A Contention-free Access Scheme and An Efficient Random Access Response Message for mMTC in 5G

• Main Authors: Huang, Teng-Wei, 黃騰葳
• Other Authors: Tseng, Yu-Chee
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/9qk9fn

碩士 === 國立交通大學 === 網路工程研究所 === 105 === Massive Machine Type Communication (mMTC) has attracted increasing attention due to the explosive growth of IoT devices. Random access (RA) for a large number of mMTC user equipments (UEs) is especially difficult since the severe collisions problem between UEs and an eNB may overwhelm the available spectrum resources. To address this issue, we propose a contention-free access scheme and an efficient RA response (RAR) message for mMTC in 5G. The core idea is to avoid collisions happened between UEs and also the one-to-one mapping mechanism applied by 4G-Long-Tern Evolution (4G-LTE). To do so, we exploit the concept of Chinese Remainder Theorem (CRT) and prime {\em factorization} to encode the {\em hint} such that UEs can extract their required information accordingly. Our simulations show that we can reduce the access delay for mMTC UEs up to 80\%. Besides, we can reduce the RAR message size by 20\%--40\%. Such reduction can be translated to around 50\% improvement of spectrum efficiency in LTE-M.