The JTRS program originated in the mid-1990s and was intended to replace the 25 to 30families of radio systems used by the military -- many of which could not communicate with eachother -- with software-based radios that could operate across the entire radio frequencyspectrum. (1) JTRS isintended to permit the Services to operate together in a "seamless" manner via wireless voice, video,and data communications through all levels of command, including direct access to near real-timeinformation from airborne and battlefield sensors. (2) Described as a "software-defined radio" JTRS is envisioned tofunction more like a computer than a conventional radio and is to be upgraded and modified tooperate with other communications systems by the addition of software as opposed to redesigninghardware - a more costly and time-consuming process. DOD also asserts that in "many cases, asingle JTRS radio with multiple waveforms (3) can replace many separate radios, simplifying maintenance" andthat because JTRS is "software programmable, they will also provide a longer functional life" (4) with both features offeringpotential long-term cost savings. It is also planned that JTRS will be interoperable with currentDOD radio systems, the Pentagon's Global Information Grid, (5) and the communicationssystems of selected allied nations. (6) JTRS has been characterized by the Army as a key complementary enabler of the FCSnetwork that would enable FCS sensors and combat systems to acquire and engage targets at adistance as well as preventing them from being engaged by enemy systems. (7) To a significant extent, theArmy has linked progress in the development of a number FCS subsystems to progress in the JTRSprogram. The JTRS program was originally broken into five "clusters' with each cluster having aparticular Service "lead." Table 1. JTRS Clusters a. Form factor radios are essentially miniaturized radios that soldiers would carry, as well as radios for weight and power-constrained platforms -- such as FCS Unattended Ground Sensors andIntelligent Munitions. In early 2004, DOD merged Clusters Three and Four into a single program -- the Airborne,Maritime, and Fixed Station Program (AMF JTRS) -- jointly managed by the Navy and the Air Force-- because studies suggested that developing the clusters together would result in a more efficientprocurement process and a better overall product. (8) All JTRS Clusters are being developed concurrently and there isno requirement that one cluster is completed before another cluster can be developed. Because theFCS program is heavily dependent on Clusters One and Five, this report will address only issuesinvolving these two clusters being developed by the Army. (9) Developmental. JTRS has experienced a numberof developmental difficulties to date. Some of the more notable difficulties are discussed in thefollowing sections. Size and Weight Constraints and Limited Range. According to a Government Accountability Office (GAO) report: To realize the full capabilities of the WidebandNetworking Waveform, (10) including transmission range, the Cluster One radio requiressignificant amounts of memory and processing power, which add to the size, weight, and powerconsumption of the radio. The added size and weight are the results of efforts to ensure the electronicparts in the radio are not overheated by the electricity needed to power the additional memory andprocessing. Thus far, the program has not been able to develop radios that meet size, weight, andpower requirements, and the current projected transmission range is only three kilometers -- wellshort of the 10-kilometer range required for the Wideband Networking Waveform ... The ClusterOne radio's size, weight, and peak power consumption exceeds helicopter platform requirements byas much as 80 percent. (11) The inability to meet these fundamental design and performance standards has raisedconcerns that Cluster One may not be able to accommodate additional waveforms (current plan isfor Cluster One to have four to eight stored waveforms) as intended and that it may be too bulky orheavy to fit into the stringently weight and size-constrained FCS Manned Ground Vehicles(MGVs) (12) as well asthe Army's helicopter fleet. Some are concerned that to meet these physical requirements, the Armymay significantly "dumb down" Cluster One performance specifications. (13) According to the Army,however, it continues to make progress in terms of reducing Cluster One's weight and size and inincreasing its transmission range, however incorporating all of the desired waveforms into ClusterOne is proving to be difficult. (14) Cluster Five radios were also reportedly experiencing similarsize, weight, and power difficulties - difficulties more