Transcript No Slide Title

VoIP over WLAN;
Technical and Business Issues
Aki Anttila, CTO, Cygate Oy
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
Backoffice
PSTN
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
Codec
Data Rate
(kbps)
MOS
Delay
(ms)
IP Bandwidth
(kbps)
G.711 PCM
64
4,3
0,125
80
G.721 ADPCM
32
4,1
0,125
40
G.726 Multirate
ADPCM
16-40
2,0-4,3
0,125
20-50
G.723 MP-MLQ
ACELP
5,3 or
6,3
4,1
70
16,3-17,1
G.728 LD-CELP
16
4,1
2
32
G.729 CS-ACELP
8
4,1
20
24
G.729a CSACELP
8
3,4
20
24
GSM RPE-LPC
13
3,9
30
?
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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 same
L2 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
802.1x Authentication
OK
EAP over RADIUS
Authentication
OK
+ 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
Providing the Network Infrastructure for the Internet Economy
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 Christensen´s ”Innovator´s Solution”
Check one (preferably both):
1)
Is there a number of people that
have not been able to do this thing or
have buyed as a service?
2)
To use the product or the service, the
users have to go to a centralized
location
Failure
Success
Check both:
1)
Is there overserved customer
segment that would buy worse and
cheaper product?
2)
Can we make a business model that
is profitable with lower gross
margins?
Check this:
1)
Is the innovation disruptive to ALL of
the players in the industry?
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Success
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
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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)?
Providing the Network Infrastructure for the Internet Economy