205:). Some of the responsibilities of a distribution point—such as defining network parameters and other "beaconing" functions—are established by the first station in an ad-hoc network. However, that station does not relay traffic between the other stations; instead, the peers communicate directly with one another. Like an infrastructure BSS, an independent BSS also has a 48-bit MAC-address-like identifier. But unlike infrastructure BSS identifiers, independent BSS identifiers are not necessarily unique: the
241:. Each node may also be an access point hosting its own basic service set, for example using the mesh BSS to provide Internet access for local users. In such a system, the BSS created by the access point is distinct from the mesh network, and a wireless client of that BSS is not part of the MBSS. The formation of the mesh BSS, as well as wireless traffic management (including path selection and forwarding) is negotiated between the
381:
know the SSID beforehand by other means (e.g. from a previous configuration). When a client wishes to associate with a network, it sends the SSID in a probe request. An access point replies with a probe response if the SSID in a probe request is the wildcard SSID (SSID is zero-length) or matches an SSID that the access point supports; otherwise the access point does not respond to the probe request.
31:
173:
infrastructure BSSID is a combination of a 24-bit organizationally unique identifier (OUI, the manufacturer's identity) and a 24-bit serial number. A BSSID with a value of all 1s is used to indicate the wildcard BSSID, usable only during probe requests or for communications that take place outside the context of a BSS.
380:
To associate with a wireless network, a station must know the network's SSID. This information is either obtained from beacons broadcast by an access point (in which case a client can passively infer whether it is in range of that network), or—if no base station is advertising the SSID—a station must
355:
layer. Thus, from the perspective of the logical link control layer, stations within an ESS may communicate with one another, and mobile stations may move transparently from one participating basic service set to another (within the same ESS). Extended service sets make possible distribution services
308:
in the context of beacon announcements, and can be used, for example, in enterprise and mesh networks to steer a client to a particular (e.g. less utilized) access point. A station may also likewise transmit packets in which the SSID field is set to null; this prompts an associated access point to
363:
are, by definition, independent from other BSSs, and an independent BSS cannot therefore be part of an extended infrastructure. In that formal sense an independent BSS has no extended service set. However, the network packets of both independent BSSs and infrastructure BSSs have a logical network
347:) is a wireless network, created by multiple access points, which appears to users as a single, seamless network, such as a network covering a home or office that is too large for reliable coverage by a single access point. It is a set of one or more infrastructure basic service sets on a common
172:
conventions. An infrastructure BSSID is usually non-configurable, in which case it is either preset during manufacture or mathematically derived from a preset value such as a serial number or a MAC address of another network interface. As with the MAC addresses used for
Ethernet devices, an
193:, is created by peer devices among themselves without network infrastructure. A temporary network created by a cellular telephone to share its Internet access with other devices is a common example. In contrast to the stations in an infrastructure-mode network, the stations in a
364:
service set identifier, and the logical link control does not distinguish between the use of that field to name an ESS network, and the use of that field to name a peer-to-peer ad hoc network. The two are effectively indistinguishable at the logical link control layer level.
638:
The owner of a Wi‑Fi access point can opt it out of Apple's
Location Services — which prevents its location from being sent to Apple to include in Apple's crowd-sourced location database — by changing the access point's SSID (name) to end with
276:, such as English. The 802.11 standards prior to the 2012 edition did not define any particular encoding or representation for SSIDs, which were expected to be treated and handled as an arbitrary sequence of 0–32 octets that are not limited to
108:
is a subgroup, within a service set, of devices that share physical-layer medium access characteristics (e.g. radio frequency, modulation scheme, security settings) such that they are wirelessly networked. The basic service set is defined by a
291:
Since the contents of an SSID field are arbitrary, the 802.11 standard permits devices to advertise the presence of a wireless network with beacon packets in which the SSID field is set to null. A null SSID (the SSID element's
78:)—typically the natural language label that users see as a network name. (For example, all of the devices that together form and use a Wi‑Fi network called "Foo" are a service set.) A service set forms a logical network of
117:) shared by all devices within it. The BSSID is a 48-bit label that conforms to MAC-48 conventions. While a device may have multiple BSSIDs, usually each BSSID is associated with at most one basic service set at a time.
