1. 8/9/ :45-3:30pm
Integrating WiFi Telephony Into the Enterprise Communications Infrastructure Organizations are become increasingly aware of the benefits VoIP provides as a collaborative communication tool. Those businesses that demand communicative flexibility and efficiency are now beginning to examine new wireless technologies to help meet these needs. The introduction of new wireless VoIP solutions can now offer the type of vital integration and convergence of multiple communication tools that today’s mobile business must have to be successful. This session will cover the development of wireless VoIP solutions, as well as the issues you need to consider before implementing a wireless communication solution: including network assessment, varying approaches to wireless design, securing your wireless network and the potential return on a wireless investment.
This will be a shared session with Spectralink.  NEC will speak first from 2:45-3:05 and Spectralink will follow from 3:05-3:25, with a 5 minute Q&A at the end.

2. Tom Grady
Product Manager
NEC Unified Solutions

3. Integrating WiFi Telephony Into the Enterprise Communications Infrastructure

4. Voice User Requirements
Coverage and Bandwidth specific to voice traffic
Site survey for voice different than for data (higher BW requires higher signal strength)
IP assessment on wired network for VoIP support may be needed
Security
Network security more intrusive to voice latency and jitter concerns
Encryption and authentication add CPU latency to voice stream
Quality of Service
Delay and jitter negatively impact voice as opposed to data
Must give priority to voice traffic over data
Admission control important in dense user environment
Mobility
Voice traffic on wireless network introduce new layers of service requirements above data traffic requirements

5. Network requirements for voice
Must Consider
Latency- the time it takes to get information through a network
Jitter- if a network provides various latency for different packets, it introduces jitter
Packet Loss- packets lost due to collisions or retransmissions
AP Handoff- the time it takes a device to re-associate and re-authenticate at Layer 2
Wireless Network Requirements for Voice
Maximum jitter < 5 msec
Maximum latency < 50 msec
Maximum Packet Loss < 1%
AP handoff < 50 msec

6. Wireless Voice Considerations
No time for retransmission of lost or corrupted packets
Real-time, full duplex voice conversations require voice packets to received within tens of milliseconds
Users are extremely very mobile
Frequent handoffs
Real-time application
Coverage issues are audible
Poor voice quality creates the perception of substandard product
Cover all user-accessible areas
Stairwells, bathrooms, break rooms and lobby areas must have coverage

7. A Site Survey Is Essential To Assure Operational and
Remember…
A Site Survey Is
Essential To Assure
Operational and
Deployment Success!!
The unfortunate thing is that this is true only for a centralized provider – someone who has to worry about consistent performance over larger areas. Definitely NOT true for the “local” early adopter folks.

8. Voice has Different Requirements
Signal Strength – “smaller” number is better (stronger signal)
Data WLAN: -85dBm
Voice WLAN: -65 to -70dBm with 15% - 25% cell overlap
Signal-to Noise Ratio – higher is better
Data WLAN: 15dB
Voice WLAN: 20dB minimum for good quality voice calls
Interference
Eliminate overlapping channel interference with proper channel assignments
Data Rate – depends on radio type – a/b/g
Will be affected by network load

9. Power and Range 11 Mbps DSSS 5.5 Mbps DSSS 2 Mbps DSSS
feet
5.5 Mbps DSSS
feet 100mW
11 Mbps DSSS
feet 100mW
Speed is determined by proximity (plus other factors)
Voice Traffic

10. Design Approaches Consider: Number of potential concurrent clients
Voice clients
Available vs. concurrent
Consider second or third overlapping access point
Consider output power constraints
Reduce cell size, hence number of concurrent clients

11. Why do a Wireless Site Survey?
To accurately determine:
The number and placement of access points (AP’s) needed for required coverage and throughput.
Where “blind spots” are, so you can avoid them.
Are there any unauthorized AP’s (rogues) already connected to your network?
Is there any RF interference present?
Big surprises during deployment are no fun and often costly

12. The Final Solution
220 feet

13. To recap… A wireless site survey accurately determines:
The number of access points (AP’s) needed for adequate coverage.
The placement of access points (AP’s) for coverage and throughput.
Where “blind spots” are, so you can avoid them.
Are there any “rogues” already connected to the network?
Is there any RF interference present?
Are there other networks in the vicinity?

14. QoS Considerations for High Quality Voice
Admission Control is required
Streaming applications need priority service
Bandwidth management required to maximize capacity and minimize contention
Battery life must be maximized
Traffic is predictable
Schedule periods of “sleep” are possible
VoIP Bandwidth Control
Dynamic QoS
Fast Handoff

15. VoWLAN: Mobility & Fast Roaming
Wireless voice users must be free to roam
Fast roaming requires sub 150ms handoffs; ideally <50ms
No dropped calls due to roaming across layer 2 AP
No dropped calls due to subnet roaming
Must be able to support security options within fast roaming constraints

16. Security Considerations for Voice
Security threats
Intercepting telephone calls is expensive relative to the value of the information
Access to corporate network is the primary issue
Usability
No established paradigm for “logging in” to a telephone
Minimize handoff duration
Clients are highly mobile
Packets have a limited useful life
Streaming application have low delay tolerance
Application specific devices
Handsets do not necessarily use standard PC operating systems
Handheld devices may have limited processing power, memory constraints, and battery life issues

17. Security Components Information access protection Key management
Encryption algorithm “scrambles” data into unintelligible information using a “key”
Data is unencrypted using the same key at the receiving end
Key management
Process for providing keys at each end of the secured link
Provides mechanism for changing keys at appropriate intervals
Authentication
Mechanism to verify identity of users
Prevents “man in the middle” attack
Message integrity
Verifies that the information current
Prevents replay or “cut and paste” attacks

18. Wi-Fi Protected Access (WPA)
Defined by the Wi-Fi Alliance
Mandatory for Wi-Fi certification
Based on IEEE i
Intended to be software/firmware upgrade from WEP for legacy wireless devices
Key elements
802.1x authentication
Extensible Authentication Protocol – Transport Layer Security (EAP-TLS) for authentication management systems
Pre-Shared Key (PSK) for real-time applications
Encryption and key rotation
Temporal Key Integrity Protocol (TKIP)
RC-4 encryption algorithm
Validation
“Michael” message integrity check (MIC)

19. Security Ramifications for Voice
Handoff authentication delay must be addressed for enterprise applications
Pre-shared key (WPA/WPAII)
Usability issues
Simple user login process
Device design
Additional processing power and memory requirements

20. Value Proposition
To build a solution platform that enables converged mobility to penetrate multiple verticals and unifies voice, multimedia and data in the wireless workspace while enabling robust mission-critical business applications and solutions
NEC's strategy is to provide the best of breed products and solutions to our customers.
Airespace
Spectralink
Vocera
We will continue to build products as well as partner with those in the industry we feel will provide our customers a total solution

21. Converged Mobility – ROI in HealthCare
2003
2006
Source: Office of Medicare and Medicaid Financing