My WiMAX Experiment - Part 4: VoIP Call Quality

Part 4 of my WiMAX Experiment deals with VoIP call quality while using the WiMAX Modem. I have placed a few calls to date and have had some great calls, but also some not-so-great calls. It seems to not only be dependant on my modem reception, but also some unknown factors which I could not quantify.

I thought that I would share recordings of some tests that I did to gauge the call quality relative to a cell phone. Note: they look like flash videos, but there is no video - only sound.

Call #1 - Cell phone call to a Vonage voice mail

• The purpose of this call was to baseline the VoIP call quality relative to a traditional cell call.

Call #2 - Gizmo call via WiMAX to a Vonage voice mail

• The proof is in the pudding, so-to-speak: my first documented test of a VoIP call with the WiMAX modem.

The VoIP call was a little unclear in spots, but I thought it was feasible, even with the latency and bandwidth I can attain with the WiMAX modem. Those initial tests gave me the courage to record a conversation with someone while connected via the WiMAX modem...

Call #3 - a real life Gizmo call to an InternetTabletTalk member via WiMAX!

• I cold-called ITT member, qwavel, by sending him a PM on Internet Tablet Talk. Since he had made some comments on my experiment, I wanted to see if he would be interested in participating in a VoIP call with me. He instantly agreed. Since I did not know of an easy way to record the call on the tablet using Gizmo, he offered to record the call on his end via his Nokia N95. Hats off to qwavel for his enthusiasm and helpful conversation!

The interesting observation I had after listening to this recording was that qwavel sounded pretty clear to me at the time of the call, but on the recording, I sounded distant and broken up frequently. If both voices were relaying through the WiMAX modem, why was there such a difference between my observation during the call, and the subsequent recording?

Stay tuned for Part 5 of my WiMAX Experiment, where I will take the show on the road - literally!