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TGaq Mini Tutorial. Authors:. Date: 2013-11-13. Abstract. TGaq Mini-Tutorial Summary of Study Group and Task Group work to date. Rationale. Existing pre-association GAS provides little detail about network services.
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TGaq Mini Tutorial Authors: Date: 2013-11-13 Stephen McCann, Blackberry
Abstract TGaq Mini-Tutorial Summary of Study Group and Task Group work to date. Stephen McCann, Blackberry
Rationale • Existing pre-association GAS provides little detail about network services. • Current mechanisms sequentially associate to available networks for discovery purposes. These are time consuming and potentially inefficient. • Existing peer to peer discovery mechanisms flood the channel with pre-association traffic. • Need to reduce power consumption through the use of efficient signalling. Stephen McCann, Blackberry
Study Group Phase • Started November 2012 • Service Discovery concept appeared in Fall 2012 • Device discovery well established • GAS – Generic Advertisement Service • ANQP – Access Network Query Protocol (11u) • RLQP – Registered Location Query Protocol (11af) • Considered mechanisms to discover available services provided by infrastructure. • IMS – IP Multimedia Subsystem • Printers Stephen McCann, Blackberry
There is interest in service discovery in the industry • IEEE 802.11 • Created new TGaq based on PAR: • 11-12-1081-06-0pad-draft-par-proposal.doc • WFA • Sent Liaison to WFA (Nov 2012) and requested feedback. • 11-12-1389-00-0000-liaison-to-wfa-802-11aq-par.doc • No comments were returned. • IETF • RFC 6763 – DNS Service Discovery • Wireless Broadband Alliance • Next Generation Hotspots, for network discovery and selection Stephen McCann, Blackberry
TGaq Scope • This amendment defines modifications to the IEEE 802.11 standard, above the physical layer (PHY), to enable delivery of pre-association Service Discovery information by IEEE 802.11 stations (STAs). Stephen McCann, Blackberry
Progress to date • Use cases collected (22) • Use case analysis complete • 11-13-0118-00-00aq-summary-of-pad-sg-use-cases.ppt • Use case analysis document • Main features of use cases at MAC layer • 11-13-0125-06-00aq-use-case-analysis.docx • Terminology document • Re-using IEEE definitions where available • 11-13-0299-03-00aq-draft-tgaq-terminology.docx • Specification Framework Document • In progress at an early stage • 11-13-0300-01-00aq-proposed-specification-framework-for-tgaq.docx Stephen McCann, Blackberry
Example Use Case • You enter IEEE meeting hotel and want to find a printer • You notice that there are many WLANs in the hotel • Networks with printers: • Hyatt: The hotel printer (free for hotel guest and 24/7 availability) • Verilan: The printer in IEEE staff office (located in a secured environment, available 9am-5pm to non-IEEE-staff) • FedEx/Kinko’s Office WLAN with one printer associated with (not free, office hours only; but has richer features) • and many other networks (e.g. AT&T) without printers. • association may require payment, only to discover that printer service is inappropriate • Problem is to determine which network to use prior to selection: • It is 1pm. You are sensitive to the security. • It is 9pm. You want high-quality print-out and cost is not an issue. • It is 11pm. You are sensitive to costs. Stephen McCann, Blackberry
Initial Proposals • Pre-association messages (PAD) • Likely to be based on GAS • Container MAC protocol to carry upper layer service discovery protocols (e.g. UPnP, Bonjour) • Provisioning and configuration of services in AP • Proxy service server connected to AP • Universal identification of services • Use a hashing algorithm • UUID, a reverse domain notation, a registry of service IDs. • Broadcast Concept • Advertisement of service information through broadcast frames. Stephen McCann, Blackberry
Proposed Architecture for 802.11aq • Extend 802.11u to support service discovery or • Define a new Service Discovery Protocol? 802.11 Scope Not in Scope of 802.11 STA AP Service Service query protocol ANQP… GAS Probe Extend ANQP or define new service query protocol Up-layer service discovery protocol Stephen McCann, Blackberry
Recapture: Two step service discovery Services from Network STA GAS AP STA Services from associated device Service Record S1: AP/Network Discovery + Service Indication S2: Detailed Service Query Based on Service Indication Service Indication, e.g. Service Bitmap Service Indication, e.g. Service Bitmap Service Indication Beacon Probe Probe response Stephen McCann, Blackberry
Other Concepts • Peer Service Discovery (PSDisc) design framework • Independent mode discovery (few STAs) • Server mode discovery (many STAs) • Provisioning of Services by Associated STAs • Registration with an AP or Proxy Server • SoftAP operation • Indicate provision of Internet connectivity • Indicate upper layer support • Lightweight and energy efficient method is desirable • Pre-association discovery for neighboring APs • Do PAD when the STA is still in association Stephen McCann, Blackberry
Construction of Draft • Build on Specification Framework Document • Normative text submissions considered this week Stephen McCann, Blackberry
Timeline – November 2013 • Approval of PAR & 5C: November 2012 • Initial TG meeting: January 2013 • Initial Working Group Letter Ballot: July 2014 • Re-circulation Working Group Letter Ballot: November 2014 • Form Sponsor Ballot Pool: May 2015 • Mandatory Editorial Check: November 2015 • Initial Sponsor Ballot: November 2015 • Sponsor Ballot Recirculation: January 2016 • Final WG/EC Approval: May 2016 • RevCom/Standards Board Approval: May 2016 Stephen McCann, Blackberry
802.11u: Advertisement Protocols ANQP Access Network Information STA AP GAS RLQP Registered Location Information PADP Beacon Service Information Probe Probe response
802.11aq: Architecture Service Information STA AP GAS Services from associated device STA Service Record S1: AP/Network Discovery + Service Indication S2: Detailed Service Query Based on Service Indication Service Indication, e.g. Service Bitmap Beacon Probe Probe response