VoIP over WLAN; Technical and Business Issues Aki Anttila, CTO, Cygate Oy

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VoIP over WLAN Technical and Business
IssuesAki Anttila, CTO, Cygate Oy
Forget 3G!
Enter VoWLAN!
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Agenda

• Motivation for this work
• VoIP-WLAN network architecture
• Technical aspects
• Business aspects
• Some new rivalries
• Conclusions

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Motivation of this work

• 3G seems to be coming
• too many trials, too many orders
• it will happen, no matter what (even without
  killer app)
• 3G is overly complex
• 3G is not designed for IP
• nor is IP designed for 3G
• Clearly, there is a need for disruption
• VoIP has already shown some maturity
• WLAN has gained significant interest
• how about combining these?

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Network architecture
PSTN
Backoffice
Serving IP network
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Technical aspects

• Each will be detailed in a later slide
• coverage
• capacity
• interference
• MAC
• roaming
• security
• MTS
• end user devices

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Coverage
Bad signal strenght
Excellent signal strenght
Remember that signal quality affects data rates
as well!
Moderate signal strenght
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Capacity
IP Bandwidth (kbps)
Delay (ms)
MOS
Data Rate (kbps)
Codec
80
0,125
4,3
64
G.711 PCM
40
0,125
4,1
32
G.721 ADPCM
20-50
0,125
2,0-4,3
16-40
G.726 Multirate ADPCM
16,3-17,1
70
4,1
5,3 or 6,3
G.723 MP-MLQ ACELP
32
2
4,1
16
G.728 LD-CELP
24
20
4,1
8
G.729 CS-ACELP
24
20
3,4
8
G.729a CS-ACELP
?
30
3,9
13
GSM RPE-LPC
8
Interference
Solution Move to 5 GHz!
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Channel MAC

• Original DCF
• implemented in all devices
• created for data traffic
• Original PCF
• not implemented, suitable for real-time traffic
• New EDCF
• support for eight traffic classes
• New HCF
• support for eight traffic classes
• support for DiffServ/IntServ

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Roaming

• ESS is a collection of APs that are connected via
  sameL2 technology (Ethernet)
• Mobility between ESS is handled via Mobile IP

Coverage area 1
Coverage area 2
Coverage area 3
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Security
EAPOW
EAP over RADIUS
improvements into RC4 cipher
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Equipment

• Mobile Telephone Switch
• SoftSwitch
• IP-PBX
• SIP server
• End device
• pure VoIP-WLAN phone
• already exists
• integrated VoIP over GPRS/WLAN/UMTS phone

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Summary of technical issues

• Already done
• end devices, MTS
• security
• roaming
• Still need to be addressed
• coverage
• capacity
• interference
• MAC

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Business aspects

• Based on Christensens Innovators Solution

• Check one (preferably both)
• Is there a number of people that have not been
  able to do this thing or have buyed as a service?
• To use the product or the service, the users have
  to go to a centralized location

Success

• Check both
• Is there overserved customer segment that would
  buy worse and cheaper product?
• Can we make a business model that is profitable
  with lower gross margins?

Failure

• Check this
• Is the innovation disruptive to ALL of the
  players in the industry?

Success
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Three categories

• Enterprises
• passes with flying colours
• Consumers
• more problematic to find a need
• Operators
• clear need exists for smaller ones
• but how to find a market?

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Competing technologies
IEEE 802.20 MBWA
VoIP over Bluetooth
3G
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Conclusions

• VoIP over WLAN is an emerging market
• there are still technical hurdles to pass
• time will take care of these
• from business side, it seems to be disruptive but
  only for business users
• thus limiting the disruptiveness of the whole
  scheme
• Choice is a difficult one
• too many technologies
• VoWLAN, VoBT, 3G, 802.20, 802.16(?)
• integration into PBX systems?
• fall back to number one (2G, 2,5G, 3G)?