pronounced as some Cluster Five versions aresupposed to weigh no more than one pound. (15) Current reports on Cluster Five progress appear to be moreoptimistic than Cluster One. General Dynamics reports that they have been able to achieve systemscompatibility between Cluster Five units and three other key FCS components, the Non-Line of SightLaunch System, the Unattended Ground Sensor, and the Intelligent Munitions System. (16) DOD convened a mini-Defense Acquisition Board (17) (DAB) for the Cluster Oneprogram on October 11, 2005 and, according to one report, plans to hold another review onNovember 21, 2005. (18) Information concerning the October 11 review was not publically released and there is some renewedconcern that the Cluster One program is in trouble. Another report suggests that the airborne versionof Cluster One, despite significant re-engineering, still exceeds weight limitations. (19) The issue appears to bethat Boeing has had difficulty reducing the radio's weight below 66 kilograms - with 52 kilogramsbeing the maximum allowable weight for the airborne version of Cluster One. (20) According to Boeingofficials, it would be possible to achieve the 52 kilogram weight limit but it would require significantdesign changes to a design that is already well established and not easily changed. (21) Despite this difficulty,certain aspects of the Cluster One program have shown improvement - according to Boeing officials- with the first version of the Wideband Networking Waveform apparently operational on someversions of Cluster One. (22) Security. Security for JTRS has emerged as asignificant developmental difficulty. According to one expert, one of the program's biggest problemsis security, "namely encryption, as JTRS encryption is software-based and is, therefore, vulnerableto hacking." (23) Computer security experts generally agree that software used for any purpose is vulnerable, as nocurrent form of computer security offers absolute security or information assurance. According toGAO, JTRS will be required to operate applications at multiple levels of security and in order tomeet this requirement, developers will have to not only account for traditional radio securitymeasures but also computer and network security measures. (24) In addition, NationalSecurity Agency (NSA) (25) security concerns about JTRS interface with radio systems ofU.S. allies, and the requirement for JTRS to be interoperable with DOD's Global Information Grid(GIG), are also expected to pose developmental challenges. (26) One such security-relatedchallenge is that DOD's Global Information Grid will also interface with the Internet, which bringswith it a whole additional set of security concerns for JTRS. (27) Interoperability with Legacy Radio Systems. Somehave expressed concerns that the goal of making JTRS "backward compatible" with legacy radiosmay be technologically infeasible. (28) Reportedly, early program attempts at cross-banding (29) to synchronize incompatible legacy radio signals proved to be too complex and current Army efforts are focusingon using the Wideband Networking Waveform to link with legacy radio frequencies. (30) One report suggests thatwhile the Wideband Networking Waveform can receive signals from legacy radios, legacy radioscannot receive signals from JTRS and to rectify this situation, the Army is looking at using 19different waveforms to facilitate JTRS transmissions to legacy systems. (31) Incorporating up to 19different waveforms into a JTRS radio has the potential to significantly increase memory andprocessing power requirements which, in turn, could drive up JTRS size, weight, and powerrequirements. Recently, the Joint Staff asked the Services to prioritize JTRS waveforms and theArmy reportedly identified four waveforms as initial priorities for FCS and other complementaryprograms. (32) Cluster One Stop Work Order. On April 25, 2005,DOD issued a "Show Cause" letter to Boeing- the lead contractor for JTRS Cluster One - stating thatit was considering cancelling the contract for the first phase of Cluster One due to Boeing's "anticipated failure to meet cost, schedule, and performance requirements." Shortly after thisdecision, work on Cluster Five was also partially suspended, due in part to developmental problems,changing technical requirements, and a contract award protest, and also because progress in ClusterFive was heavily leveraged against progress on Cluster One. (33) As a result of the workstoppage, DOD lifted its requirement for Services to obtain a DOD waiver before purchasingnon-JTRS radios and the Services were authorized to purchase legacy radios, such as the SingleChannel Ground and Airborne Radio System (SINCGARS), which has been in service since