356:
such as centralized authentication. From the perspective of the link layer, all stations within an ESS are all on the same link, and transfer from one BSS to another is transparent to logical link control.
309:
send the station a list of supported SSIDs. Once a device has associated with a basic service set, for efficiency, the SSID is not sent within packet headers; only BSSIDs are used for addressing.
197:
communicate directly with one another, i.e. without a dependence on a distribution point to relay traffic between them. In this form of peer-to-peer wireless networking, the peers form an
46:). Notebook_My is able to automatically roam between the two BSSs, without the user having to explicitly connect to the second network. Note that in the diagram the incorrect label
165:
type discussed below.) The operating parameters of the infrastructure BSS are defined by the AP. The Wi‑Fi segments of common home and business networks are examples of this type.
844:, IEEE Standard for Information technology—Telecommunications and information exchange between systems, New York, NY: The Institute of Electrical and Electronics Engineers, Inc,
821:, IEEE Standard for Information technology — Telecommunications and information exchange between systems, Piscataway, NJ: Institute of Electrical and Electronics Engineers,
870:, IEEE Standard for Information technology— Telecommunications and information exchange between systems, Piscataway, NJ: Institute of Electrical and Electronics Engineers,
245:
of the mesh infrastructure. The mesh BSS is distinct from the networks (which may also be wireless) used by a mesh's redistribution points to communicate with one another.
748:
Lindqvist, Janne; Aura, Tuomas; Danezis, George; Koponen, Teemu; Myllyniemi, Annu; Mäki, Jussi; Roe, Michael (2009), "Privacy-preserving 802.11 Access-point
Discovery",
402:
894:
875:
849:
826:
775:
735:
548:"Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Sponsored by the LAN/MAN Standards Committee"
351:(i.e. same IP subnet and VLAN). Key to the concept is that the participating basic service sets appear as a single network to the
914:
812:"Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, Amendment 6 (IEEE Std 802.11p-2010)"
265:
by stations in beacon packets to announce the presence of a network and seen by users as a wireless network name.
403:"Understanding the Network Terms SSID, BSSID, and ESSID – Technical Documentation – Support – Juniper Networks"
360:
194:
753:
861:"Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications (IEEE Std 802.11-2007)"
838:"Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications (IEEE Std 802.11-2012)"
794:
320:
288:
text. Wireless network stacks must still be prepared to handle all possible values in the SSID field.
352:
348:
277:
758:
268:
Unlike basic service set identifiers, SSIDs are usually customizable. These SSIDs can be zero to 32
120:
A basic service set should not be confused with the coverage area of an access point, known as the
811:
781:
213:
bit of the address is always set to 1 (local), and the remaining 46 bits are randomly generated.
860:
168:
Each basic service set has a unique identifier, a BSSID, which is a 48-bit number that follows
82:
operating with shared link-layer networking parameters; they form one logical network segment.
890:
871:
845:
822:
771:
316:
269:
242:
763:
273:
67:
802:
Proceedings of the 5th USENIX Symposium on
Networked Systems Design and Implementation
908:
793:
Murty, Rohan; Padhye, Jitendra; Chandra, Ranveer; Wolman, Alec; Zill, Brian (2008),
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785:
580:
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238:
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454:
452:
169:
837:
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312:
767:
262:
649:
647:
621:
328:
285:
750:
Proceedings of the Second ACM Conference on
Wireless Network Security
17:
30:
742:, Piscataway, NJ: Institute of Electrical and Electronics Engineers
547:
58:
In IEEE 802.11 wireless local area networking standards (including
715:"Tatsächliche und rechtliche Risiken drahtloser Computernetzwerke"
713:
Dornseif, Maximillian; Schumann, Kay H.; Klein, Christian (2002),
281:
280:. IEEE Std 802.11-2012 defines a flag to express that the SSID is
59:
29:
622:"About privacy and Location Services in iOS, iPadOS, and watchOS"
331:
from being included in Apple's crowdsourced location databases.
