The first results from the LTE SAE Trial Initiative (LSTI) 's carrier participants show that most mobile operators are still in the very early stages of testing next-gen mobile broadband Long Term Evolution (LTE) and Evolved Packet Core (EPC) technology.

Remi Thomas, director of the LTE EPC program at Orange (NYSE: FTE), shared trial results, including latency and throughput details (on which more later), from seven mobile operators at the Next Generation Networks & Basestations 2010 conference in Bath, UK, Monday.

Thanks to the European travel chaos caused by ash from Iceland's Eyjafjallajoekull (pronounced Eyjafjallajoekull) volcano, Thomas delivered his keynote from Italy via audio link.

With commercial LTE networks already up and running at Telia Company in Norway and Sweden, as well as the commercial LTE launch commitments from Verizon Wireless in the fourth quarter and NTT DoCoMo Inc. (NYSE: DCM) in December this year, it's easy to lose sight of how early it is in the industry's development of LTE standards-based, interoperable network equipment and devices. (See LTE Watch: Verizon Goes Live in Q4, MWC 2010: TeliaSonera's LTE Progress, and NSN Replaces Huawei in Euro LTE Rollout.)

The LSTI was created to ensure that the LTE and EPC standards are implemented in the same way across all operators and vendors. It has already completed proof-of-concept and some interoperability testing. Now the group has moved on to friendly customer trials at some mobile operators. (See LSTI Launches LTE Interop Tests.)

The following 10 mobile operators have committed to performing the LSTI trials

The trials have been set up to test network latency, state transition (which means the change from idle to active mode in mobile devices), throughput, and cell capacity/cell load.

Thomas shared some details from the latency and throughput tests. In the trials, the latency result was 17 to 27 milliseconds for a round trip measured from a user device to an application server in the network.

In the throughput results, Thomas said, the measured peak rates for frequency division duplex (FDD) and time division duplex (TDD), normalized to 20MHz, either met or exceeded 100 Mbit/s in the downlink and 30 Mbit/s to 50 Mbit/s on the uplink.

According to Gabriel Brown, senior analyst at Heavy Reading, the key metrics are latency and state transitions -- that is, the time it takes for data to go across the network from a mobile device and back again, and the amount of time a device takes to go from idle to active mode -- because these affect the user experience.

"These are key -- they're what people often notice, rather than the actual bit rate," says Brown.

The analyst also notes that, while the LSTI test results are indicative of the industry's current progress, the data provided is only what the operators have agreed to share with each other in this initiative. "It's representative, but not the full picture," he says, noting that operators have their own LTE test programs.

The next steps for LSTI are further radio access trials and end-to-end trials with integrated EPC on commercial platforms throughout 2010.

— Michelle Donegan, European Editor, Light Reading Mobile