the1980s. (34) JTRS Alternatives. Some analysts suggest that thereare alternatives to JTRS that are already commercially available. Companies such as HarrisCorporation -- a Cluster One team member - produces a software-defined radio (Falcon IIAN/PRC-117F(C)) and Thales -- a Cluster Five team member and the lead contractor for SOCOM'sCluster Two radio -- both produce software-defined radios that are already in use in the field. (35) It should be noted,however, that these software-defined radios currently in use only run a subset of the current forcewaveforms, and the Wideband Networking Waveform and Soldier Radio Waveform -- both FCSprogram requirements -- would not be available on these radios. (36) Another possible solutioncould be to use existing software-defined radios and to acquire a commercial wideband system suchas WiMax (37) -- anon-line-of-sight commercial broadband networking technology that could be modified for militaryuse. (38) Experts suggestthat a system such as WiMax could provide the military with more bandwidth and enhancedover-the-horizon mobile communications. (39) The Army asserts, however, that if a system such as WiMax wasadopted for use, that it would require NSA certification not unlike current certification efforts forJTRS. (40) The greaterbandwidth and over-the-horizon mobile features of WiMax could address concerns that FCS mightnot have sufficient bandwidth and the perceived over-reliance on unmanned aerial vehicles (UAVs)and other airborne platforms - which are subject to hostile fire and weather constraints - to retransmitJTRS signals over extended distances. Boeing Retains Cluster One Contract. On July 19,2005, the Army reportedly decided to keep Boeing as the Cluster One lead contractor but wouldcontinue to assess the program's progress. (41) No details were publically released as to why the Army decidedto keep Boeing as the lead contractor but some suggest that it was not because Boeing demonstratedprogress in correcting noted design deficiencies, but instead because Boeing had a strong legal caseagainst the Army if the Army had decided to terminate its contract with Boeing. Work on ClusterFive radios - which, unlike Boeing, was never formally suspended by DOD - has continued in areasthat were not dependent on Cluster One technologies and General Dynamics has reportedly madeprogress in addressing size and power concerns raised by GAO in their report. (42) Experimentation. In October 2005, the Armyinitiated what it calls "Experiment 1.1" to test elements of the FCS network - including JTRS. (43) The experiment, slatedto run through early 2006, is to test other network components including the System of SystemsCommon Operating Environment (SOSCE) (44) and Networked Battle Command Systems. (45) The intent is to test thenetwork inside of formations and down to the soldier level and also to link sensors to soldiers andvarious FCS items in preliminary stages of development such as unmanned aerial vehicles (UAVs),unmanned ground vehicles (UGVs) and unattended munitions systems. Because manned groundvehicles are not yet developed, network items - including JTRS- are to be placed in surrogatevehicles (modified High Mobility Multi-Wheeled Vehicles -- HMMWVs). These vehicles are to use early developmental models of the Cluster One radio. The programmanager for FCS, Brigadier General Charles Cartwright, expects to receive 42 "pre-engineering"development models of Cluster One in December 2005 and also plans on using Cluster Five unitsin Experiment 1.1 -- and, possibly, a second "Experiment" -- in 2006. (46) The Army has a number of specific objectives for Experiment 1.1 including: FCS risk mitigation; Support the development of the Army's modular force Brigade Combat Teams(BCTs); (47) Gain knowledge to support further development of FCScapabilities; Provide information that could lead to program improvements and perhapsmore rapid development, and To show the progress and maturity of the FCS program and the FCS networkin an operational environment. (48) Given these objectives, it is not unreasonable to assume that the early development models of JTRSCluster one will undergo considerable experimentation and testing. If this is the case, theexperiment's results could potentially have significant ramifications for the future of the Cluster Oneprogram, particularly if Cluster One's performance fails to meet the Army's expectations. Spin Out One. The Army's FCS program consistsof four "spin outs" -- formerly known as spirals -- that will introduce FCS technologies and systemsto the current force. These fielding spin outs are slated to occur in 2008, 2010, 2012, and 2014 toan experimental brigade and then two years later to the rest of the Army. The first