WASHINGTON — The struggle to create a single U.S. Army network is growing more complicated, thanks to delays in programs of record even as soldiers in Afghanistan request more communications gear.

Take the Ground Mobile Radio (GMR), whose fall 2010 limited user test could be pushed back to April or even early next summer, an Army source said.

Part of the Joint Tactical Radio System (JTRS) program, the Boeing-built GMR is a four-channel radio-computer meant to put a secure broadband link in vehicles roaming the battlefield.

Pentagon acquisition executive Ashton Carter has approved the purchase of 87 low-rate initial production GMRs, which are planned to deploy with the 1st Armored Division’s 3rd Brigade to Afghanistan in 2012.

That production-representative version also is playing in the Army’s limited user test for Increment 1 of the Early Infantry Brigade Combat Team suite of gear. Carter will hear about those results in December and decide whether to permit the Army to outfit two more brigades with the gear.

According to the Army source, the GMR schedule delay has not been made official, but it is likely. It will give the Army time to include additional tests requested by the Office of the Secretary of Defense, the source said. Extra time also is needed to fully develop the Wideband Networking Waveform (WNW) before testing, the source said.

Depending on how long the delay lasts, it could affect plans to buy radios for six brigades — the ones after the first three — slated to get the new equipment, the Army source said.

Competitors to JTRS products are using such delays to sell their radios to the Army.

Harris Corp.’s AN/PRC-117G radio can not do everything the GMR can; for example, it has just one or two channels to the GMR’s four. But it costs about $70,000, while the GMR costs about $320,000, according to one Army comparison. And it is in demand by soldiers in combat.

Harris says the U.S. military has ordered about 9,000 117Gs to date, of which 6,000 have been delivered and about 2,000 are in Iraq, Afghanistan and elsewhere. This includes two new urgent operational needs statements that have the company building and delivering more radios for troops in Afghanistan, said Dennis Moran, Harris’ vice president of government business development.

Like Harris, Raytheon and ITT are also pitching less-expensive radios that can do a lot of what GMR can do. Moran does not call the 117G a direct competitor to the GMR, but describes its capability as somewhere between the GMR and General Dynamics’ JTRS Handheld, Manpack, Small Form Fit radio.

Still, Moran said, the Harris radio can meet the more critical requirements demanded of both program­of-record radios.

Some in the Army have criticized the 117G because its highest-performance waveform, the Advanced Networking Wideband Waveform (ANW2), is a proprietary development of Harris.

Moran said that is just because the top-end waveforms developed by the JTRS program — WNW and the Soldier Radio Waveform (SRW) — were not ready soon enough.

Harris says ANW2’s capabilities are between those of WNW and SRW.

“It is only here because the others are late,” Moran said.

The 117Gs headed to Afghanistan also carry the older waveforms like the Single Channel Ground and Airborne Radio System (SINCGARS) and newer capabilities like the Remotely Operated Video Enhanced Receiver (ROVER). Combined with ANW2, the radio allows data sharing with lower and lower echelons — a prime goal of Army networking.

Moran said WNW and SRW would come to the 117G when they become available. The radio is porting SRW, and Moran expects next summer’s software upgrade to include a certified version.

He also said Harris offered to license its ANW2 waveform for government use, making its pitch in an Oct. 15, 2009, letter to Ron Jost in the office of the assistant secretary of defense for networks and information integration. The company never received a formal response to the letter, he said.

“I like what we’re trying to do with the JTRS program and the nonproprietary nature of the waveforms that we’re providing,” said Gen. Peter Chiarelli, vice chief of the Army, at a Sept. 22 lunch here.

Still, Army leaders are assessing their options as they await test results out of the JTRS and brigade combat team modernization program. For now, Chiarelli and other Army leaders stand behind the programs of record, but are encouraged by what they are learning from the networking technologies fielded to Afghanistan.

“I really like where we’re going,” Chiarelli said. “If there’s anything I’m seeing from down range, it’s the soldiers’ belief that command and control on the move and the ability to pass data down to the edge is an important factor and something that they’re demanding.”