other MSTAs or MLSTAs. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Backup B – Background Info July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Backup B – Background Info Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 N.2 Terminology […] The DS enables communication between MUs and the construction of collections of APs. To enable communication between MUs and a non-IEEE-802.11-LAN entity requires the presence of a (logical) portal from the DS to the non-IEEE-802.11 LAN. […] Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

6.1, Fig. 1 Reference model according to [1] July 2008 July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 6.1, Fig. 1 Reference model according to [1] Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Bridge vs. Distribution System July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Bridge vs. Distribution System An 802 bridge connects 802 networks The DS is a logical concept that connects 802.11 networks and (via a portal) non-802.11 networks Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Backup C – Comments July 2008 July 2008 doc.: IEEE 802.11-08/xxxxr0 Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Annex C – Comments The following pages copy some randomly selected comments that 802.11s received during its second letter ballot. The comments address issues with the 802.11s terms and definitions. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1867 Comment MPs set the ESS and IBSS subfields to 0 in transmitted Beacon and Probe Response management frames. Recommended Change An MP can be an AP, and this conflicts with the first sentence. Reword: “An MP that is a non-AP STA sets the ESS and IBSS subfields to 0 in transmitted Beacon and Probe Response management frames.” It’s not easy for non-802.11s members to understand the MP concept Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

CID 1949 We didn’t do our homework to explain the 802.11s concepts July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1949 Comment This subclause talks about each PHY on a different channel, but it fails to acknowledge that there is a 1:1 correspondence between MAC and PHY - i.e. there are no rules in the MAC that allow a MAC entity to talk to multiple PHY entities on different channels (e.g. channel access and NAV are clearly channel specific). Furthermore, the architecture is silent on whether an MLME can be shared between multiple MAC entities. I believe some of the state in the MLME is clearly MAC-instance specific (e.g. TSF time), while others may not be. There are no clause 10 interfaces that would allow a dual-channel devices to bridge mesh management frames between different MLME instances. Recommended Change Draw me an architecture including multiple PHY instances and tell me whether there are one or more MAC instances (I won't believe any answer that says there's a single MAC instance), and one or more MLME instances. If there are more than one MLME instance provide the interfaces at the top of the MLME to bridge the Mesh management frames betweent the different instances. If there is a single MLME instance, update the MLME description to describe how it manages multiple MAC instances. We didn’t do our homework to explain the 802.11s concepts Multi-radio solutions are not well explained Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

CID 1816 Mesh network? Mesh? Mesh BSS? Mesh as adjective? Meshing? July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1816 Comment In the same paragraph in 5.2.11.2 and elsewhere it appears the terms “mesh network” and “mesh” are being used interchangeably. This is confusing. Recommended Change Suggest only use “mesh” as an adjective (mesh network, mesh point, etc) and use “mesh network” throughout when referring to the network itself. This may help is reducing confusion and circular definitions. Mesh network? Mesh? Mesh BSS? Mesh as adjective? Meshing? That’s all very mes{s|h}y … Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1793 Comment What is the correct name for "the Address 3" field. The figure shows the text "BSSID" being deleted but the text talks about "Address 3 (BSSID) field" and in bullet d) it talks about the BSSID field. Recommended Change I would suggest that on line 17 you state "The Address 3 (BSSID) field of the management frame is set to the BSSID and is determined as follows:", on bullet d) change "BSSID filed" to "Address 3 (BSSID) field", and then on line 44 replace "Address 3" with "Address 3 (BSSID)" BSSID? We failed to explain what kind of network (BSS?) 802.11s defines. Readers do not understand our basic concepts Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

CID 1781 Mesh network? Mesh? Mesh BSS? Mesh as adjective? Meshing? July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1781 Comment The definition of mesh leads to circular definitions - it points to mesh points (which points to mesh services) and mesh services which in turn points to mesh. Also should this rather be "mesh network" rather than "mesh" Recommended Change Change to definition of "mesh network", using similar text to that in 5.2.11.2, so that the other definitions become meaningful rather than circular. Mesh network? Mesh? Mesh BSS? Mesh as adjective? Meshing? That’s all very mes{s|h}y … Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

CID 1757 Comment Recommended Change July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1757 Comment the term "proxy MP" is used in a number of places but it is never defined properly Recommended Change Define "proxy MP" Once more we didn’t do our home works … Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

