CableMatrix bringing cable telephony to WiMAX

Voice over IP may not be in the WiMAX certification queue for some time, but CableMatrix has delivered up a policy management engine that it says will deliver VoIP over Fixed and Mobile WiMAX networks today.

CableMatrix isn't a VoIP company per se, rather it's a policy management software provider that powers online gaming, video conferencing, streaming media and traffic prioritization — basically any service that relies on quality of service to ferry its packets across the network. As its name implies, CableMatrix cut its teeth in the cable industry, supplying the policy engine behind cable providers' packet telephony service. It's expanding from the realm, though, and according to Jay Malin, vice president of business development, it's ready to tackle the newest of access technologies, WiMAX.

It may not appear so at first glance, but DOCSIS is surprisingly similar to IEEE 802.16e in its delivery of packets, Malin said. CableMatrix is simply extending that cable expertise to the new technology. Although that may seem like a complete shift in customer focus, Malin said CableMatrix has found many of its cable customers are interested in WiMAX as a way to extend their networks to businesses and areas not easily connected to the existing cable plant.

“A lot of cable companies are already in the WiMAX Forum,” Malin said. “We would be in an ideal situation to help those companies looking for a dual-access solution.”

In fact, CableMatrix has built an access-agnostic solution, designed to integrate with the IP multimedia subsystem solutions carriers are weighing today. So CableMatrix could use its policy manager to extend the same application over either pipe, whether it be VoIP, gaming or video.

CableMatrix' manager runs in the network core, where it is alerted every time a call is placed. The manager then sends a message to the VoIP application server, which sends a message back to a scheduler at the base station. The scheduler reserves bandwidth over the access pipe, and then provisions that video as soon as the application server alerts the scheduler the call has been answered. From the CableMatrix engine's point of view, it doesn't matter if it's scheduling that bandwidth from the base station or the cable modem termination system.

The tricky thing is when WiMAX starts going mobile. Although the CableMatrix engine can easily trade off applications between the wireless and cable networks, it hasn't yet had to deal with handing off between base stations on a single network. While CableMatrix hasn't decided on a definitive mechanism for dealing with WiMAX's mobile ways, it will likely use its manager software to allocate bandwidth simultaneously on both WiMAX base stations as a customer crosses one cell edge to another. It's a complicated procedure, but certainly not impossible, Malin said.