CTIA: Acme Packet prepares for voice over LTE

Acme Packet (NASDAQ:APKT) has upgraded its Net-Net Session Director for voice over long-term evolution (LTE), anticipating a wave of new VoIP deployments in the next two years as its operators roll out the all-IP mobile broadband architecture. The session border controller (SBC) now supports the 3GPP’s single-radio voice call continuity (SRVCC) function, which allows the IP Multimedia Subsystem (IMS) core to hand over a packet call from the LTE network to the circuit-switched 2G/3G network.

But Acme is going one further, announcing software enhancements to the SBC that will meet future VoLTE standards, allowing operators to hand off calls in the access network, where response is faster rather, than in the core network. Called the access transfer control function, the expected specification in the forthcoming 3GPP Release 10 standard alleviates growing concern from operators that latency in the network will cause most calls to fail before they can be properly converted from the IP to the circuit core, said Kevin Mitchell, director for solutions marketing at Acme Packet.

“The SBC sits on the edge of the network, so we’re perfectly placed to take over these functions,” Mitchell said. “In LTE, we see access SBCs being deployed northbound of the [packet data network] gateway.”

That would put the Acme Packet call handover element one or two steps removed the mobility management element of the mobile core, where the call transfer would be initiated, Mitchell said. While 3GPP Release 10 hasn’t been finalized, most of its key elements have been frozen pending a final vote, so Acme Packet expects the proposed access transfer component to stand. If there are any minor changes when the standard is finalized, its SBC would require only a software upgrade to implement them, Mitchell said.

Verizon Wireless (NYSE:VZ, NYSE:VOD) has already begun moving to VoLTE, announcing its first successful LTE-VoIP call at Mobile World Congress last month and planning for the industry’s first launch of a commercial carrier-VoIP service next year (CP: Verizon to start shifting to LTE-only phones in 2013). MetroPCS (NYSE:PCS) is also in the process of moving its circuit-switched services over to the packet LTE network. It’s already started running all SMS and MMS from its LTE customers’ phones over its Mavenir IMS core.

But neither of those operators will use SRVCC to move calls between their CDMA and LTE networks, for the simple reason that SRVCC isn’t supported by the 3GPP2, CDMA’s standards body (CP: Verizon the exception in 2G-LTE voice integration). GSM operators are moving more slowly to LTE than their CDMA counterparts and thus more slowly to VoIP.

But Mitchell said that GSM operators also have many more VoIP options, putting them in no hurry to make the transition. While Verizon and Metro effectively will run separate circuit and VoIP networks just as they maintain separate 3G and LTE data networks, GSM operators will be able to gradually introduce VoIP as they build their LTE networks, falling back on 2G circuit services where the LTE network is unavailable.