Mobility-Hungry Army Awaits Wireless Upgrades
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| Emerging wireless standards will enable any person or object to act as a relay or access point to the network, creating more fluid, versatile communications on the battlefield. |
U.S. Army leaders are chomping at the data bit for ratification of emerging standards that would improve the quality of voice communications over wireless networks and would enable long-range, high-speed broadband connectivity on the fly. The field of wireless 802 series protocols now under development by the
Wireless advocate Lt. Gen. Steven W. Boutelle,
The commercial wireless world is certainly not waiting for the military, which represents a tiny portion of its potential market. Dr. Edward M. Siomacco, director of technology, Army Chief Information Office, G-6, says, “We may be millions and millions of dollars, but we’re not billions and billions. The industry guys will build to a standard, and we would then leverage whatever they gravitate toward.”
Al Arsenault, senior security engineer, BBN Technologies Incorporated,
Industry is not waiting for IEEE to ratify the new standards either. Technology firms already are producing early hardware products for pending standards, Gen. Boutelle says. For instance, one commercial vendor has fielded a hub that adheres to the IEEE’s unreleased 802.11e standard addressing quality of service for voice over Internet protocol (VoIP), he says.
The 802.11e draft standard proposes designating two operating modes for each wireless access point to support quality of service. One mode gives VoIP priority over data transmission. Data can absorb slight transmission hiccups better than time-delay-sensitive voice communications. The other 802.11e mode polls base stations during down time to schedule packet delivery, again giving priority to voice and video applications.
The 802.11e protocol is slated for ratification later this year, but products implementing the standard are available now. “It’s early adoption, which means that once the standard is finalized, [the vendor] might have to adjust the product,” Gen. Boutelle says. The IEEE 802 standards now under review are “the really exciting ones,” the general adds.
But Gen. Boutelle tempers his enthusiasm for wireless technology by recognizing the decade-long effort to lace the world together with fiber optics. The preamble to any wireless technology discussion, the general says, has to include the roughly $1 trillion the telecommunications industry spent to lay fiber worldwide. The fiber network’s optical switching systems keep improving, allowing more and more bandwidth access along those cables. Over the next few years, technology will bump the current 10-gigabyte-per-second transmission rates up to 800 gigabytes per second, Gen. Boutelle says. “The next step is to extend that fiber into the wireless medium,” he adds.
Two IEEE standards now being considered for ratification—802.16e and 802.20—are gaining traction on the Army’s charted course to integrate long-range, mobile wireless communications. Both standards focus on a metropolitan area network (MAN) capability that would provide services similar to those of cable modem or digital subscriber line (DSL) to wireless network clients operating on the go.
The 802.16e standard amends the currently approved 802.16 standard, which specializes in point-to-multipoint broadband wireless access in the 2-gigahertz to 11-gigahertz range. Champions of 802.16 certified technology, also referred to as WiMAX—for worldwide interoperability for microwave access—claim that base stations operating on the standard can transmit high-speed Internet service up to a radius of 31 miles and eventually will cover an entire metropolitan area. Some major cities such as
While the 802.16 standard addresses only fixed systems, the 802.16e amendment’s mobility component registers as a big plus for military units seeking increased fluidity and flexibility. The amendment would give a military convoy, for example, wireless voice and data communications mobility within a 31-mile radius and, according to one report, broadband connectivity even when traveling at speeds of roughly 90 miles per hour.
Such broad transmission coverage bodes well for a military seeking to take advantage of mobile ad hoc networks. The 802.16e standard enables military units far from a base station to deploy decentralized, distributive ad hoc networks that can access the Global Information Grid. Luiz A. DaSilva, an associate professor of electrical and computer engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, says when technology using the 802.16e standard is implemented, an individual, a vehicle and even an unmanned aerial vehicle can be a relay or access point to the server. “Everyone can act as a relay for everyone else,” DaSilva says.
IEEE ratification of the 802.16e protocol, which involves devices operating in the 2-gigahertz to 6-gigahertz band, is expected in late 2005.
If ratified, the 802.20 MAN protocol would also best current IEEE 802.11 range and mobility capabilities. The mobility-centric 802.20 protocol would extend wireless coverage to 9.3 miles while enabling 1-megabyte-per-second or more transmission rates, equivalent to DSL and cable modem speeds. The standard focuses on delivering a roaming cell-like wireless broadband capability in the 3.5-gigahertz band to users traveling at high speeds.
