doc.: ieee 802.11-13/1061r0 submission september 2013 jeongki kim, lg electronicsslide 1 multicast...
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doc.: IEEE /1061r0 Submission Real-time multicast/broadcast services in HEW usage models Video/audio streaming is the main application in HEW usage models [1] –1a (stadium): Users are receiving VHD video feed highly compressed –1b (stations): TV, VOD, Video conference; VHD highly compressed - 50% of users –1c (exhibition): VOD; VHD highly compressed - 60% of users –1d (shopping mall): highly compressed web video, Multicast –1e (e-education): Video streaming among teacher and students –…. Unicast transmission becomes inefficient when the same content is streamed to dense STAs HEW needs to consider an efficient method to support multicast/broadcast services in dense WLAN September 2013 Jeongki Kim, LG ElectronicsSlide 3TRANSCRIPT
doc.: IEEE 802.11-13/1061r0
Submission
September 2013
Jeongki Kim, LG ElectronicsSlide 1
Multicast Transmission for HEW
Date: 2013-09-16Authors:
Name Affiliations Address Phone EmailJeongki Kim LG Electronics
19, Yangjea-daero 11gil, Seocho-gu,
Seoul 137-130, Korea
[email protected] Park LG Electronics [email protected] Kim LG Electronics [email protected] Ryu LG Electronics [email protected] Cho LG Electronics [email protected]
doc.: IEEE 802.11-13/1061r0
Submission
Abstract
• This contribution introduces an efficient multicast transmission method in dense WLAN environment.
September 2013
Slide 2 Jeongki Kim, LG Electronics
doc.: IEEE 802.11-13/1061r0
Submission
Real-time multicast/broadcast services in HEW usage models
• Video/audio streaming is the main application in HEW usage models [1]
– 1a (stadium): Users are receiving VHD video feed highly compressed – 1b (stations): TV, VOD, Video conference; VHD highly compressed - 50% of users– 1c (exhibition): VOD; VHD highly compressed - 60% of users– 1d (shopping mall): highly compressed web video, Multicast– 1e (e-education): Video streaming among teacher and students– ….
• Unicast transmission becomes inefficient when the same content is streamed to dense STAs
• HEW needs to consider an efficient method to support multicast/broadcast services in dense WLAN
September 2013
Jeongki Kim, LG ElectronicsSlide 3
doc.: IEEE 802.11-13/1061r0
Submission
Multicast/broadcast in legacy system (1/2)
September 2013
Slide 4
• Group addressed TX in 802.11-2012[2]– If any STA in its BSS is in PS mode, the AP shall buffer all group
addressed BUs (GA BUs) and deliver them to all STAs immediately following the next Beacon frame containing a DTIM transmission• The lowest DTIM Interval is the Beacon Interval (e.g., 100ms) • Jitter/delay of the video traffic: < 10 or 20 ms [1]
* GA BUs: Group addressed bufferable units
Jeongki Kim, LG Electronics
doc.: IEEE 802.11-13/1061r0
Submission
Multicast/broadcast in legacy system (2/2)
September 2013
Jeongki Kim, LG ElectronicsSlide 5
• GCR-SP in 802.11aa [3]– GCR-SP (groupcast with retries – service period) transmits GCR group
addressed frames at intervals, where the interval between transmissions might be smaller than the beacon interval.
* GA BUs: Group addressed bufferable units
doc.: IEEE 802.11-13/1061r0
Submission
Problem definition
September 2013
• Contention with unicast traffic– Unexpected STA’s transmission interferes the resources allocated by GCR-SP
• e.g., power saving STAs, other BSS STAs– Multicast transmission is deferred if channel is occupied by unicast traffic– Contention with unicast traffic becomes severe in dense WLAN environment,
which degrades multicast service quality* GA BUs: Group addressed bufferable units
Jeongki Kim, LG ElectronicsSlide 6
doc.: IEEE 802.11-13/1061r0
Submission
Enhanced multicast for HEW• Dedicated multicast channel
– Channel on which AP sends multicast data and non-AP STA is not allowed to access• Unicast service is provided in non-dedicated multicast channel
– A STA performs association in the primary channel• Detailed structure and procedure on dedicated multicast channel is FFS
– How to implement unicast service and multicast service (e.g., multiple RFs)– How not to allow non-AP STA’s access to dedicated multicast channel – How to transmit the multicast data on dedicated multicast channel (e.g.,
reusing/enhancement of legacy methods)– How to use the dedicated multicast channel among neighbor BSSs
• Dedicated multicast channel usually considers planned deployment– e.g., stadium, concert hall
September 2013
Jeongki Kim, LG ElectronicsSlide 7
doc.: IEEE 802.11-13/1061r0
Submission
Dedicated multicast channel example
• Use cases– Venue: Stadium, Concert hall– Applications: Live video/audio
(e.g., live camera feeds, ESPN/MLB live Broadcast)
• Deployment example– Four available channels– One dedicated multicast channel– Two RFs in AP– Channels can be configured by
venue owner or WLAN provider at installation
September 2013
Jeongki Kim, LG ElectronicsSlide 8
doc.: IEEE 802.11-13/1061r0
Submission
Conclusion
• Multicast/broadcast transmissions are considered in many HEW usage models
• Dedicated multicast channel is proposed to avoid quality degradation of multicast service by contention with unicast traffic
• Need more discussion on the following issues:– How to provide coexistence between unicast and multicast service– How not to allow non-AP STA’s access to dedicated multicast channel– How to transmit the multicast data on dedicated multicast channel– How to use dedicated multicast channel in OBSSs
September 2013
Jeongki Kim, LG ElectronicsSlide 9
doc.: IEEE 802.11-13/1061r0
Submission
References
• [1] IEEE 802.11-13/0657r6 Usage models and requirements for IEEE 802.11 High Efficiency WLAN study group (HEW SG)
• [2] IEEE Std 802.11TM-2012• [3] IEEE Std 802.11aaTM-2012
Jeongki Kim, LG ElectronicsSlide 10
September 2013