79:
565:
563:
561:
261:) defines or extends a service set. Normally it is broadcast
810:
Stacey, Robert; Ecclesine, Peter; et al., eds. (2010),
804:, NSDI '08, Berkeley, CA: USENIX Association, pp. 73–88
868:
842:
819:
887:
Interconnecting Smart
Objects with IP: The Next Internet
209:
bit of the address is always set to 0 (individual), the
800:, in Crowcroft, Jon; Dahlin, Mike; et al. (eds.),
740:
IEEE 802 LAN/MAN Standards
Committee Meeting, July 2004
795:"Designing High Performance Enterprise Wi-Fi Networks"
679:
677:
836:
Stephens, Adrian P.; Ecclesine, Peter, eds. (2012),
153:) for other devices to join. (Note that the term
145:is created by an infrastructure device called an
27:Group of all devices on the same wireless network
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885:Vasseur, Jean-Philippe; Dunkels, Adam (2010),
752:, WiSec '09, New York: ACM, pp. 123–130,
518:
300:in IEEE 802.11 standards documents, and as a
272:long, and are, for convenience, usually in a
8:
859:Cole, Terry L.; Barber, Simon, eds. (2007),
569:
161:used for this type of BSS but refers to the
38:called "WiFi Knowledge" consisting of two
757:
394:
373:
48:ESSID (Extended Service Set Identifier)
683:
7:
889:, Burlington, MA: Morgan Kaufmann,
296:field is set to zero) is called a
25:
359:The basic service sets formed in
229:) is a self-contained network of
722:Datenschutz und Datensicherheit
284:-encoded and could contain any
1:
199:independent basic service set
111:basic service set identifier
931:
519:Vasseur & Dunkels 2010
85:A service set is either a
361:wireless ad hoc networks
319:interpret the SSID of a
768:10.1145/1514274.1514293
587:, § 11.1.3.2.1, p. 422.
349:logical network segment
195:wireless ad hoc network
132:Basic service set types
473:, § 4.10.4, pp. 88–90.
434:, § 4.10.3, pp. 84–88.
255:service set identifier
249:Service set identifier
223:mesh basic service set
72:service set identifier
70:devices which share a
55:
52:service set identifier
609:Lindqvist, et al 2009
461:, § 7.1.3.3.3, p. 65.
33:
696:IEEE Std 802.11-2007
669:IEEE Std 802.11-2007
654:IEEE Std 802.11-2007
597:Dornseif, et al 2002
585:IEEE Std 802.11-2007
536:, § 7.3.2.1, p. 101.
534:IEEE Std 802.11-2007
507:IEEE Std 802.11-2012
495:IEEE Std 802.11-2007
483:IEEE Std 802.11-2007
471:IEEE Std 802.11-2012
459:IEEE Std 802.11-2007
444:IEEE Std 802.11-2007
432:IEEE Std 802.11-2012
420:IEEE Std 802.11-2007
353:logical link control
341:extended service set
335:Extended service set
278:printable characters
95:extended service set
915:Wireless networking
734:Edney, Jon (2004),
671:, § 5.2.3.1, p. 26.
446:, § 7.1.3.3, p. 6.
321:Wi‑Fi access point
143:infrastructure BSS
122:basic service area
56:
40:basic service sets
896:978-0-12-375166-9
877:978-0-7381-5656-9
851:978-0-7381-7245-3
828:978-0-7381-6324-6
777:978-1-60558-460-7
736:"What is an ESS?"
570:Murty, et al 2008
317:location services
302:no broadcast SSID
106:basic service set
87:basic service set
16:(Redirected from
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552:IEEE 802.11-2012
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207:individual/group
68:wireless network
34:An example of a
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50:refers to the
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706:Works cited
306:hidden SSID
177:Independent
170:MAC address
163:independent
64:service set
36:service set
684:Edney 2004
389:References
323:ending in
754:CiteSeerX
639:"_nomap."
909:Category
728:(4): 1–5
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313:Apple
282:UTF-8
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634:2024
259:SSID
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