Information systems technician (United States Navy)
Information systems technician is a rating for United States Navy and United States Coast Guard enlisted personnel, specializing in communications technology. Information systems technician submarines is a rating for U. S. Navy submariners; the Information systems technician rating corresponds to the new Navy Occupational Specialty code B460 while the information systems technician submarines rating corresponds to Navy Occupational Specialty code C260. Information systems technician is a U. S. Navy and Coast Guard specific job known as an enlisted rating; the other U. S. Armed Forces have similar positions, but with different titles utilized Information systems technicians design, install and maintain state-of-the-art information systems; this technology includes local and wide area networks, mainframe and microcomputer systems and associated peripheral devices. They write programs to handle the collection and distribution of data for a wide variety of applications and requirements, they perform the functions of a computer system analyst, operate telecommunications systems including automated networks and the full spectrum of data links and circuits.
The IT rating is one of the most diverse ratings in the US Navy. The IT rating was created in 1997 from a combination of two previous Navy ratings - radioman and data processing technician. A third rating, cryptologic technician communications merged with IT in October, 2005. In February 2010, the IT rating was incorporated into the Information Dominance Corps. IT candidates attend "A" school at Corry Station in Florida. Schooling is instructor led; the schooling can be taught digitally by the software Acuitus, where you are self paced and learn from modules. The Marine radio operator and data systems school is located at MCESS 29 Palms and Army computer systems school is located at Fort Gordon, Georgia; the combining of rating in the Navy has been in place since 1990. There were many combination of both operation ratings to best fit the class of ship. Many duties of the IT rating are still evolving; the radioman and data processing technician ratings were merged in November 1998, keeping the radioman name.
In November 1999 the rating was re-designated information systems technician. Both radiomen and data processing technicians in the Navy had to undergo general rate training and take a computer-based exam in order to be designated under the new IT rating whereas to the radiomen, most of them had a general knowledge in basic computer fundamentals and maintenance. In 1996 the submarine force merged radioman with electronics technicians and electronic warfare specialist; the ITS rating for submarines was created in December 2010. The Coast Guard radioman rating was renamed telecommunications specialist in 1995, which split in 2003 to make up the information system technician and operations specialist ratings; the Coast Guard telephone technician rating was merged into the IT rating in 2003. While there is a community-specific Information Dominance Corps warfare qualification for ITs, the IT rating is one of the few ratings that can qualify in all aspects of naval warfare, such as: Aircrew - responsible for the operation and troubleshooting of the radios, antennas and cryptographic equipment on TACAMO and AWACS missions.
Seabee Surface warfare - responsible for maintaining communication links, troubleshooting radio and computer equipment, satellite communications, cryptographic equipment, is responsible for the administration of the shipboard LAN, WAN links, servers/networking equipment. Expeditionary Warfare Fleet Marine Force - responsible for landing after the Marines have secured an area to set up fleet communications and cryptographic equipment to support joint communications within a battlefield environment; this includes configuring JWICS, Defense Message System, AUTODIN communications in order for combatants to maintain command communications and control superiority. SEAL Special warfare combatant-craft crewmen Submarines List of United States Navy ratings Information Systems Technician. Navy Enlisted Occupational Standards for IT. Retrieved 2012-07-16. Information Systems Technician Submarines. Navy Enlisted Occupational Standards for ITS. Updated: January 2012. Retrieved 2012-07-16
Signals intelligence is intelligence-gathering by interception of signals, whether communications between people or from electronic signals not directly used in communication. Signals intelligence is a subset of intelligence collection management; as sensitive information is encrypted, signals intelligence in turn involves the use of cryptanalysis to decipher the messages. Traffic analysis—the study of, signaling whom and in what quantity—is used to derive information. Electronic interception appeared as early as 1900, during the Boer War of 1899-1902; the British Royal Navy had installed wireless sets produced by Marconi on board their ships in the late 1890s and the British Army used some limited wireless signalling. The Boers captured some wireless used them to make vital transmissions. Since the British were the only people transmitting at the time, no special interpretation of the signals that were intercepted by the British was necessary; the birth of signals intelligence in a modern sense dates from the Russo-Japanese War of 1904-1905.