CID 1470 Replacing MP by the term Mesh STA is simple July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1470 Comment If we need to replace "non-AP STAs " by "non-AP STAs or MPs" then regretfully I fear that there are hundreds of instances where this change is needed. Recommended Change Judging by the size of the document, this work may not be complete. If required, please audit every instance of non-AP STA in your baseline (including 11k, 11r, 11y, 11v?, 11u?, 11p?) and correct where needed Replacing MP by the term Mesh STA is simple Solves our problems Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

CID 1459 Comment Recommended Change July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1459 Comment An MP is always a STA. STA or MP = STA. Thus I assume something extra is meant here - what? "non-AP STA or MP" Recommended Change fix Replacing MP by the term Mesh STA is simple Solves our problems Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

CID 1271 802.1 has a well defined set of terms July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1271 Comment The term "End-user devices" is ambiguous. Such a device could be end stations or access units per the preceding paragraph. Clarify with a non-ambiguous term. Suggest tying the text back to the previous paragraph by reusing the term introduced there, i.e., "end stations". Recommended Change change "End-user devices" to "end stations" [two instances] 802.1 has a well defined set of terms 802.11s often violates the 802 generic language Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1266 Comment Figure s1 confuses the notion of the logical AP entity with the physical implementation of an Access Unit device (which contains an AP). APs don't connect to an external network they connect to the DS, which further connects to a non-802.11 LAN via a portal. Recommended Change There are a couple of different ways to fix the figure. Either relabel the AP boxes in the figure as Access Units (and show the AP as a sub-box within each Access Unit) [note, even that isn't fully correct, but at least it is consitent in so far as the detail it shows], or show the APs connecting to a common DS, which in turn connects to the "external", or non-802.11 network via a portal. Once in sponsor ballot, we could delay until forever if we do not precisely define our boundaries Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 CID 1188 Comment The statement "STAs associate with APs to gain access to the network.", especially as backed up by Figure s2 on page 6, seems to assume that STAs versus APs and STAs versus MPs are disjoint. But APs and MPs are STAs also. Recommended Change Replace with "STAs that are neither APs nor MPs associate with APs to gain access to the network." or the like. 802.11s must be careful about the current 802.11 WG understanding of APs and STAs Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Backup E – Easily resolvable issues July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Backup E – Easily resolvable issues Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Annex E – Easily resolvable issues July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Annex E – Easily resolvable issues The following pages contain some issues that can be easily addressed with simple changes of the 802.11s terminologies. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

7.3.2.29 EDCA Parameter Set element July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 7.3.2.29 EDCA Parameter Set element 802.11s The default values used by non-AP STAs and MPs for the parameters in the EDCA Parameter Set element are defined in Table 7-37. Will become No change to 802.11-2007 necessary Sentence can be deleted from 802.11s Well defined in 802.11-2007 MSTA is non-AP STA Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

7.1.3.1.6 Power Management field July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 7.1.3.1.6 Power Management field 802.11s A value of 1 indicates that the STA or MP will be in PS mode. A value of 0 indicates that the STA or MP will be in active mode. This field is always set to 0 in frames transmitted by an AP. Will become No change to 802.11-2007 necessary Sentence can be deleted from 802.11s Well defined in 802.11-2007 Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

7.2.1.4 PS-Poll frame format 802.11s What is an MP outside a mesh? July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 7.2.1.4 PS-Poll frame format 802.11s When the frame is transmitted by an MP in a mesh, … What is an MP outside a mesh? A STA? Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Backup H – History July 2008 July 2008 doc.: IEEE 802.11-08/xxxxr0 Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

MP – Where does the name come from? July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 MP – Where does the name come from? In May 2004, some members of the Mesh SG developed a set of terms. In the beginning, the group considered the PAR as the basic source for its definitions. Since the PAR described a mesh built by Access Points (APs), the basic entity was denoted as Mesh Access Point (MAP). In the following discussion, however, the group argued that the AP functionality might not be mandatory to participate in a mesh. Especially, it seem to be desirable to provide a device category that would relay data between MAPs without the device itself being an AP. Thus, the term “access” was stripped of the MAP and the “Mesh Point” (MP) was born. Thus, the MP definition relates back to the old PAR. While the initial the creation of the term MP happened more or less by accident, the current PAR does no longer foresee a mesh that solely bases on APs. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Backup P – Project Authorization Request July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 Backup P – Project Authorization Request Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

