No Strings

Feb. 15, 2005
Advancements in Short Range Wireless Communications

Clear, reliable communication is always a primary concern for soldiers during various missions. The ability for soldiers to communicate with each other easily and effectively is key to performing successful operations, and has proven to be a challenging problem to overcome in military field operations.

It's hard to imagine in a "world gone wireless" that soldiers still rely on hand signals and interphone cords for communication while performing complex and often times dangerous tasks.

Communication Needs

When a CH-47 Chinook flies into an area carrying a multi-ton load harnessed to the bottom of the helicopter, the loadmaster on board has no verbal communication with the ground troops waiting for the cargo. They rely strictly on visual signals to direct the loadmaster (who in turn relays to the pilot) how far to lower the cargo and the aircraft. Imagine what a dangerous position the ground troops are in to be visible to the loadmaster and yet remain a safe distance from the cargo being dropped.

When a HH-60 Pave Hawk performs a search and rescue operation, the rescue crewman is lowered down from the aircraft on a harness; he/she is also limited to hand signals to the pilot and crew on board the aircraft. This proves to be extremely dangerous when lowered into violent seas and/or in dangerous combat conditions.

Short-range communications are virtually non-existent when Air Force crewmen perform critical cargo drops; when US Coast Guard response boats are sent into unstable waters; when a US Marine squad is deployed into the battlefield or when a US Army crew disembarks from an armored vehicle. Even fundamental operations such as aircraft towing and pushback for commercial airlines require one operator to be connected to the aircraft through a long interphone cord with no communication to the wing walkers or tug driver.

Developing a Solution

In the summer of 2000, the US Army Aircrew Integrated Systems Project Office contracted Telephonics to perform a study of wireless intercommunication technology under a program called AWIS (Aircraft Wireless Intercom System). The goal of the program was to identify the best method of facilitating wireless communication between crewmembers during hot refueling, loading, off-loading and rearming. Telephonics successfully conducted the study and was subsequently contracted for the design and development stage of the program. In 2003, final tests and qualification were completed, and AWIS was added to the Air Warrior program ( The Air Warrior system integrates all aviation life-support and mission equipment into an aircrew ensemble. AWIS will be included in the ensemble and be outfitted on every CH-47 and UH-60 in the Army fleet.

AWIS was the first stepping-stone to a wider military utilization of wireless intercommunications. Realizing that similar communication deficiencies existed across multiple applications, Telephonics initiated a research effort to understand the scope of the problem and create a solution for all DOD agencies.

In 2004 Telephonics launched its latest product line — TruLink®. This system has all the functionality of AWIS with the added flexibility to work across multiple applications in various environments.

TruLink Overview

TruLink is a full duplex, frequency hopping spread spectrum system, operating within the 2.4 GHz band. The system provides 50 independent channels. On any one of those channels, 31 operators can monitor a single channel. On any single channel, six operators can speak simultaneously providing true intercom capability.

TruLink has three configurations: first, a stand-alone intercom system where an access point can interface to up to three long-range radios. The wireless users in this configuration can transmit and receive over the radios and maintain private intercom capability among each other.

The second configuration acts as a soldier's short-range tactical radio. Here, each soldier's wireless radio networks together to allow squad level intercommunications.

The third configuration operates as an extension to an existing hardwired intercom. The system can interface to any aircraft or vehicle intercom system through an access point. This allows the hardwired system to remain in place, while expanding communications to the wireless operators.

TruLink performs in harsh conditions and in high-noise surroundings. It is equipped with an external microphone that provides noise reduction to improve speech intelligibility. The system also offers an adaptive VOX (Voice Activated Switch) feature so soldiers are not constantly changing VOX levels due to varying noise conditions. The adaptive VOX eliminates white noise susceptible in HOT MIC mode, and restriction of PTT — the unit truly is hands-free.

Short Range Communication Network

The flexibility of TruLink across multiple platforms and agencies allows for the opportunity to create an interoperable short-range communication network.

TruLink can provide soldier-to-soldier communications and connection to any platform carrying an access point. This creates an entire communication network where any operator can speak to any platform or soldier over the intercom net by simply selecting the appropriate channel.

TruLink's unique intercom capability and communications is far superior to other similar systems. Some two-way radios, such as the Personal Role Radio may prove useful for simple tactical communications, but do not meet all the operational needs of the soldier. For example, working only in simplex operation (one speaker at a time), the PRR can only allow one operator to tie into a hard-wired intercom system. The system is further restricted with no connection to long-range radios.

Successful Launch

Since its introduction, TruLink has been successfully contracted for projects within the DOD and other agencies. Outside of the US Army, the US Navy has selected the system for new Mine Search Crafts, the US Marines for Bridge Building Brigades and Project Deep Blue, US Customs for Drug Interdiction boats and Textron Land Systems for there new Armored Security Vehicle.

As requirements continue to evolve for full duplex, wireless intercommunications systems such as Telephonics' TruLink will continue to set new standards. In the future, this technology will be accessible to soldiers and crewmen across all agencies, enabling them to perform their missions more efficiently, and safely.

For more information on Telephonics' TruLink Wireless Intercom System or other technology, please visit us at

Thomas Lavalle is a Business Development Associate at Telephonics Corporation, Communication Systems Division.