Scalable — Adaptable — Affordable
The future of affordable handheld communications for the soldier relies on scalable networked multi-hop radios which can leverage inexpensive hardware based on commercial processes. Through the Defense Advanced Research Project’s Agency’s (DARPA) Wireless Network after Next (WNaN) program, BBN is developing a new networking waveform and inexpensive radio which takes combines multiple new technologies to create scalable, adaptive, ad hoc networks which meet the challenges of tomorrow’s soldier missions.
The low cost WNaN system provides a robust mobile ad hoc network (MANET) with dynamic spectrum access (DSA), disruption tolerant networking (DTN), and multiple cooperative transceivers on a compact, hand-held platform. As a result of the network being enabled by these highly innovative capabilities, WNaN allows operation in dense signal environments with cell-phone quality voice without dropping calls, facilitates mission command through the ability to easily set up to 128 call groups, and maintains situational awareness (SA) even when communications are interrupted. Because the WNaN software is delivered on low cost, commercially available components, WNaN radios can enable soldiers at every operational level to have a reliable communications device.
Dynamic Spectrum Access (DSA)
Today’s military radios rely on complex frequency pre-planning and fixed frequency assignments. This increases the time required to plan a mission, complicates in-field tactical flexibility, creates a significant logistical tail, and will not scale to large numbers of radios. Raytheon BBN’s WNaN includes Dynamic Spectrum Access (DSA) techniques that sense which spectrum is in use and which is available. When combined with strict policy compliance checking, this allows WNaN radios to dynamically use spectrum that is otherwise unoccupied and to automatically shift the frequencies that are in use to optimize the network topology based on communications capabilities and traffic load.
Exploiting Multiple Transceivers
To scale in density or network size, future tactical radios will need multiple channels. The MAC and network protocols of the Raytheon BBN WNaN were designed from the beginning to operate efficiently over 1, 2, 4, 6, or even more channels. WNaN uses dynamic spectrum access and frequency agility to choose the right topology for the current mission and traffic requirements.
Disruption Tolerant Networking
RF communication is unreliable. Today’s networking protocols all drop packets immediately if any node along the path loses the route to the destination. This is unacceptable in most military environments because links change often. Raytheon BBN’s WNaN includes Disruption Tolerant Networking (DTN) technologies that allow the nodes to store packets temporarily during link outages. In field experiments, we have delivered 100% of the traffic in situations where traditional IP-networking delivered less than 10%. Furthermore, the WNaN DTN implementation can operate underneath the standard IP stack, so that existing applications do not have to be modified to get DTN services. All of today’s IP applications can access DTN service using WNaN.
Multicast Voice with Quality of Service
The most fundamental way for people to communicate is voice. WNaN provides multicast voice with quality of service to provide an unlimited number of configurable call groups available to anyone at any time with the kind of quality of service support that is needed to support military-grade voice service. The quality of service capabilities also extend to high-priority application data, guaranteeing that the most important data makes it through the clutter of other information on the network.
Embedded Implementation without Limiting Capabilities
The WNaN protocols are designed for small handheld devices. They include energy conserving capabilities to extend battery life and are targeted for embedded operating systems and processors. The protocols do not sacrifice performance to be portable across hardware architectures.
We have demonstrated WNaN performance at large scaling, proving that WNaN is scalable to the needs of our military. In August 2010 Raytheon BBN conducted a 102-node WNaN demonstration that included a mix of voice and data traffic in a simulated tactical environment.
The WNaN system participated in the US Army’s Network Integration Evaluation (NIE) 12.1 as a System Under Evaluation (SUE) in which soldiers from the 2nd Brigade, 1st Armored Division assessed the capabilities of the system in live training scenarios with 35 dismount and vehicular WNaN radios using up to 16 call groups. The NIE 12.1 participation followed a series of previous demonstrations where WNaN surpassed scalability requirements by successfully transmitting voice and data traffic across 102 nodes in a tactical environment. In coordination with DARPA, the US Army has purchased 120 Version 4 (next generation) WNaN radios in support of the NIE 13.1 experiment. The version 4 radio dramatically reduces the size, weight, and power requirements compared to the earlier version used at NIE 12.1 and increases battery life to over 10 hours.