Many of the early concepts explored by DARPA in the mid-1990s also played in the development of command, control, and communications technologies that changed how the DOD operated. The commercial applications of these technologies found their way into products in the 2000s. One example was DARPA’s Personal Assistant that Learns (PAL) project, which opened pathways to the development of popular commercial voice-response software applications such as Siri and Alexa. “You start to see a lot of growth as these things went out into the commercial world,” Hendler observed, “but if you trace back a lot of that work to its roots, you’ll find DARPA’s fingerprints.”
Many of the early concepts explored by DARPA in the mid-1990s also played in the development of command, control, and communications technologies that changed how the DOD operated. The commercial applications of these technologies found their way into products in the 2000s.
Another outgrowth of DARPA’s funding early in the new century was the application of machine-learning and artificial intelligence (AI) technologies on the web. The development of machine-learning systems led to the creation of new applications and practices such as data-mining, which opened new avenues for rapid analysis and use of massive data sets across the internet. DARPA was a key developer of these machine-learning technologies, and much of the current boom in big data grew out of DARPA’s investments.
The Wireless Internet and Beyond
The packet-switching technology that helped launch ARPANET also led to another networking revolution. Packet-switching-based messages based on TCP/IP standards were originally sent via telephone wires, but the same information subsequently was converted into radio signals that could be transmitted via satellite relay stations. Later, this approach was applied to terrestrial radios, said Randy Katz, Vice Chancellor for Research at the University of California, Berkeley.
In the late 1970s, DARPA launched a program to develop a packet radio networking system. Intended to support DOD requirements for mobile wireless networking, the challenge was to make the radios operate in tactical environments. This presented completely different engineering constraints compared to the fixed ARPANET infrastructure. “The packet radio program of the late 1970s was focused on, maybe not sending as many bits, but in a much more challenged environment, much more dynamic … because that mirrored the typical battlefield application,” Katz said.
Commercial wireless applications did not become profitable until the late 1980s, with the development of the predecessor of Wi-Fi technology. Advances in miniaturization also helped drive what would become the wireless revolution. Katz noted that in the late 1970s, the technology that would eventually become the basis of cell phone communication filled a large van, largely because of the computational power required to run the software-intensive TCP/IP framework. By the late 1980s, the system was miniaturized down to a small computer with an antenna in a package roughly the size of a pack of cigarettes.
It is best to view the advent of wireless communications in terms of mobile computing, Katz explained. This was driven by the co-evolution of computer miniaturization with the networking technology developed by ARPANET and NSFNET. This allowed computers, and what would become smartphones, to be connected wirelessly using the emerging technology of Wi-Fi.
Katz joined DARPA in the early 1990s to head the Global Mobile Information Systems (GloMo) program, which aimed to accelerate the development of mobile computing (later in the same decade, Katz would become deputy director of DARPA’s Computing Systems and Technology Office). GloMo looked at dual-use technologies for digitizing military and civilian communications. Katz noted that beginning in the early 1990s, DARPA became very interested in mobility and wireless networking to support the DOD’s efforts to modernize its communications and command and control systems.
Much of DARPA’s work at the time in this area was in understanding how mobile wireless systems could be scaled up and operate in a changing environment. These mobile networks also had to be backward compatible with all the information and resources already available on the internet, Katz said. Scientists and engineers also had to ponder how mobile devices could exchange information without a centralized network or set of servers. “All of these ideas really blossomed in the time frame of the late 1990s into the early 2000s,” he said.
Wireless networking and broadband will continue to influence near- and long-term computing for both commercial and military applications, Cerf said. The advent of the first true smartphones in the early 2000s (capable of internet access, GPS location, video recording/cameras, and high-speed wireless network access) and the release of the Apple iPhone in 2007 heralded the beginning of the current era of ubiquitous access to data. An infrastructure of blanket Wi-Fi and cellular coverage in most urban areas across the globe has greatly expanded ease of access.