Participating Vendors
Hitachi Cable, SpectraLink and Vocera Communications
TESTING SCENARIO
We tested Vo-Fi devices on our Cisco WLAN infrastructure, which consisted of a Cisco 4402 Wireless LAN controller communicating over LWAPP to dual-band Cisco 1240AG APs, and our Asterisk PBX. To assess voice quality we used Agilent's Voice Quality Tester Telegra-R, which sends a prerecorded human voice through each handset and assigns a MOS (mean opinion score) to the received signal. We worked inside an RF-shielded chamber.
We generated background traffic by having Ixia's Chariot 5.0 send a 100-kilobyte file for the duration of our testing.
To test for QoS we connected the handsets to our Agilent Voice Quality Tester and placed a call with a SIP-based Polycom IP500 connected over Ethernet to our Asterisk PBX. In scenarios with QoS disabled, each handset was associated to one SSID configured to use the Silver (Best Effort) QOS profile. Where QoS was enabled, we associated each handset to an SSID with QOS profile Platinum (Voice), which provided priority queuing for voice packets.
We measured roaming performance using Azimuth Systems' Phone Roaming script and two Cisco 1240AG APs, one on Channel 1 and the other on Channel 11, placed in isolation chambers and connected over RF cables to the Azimuth chassis. Through the use of variable attenuators, the Azimuth system moved one AP closer to the VoFi phone while moving the other away by increasing or decreasing path loss.
For unsecured roams, we configured our infrastructure with open authentication and encryption disabled. For secure roams we used WPA-PSK (TKIP-based) encryption, which involves only AP-to-handset interaction and forgoes 802.1x back-end infrastructure concerns that can add to roaming times.
For a more on the test specifics, go to nwcreports.com.
SCORING CRITERIA
We did not issue a report card.
RESULTS
Hitachi Cable's WirelessIP5000E Vo-Fi handset doesn't require back-end gateways or telephony servers. If you want direct, standards-based integration into an existing PBX, the IP5000 is appealing. Hitachi's handset is ahead of the curve in wireless standards support and security features, and the company blew away the competition on price because its IP5000 handsets do not need a back-end server.
SpectraLink NetLink system is available in two versions, to support circuit-switched PBXs through the NetLink Telephony Gateway or for direct communications between handsets and an IP PBX. We found voice quality consistently high in all scenarios except when QoS mechanisms were disabled. We also got a peek at SpectraLink's OAI (Open Application Interface) Gateway, which lets third-party applications send and receive text messages from NetLink handsets.
The Vocera Communications System is unique, using small, lightweight speaker-phone badges and voice recognition to allow hands-free communications. This is particularly useful in verticals, such as retail and health care, where mobile workers must remain accessible but on the move. Vocera supports WEP, WPA-PSK and 802.1X mechanisms including EAP-LEAP and EAP-PEAP for wireless security, and we found the speech-recognition system effective and intuitive.
Find our complete product evaluation at NWCREPORTS.COM. Go to nwcanalytics.com for our original in-depth research and analysis on the Vo-Fi arena.