spin out of FCStechnology in 2008 is to emphasize improved munitions and sensors connected in an initial versionof network capabilities. (49) These network capabilities are thought to include Clusters Oneand Five, Wideband Networking Waveform, Warfighters Information Network-Tactical(WIN-T), (50) and theSystem of Systems Common Operating Environment (SOSCOE). In Spin Out One, Clusters One andFive are planned to be used in conjunction with other FCS systems such as Unattended GroundSensors (UGS), the Intelligent Munitions System (IMS), and the pre-production model of theNon-Line of Sight Cannon (NLOS-C). GAO asserts that "it is unlikely that Cluster One radios will be available for the first spiral[now referred to as spin out] of the FCS network, slated for FY2008 and that Cluster Five radiosmight not be available for the first spiral." (51) Some reports suggest that JTRS program progress is being made,particularly in the Cluster Five program where technology workarounds necessitated by the ClusterOne stop work order, have helped Cluster Five to "achieve a degree of compatibility" with other FCScomponents due to be tested in Spin Out One. (52) If, however, Cluster One and Five are not available by 2008,reports suggest that the Army is planning to use pre-production models and/or surrogate softwaredefined radios of lesser capabilities in their place. (53) On July 28, 2005 the JTRS program underwent a Defense Acquisition Board (DAB) reviewand although results have not been publically disclosed, the Secretary of the Army, Francis Harvey,reportedly acknowledged that DOD would restructure the entire JTRS program. (54) In August, the JTRS JointProgram Executive Office (JPEO) submitted a proposal to DOD which details how it would manageall JTRS Cluster efforts (as opposed to the management structure depicted in Table 1) with the intentof achieving near-term success by delivering usable capabilities to the field now, while pursuing thelong term goal of fielding a complete interoperable software defined radio over time. (55) Preceding the JTRSprogram restructuring, Boeing and Science Applications International Corporation (SAIC) -- whoserve as lead systems integrators for the entire 18 system FCS program -- announced in June 2004that Cluster One and Five programs would be restructured to better meet the needs of the FCSprogram. (56) Whilesupporters suggest that this restructuring might help to focus JTRS development efforts and providedefinitive design guidance to JTRS developers, critics say that this is just another in a series ofprogram "restructurings" -- the Army added two years of additional effort and $458 million toCluster One in December 2004 to address developmental problems (57) -- for a program that startedin 1999 and "has a long ways to go before it can be used in military operations." (58) According to GAO, (59) the Cluster One program is expected to cost $15.6 billion todevelop and acquire over 100,000 Cluster One radios and $8.5 billion to develop and acquire over300,000 Cluster Five radios, and the Army has reportedly requested $156.7 million in FY2006 forJTRS. (60) Cost growthfor Cluster One has been of significant concern as noted by GAO: Since the program entered systems development in2002, the contractor has overrun cost estimates by $93 million - nearly 28 percent above what wasplanned. Although the program attempted to stabilize costs by adding approximately $200 millionto the contract in January 2004, costs continued to grow steadily thereafter. In addition, thecontractor has increasingly fallen behind schedule and has had to devote more resources thanoriginally planned. In January 2005, the prime contractor estimated that the total costs for the ClusterOne radio and waveform development would be $531 million more than what was originallybudgeted, reaching $898 million at completion. However, according to program officials, sincecontract award, the prime contractor has not demonstrated strong cost estimating and costmanagement techniques, and it is difficult to estimate with any confidence what the overall programis likely to cost. (61) Given this history of cost overruns and the inability to forecast and manage program costs,some say a strong case could be made to permanently stop work on Cluster One while still in theProduct Development and Demonstration Phase of development, and transfer program elements thatshow promise to another developer already in the JTRS program or a developer not in the programbut with demonstrated communications systems proficiency. The Senate passed its version of the FY2006 Defense Authorization Bill ( S. 1042 ) on November 15. A conference agreement on the Defense Appropriations Bill( H.R. 2863 ) has been delayed in part