As the Russian fleet prepared for conflict with Japan in 1904, the British ship HMS Diana stationed in the Suez Canal intercepted Russian naval wireless signals being sent out for the mobilization of the fleet, for the first time in history. Over the course of the First World War, the new method of signals intelligence reached maturity. Failure to properly protect its communications fatally compromised the Russian Army in its advance early in World War I and led to their disastrous defeat by the Germans under Ludendorff and Hindenburg at the Battle of Tannenberg. In 1918, French intercept personnel captured a message written in the new ADFGVX cipher, cryptanalyzed by Georges Painvin; this gave the Allies advance warning of the German 1918 Spring offensive. The British in particular built up great expertise in the newly emerging field of signals intelligence and codebreaking. On the declaration of war, Britain cut all German undersea cables; this forced the Germans to use either a telegraph line that connected through the British network and could be tapped, or through radio which the British could intercept.
Rear-Admiral Henry Oliver appointed Sir Alfred Ewing to establish an interception and decryption service at the Admiralty. An interception service known as'Y' service, together with the post office and Marconi stations grew to the point where the British could intercept all official German messages; the German fleet was in the habit each day of wirelessing the exact position of each ship and giving regular position reports when at sea. It was possible to build up a precise picture of the normal operation of the High Seas Fleet, to infer from the routes they chose where defensive minefields had been placed and where it was safe for ships to operate. Whenever a change to the normal pattern was seen, it signalled that some operation was about to take place and a warning could be given. Detailed information about submarine movements was available; the use of radio receiving equipment to pinpoint the location of the transmitter was developed during the war. Captain H. J. Round working for Marconi, began carrying out experiments with direction finding radio equipment for the army in France in 1915.
By May 1915, the Admiralty was able to track German submarines crossing the North Sea. Some of these stations acted as'Y' stations to collect German messages, but a new section was created within Room 40 to plot the positions of ships from the directional reports. Room 40 played an important role in several naval engagements during the war, notably in detecting major German sorties into the North Sea; the battle of Dogger Bank was won in no small part due to the intercepts that allowed the Navy to position its ships in the right place. It played a vital role in subsequent naval clashes, including at the Battle of Jutland as the British fleet was sent out to intercept them; the direction-finding capability allowed for the tracking and location of German ships and Zeppelins. The system was so successful, that by the end of the war over 80 million words, comprising the totality of German wireless transmission over the course of the war had been intercepted by the operators of the Y-stations and decrypted.
However its most astonishing success was in decrypting the Zimmermann Telegram, a telegram from the German Foreign Office sent via Washington to its ambassador Heinrich von Eckardt in Mexico. With the importance of interception and decryption established by the wartime experience, countries established permanent agencies dedicated to this task in the interwar period. In 1919, the British Cabinet's Secret Service Committee, chaired by Lord Curzon, recommended that a peace-time codebreaking agency should be created; the Government Code and Cypher School was the first peace-time codebreaking agency, with a public function "to advise as to the security of codes and cyphers used by all Government departments and to assist in their provision", but with a secret directive to "study the methods of cypher communications used by foreign powers". GC&CS formed on 1 November 1919, produced its first decrypt on 19 October. By 1940, GC&CS was working on the diplomatic codes and ciphers of 26 countries, tackling over 150 diplomatic cryptosystems.
The US Cipher Bureau was established in 1919 and achieved some success at the Washington Naval Conference in 1921, through cryptanalysis by Herbert Yardley. Secretary of War Henry L. Stimson closed the US Cipher Bureau in 1929 with the words "Gentlemen do not read each other's mail." The use of SIGINT had greater implications during World War II. The combined effort of intercepts and cryp
AN/SLQ-32 Electronic Warfare Suite
The AN/SLQ-32 is a shipboard electronic warfare suite built by the Raytheon Company of Goleta and The Hughes Aircraft Company. It is the primary electronic warfare system in use by U. S. Navy ships. Referred to by its operators as the "slick-32"; the SLQ-32 was conceived in the 1970s to augment the AN/WLR-1, in service since the early 1960s. It was determined to save costs to replace the various WLR-1 series suites with the SLQ-32 as a stand-alone system; as designed, the SLQ-32 was produced in three variants, the 1, 2 and 3. In its service life, two additional versions were built, the 4 and 5; the Air Transport Rack sized processors were supplied by ROLM Mil-Spec Computers in San Jose, CA. SLQ-321 – A simple threat warning receiver, it was capable of receiving high-band radar signals of the type carried on missiles and aircraft; the 1 was installed on small combatants such as frigates. This variant of the system is being phased out as current ships equipped become decommissioned. SLQ-322 – Initially the most common variant, the 2 added the ability to receive surveillance and targeting radars.
