Off-campus WSU users: To download campus access dissertations, please use the following link to log into our proxy server with your WSU access ID and password, then click the "Off-campus Download" button below.

Non-WSU users: Please talk to your librarian about requesting this dissertation through interlibrary loan.

Access Type

WSU Access

Date of Award

January 2020

Degree Type


Degree Name



Electrical and Computer Engineering

First Advisor

John Q. Liu


The European emergency call system that’s based on 2G/3G (GSM/UMTS) cellular network has been in deployment since April 2018. This system is a two-decade-long effort from multiple parties to ensure vehicular safety. Due to its legacy nature, the system is deployed with circuit-switched technology which is being phased out in many parts of the world. The packet-switched based 4G/LTE technology provides more bandwidths thus faster data speeds and more content for more users. There is a strong discussion in the mobile communications community that 3G will be phased out before 2G where 2G will still be present due to its more stable coverage. Thus, the study of emergency call system performance in the 4G/LTE environment becomes of interest since 2G and 4G/LTE will co-exist for a very long time. Unlike the United States, the European Union and China keep the current CS network, and several standard bodies have already started the discussion of PS-network based emergency call proposals. The Internet Engineering Task Force group is currently working on the next generation PS-based emergency call system specification within Europe and Automated Crash Notification globally. China is working on its own emergency call system and is scheduled to release as a mandatory standard by the year 2020.

The test setup leverages the 3GPP TS 26.267/268/269 standards and implements data transmission on the VoLTE network. The proposed methods create a testbed to measure the Key Performance Indicator of transmission timing and compare it to the current SMS-based commercial system. Based on 5000 error-free data samples, over 99.58% of the transmission can be completed within 4 seconds with a mean of 0.5488 seconds with stationary VoLTE and slightly decreased performance with mobile VoLTE when LTE coverage is sufficient enough to maintain a connection. Also based on 5000 data samples, the SMS-based system has a 99.15% of successful transmission rate and 75.63% of the successful transmissions can be completed within 4 seconds with a mean of 3.1 seconds.

Off-campus Download