doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 1
TGaq Mini TutorialDate: 2013-11-13
Name Company Address Phone email
Stephen McCann Blackberry Ltd 200 Bath Road, Slough, Berkshire, SL1 3XE, UK
+44 1753 667099 [email protected]
Authors:
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 2
Abstract
TGaq Mini-TutorialSummary of Study Group and Task Group
work to date.
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 3
Rationale
• Existing pre-association GAS provides little detail about network services.
• Current mechanism which is to sequentially associate to available networks for discovery purposes is time consuming and potentially costly.
• Existing peer to peer discovery mechanisms flood the channel with pre-association traffic.
• Need to reduce power consumption through the use of efficient signalling.
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 4
Study Group Phase
• Started November 2012• Service Discovery concept appeared in Fall 2012• Device discovery well established• GAS
– ANQP– RLQP
• Considered mechanisms to discover available services provided by infrastructure.– IMS– Printers
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 5
Development of PAR & 5C
• Occurred about the same time as Service Discovery groups started in the Wi-Fi Alliance.
• No initial intention for Wi-Fi Alliance to build on TGaq. More of a co-incidental start.
• TGaq PAR narrowed to avoid overlaps with Wi-Fi Alliance– Specifically avoid peer to peer service discovery
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 6
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).
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 7
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
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 8
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.
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 9
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 service 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.
doc.: IEEE 802.11-13/1313r2
Submission
Proposed Architecture for 802.11aq• Extend 802.11u to support service discovery or• Define a new Service Discovery Protocol?
Slide 10
STA AP Service
GAS
ANQP…
802.11 Scope Not in Scope of 802.11
Extend ANQP ordefine new servicequery protocol
Service query protocol
Up-layer servicediscovery protocol
Probe
November 2013
Stephen McCann, Blackberry
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 11
AP1
AP2
STA
Network
Local Access Network Service
Transaction Proxy (TPX)
Pre-association Messages
Service Query Messages
doc.: IEEE 802.11-13/1313r2
Submission
STA
AP
Beacon
Probe Proberesponse
Slide 12
STA
S1: AP/Network Discovery + Service Indication
Services from Network
S2: Detailed Service QueryBased on Service Indication
GAS
Recapture: Two step service discovery
Services from associated device
Service Record
Service Indication
Service Indication, e.g. Service Bitmap
Service Indication, e.g. Service Bitmap
November 2013
Stephen McCann, Blackberry
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 13
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
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 14
Construction of Draft
• Build on Specification Framework Document• Normative text submissions considered this week
doc.: IEEE 802.11-13/1313r2
Submission
November 2013
Stephen McCann, BlackberrySlide 15
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