This provided a passive targeting capability for Harpoon missile-equipped ships. The 2 was installed on frigates, 270-foot Coast Guard Cutters. SLQ-323 – Expanding on the 2's capabilities, the 3 added active radar-jamming capability; the 3 was installed on various combatants such as cruisers, large amphibious ships and high-value replenishment vessels. SLQ-324 – Designed for installation on aircraft carriers, the 4 consisted of two 3 systems, one for each side of the ship, tied to a common computer and display console. Additional line replaceable units and software were added to support the wide separation of the two antenna/electronics enclosures. SLQ-325 – The 5 was built as a response to the Stark incident in 1987; the 5 incorporated a compact version of the 3 system intended to give active jamming capability to the Perry class FFG's, which were too small to carry a full 3. All versions of the SLQ-32, with the exception of the 4, are interfaced with the MK36 Decoy Launching System, able to launch chaff and infrared decoys under the control of the SLQ-32.
The number and arrangement of MK36 launchers installed depends on the size of the ship, ranging from two launchers on a small combatant to as many as ten on an aircraft carrier. A growing number of systems are being upgraded to incorporate the multi-national MK-53 Nulka system; the original modular design was intended to allow upgrades of the system from one variant to the next by installing additional equipment as required. Starting in the early 1990s, a program was begun to upgrade all SLQ-32s in the U. S. fleet. Most 1 systems were upgraded to 2, most 2 systems were upgraded to 3; this was carried out during a major ship overhaul. The initial procurement process was built around a “design to price” concept in which the final delivery cost per system was fixed in the contract; the SLQ-32 was designed to support the protection of ships against anti-ship missiles in an open sea environment. After initial deployment of the system, naval roles began to change requiring ships to operate much closer to shore in denser signal environments.
This change in roles required changes to the SLQ-32 systems. With experience gained working with the SLQ-32, coupled with improvements to the hardware and software and operators overcame the initial problems; the SLQ-32 is now the mainstay of surface electronic warfare in the U. S. Navy and U. S. Coast Guard's WMEC 270-foot Class Ships. In 1996, a program called the Advanced Integrated Electronic Warfare System was begun to develop a replacement for the SLQ-32. Designated the AN/SLY-2, AIEWS reached the prototype stage by 1999, but funding was withdrawn in April 2002 due to ballooning costs and constant delays in the projects development, it has since been replaced with Surface Electronic Warfare Improvement Program, which will replace the existing SLQ-32 hardware and technology in an evolutionary fashion. As of September 2013 SEWIP Block 2 upgrades were first installed on Burke-class destroyers in 2014, with full-rate production scheduled for mid-2015. Block 2 improved detection capabilities. SEWIP Block 2 was tested on USS Freedom in December 2014.
Electronic Warfare ELINT U. S. Navy Raytheon Federation of American Scientists: AN/SLQ-32 Electronic Warfare system Raytheon Product Description for the AN/SLQ-32 AN/SLQ-32 in the Warfighters Encyclopedia AN/SLQ-325 Data Sheet EXHIBIT R-2, RDT&E Budget Item Justification Surface Electronic Warfare Improvement Program
Information Operations (United States)
Information Operations is a category of direct and indirect support operations for the United States Military. By definition in Joint Publication 3-13, "IO are described as the integrated employment of electronic warfare, computer network operations, psychological operations, military deception, operations security, in concert with specified supporting and related capabilities, to influence, corrupt or usurp adversarial human and automated decision making while protecting our own." Information Operations are actions taken to affect adversary information and information systems while defending one's own information and information systems. Electronic warfare refers to any action involving the use of the electromagnetic spectrum or directed energy to control the spectrum, attack an enemy, or impede enemy assaults via the spectrum; the purpose of electronic warfare is to deny the opponent the advantage of, ensure friendly unimpeded access to, the EM spectrum. EW can be applied from air, sea and space by manned and unmanned systems, can target communication, radar, or other services.
