NB-IoT容量研究

Capacity of NB-IoT

NB-IoT是基于LTE协议,设计目标包括广覆盖、大连接、低功耗、低成本4大特性,单小区服务物联终端数量超5万台.需要注意的是该5万连接数是建立在终端极低的激活比、离散的接入时刻和用户分布以及标准的发送分组大小之基础上.一旦大量的用户并发接入,可能引起网络阻塞、终端无法正常收发数据.主要对表类终端业务流程进行梳理和分析,剖析不同业务流程下终端对无线资源的消耗,并结合理论分析得出网络容量瓶颈,为后续NB网络优化提供方向.

NB-IoT is based on the LTE protoc01.Its design goals include wide coverage,large connectivity,low power consumption and low cost.The number ofsingle-cell service loT terminals exceeds 5W million【1,2】.It should be noted that the 50,000 connection number is based on the extremely low activation ratio ofthe terminal,the discrete access time and user distribution and the standard packet size.Once a large number of users concurrently access,it may cause the network to block and the terminal cannot send and receive data normally.The business processes of the table terminal were mainly analyzed such as the RRC connection process,the attach process,the table data reporting process,etc.,the consumption of wireless resources by terminals under different business processes Was analyzed,and the theoretical analysis Was combined to obtain the network capacity bottleneck.Direction for subsequent NB network optimization was provided.