Mobilkommunikation: Drahtlose LANs Drahtlose LANs (3. Teil) 7.0.2 Bluetooth.
Performance Characterization of Voice over Wireless LANs Lionel PEREZ June 2nd, 2005.
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Transcript of Performance Characterization of Voice over Wireless LANs Lionel PEREZ June 2nd, 2005.
Performance Characterization of Voice over Wireless
LANsLionel PEREZ
June 2nd, 2005
Master Thesis Project - Lionel Perez – June 2005 — 2
Agenda
> Abstract
> Specific Tasks
> Available Material
> Achieved Tasks
> References
> Support
> Related Work
Master Thesis Project - Lionel Perez – June 2005 — 3
Abstract
> VoIP over WLANs, the « killer application »
> Inexpensive and convenient mobile telephony
> Good voice quality required for success
> Can IEEE 802.11 WLANs provide such quality?
Master Thesis Project - Lionel Perez – June 2005 — 4
More parameters than wired LAN !
> Loss, Delay, Jitter
> Impact of rate adaptation, power management on loss, delay, jitter
> Impact of encrypction on loss, delay, jitter
> Impact of RTS/CTS on loss, delay, jitter
> Association performance, Authentication performance,
> Roaming time, Rate adaptation time,
> QoS (EDCF, WMM, WMM-SA)
> Packet size
Master Thesis Project - Lionel Perez – June 2005 — 5
Abstract
> Purposes of the project:
• Characterize the performance of a telephony solution based on Voice over IP over Wireless LANs (VoWLAN)
• Conduct measurements and simulation to identify the most significant parameters impacting voice quality
• Market and Strategy requirements:– Avoid time and cost-intensive tests– Independence from OEMs
Master Thesis Project - Lionel Perez – June 2005 — 6
Proposed Tasks 1/2
> Learn about the relationship between traffic parameters (delay, jitter, packet losses) and voice quality (MOS ,E-model: R-Value)
> Explore different scenarios that directly impact these parameters:• the QoS mechanisms implemented (802.11e)?• the security features (802.11i)?• 802.11a,b or g ?• the codec (opt)?• the signalling protocol (opt)?
Master Thesis Project - Lionel Perez – June 2005 — 7
Proposed Tasks 2/2
> Perform measurements of these parameters under the different possible considerations
> Use the ns2 network simulator or other (OMNET++?) to model and simulate some of these configurations
>Define key tests to be conducted in order to ensure a given performance
Master Thesis Project - Lionel Perez – June 2005 — 8
Available Material
> The « alpha test »: the VoWLAN solution deployed in our premises
> The «platform» (testing lab)
> PCs and laptops equiped with NICs
> Wireless Switches, Access Points, Wifi phones
> Professional measurement tools:• 2 Veriwave Tests Units• Wildpacket’s Airopeek• Airmagnet Laptop• Ixia Ixchariot
Master Thesis Project - Lionel Perez – June 2005 — 9
Achieved Tasks
> Bibliographical Research Complete
> Read the key articles
> Understand the available tools
> Discover ns2
> During the internship:• Discover Alcatel’s VoWLAN Solution• Evaluate Sigmum Wiplan (Planning Software)• Conduct Site Surveys• Basic mock-up configuration• The VoWLAN toolkit
Master Thesis Project - Lionel Perez – June 2005 — 10
Related Work
> “Can I add a VoIP call?”, S. Garg and M. Kappes
> Voice over IEEE 802.11b Capacity, Coupechoux, Kumar, Brignol (Alcatel), 2004
> Simulation of 802.11e
> Basic security features (WEP)
> New QoS mechanisms?
> New Security mechnisms?
> New Power Management mechanisms?
Master Thesis Project - Lionel Perez – June 2005 — 11
Support
> Supervisor:• Michel Mouton
> Additional Support:• Jean-Michel Lauriol• Daniel Le Bars• The WLAN team: Architecture, QoS, Security,
Interoperability, OXE/OXO
Master Thesis Project - Lionel Perez – June 2005 — 12
Thank you.
Master Thesis Project - Lionel Perez – June 2005 — 13
OXE-WLAN solution
UA 850000
ACS 172.25.115.226
WLAN OmniAccess
SLK0 855000172.25.114.2109D:28
OmniSwitch Router
SVP Server (with GK)172.25.114.196
Management: Port 1 172.25.115.229Vlan 99Voice:Port 1 172.25.114.197Vlan 31Data:Port 1 172.25.114.34Vlan 30
CS 172.25.114.194GD 172.25.114.195
UA 850001
172.25.114.193
NAT : 172.25.114.210-.219
172.25.114.220-.229
SLK1 855001172.25.114.2119E:69
SLK2 855002172.25.114.212BE:01
IP 853000172.25.114.230
IP 853001172.25.114.231
SLK3 855003172.25.114.213DD:30
172.25.114.33
Vlan Voice:172.25.114.192255.255.255.192
Vlan Data:172.25.114.32255.255.255.240
Vlan Management:172.25.115.229255.255.255.240
172.25.115.225
Laptop172.25.114.35
Radius, TFTP172.25.115.232
OXE