EW includes three major subdivisions: Electronic Attack, Electronic Protection, Electronic warfare Support. EW as an IO Core Capability. EW contributes to the success of IO by using offensive and defensive tactics and techniques in a variety of combinations to shape and exploit adversarial use of the EM spectrum while protecting friendly freedom of action in that spectrum. Expanding reliance on the EM spectrum for informational purposes increases both the potential and the challenges of EW in IO; the increasing prevalence of wireless telephone and computer usage extends both the utility and threat of EW, offering opportunities to exploit an adversary’s electronic vulnerabilities and a requirement to identify and protect our own from similar exploitation. As the use of the EM spectrum has become universal in military operations, so has EW become involved in all aspects of IO. All of the core and related IO capabilities either directly use EW or indirectly benefit from EW. In order to coordinate and deconflict EW, more broadly all military usage of the EM spectrum, an electronic warfare coordination cell should be established by the JFC to reside with the component commander most appropriate to the operation.
In addition, all joint operations require a joint restricted frequency list. This list specifies protected and taboo frequencies that should not be disrupted without prior coordination and planning, either because of friendly use or friendly exploitation; this is maintained and promulgated by the communications system directorate of a joint staff in coordination with J-3 and the joint commander’s electronic warfare staff. Domination of the Electromagnetic Spectrum. DOD now emphasizes maximum control of the entire electromagnetic spectrum, including the capability to disrupt all current and future communication systems and weapons systems; this may include: navigation warfare, including methods for offensive space operations where global positioning satellites may be disrupted. CNO as an IO Core Capability; the increasing reliance of unsophisticated militaries and terrorist groups on computers and computer networks to pass information to C2 forces reinforces the importance of CNO in IO plans and activities.
As the capability of computers and the range of their employment broadens, new vulnerabilities and opportunities will continue to develop. This offers both opportunities to attack and exploit an adversary’s computer system weaknesses and a requirement to identify and protect our own from similar attack or exploitation. Computer network attack. Actions taken through the use of computer networks to disrupt, degrade, or destroy information resident in computers and computer networks, or the computers and networks themselves. Called CNA. Computer network defense. Actions taken through the use of computer networks to protect, analyze and respond to unauthorized activity within Department of Defense information systems and computer networks. Called CND.computer network exploitation. Enabling operations and intelligence collection capabilities conducted through the use of computer networks to gather data from target or adversary automated information systems or networks. Called CNE. PSYOP as an IO Core Capability.
PSYOP has a central role in the achievement of IO objectives in support of the JFC. In today’s information environment PSYOP conducted at the tactical level can have strategic effects. Therefore, PSYOP has an approval process that must be understood and the necessity for timely decisions is fundamental to effective PSYOP and IO; this is important in the early stages of an operation given the time it takes to develop, produce, distribute and evaluate PSYOP products and actions. All PSYOP are conducted under the authority of interagency-coordinated and OSD approved PSYOP programs; the PSYOP program approval process at the national level requires time for sufficient coordination and resolution of issues. A JFC must have an approved PSYOP program, execution authority, delegation of product approval authority before PSYOP execution can begin. JFCs should request PSYOP planners during the initial crisis stages to ensure the JFC has plenty of lead time to obtain the proper a
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. It is the largest and most capable navy in the world and it has been estimated that in terms of tonnage of its active battle fleet alone, it is larger than the next 13 navies combined, which includes 11 U. S. allies or partner nations. With the highest combined battle fleet tonnage and the world's largest aircraft carrier fleet, with eleven in service, two new carriers under construction. With 319,421 personnel on active duty and 99,616 in the Ready Reserve, the Navy is the third largest of the service branches, it has 282 deployable combat vessels and more than 3,700 operational aircraft as of March 2018, making it the second-largest air force in the world, after the United States Air Force. The U. S. Navy traces its origins to the Continental Navy, established during the American Revolutionary War and was disbanded as a separate entity shortly thereafter.
The U. S. Navy played a major role in the American Civil War by blockading the Confederacy and seizing control of its rivers, it played the central role in the World War II defeat of Imperial Japan. The US Navy emerged from World War II as the most powerful navy in the world; the 21st century U. S. Navy maintains a sizable global presence, deploying in strength in such areas as the Western Pacific, the Mediterranean, the Indian Ocean, it is a blue-water navy with the ability to project force onto the littoral regions of the world, engage in forward deployments during peacetime and respond to regional crises, making it a frequent actor in U. S. foreign and military policy. The Navy is administratively managed by the Department of the Navy, headed by the civilian Secretary of the Navy; the Department of the Navy is itself a division of the Department of Defense, headed by the Secretary of Defense. The Chief of Naval Operations is the most senior naval officer serving in the Department of the Navy.
