Cellular networks have become a part of the infrastructure that we rely on without pausing to think of the enormous complexity that underlies such networks. These networks serve an amazing diversity of mobile devices and operate in an amazing diversity of radio environments. Failures in such networks are not uncommon and we take their consequences in our stride as a fact of life, complaining about call drops and data disconnections. Similarly, we also encounter performance degradations, either in voice quality of calls or connection speeds. With the fast increasing amount of traffic on cellular networks and the cellular spectrum crunch, these conditions are expected to become more severe in the near to mid-term future. Further, in today's networks, there is no facility to provide services to a device by orchestrating an entire network of geographically dispersed mobile devices, such as, for providing a "video" of the path of an oncoming tornado.
In this project, the researchers put forward the view that rather than reactive management of failures or performance degradations, there is a need to build into cellular networks, proactive management of such events. The primary difficulty for this is that, to the end devices, the network is considered essentially as a black box. Conditions about the network, such as, congestion or overload of some elements of the cellular infrastructure, are not made visible to the applications on the mobile end devices. Likewise, much of the application eco-system within a device is not made visible to the network. Thus, it is not known to the network what is the latency requirement of some application or what demand it is going to place in the near future on the network. The proposed solution approach will turn this black box approach on its head and enable proactive fault and performance management and an entirely new class of applications through cooperation between the network and the devices, a Tango of sorts.
The project goals will be accomplished through two synergistic project thrusts. In the first, called "Fault Management and Orchestrated Services", the team will develop computational and statistical models for the real-time cellular data and analytics tools for the same, machine learning algorithms for predicting hard and soft failures, and mitigation actions for avoiding predicted failures. It will also develop orchestrated services between the cellular network and the end users to achieve system-wide goals under the broad umbrella of "participatory sensing". In the second thrust, called "Performance-driven Design", the team will develop an API that will allow the cellular devices and the cellular network to cooperate for achieving common desired system-level properties, such as, higher data bandwidth. It will provide advanced traffic management schemes through back-filling of delay-tolerant traffic and computation offloading from the mobile devices, leveraging a team member's recent efforts in the Cirrus Clouds Project. The project will result in the development of a miniature LTE/UMTS testbed for open experimentation, open data access, and evaluation of the protocols mentioned above.
