The next few years form a critical stage in the evolution of broadband Public Safety Networks (PSNs); we anticipate that key PSN-related issues including coverage and capacity extension methods, support for end-to-end Quality of Service Priority and Preemption (QPP), failure resilience, and multicast will be fully standardized (reach final and stable version) only after this time, given the current lack of fully-compliant chips and interoperability tests in some aspects. We have already obtained a number of important results that can inform and impact handling of Mission Critical Voice (MCV), Mission Critical Push-To-Talk (MCPTT), general QPP support, as well as general coverage enhancement and reconfiguration methods in future PSN networks. In particular, our pioneering study on the analysis of potential spectrum savings and improving first responder (FR) communications by using Multicast-broadcast single-frequency network (MBSFN) and our results on optimal selection of channel parameters for PSN applications in Long-Term Evolution (LTE) Direct are useful for MCV, MCPTT and general QPP support. Our work on FR trajectory-based mobile base station placement is important for general coverage enhancement and reconfiguration, and useful to FR communications and operations. Several articles are already published from the results of this research, and additional articles are expected to be submitted. - July 2019
Principle Investigator: Rajarathnam Chandramouli
Resilient communications and computing (during emergencies and day-to-day operations) are key metrics for public safety applications and services. Resilience includes: (a) the ability to intelligently mitigate radio interference and backhaul congestion (e.g., end-to-end optimized cognitive radio networking); (b) the ability to cache and access data, deliver applications and host services even when the backhaul link to a core data center has failed or is severely degraded; and (c) smart computing to prolong the battery life of ﬁrst responder mobile devices, mobile computing gateways, and mobile and wireless sensors.
During an emergency, very often, the general public competes with public safety organizations (PSOs) for wireless network resources, mobile applications and services. This puts severe pressure and variability on latency and bandwidth available to PSOs that share public cellular networks, in times of need. The same is true when several PSOs share dedicated wireless networks for real-time and bandwidth hungry applications. Therefore, building cognitive wireless networks that sense mobile networks end-to-end for adapting communications and computing decisions to (stochastic) interference, congestion, coverage and capacity, is critical.
“Fog” brings “Cloud” closer to the end users, i.e., to the network edge for hyper local access and services, thereby building resilience against core infrastructure failures. Therefore, the two major goals of this project: (a) resilient fog heterogeneous wireless networking (HetNet) and (b) resilient fog heterogenous computing, are addressed by the following R&D tasks:
These tasks address Routing and Mobility Across Heterogeneous and Opportunistic Net-works and, Data Management, Access, and Consistency areas within the Resilient Systems theme. The proposed HetNet devices (router+computing device) along with a LiteEPC will be deployed in police cars at Brookline PD and tested. Resilience and robustness of the system under diﬀerent mobility conditions will be evaluated. Extreme wireless/core network conditions will be emulated in the ﬁeld. The successful demonstration, pilot trial and product delivery to the Brookline PD is expected to inform future U.S. (and global) spectrum policies for public safety communications.