The mission of the Navy is to maintain and equip combat-ready Naval forces capable of winning wars, deterring aggression and maintaining freedom of the seas. The U. S. Navy is a seaborne branch of the military of the United States; the Navy's three primary areas of responsibility: The preparation of naval forces necessary for the effective prosecution of war. The maintenance of naval aviation, including land-based naval aviation, air transport essential for naval operations, all air weapons and air techniques involved in the operations and activities of the Navy; the development of aircraft, tactics, technique and equipment of naval combat and service elements. U. S. Navy training manuals state that the mission of the U. S. Armed Forces is "to be prepared to conduct prompt and sustained combat operations in support of the national interest." As part of that establishment, the U. S. Navy's functions comprise sea control, power projection and nuclear deterrence, in addition to "sealift" duties, it follows as certain as that night succeeds the day, that without a decisive naval force we can do nothing definitive, with it, everything honorable and glorious.
Naval power... is the natural defense of the United States The Navy was rooted in the colonial seafaring tradition, which produced a large community of sailors and shipbuilders. In the early stages of the American Revolutionary War, Massachusetts had its own Massachusetts Naval Militia; the rationale for establishing a national navy was debated in the Second Continental Congress. Supporters argued that a navy would protect shipping, defend the coast, make it easier to seek out support from foreign countries. Detractors countered that challenging the British Royal Navy the world's preeminent naval power, was a foolish undertaking. Commander in Chief George Washington resolved the debate when he commissioned the ocean-going schooner USS Hannah to interdict British merchant ships and reported the captures to the Congress. On 13 October 1775, the Continental Congress authorized the purchase of two vessels to be armed for a cruise against British merchant ships. S. Navy; the Continental Navy achieved mixed results.
In August 1785, after the Revolutionary War had drawn to a close, Congress had sold Alliance, the last ship remaining in the Continental Navy due to a lack of funds to maintain the ship or support a navy. In 1972, the Chief of Naval Operations, Admiral Elmo Zumwalt, authorized the Navy to celebrate its birthday on 13 October to honor the establishment of the Continental Navy in 1775; the United States was without a navy for nearly a decade, a state of affairs that exposed U. S. maritime merchant ships to a series of attacks by the Barbary pirates. The sole armed maritime presence between 1790 and the launching of the U. S. Navy's first warships in 1797 was the U. S. Revenue-Marine, the primary predecessor of the U. S. Coast Guard. Although the USRCS conducted operations against the pirates, their depredations far outstripped its abilities and Congress passed the Naval Act of 1794 that established a permanent standing navy on 27 March 1794; the Naval Act ordered the construction and manning of six frigates and, by October 1797, the first three were brought into service: USS United States, USS Constellation, USS Constitution.
Due to his strong posture on having a strong standing Navy during this period, John Adams is "often called the father of the American Navy". In 1798–99 the Navy was involved in an undeclared Quasi-War with France. From 18
Legalman is a United States Navy occupational rating. Legalmen: Perform paralegal duties under the direction and supervision of Judge Advocates in providing and administering legal services, including matters concerned with military justice, administrative discharges, admiralty law and legal assistance Record and transcribe proceedings of courts-martial, courts of inquiry and military commissions and prepare and submit necessary records and reports Prepare correspondence Conduct interviews Serve as military notary publics Perform legal research of pertinent material for evaluation Provide advice and assistance to personnel and command on matters of legal administration List of United States Navy ratings § Administration, deck and weapons specialty ratings Uniforms of the United States Marine Corps § Wear by Navy personnel
United States Naval Special Warfare Command
The United States Naval Special Warfare Command known as NSWC or WARCOM is the Naval component of United States Special Operations Command, the unified command responsible for overseeing and conducting the nation's special operations and missions. Originating in the unconventional naval units formed during the Second World War, NSWC was established on April 16, 1987 at Naval Amphibious Base Coronado in San Diego, California, its mission is to provide leadership, doctrinal guidance and oversight to special operations carried out in maritime and littoral environments. NSWC specializes in a broad range of tactical areas, including unconventional warfare, direct action, special reconnaissance, personnel recovery. NSWC is organized around eight Navy SEAL teams, three special boat teams, various supporting commands, totaling 9,200 personnel. Units can operate independently, as part of U. S. Navy carrier battle groups and amphibious ready groups, or integrated with other U. S. special operations forces.
