CTI and Delay/Disruption Tolerant Networking (DTN) for the Air Force.

We helped Northrop Grumman build the "Interim Capability for Airborne Networking (ICAN)" system, which is deployed aboard the Joint Surveillance Target Attack Radar System (JSTARS) aircraft fleet and is in active use in multiple operational theaters. We are helping them upgrade and integrate it onto other military platforms as the "Joint Capability for Airborne Networking (JCAN)". We developed a similar system for the US Navy submarine community, referred to as the Application Traffic Controller (ATC).

What most of our recent work has in common is a focus on preserving and accelerating mobile wireless access to network services and data.

We use 2 complementary approaches to achieve this:

(1) When multiple wireless links are available, rather than selecting a single 'best' choice, we automatically and transparently aggregate their bandwidth. This goes far beyond traditional Link Layer bonding, which can only load balance over multiple links of the same type that connect a single pair of routers back-to-back; we load balance across links of different types that connect to different routers (say, SATCOM via an earth station in Hawaii and HF via a SCOPE command base station in California, to ultimately reach an end system anywhere on the Inter/NIPR/SIPR-net). This enables very smooth handoff and higher user data rates.

(2) Our Delay/Disruption Tolerant Networking (DTN) middleware transparently proxies legacy TCP/IP and emerging GIG applications so the service they provide can withstand long variable delays and total outages of the underlying wireless links.

This uses several techniques: persistent transport layer connections; queuing of requests made while links are unavailable, for automatic servicing when links are restored; caching of responses; etc.

Together, these enable roaming, not only from access point to access point, but between different air access technologies, using more than one link when available to accelerate transfers, and preserving access to services and data (insofar as possible) even when no links are available.

We have integrated numerous types of military radios, enabling smooth handoff between them and load balancing across them; and link up/down transitions are completely routine for us, we completely mask them from applications in all but the most severe cases, and automatically reconnect/retransmit, etc. as needed.