National Security and Emergency Preparedness (NS/EP) responders require higher call completion and signal quality than the average commercial wireless user. Next Generation Network Priority Service (NGN-PS) 4G Long Term Evolution (LTE) mechanisms, like Paging Priority or Establishment Cause, can be used by network designers to improve NS/EP user’s communications experience. However, NGN-PS controls must not interfere with 2G/3G cellular programs like Wireless Priority Services (WPS).
The Public Safety Communications Research (PSCR) program is conducting a priority services evaluations project to increase understanding of priority service interactions to help determine if the user’s experience is improved and if legacy features are adversely impacted.
The Department of Homeland Security’s Office of Emergency Communication (DHS-OEC) is responsible for administering both the Government Emergency Telecommunications Service (GETS) and Wireless Priority Service (WPS) programs. Both programs offer their users an alternative method for call completion when either the Public Switched Telephone Network (PSTN) or a commercial wireless network is congested. WPS users dial a special access code before their destination phone number on a registered wireless device, while GETS users must dial a specific access telephone number followed by their 12-digit Personal Identification Number (PIN) and intended destination number.
WPS and GETS are funded by DHS-OEC and implemented via contracts with the major wireline and wireless carriers. WPS has not yet been implemented in 4G and it is unknown how the mobile network operators (MNOs) will execute priority services. MNOs may use a mix of NGN-PS mechanisms to deliver the WPS functionality that users of 2G and 3G wireless have come to rely on. The goal of this project is to validate the design proposed by an MNO before a contract is signed.
PSCR constructed an LTE testbed capable of simulating both public safety and commercial band class LTE networks. The testbed was first used to conduct a functional evaluation of all the NGN-PS mechanisms, e.g. Allocation and Retention Policy, Access Class Barring/Restriction, and Access Point Name, in a simulated environment. The second phase of testing utilized a simulated UE, eNodeB (eNB), and Packet Data Network to evaluate the ways NGN-PS mechanisms are implemented at a packet level in state of the industry Evolved Packet Cores. The final phase of testing will take a packet-level look at the NGN-PS mechanisms through the entire LTE ecosystem using consumer and carrier-grade equipment (e.g. Commercial Off The Shelf UEs, public safety and commercial band class eNBs, carrier grade, and virtualized EPCs). This equipment is connected to a Packet Data Network that supports data, voice, and video applications.
Public safety telecommunications users comprise a large segment of the GETS/WPS subscriber base, and the effectiveness of NGN-PS has a direct effect on their ability to perform essential job functions. WPS/GETS and NGN-PS help ensure that first responder voice, video, and data capabilities are operational during a national emergency.