802.11u
What is IEEE 802.11u?
IEEE 802.11u is an amendment to the Wi-Fi standard that enables interworking with external networks and improves network discovery and selection.
When was 802.11u introduced?
It was ratified in 2011 to enhance seamless roaming and network selection for Wi-Fi clients.
What problem does 802.11u solve?
It facilitates better integration between Wi-Fi and cellular networks, enabling automatic network discovery, selection, and connection.
How does 802.11u improve network discovery?
It provides mechanisms for access points to advertise information about network capabilities, roaming agreements, and available services before association.
What is Access Network Query Protocol (ANQP)?
ANQP is a feature introduced in 802.11u that allows clients to query APs for detailed network information before connecting.
Does 802.11u support Hotspot 2.0?
Yes, 802.11u is a foundational standard for Hotspot 2.0, which enables seamless Wi-Fi roaming and authentication similar to cellular networks.
How does 802.11u help with seamless roaming?
By enabling pre-association querying of network info and supporting automatic network selection, it facilitates smoother transitions between Wi-Fi networks.
Which OSI layer does 802.11u operate on?
It operates primarily at the Data Link Layer (Layer 2), enhancing MAC layer functions for network discovery and selection.
Is 802.11u backward compatible?
Yes, devices and networks without 802.11u support can still operate normally, but without the enhanced interworking features.
What kind of information can ANQP provide?
ANQP can provide info about roaming consortiums, network authentication methods, IP address types, and more.
Does 802.11u improve security?
It does not directly enhance encryption but supports better network selection to avoid insecure networks.
How does 802.11u relate to cellular networks?
It enables Wi-Fi networks to advertise roaming agreements and facilitates offloading traffic from cellular to Wi-Fi.
Can 802.11u be used in enterprise networks?
Yes, enterprises can use 802.11u features to provide seamless guest access and network selection.
Is 802.11u required for Hotspot 2.0?
Yes, Hotspot 2.0 depends on 802.11u for its network discovery and roaming capabilities.
What devices support 802.11u?
Modern smartphones, tablets, and Wi-Fi access points supporting Hotspot 2.0 usually implement 802.11u.
Does 802.11u impact battery life?
It can reduce power consumption by allowing devices to select optimal networks quickly.
How does 802.11u improve user experience?
By enabling automatic network selection and seamless roaming, it provides faster, more reliable Wi-Fi connections.
Is 802.11u widely adopted?
Adoption is growing, especially in public hotspots and cellular offloading scenarios, often as part of Hotspot 2.0.
Topics in this section,
In this section, you are going to learn
Terminology
Version Info
rfc details
setup
setup
mac features
Medium Access Functions and their inner working
Supported Frequency Bands in 802.11u
List of Physical Features
Power Saving Mechanisms in IEEE 802.11u
Interoperability Mechanisms in IEEE 802.11u
End-User Products that support 802.11u
Protocol Packet Details
Basic Features
Reference links