1. Multicast over WLAN Date: 2005-05-11 Authors: May 2005 March 2005
doc.: IEEE /0169r0
May 2005
Multicast over WLAN
Date:
Authors:
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Jesse Walker, Intel
Lars Falk, TeliaSonera

2. Omer Ben-Shalom Dave Brooks Kevin Heine Jesse Walker Intel Corporation
May 2005
Multicast over WLAN
Omer Ben-Shalom
Dave Brooks
Kevin Heine
Jesse Walker
Intel Corporation
Jesse Walker, Intel

3. Multicast over WLAN Problem Statement
May 2005
Multicast over WLAN
Problem Statement
Multicast is becoming a required capability for
Corporate broadcast from CEOs,
Delivery of Live conference,
Group business updates, etc.
Mesh routing
802.11e standard will not provide QoS for multicast to work over the WLAN.
Multicast-based applications appear to break when there are 2 or more client STAs
Jesse Walker, Intel

4. Multicast over WLAN The Data
May 2005
Multicast over WLAN
The Data
Empirical Data comparison from LAN to WLAN
LAB Data details packet analysis
Single client association and multiple client association included in the comparisons
Jesse Walker, Intel

5. Multicast over Ethernet ~100Kbps bandwidth
May 2005
Multicast over Ethernet ~100Kbps bandwidth
Recovered and Lost is 0
Provides Excellent User Experience
Frame Rate and Actual Rate nearly the same
Jesse Walker, Intel

6. Multicast over WLAN(11b) Single Client Association 100Kbps bandwidth
May 2005
Multicast over WLAN(11b) Single Client Association 100Kbps bandwidth
Recovered = 129 Lost = 24
User Experience Acceptable
Frame rate and Actual rate nearly the same
Jesse Walker, Intel

7. Multicast over WLAN(11b) Multiple User Association
May 2005
Multicast over WLAN(11b) Multiple User Association
Recovered = 116
Lost = 527
User Experience Unacceptable to many frame drops video and audio freezes
Frame rate and Actual rate a major problem
Jesse Walker, Intel

8. Multicast over WLAN(11a) Single User
May 2005
Multicast over WLAN(11a) Single User
Recovered = 74 Lost = 37
User Experience Good – slightly better that 11b single user
Frame rate and Actual rate nearly the same
Jesse Walker, Intel

9. Multicast over WLAN(11a) Lab detailed results Single User on AP
May 2005
Multicast over WLAN(11a) Lab detailed results Single User on AP
Packet Capture Data Filtered by Protocol
Multicast packets = purple line
X-Axis Time Frame Seconds
Jesse Walker, Intel

10. Multicast over WLAN(11a) Multiple-User Association
May 2005
Multicast over WLAN(11a) Multiple-User Association
Packet Capture Data Filtered by Protocol
Multicast packets cyan colored line – with lots of drops in packets
X-Axis Time Frame in Seconds
Jesse Walker, Intel

11. Multicast over WLAN Summary
May 2005
Multicast over WLAN
Summary
Multicast does work over WLAN on either A or B radios with a single user associated on an AP
Multicast appears to become un-useable with multiple client associations on an AP.
We do not know yet whether this is an implementation or a specification error
If this behavior is a specification error, then the IEEE WG needs to address the observed performance of multicast traffic with multiple users.
Jesse Walker, Intel