Priority service for CSfC secure mobile communication over LTE networks for national security and emergency preparedness

Abstract

Legacy secure mobile communications systems based on Secure Communications Interoperability Protocol (SCIP) and 2G cellular networks are at end-of-life and are being replaced with National Security Agency (NSA) Commercial Solutions for Classified (CSfC) over 4G Long Term Evolution (LTE) cellular networks. A key challenge in this transition is that CSfC is incompatible with legacy wireless priority service (WPS) used to ensure that senior leaders and key personnel can communicate during National Security and Emergency Preparedness (NS/EP) events. This paper describes a solution framework for an NS/EP priority service to support CSfC-based secure mobile communications over LTE networks. The solution is standards-based to facilitate implementation in public cellular networks. End-to-end priority treatment is addressed across each major network segment, including (a) the LTE radio network, (b) the LTE core network, and (c) the wireline transport network. Priority in the LTE radio network is subdivided into access priority, admission priority, and scheduling priority. A bearer model with associated quality of service (QoS) is defined for priority treatment through the LTE core network. Priority is maintained across the wireline transport network using Diff-Serv Code Point (DSCP) packet markings. This solution may be used as a secure mobile addition to the NS/EP Next Generation Network Priority Services (NGN-PS) for LTE that are being specified by the Department of Homeland Security (DHS) Office of Emergency Communications (OEC) for unclassified voice, video, and data services.