because the House has not formally appointedconferees. Both the Senate and House Reports recommend cuts for the entire JTRS program and theArmy's JTRS programs are addressed in the following sections: Senate - In its report on the FY2006 Defense Authorization Bill (62) the Senate AppropriationsCommittee voiced its support for JTRS and the ongoing JTRS review by DOD's Program ExecutiveOffice (PEO) but noted "the Army's Cluster 1 program faces significant technical challenges" furthernoting that "these challenges could impact the program efforts in the Navy and Air Force." TheAppropriations Committee also called for a DOD assessment and a revised JTRS program plan tobe provided to the defense committees. Committee recommended adjustments for the Army'sprograms are in Table 2 . Table 2. Army JTRS Senate-Recommended Adjustments --FY2006 Defense Appropriations ($ thousands) House -- The House Appropriations Committee Report on the FY2006 DefenseAppropriations bill (64) while critical of the Army's Cluster One and Five programs recommended fully funding waveformdevelopment and funding to continue hardware development. The House also calls for a detailedDOD report on JTRS to the House Armed Service Committee. Appropriations Committeerecommended adjustments for the Army's programs are in Table 3 . Table 3. Army JTRS House-Recommended Adjustments --FY2006 Defense Appropriations ($ thousands) a. Includes requested amounts for JTRS waveform development and Program Management Office activities and Cluster One and Five hardware development. JTRS aviation development andintegration amounts are not included in JTRS program total. b. This reduction is for the integration of aircraft (helicopter) versions of JTRS Cluster One units. With these House and Senate figures, it is unlikely that a conference committee would fullyfund the JTRS program; actual recommended program cuts for the FY2006 Defense Appropriationsbill are pending the outcome of a conference. It is unclear how these yet-to-be-determined programcuts would impact not only the Cluster One and Five programs, but also how they would impact theoverall FCS program. Following a House-Senate conference report, the Army would likely issuean assessment on how the cuts impact both the JTRS and FCS programs. The Viability of the Cluster One Program. Whileboth Clusters One and Five have experienced a number of developmental difficulties, it appears thatthe Cluster Five program has "divorced" itself from Cluster One through technological workaroundsand has achieved a degree of program success reportedly having achieved compatibility with anumber of FCS systems. Cluster One, however, seems to be progressing to a lesser extent with itsfirst "test" likely to be in Experiment 1.1 later on in 2005. The performance of Cluster One in thisexperiment might prove to be a useful metric to help decision- makers determine if the Cluster Oneprogram is a viable one or if another course of action should be pursued. Although not believed tobe included in Experiment 1.1, the airborne version of Cluster One might warrant furtherexamination. It appears that in order for the airborne version to meet the weight limit of 52 kilogramsthat significant capability trade offs may be required to this system that is already in the advancedphases of development - likely resulting in additional delays and significantly increased costs. Given this situation, Congress might review the Army's performance expectations for ClusterOne during Experiment 1.1 testing. Will Cluster One's performance impact on the Army's decisionto continue with what some call a "troubled program" or will the Army opt to stick with ClusterOne's developers no matter what the outcome, and attempt to rectify identified deficiencies throughadditional funds and further program delays? Another issue that might be considered forcongressional review is the state of the airborne version of Cluster One. Some suggest that theprogram has reached an impasse due to aircraft weight and size constraints, and that the only wayto meet these requirements is to redesign the system into a significantly less-capable version -- acourse of action that could further delay the program and carry with it significant cost implications. Security. Congress may decide to examine theissue of security in greater detail. According to GAO, in addition to a requirement to change JTRShardware to accommodate processing and memory capacity upgrades for enhanced security, thecurrent design of JTRS has been judged by the National Security Agency as: Not sufficient to meet security requirements to operatein an open networked environment. Specifically, particular versions of JTRS radios will be used byallied and coalition forces, requiring