PAR – 5.4 Purpose July 2008 Old version Current version doc.: IEEE 802.11-08/xxxxr0 July 2008 PAR – 5.4 Purpose Old version The IEEE 802.11-1999 (2003 edition) standard provides a four-address frame format for exchanging data packets between Access Points (APs) for the purpose of creating a Wireless Distribution System (WDS), but does not define how to configure or use a WDS. The purpose of the project is to provide a protocol for auto-configuring paths between APs over self-configuring multi-hop topologies in a WDS to support both broadcast/multicast and unicast traffic in an ESS Mesh using the four-address frame format or an extension. Current version The IEEE 802.11 standard provides a four-address frame format for exchanging data packets between stations for the purpose of creating a Wireless Distribution System (WDS), but does not define how to configure or use a WDS. The purpose of this amendment is to provide a protocol for auto-configuring paths between stations over self-configuring multi-hop topologies in a WDS to support both broadcast/multicast and unicast traffic in a Mesh using the four-address frame format or an extension Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

PAR – 5.5 Need for the Project July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 PAR – 5.5 Need for the Project At present, standard Wireless Local Area Network (WLAN) infrastructure is interconnected using Ethernet Local Area Networks (LANs) and is, therefore, fixed. One trend is toward increased information bandwidth, accompanied by a commensurate reduction in communication range, but with no lesser requirement for communication coverage. The other is the trend toward mobile computing applications that will require mobile infrastructure in addition to mobility for end users. In both instances, Mesh provides a solution via multi-hop wireless delivery among WLAN stations. Using Mesh, coverage within a house, a hospital, a hotel, an airport, a neighborhood, a campus, etc., may be extended wirelessly and without manual configuration other than setting the SSID (Service Set Identifier) and/or AP introduction. Mesh also supports a new class of IEEE 802.11 applications that require untethered/unlicensed infrastructure. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

PAR – 7.4 Additional Explanatory Notes July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 PAR – 7.4 Additional Explanatory Notes This PAR modification is to revise multiple sections so that P802.11s (Mesh Networking) will be applicable to 802.11 stations, rather than being restricted to Access Points and Extended Service Sets. In addition, document references and the expected Sponsor Ballot and Completion dates are updated to reflect the current estimated schedule for P802.11s. Item 5.2, Scope of the Project: An IEEE 802.11 Mesh is a collection of stations interconnected with wireless links that enable automatic topology learning and dynamic path configuration. The proposed amendment shall be an extension to the IEEE 802.11 MAC (Medium Access Control). The amendment will define an architecture and protocol for providing an IEEE 802.11 Mesh using the IEEE 802.11 MAC to create an IEEE 802.11 Wireless Distribution System that supports both broadcast/multicast and unicast delivery at the MAC layer using radio-aware metrics over self-configuring multi-hop topologies. A Mesh is functionally equivalent to a wired ESS, with respect to the non-Mesh Stations (STAs) relationship with the Basic Service Set (BSS) and ESS. The amendment shall enable interoperable formation and operation of a Mesh, but shall be extensible to allow for alternative path selection metrics and/or protocols based on application requirements. A target configuration is up to 32 devices participating as forwarders in the Mesh. However, larger configurations may also be contemplated by the standard. It is intended that the architecture defined by the amendment shall allow a Mesh to interface with higher layers and to connect with other networks using higher layer protocols. The amendment shall utilize existing IEEE 802.11 security mechanisms, or an extension thereof, for the purpose of securing a Mesh in which all of the stations are controlled by a single logical administrative entity for security. The amendment shall allow the use of one or more IEEE 802.11 radios on each station in the Mesh. Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

Backup R – References July 2008 July 2008 doc.: IEEE 802.11-08/xxxxr0 Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips

References [1] IEEE 802-2001 [2] IEEE 802.11-2007 July 2008 doc.: IEEE 802.11-08/xxxxr0 July 2008 References [1] IEEE 802-2001 [2] IEEE 802.11-2007 [3] IEEE 802.11s/D2.00 [4] 11-06-1371-01-000s [5] IEEE 802.11s PAR Version 2004 and 2006 Guido R. Hiertz et al., Philips Guido R. Hiertz et al., Philips