“We’re talking about moving pretty fast, in the 100- to 150-mile-per-hour range,” Stanley Fong, chief, Cryptographic Modernization Project Management Office, Communications-Electronics Research, Development and Engineering Center (CERDEC), Fort Monmouth, New Jersey. With either the 802.16e or 802.20 standard, Army communicators could carry less equipment, install fewer access points and still have roaming service, he says. “Range is a big benefit with these standards,” Fong says. The 802.20 draft standard has yet to be submitted and likely will not be ratified until 2006, according to Army officials.
Proponents of 802.16e envision mobile users accessing wireless networks through personal digital assistants and computer laptops, while 802.20’s interface seeks to tackle high-speed mobility capabilities.
The Army also will benefit from a wireless protocol that enables the transfer of an ongoing call or data session back and forth from one network to different types of networks. While current 802.11 standards do not support the handoff of services between disparate networks, IEEE’s 802.21 multimedia independent handover standard would provide seamless conveyance to and from Global System Mobile, cellular, Bluetooth, wireless fidelity (Wi-Fi), 802 network and general packet radio service communications.
The 802.21 standard allows a user to talk over a wired local area network with an Internet protocol telephone or to communicate over any wireless network. “You can talk through your wireless network at home, but when you get out of range, it automatically switches over to your cell service provider and then back again,” Gen. Boutelle says. The 802.21 protocol allows use by multiple vendors and clients. Users also may engage in ad hoc teleconferencing.
From a warfighting perspective, the 802.21 standard promises to allow reliable and flexible communications by taking advantage of existing networks within an area of operation. For example, a user could move from a hotel wireless Internet hot spot to a coffeehouse that is providing free service to a field environment without a break in service. “If the Army adopts those protocols, then all of a sudden I’m operating in a field environment on Secret and Top Secret level,” Gen. Boutelle says.
IEEE working groups also are developing 802.11 standards that would enable fast roaming from access point to access point. The 802.11r addresses unacceptably long delays for time-sensitive voice over wireless local area network (VoWLAN) applications. This standard would allow wireless devices moving away from one access point to reassociate with a new access point quickly. A draft 802.11k standard would give users load-balancing information on available access points before associating with a new access point. That standard may be ratified in late 2005, according to Army officials.
Two more 802.11 standards promise to expand bandwidth efficiency at access points and to minimize interference from neighboring devices. Slated for ratification in 2006, IEEE’s 802.11n extended range increased bandwidth standard addresses the low number of VoWLAN sessions supported per wireless access point by seeking to improve bandwidth to 100 megabytes per second or faster. The improvement would allow more VoWLAN sessions while supporting other wireless local area network client services. It also would be compatible with current 802.11 networks.
Another IEEE work group is grappling with the issue of interference from adjacent devices. The 802.11h standard will attempt to allow wireless devices to change channels when detecting interference from another device and to reduce radio frequency output power to diminish the risk of interference. The dynamic frequency selection (DFS) and transmit power control features operate only in the 5-gigahertz band 802.11a uses but not by the more popular 802.11b and 802.11g technologies. Those standards operate in the 2.4-gigahertz band. Without DFS, wireless networks are susceptible to interference from incumbent radar systems operating in the 5-gigahertz band. Both standards will improve the reliability and quality of voice communications.
The flood of 802 standards spilling into the marketplace represents a marked change from the dry wireless days of just six years ago. “There was nothing you could grab in this environment,” Gen. Boutelle says. Now the technology is experiencing “explosive growth,” he says, and the Army is gearing up for implementation.
Early Army adoption of emerging wireless technologies will probably appear first in universal handsets as part of the Warfighter Information Network–Tactical (WIN-T) program, Gen. Boutelle says. WIN-T is the Army’s effort to bring mobile communications to soldiers through sensors and ground, air and space platforms. The general also foresees wireless applications quickly being integrated into the Land Warrior program, which seeks to make every soldier an individual weapons platform. Command centers also will snatch up wireless technologies. Says Gen. Boutelle, “It’s already starting to hit.”
Web Resources
WiMAX Forum: www.wimaxforum.org