the Army to release specific source code of the softwarearchitecture to these forces. To address the release, the National Security Agency has requiredchanges to the security architecture. (65) Although GAO expresses security concerns about JTRS use by allied and coalition forces,it is not readily apparent how pervasive a problem security is for JTRS and other components of theFCS network. Given the stated security challenges of software-defined radios, it is conceivable thateven if Cluster One and Five can meet the Army's communications and data transmissionrequirements, that security deficiencies might preclude the operational employment of Clusters Oneand Five. It can be argued that network security would take on an even a more significant role in FCSthan compared to the Army's current force. FCS Manned Ground Vehicles -- lighter and less heavilyarmored than the M-1 Abrams and M-2 Bradleys that they are intended to replace -- would relyextensively on situational awareness provided through the FCS Network for their survivability.Furthermore, this network-provided situational awareness would have a significant impact on FCS'sability to engage enemy forces beyond line-of-sight. Given this significant reliance on the FCSNetwork for survivability and for target acquisition and engagement, potential adversaries might seekto identify and exploit security weaknesses in the FCS network -- including JTRS -- as a means toattack FCS units. One potential adversary -- China -- has "likely established information warfareunits to deploy viruses to attack enemy computer systems and networks" and China's "recentexercises have incorporated offensive [computer] operations, primarily as first strike against enemynetworks." (66) Apotential scenario for consideration is that if an adversary obtained FCS-related source code, theycould engineer a virus that could be introduced into the FCS network and computers. While somemay consider this an improbable scenario, the reported recent discovery by Russian security expertsof the first known computer virus spread by cell phone networks suggests otherwise. (67) The Army is not unaware of these security challenges and notes that network security andinformation assurance are an "ever growing priority, regardless of FCS development." (68) As part of this recognition,the Army FCS program conducts bi-monthly information assurance architecture developmentreviews with the Army staff sections responsible for Intelligence (G-2) and Information andCommunications (G-6) and the National Security Agency and Office of the Secretary ofDefense. (69) JTRS Alternatives. With its history ofdevelopmental difficulties, program delays, and additional costs, some suggest that the JTRS ClusterOne program might be a candidate for cancellation. In this view, Congress might opt to explorealternatives to Cluster One with the Army and DOD. A possible starting point for such a reviewmight be an examination of software-defined radios already in service within the U.S. military orcommercially available through other manufacturers. Some critics argue that the military shouldadopt commercially available and emerging telecommunications technology. One example of sucha technology is third- generation cellular technologies that encompass streaming video, nettedcommunications, and data and voice communications over Internet provider networks. (70) While proponentsmaintain that third-generation cellular could exceed JTRS performance capabilities, critics of thecommercial approach note that these technologies need to be ruggedized, customized to fit onspecific vehicles and systems, and require specialized encryption, and therefore the "off the shelfapproach" might be equally as expensive as developing JTRS. After a thorough technical andcost-based evaluation of these and other JTRS alternatives, some project the best course of actionmay be to continue Cluster One development as currently planned.

Summary:
The Joint Tactical Radio System (JTRS) is a Department of Defense (DOD) program thatwould play a significant role in the U.S Army's proposed Future Combat System (FCS) program. (For a more detailed description of the FCS program see CRS Report RL32888 , The Army's FutureCombat System(FCS): Background and Issues for Congress , by [author name scrubbed].) JTRS,envisioned as a family of software programmable radios, has been described as the "backbone" ofthe FCS and is intended to link the 18 manned and unmanned systems that would constitute FCS.Two JTRS sub-programs managed by the Army -- Cluster One and Cluster Five -- have experienceddevelopmental difficulties, delays, and cost overruns which calls into question their viability. Thisreport will be updated on a periodic basis.