Wireless Device
Convergence
Spring 2005 CSG Meeting
Jim Jokl
[email protected]
1
UVa Perspective / Background
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Initial interest to deploy an integrated Wireless
Office solution in the late 1990s
Goal – better support for mobile users
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Tight integration with campus PBX
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No/low-cost for on-campus wireless calls
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Dial plan
Voice mail
Calling features (hold, forwarding, transfer, etc)
Fund/deploy in-building wireless cellular coverage
Standard cell phone when used off-campus
Very close in RFP process with two vendors at
different times
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One vendor lost project funding during the .com bust
2
Some Intermediate Devices
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Symbol NetVision phone
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Cisco 7920 phone
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Used our Cisco Call Manager
No voice mail integration with main
system
Vocera
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Used our Cisco Call Manager
No voice mail integration with main
system
Implements its own voice mail,
text messaging, etc
Compaq iPAQ with VoIP software
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iPAQ also enabled messaging
applications (email & calendar) and
web access
3
Some Intermediate Devices
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Blackberry
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Palm Treo
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Early devices were primary for messaging
Phone available on some models now
Messaging and cellular voice services
T-mobile and iPAQ 6315
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Voice and access to cellular-based messaging
WLAN access for normal Pocket PC applications
Shifts automatically between cellular and WiFi
internet access
4
Integrated WLAN VoIP and Cellular
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Nokia announcement a couple of years ago
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Seemed to imply that they were going to develop an
integrated Cellular and WLAN VoIP device
Quiet with no additional information for a long time
Communicator 9500 promised for 2005
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Cellular and WLAN radios
Email: POP3, IMAP4
Browsing
Camera, messaging, etc
Usual office-type support tools (spreadsheet, etc)
However, no mention of WLAN VoIP; instead appears to
be a competitor to the iPAQ
5
Technical Background
Wireless Transmission Standards
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On the cellular side
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GSM (Global System for Mobile Communication)
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Used widely in the rest of the world
A few carriers in the US use GSM
 Cingular/AT&T
 T-Mobile
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CDMA (Code Division Multiple Access)
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Not widely used outside of the US
Quite common in the US
 Sprint PCS
 Verizon
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GSM data throughput somewhat slower than
that of CDMA
6
Technical Background
Wireless Transmission Standards
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On the WLAN side
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802.11 b/g
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11 or 54 Mbps peak speed in the 2.4 GHz band
Three non-overlapping channels available for RF
coverage design and handling peak loads
Interference often exists due to multiple services that
operate in this band
802.11a
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54 Mbps peak speed in 5 GHz band
Twelve non-overlapping channels available
Typically covers ½ to ⅔ of the area of 802.11 b/g
Relatively free from interference
7
Current Motivations for Integration
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Original Wireless Office goals
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Tight PBX integration, single voice mail, dial plan, calling
features, etc
Lower cost for on-campus wireless calls
Additional drivers
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Messaging (email and calendar) integration
In-building cellular coverage is problematic in many
university buildings
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Enhance cellular or WLAN coverage?
Need for superior in-building capacity to remove legacy
phones
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Leaky coax cellular solutions support a limited number of
simultaneous calls
Voice over WLAN can support many calls per AP
8
Current Motivations for Integration
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Additional drivers continued
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Cost
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Estimates are that 1/3 of cellular calls are within the
boundaries of an enterprise
This percentage would likely grow if in-building calls
were perceived as free by the cell phone user
9
Critical WLAN Issues for VoWLAN
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Access point placement to meet call
density needs
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802.11b can support ~8 calls per access point
802.11g and 802.11a can support ~20 calls
per access point
Mechanisms to protect portable device
battery life
 WLAN roaming within a building and
across subnets
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10
Critical WLAN Issues for VoWLAN
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Wireless LAN QoS
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SpectraLink Voice Priority Protocol (SVP)
WiFi Alliance
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WME (Wireless Media Extensions)
Four priorities (voice, video, best effort, and low)
802.11e standard in progress
Wireless LAN Security
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Authentication & encryption
WiFi Alliance WPA (Wi-Fi Protected Access)
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EAP for authentication, TKIP for encryption
802.11i standard is ratified
11
Interesting Solution
Avaya, Motorola, Proxim System
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Overall solution implements
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Automatic roaming between cellular and WLAN
networks
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Call handoff between cellular and WLAN networks
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Roaming within the WLAN network
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Single phone number
Single voice mail box
Data messaging services (Email, calendar,
directory access, etc)
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12
Interesting Solution
Avaya, Motorola, Proxim System
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Motorola
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Converged handset
Wireless Services Manager
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Avaya/Proxim
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WLAN to Cellular handoffs
SIP proxy/registrar/subscriber configuration
Access points and gateways that provide QoS, security,
roaming, call admission control, and device power
management features
Avaya
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Avaya Communications Manager
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Telephony features, part of cellular/WLAN handoff, E911
13
Interesting Solution
Avaya, Motorola, Proxim System
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Wireless: GSM and 802.11a
Battery life
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50 – 80 hours standby
150 – 190 minutes talk time
Security: WPA and EAP-TLS
QoS: pre-802.11e
SIP for VoWLAN
Windows CE .NET
Browser: HTML & WAP 2.0
Email client, calendar sync
14
Some Q&A on the
Motorola, Avaya, Proxim System
CDMA support is planned but no timeline is
available
 802.11a is the planned WLAN radio
infrastructure
 Timeline: summer/fall 2005
 Proprietary vs. standards-based technology
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Power management work contributed to
802.11e and 802.11k
Pre-authentication fast roaming work submitted
to 802.11r
15
Summary
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The Motorola, Avaya, Proxim group
appears to be furthest along in this space
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but talk to your favorite vendors …
What about the big wireless carriers?
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Do they consider this a good idea?
Consider home users over the long run
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Remember that these devices are provide
both converged voice and data
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Expect to see lots of new products and
services in this space over the next few
years
16
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Questions / discussion
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Thanks
17