End-to-End Quality Priority and Pre-emption

Summary

The management of radio and network infrastructure resources in a nationwide interoperable network is critical to maintaining effective operations during periods of congestion, particularly when there are large incidents involving many public safety users in a small area. Quality of Service (QoS), Priority, and Pre-emption (QPP) capabilities will provide FirstNet with the ability to efficiently manage Long Term Evolution (LTE) radio and network resources. The Public Safety Communications Research (PSCR) program is researching the complete set of LTE capabilities that can enable a public safety nationwide network to implement QPP from mobile devices through the network core. This will ensure that priority public safety users gain and maintain access to critical FirstNet resources when demand exceeds capacity.

Description

Video frame for a high, medium, and low priority user in a congested network

The Middle Class Tax Relief and Job Creation Act of 2012 (H.R. 3630) appropriated $7 billion for the establishment of a nationwide interoperable public safety broadband network under FirstNet, an independent authority in the National Telecommunications and Information Administration (NTIA). FirstNet will provide first responders with dedicated and prioritized access to high-speed data, voice, and other mission critical applications. This nationwide network will enable public safety agencies at the federal, state, and local levels to effectively conduct their mission by establishing a common communications system based on 3GPP LTE standards. PSCR, a joint National Institute for Standards and Technology (NIST) and NTIA program, is sponsored by FirstNet to measure QPP behavior through an entire real LTE system from mobile devices through the network core. In FY2015, FirstNet sponsored QPP research to measure the technical mechanisms available with simulated user devices at the eNodeB. For FY2016, QPP research builds upon previous work by testing real user equipment and examining complete LTE network behavior.

AN INNOVATIVE APPROACH

PSCR has extensive expertise in QPP, primarily through its sponsored work in FY2015 for FirstNet.  PSCR also leverages cooperative research and development agreements (CRADAs) with industry partners who provide vendor products and support.  
During FY2015 research, PSCR developed testing, measurement, and analysis methods/capabilities for determining the effectiveness of QPP mechanisms in a real LTE system. The FY2016 End-to-End QPP research will build upon PSCR’s existing expertise and capability set with the following approach:
•    Measure the ability of the LTE system to provide priority radio resource control access to the network for real mobile devices
•    Measure throughput, dedicated bearer allocation, pre-emption, and QoS performance based on user priority
•    Determine and measure the ability of real mobile devices to initiate dedicated bearers
•    Measure the performance of QPP management from the user device through network interfaces
•    Define common QPP performance metrics that measure network loading, QPP management effectiveness, and resulting user experience

VALUE TO PUBLIC SAFETY

FirstNet’s ability to manage network resources is critical in establishing an LTE network that provides priority public safety users with the tools they need to accomplish their mission. This research will result in FirstNet operators properly implementing and leveraging QPP capabilities, which will enable maximized network and priority user performance throughout the entire