Joint node clustering and data caching access method in narrow-band IOT

Abstract

The invention discloses a joint node clustering and data caching access method in a narrow-band IOT. The method comprises the steps that: (1), a base station divides cell nodes into three levels according to the coupling loss; nodes in the same level are divided into M clusters according to spatial positions; and, in combination with node position distribution in each cluster, a specific node is selected for each cluster, and used as a relay node having a caching function; (2), a single time slot access preamble is divided into two parts denoted by K<1> and K<2>; and an access period is divided into two parts denoted by T<1> and T<2>; (3), an ordinary node is accessed to the relay node by selecting and sending the K<1> preamble; node information is cached in the relay node; after caching in a T<1> time slot, the relay node is accessed to the base station by selecting and sending the K<2> preamble; cache information is sent to the base station; and thus, uplink synchronization from eachordinary node to the base station is completed; and (4), the access success rate is calculated; and a best division method of preamble resources and access time slots in the step (2) is determined when the maximum access rate is reached.

Description

technical field [0001] The invention relates to the field of node random access in the narrowband Internet of Things, in particular to a random access method of node clustering, relay node caching, and relay access in the narrowband Internet of Things. Background technique [0002] Narrowband IoT is a cellular IoT technology produced as an IoT service for low-power wide-area coverage. Its advantages lie in deep coverage, low terminal power consumption, low cost, and support for large-scale connections. Narrowband IoT technology has a wide range of applications, and its main services are divided into periodic upload services, event-triggered services, software update / update configuration services, and network command services. [0003] Narrowband IoT supports the deployment of tens of thousands of terminals in a single cell. In view of its narrowband system characteristics, the maximum access channel frequency band is only 180KHZ, and it adopts a unique frequency hopping prea...

AI Technical Summary

Problems solved by technology

If a preamble is selected by multiple terminals, access conflicts occur when these terminals send the preamble, and the base station cannot judge the terminal information, so it cannot send a random access response to the terminal, resulting in continuous access failures, and the access success rate is extremely low. Low

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