VoIP over WLAN (Voice over IP over Wireless Local Area Network)

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VoIP over WLAN(Voice over IP over Wireless Local
Area Network)
Diplomityöseminaari 1.6.2004 Heikki Hintikka at
Song Networks Oy Supervisor Professor Heikki
Hämmäinen Instructor Pauli Saari, Quality
Management Director
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Contents

• The concept of VoIP over WLAN
• Aims of research, main objectives
• WLAN
• Basics, factors of success, standards and future
• VoIP
• VoIP and speech, protocols, QoS
• Security
• standards methods, currently (encryption,
  authentication), future
• Devices and products
• Deployment environments
• example of hotspot, SOHO environment
• provisioning model
• TESTING (Access Link SOHO environment)
• Markets and forecast

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VoIP over WLAN the concept
VoIP
WLAN
Free phone calls over the Internet No toll
quality voice service like PSTN Used in many
enterprise environments QoS factors very
important for voice quality
Wireless broadband up to 54 Mbps Data rates
depend on distance Standards evolving to meet
user needs Still challenges to face
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Thesis ToC

• 1 INTRODUCTION
• 1.1 Background to VoWLAN
• 1.2 Main issues in VoWLANs
• 1.3 Problem definition
• 1.4 Scope of study
• 1.5 Methodology
• 1.6 Structure of the study
• 2 WLAN
• 3 VoIP
• 4 Usability and Deployment
• 5 Testing of VoWLAN (SOHO environment)
• 6 Market and Business Analysis
• 7 Trends and Forecast

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WLAN (Wireless Local Area Network)

• Benefits
• wireless broadband, low cost equipment,
  easy-to-use
• Drawbacks
• Issues with security, QoS, usability (roaming)
• 3 types of architecture
• Infrastructure
• Ad-hoc
• Mesh networking
• Radio interface frequency bands, channels
• Standard family (IEEE 802.11) evolving

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IEEE 802.11 (WLAN) standards
802.11b DSSS 11 Mbps 2,4 GHz
802.11e
802.11f
802.11i
802.11g
802.11a 54 Mbps 5
GHz OFDM
802.11h
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WLANs four Ss main criterias

• Security
• user data integrity, secure authentication,
  encryption
• Service quality
• real-time applications (voice/video), QoS
• Support
• operational, functionality, interoperability,
  performance
• Scalability
• flexible, easy-to-use services, develop higher
  quality

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VoIP

• Voice over IP networks (RTP/UDP), Internet
  best-effort
• SIP (IETF) and H.323 (ITU-T), multimedia support
• Gaining market space in enterprises
• --gt support for only one network
• An important component in video calls
• Many challenges when transmission media is
  wireless
• QoS parameters (delay, jitter, packet loss)
• Security features increase delay etc.

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QoS (Quality of Service)

• These QoS components ensure the performance of
  voice calls across a data network
• Delay (ms)
• Jitter (ms)
• Packet Loss ()
• Congestion in access points
• WLANs get disturbance of external factors
• Bluetooth, microwave oven, trees, obstacles
• Channel overlapping
• Handover improvement

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Security

• Encryption mechanisms
• WEP Wired Equivent Privacy, weak nowadays
• TKIP Temporary Key Integrity Protocol, taken
  WEPs place
• CCMP / AES (in 802.11i)
• Authentication
• WPA (Wi-Fi Protected Access) port-based 802.1X
  EAPs/TKIP
• 802.11i WPA extension plus other features
• CCMP/AES
• pre-authentication

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Evolution of WLAN security
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Devices and products

• End user devices PDAs, laptops, smart phones
  etc.
• Network elements
• Usability important
• Features and characteristics
• interoperability
• seamless handover
• roaming
• hybrid solutions

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Deployment environments Hotspot example
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Provisioning model one bill roaming
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Testing of VoIP over WLAN - SOHO

• Prioritizing VoWLAN in SOHO environment

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Results QoS parameters delay and jitter
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VoIP prioritizing in hotspots
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Markets forecast

• Markets are growing fast price erosion
• Multiple manufacturers making devices
• inter-network capabilities (GSM/GPRS/CDMA)
• WISPs, network operators, alliances,
• roaming coverage/clients
• Competitors?
• 3G, UWB, Bluetooth, WiMAX
• Different stakeholders in business

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Conclusions and future work

• Conclusions
• Overcoming QoS and security issues in VoWLAN
  designs and implementations
• Overcoming security flaws will be addressed by
  upcoming IEEE 802.11i standard
• technical and economic business issues dealt with
• Essential for providing QoS is to priritize VoIP
  streaming
• Future work
• traffic congestion in QoS guaranteed networks,
  where 802.11e has been implemented
• Roaming, handover time reducement, standard
  affects in general
• Support and interoperability