Wireless Network After Next (WNAN)

Portable — Durable — Scalable — Affordable

The future of affordable handheld communications for the individual warfighter will rely on leveraging inexpensive commercial parts and processes to build networked radios that are flexible, capable, and inexpensive. However, to take advantage of low cost hardware, it will be critical to have network software that works around hardware limitations and exploits the capabilities while meeting scalability and flexibility requirements. These are the challenges that must be overcome to deliver reliable communications to all warfighters.

Under the DARPA Wireless Network After Next (WNaN) program sponsored by DARPA and the Air Force Research Laboratory, BBN is meeting this challenge by developing scalable, adaptive, ad hoc networks that use very inexpensive yet flexible software radios. BBN is working with M/A-COM, who is building the radio hardware.

Dynamic Spectrum Access (DSA)

Today’s military radios relay 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. 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 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 looses the route to the destination. This is unacceptable in most military environments because links change often. 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.

Content Based Access

When there are many IP-capable radios are in the field, there is a lot of data availability, but retrieving that data on current networks requires users to know the exact filename, transport protocol, and node. WNaN includes Content Based Access (CBA) techniques that allow users to query the network to find information. CBA can also automatically pre-place certain types of critical data (such as maps), around the network to minimize the time and bandwidth used to get the data when queries are entered.

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.