Mobile voice over Wi-Fi at 130 km/h

Just as I was reading Verizon’s latest proclamation that “with Wi-Fi, you are limited to one spot” (see Verizon’s latest wireless FUD in Texas), in comes a Skype call from Martyn Levy of RoamAD who tells me that the world’s first highway Wi-Fi mobile voice network has been successfully tested on a US interstate highway – the Canamex Interstate Highway (I-19) from Rio Rico to a point south of Green Valley, Arizona. Wi-VOD deployed it using a Department of Homeland Security grant; the network is managed by the Arizona Telecommunications and Information Council. Get this: Wi-VOD claims it was able to make multi-party VoIP conference calls at speeds in excess of 130 kilometres per hour (80mph) sustained over the entire network.

Before you all start yakking on your Wi-Fi PDAs breaking Arizona speeding laws, please note that the network is for public safety personnel (police, fire, ambulance and border partrol) first, with various community agencies, schools, business and local residents being added as the deployment expands beyond its targeted coverage areas. [Attention anti-muni broadband legislators: check out this deployment.]

Commenting on the test, Chief Mike Foster, Rio Rico Fire Department said: “We needed to increase our ability to communicate in the field. Having mobile voice and high-speed Internet access in our mobile units on the highways delivers what we are looking for. The speed at which the mobile VoIP worked was very impressive. It will greatly increase our in-field communications and effectiveness.”

Wi-VOD demonstrated the first phase of the network, 4.9 miles (8 km), earlier this month. The network contained four RoamAD network nodes located on average 1.2 miles (less than 2 km) apart and interconnected wirelessly. The network will be expanded to cover 32 continuous miles (54 km) of highway and is scheduled for completion before May of this year. According to Verizon, this is impossible.

Read more about Verizon’s wireless FUD on Glenn’s site. It’s pretty hilarious after the Rio Rico public safety officers’ experience with mobile Wi-Fi.

UPDATE (7 June 2005): GovTech finally got around to writing about this. Read the article here. There’s a lot of information on where they got the funding:

In May 2004, the Department of Homeland Security’s Information Technology and Evaluation Program (ITEP) announced a grant competition to focus on using IT to improve information sharing and integration, especially among first responders.

The ATIC and GITA applied for a grant to test deployment of a Wi-Fi network along one portion of the CANAMEX Corridor to serve first responders with voice and data transmission.

Last fall, the ITEP awarded the Arizona Division of Emergency Management (ADEM) $499,821 to test the Wi-Fi network. Updike said the ITEP generally disburses grants to agencies that are familiar with the DHS’ administrative processes, so ADEM will administer the grant money, while GITA will oversee the project and ATIC will implement it.


Ken DiPietro of New-ISP, NextGenCommunications writes:

That is a great press release but they are a little late – like four years! As quoted from Steve Stroh’s blog,

“Mobile-enabled BWIA Technology is so available, so off-the-shelf, that I wrote a feature article about it in FOCUS On Broadband Wireless Internet Access… in 2001! The article was a profile of Odessa Office Equipment, a Wireless Internet Service Provider (WISP) serving the Eastern Washington community of Odessa and surrounding areas. Here’s the relevant excerpt from the article:

One of the more startling demonstrations of OOE’s wireless Internet access service that I was given during my stay was mobile wireless Internet access. OOE has outfitted several patrol cars from the local Sheriff’s department for wireless Internet access, which is accessed via existing laptop computers. Reports can be composed in the field, and transmitted via email. Deputy Kelly, who graciously gave me a brief ride to demonstrate the system, was startled when I burst out laughing at the situation of, being mobile in Odessa Washington… I had better [mobile] Internet connectivity than what was available to me at my home in Woodinville, Washington only a few miles away from the high-tech

colossus of Microsoft Corp. in Redmond, Washington. I can attest that mobile Internet access in Odessa Washington works, and works well.

Steve’s blog (and this quote) can be found at


Marlon Schafer says:

For the record my longest mobile wireless link was from a cop car that was approximately 15 miles from the tower site. And yes it’s all at legal power levels. That gives us something like 6000 square miles of coverage now, and one can roam anywhere in it with off the shelf hardware.

Check out:


  1. Wi-Fi: Safe at Any Speed

    RoamAD tested VoIP at 130 kph in Arizona: RoamAD worked with Wi-VOD in Arizona using a Homeland Security grant to test whether multi-party VoIP calls could work at speeds up to 130 km/hour (about 80 mph): I’ll save you the suspense. They did work just…

  2. VoIP over WiFi tested for public safety but at what cost?

    Very geeky. RoamAD and WI-VOD have just finished testing for VoIP over WiFi up to 80mph in Arizona. This was funded by a Homeland Security grant for public safety personnel. Slashdot and WNN via MuniWireless…

  3. Mobile VoIP Over WiFi

    Via Slashdot, MuniWireless is reporting a successful test of multi-party VoIP calls over WiFi at 130 kph.

  4. Driveing and Surfing what could be better~

    According to both Slashdot and MuniWifi this morning the first test of a highway mobile wifi network has been successful…now if only they would build one along my commonly traveled work paths I would be set.

  5. Driving and Surfing what could be better~

    According to both Slashdot and MuniWifi this morning the first test of a highway mobile wifi network has been successful…now if only they would build one along my commonly traveled work paths I would be set.

  6. I dont get it … why do people think WiFi has a particular speed limit? As if you could actually out run the packets in your car.

    Unless you placed access points every 2 feet, roaming is not going to be a problem.

    Nevermind the fact that a DSSS 802.11 radio signal can withstand a very large amount of doppler shift without any noticable impact.

  7. […] Note: Martyn Levy of RoamAD is here with me at the Muniwireless Atlanta Conference. He will be talking about a public safety network in Rio Rico, Arizona that uses RoamAD equipment — for mobile VOIP! I have previously written about the Rio Rico project (“Mobile Voice over Wi-Fi at 130km/h”). In Municipal Wireless/Projects Posted Monday, March 6, 2006 […]