Posted by John Keller

ARLINGTON, Va., 10 Feb. 2012. Military communications experts at the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., are asking for industry's help in providing pervasive, high-throughput military cell phone-like communications to deployed military units by using a mobile backbone that provides communications over long distances to military units on the move.

DARPA on Wednesday released a broad-agency announcement (DARPA-BAA-12-27) for the Fixed Wireless at a Distance program, which among other goals seeks to overcome the limitations of today's military mobile ad-hoc networks (MANETs) that progressively limit service to individual users as the network grows.

Deployed U.S. military forces today often use mobile ad-hoc networks at the front lines of battle to relay traffic beyond the range of an individual radio to provide communication services to the largest area possible. Today's MANETs scale to about 100 nodes before performance degrades to unacceptably low levels, DARPA officials say.

The Fixed Wireless at a Distance program seeks to develop mobile communications infrastructure that interconnects small groups of military radios, similarly to commercial cellular telephone base stations and WiFi access points. DARPA researchers are interested in a kind of scaling capability similar to commercial cell phone networks, which operators often push to their capacity limits.

Unlike a commercial cell phone network, however, DARPA wants to develop wireless communications capability that not only emphasizes geographic coverage rather than limiting interference, but also that supports mobile front-line military forces where infrastructure cannot always be installed in advance of military operations.

This pervasive wireless military communications capability must be able to support relatively old military radios now in the field, commercial communications systems, and enhanced-range communications devices. Each transceiver may include 3G or 4G commercial cellular and commercial Wi-Fi base station technology to support communications over a few miles.

At the same time, technology developed must support conventional military radios over distances of three to 12 miles, as well as specially equipped multiple-input and multiple-output (MIMO) military client radios with two to 20 simultaneous coherent signal streams at distances farther than 30 miles.

Technology options under consideration include increasing transmit power or receive sensitivity; increasing base station antenna height; increasing base station antenna gain; and space-time coding.

DARPA researchers also are interested in technologies to improve deployment and operation of fixed-infrastructure systems, as well as exploring new kinds of network architectures that such long-range data communications to, from, and among deployed military forces might enable.

Companies interested in participating in the Fixed Wireless at a Distance program should send abstracts to DARPA no later than 16 March 2012, and full proposals no later than 13 April 2012. DARPA also is sponsoring a proposer's day to brief industry on the program from 8:30 a.m. to 5 p.m. 16 Feb. 2012 at the Capital Conference Center, 3601 Wilson Blvd., in Arlington, Va.

Register for the proposer's day online at www.schafertmd.com/conference/fwad/pd201202/registration. Send questions, abstracts, and proposals to DARPA by e-mail at DARPA-BAA-12-27@darpa.mil.

More information is online at https://www.fbo.gov/spg/ODA/DARPA/CMO/BAA-12-27/listing.html.