By utilizing the Navy's ships and overseas facilities, NSWC forces can be deployed almost anywhere in the world. Today's Naval Special Warfare operators can trace their origins to the Scouts and Raiders, Naval Combat Demolition Units, Office of Strategic Services Operational Swimmers, Underwater Demolition Teams, Motor Torpedo Boat Squadrons of World War II. In the Vietnam era, the Navy drew most of its SEALs from the Underwater Demolition Teams. Navy SEALs traced their origin to the Scouts and Raiders while the Underwater Demolition Teams traced theirs to the Navy Combat Demolition Units. However, in 1983 the Underwater Demolition Teams were merged with the SEAL Teams. This, in turn, merged their ancestry. While none of those early organizations have survived to present, their pioneering efforts in unconventional warfare are mirrored in the missions and professionalism of the present Naval Special Warfare warriors. To meet the need for a beach reconnaissance force, selected Army and Marine Corps personnel assembled at Amphibious Training Base Little Creek, Virginia, on 15 August 1942 to begin Amphibious Scouts and Raiders training.
The Scouts and Raiders mission was to identify and reconnoiter the objective beach, maintain a position on the designated beach prior to a landing and guide the assault waves to the landing beach. An extensive history of Naval Special Warfare, written by men who served in the various units, is available at the National Navy UDT-SEAL Museum website, with a matchless collection of artifacts from that era on display at the facility. By the time the United States became involved in World War II, Adolf Hitler and the Axis forces had control over a large portion of Europe and North Africa. If the Allied forces were to stand a chance, there would have to be several full-scale landings; the U. S. Navy decided, they needed men to reconnoiter the landing beaches, take note of obstacles and defenses and guide the landing forces in. During the war, the Army Engineers passed down demolition jobs to the U. S. Navy, they were to clear any obstacles and/or defenses in the near shore area, beginning a tradition that continues today.
The Navy Scouts and Raiders were created before the Navy Combat Demolition Units. The Scouts and Raiders were first formed 15 August 1942, nine months after the attack on Pearl Harbor, from the Observer Group, a joint Marine Corps–Army–Navy unit; the Observer Group was the first unit trained in amphibious reconnaissance. They trained in inflatable boat insertions from submarines around the Chesapeake Bay and at the Amphibious Training Base Little Creek in Virginia and in Fort Pierce, Florida, they were training for an intense clandestine mission in North Africa. With US Marines limited to the Pacific Theatre of Operations, the Observer Group was disbanded, with the Marine Corps counterpart forming the Amphib Recon Company; the U. S. Navy began the Scouts and Raiders to provide reconnaissance and raiding missions to support amphibious landings; the unit could conduct raids and sabotage missions from a pair of men to platoon-sized operations. The unit continued its deployment to North Africa as planned.
Robert Halperin, a former NFL football player and future Olympic medalist, received a Presidential Citation and the Navy Cross for his work during the amphibious landings in French Morocco. This was just the first of many war-time missions for Raiders; the first group included Phil H. Bucklew, the "Father of Naval Special Warfare", after whom the Naval Special Warfare Center building is named. Commissioned in October 1942, this group saw combat in November 1942 during Operation Torch on the North African coast. Scouts and Raiders supported landings in Sicily, Anzio and southern France. A combined operations joint US-Australian unit, Special Service Unit No. 1, was established on 7 July 1943. Its first mission, in September 1943, was at Finschafen on New Guinea. Operations were at Gasmata, Cape Gloucester, the East and South coast of New Britain, all without any loss of personnel. Conflicts arose over operational matters, the unit was dissolved; the US Navy personnel from SSU 1 became the basis of the 7th Amphibious Scouts.
They received a new mission, to go ashore with the assault boats, buoy channels, erect markers for the incoming craft, handle casualties, take offshore soundings, blow up beach obstacles and maintain voice communications lin