Newer LPWAN operator networks, such as NB-IoT, have only recently come to life and therefore, some potential features are not yet in widespread use. This is why they are researched in the thesis in detail.
The NB-IoT network is described and its key advantages are presented. As one of the key features of the network is low consumption, a more advanced function of delivery without the use of an IP stack, which offers additional savings in the field of overhead and energy consumption, has been investigated in detail. Throughout the thesis, the function is compared to the usual way of communication using an IP stack. NIDD can only be performed by transferring data over a non-access stratum, the advantages of which I have highlighted.
Both methods of NIDD implementation are presented in detail. The method using the SGi tunnel is not standardized in detail and does not bring as many advantages as the method using the SCEF element. This opens a new way to communicate with the 3GPP network and also with the IoT device. Ways to use the SCEF APIs are presented. Savings in overheads are broken down in detail and compared to communications where an IP stack is used. Benefits in terms of security, economic savings, energy consumption, accessibility, and roaming are also described.
A comparison of the NB-IoT network with the competing LoRaWAN is also included. The comparison is interesting considering the research of the NIDD function, as LoRaWAN uses a similar delivery method as with the mentioned function.
Below, the NIDD function is tested with the NB-IoT module, which, in addition to NIDD, also supports the newer release of the network. The initial difficulties in using the technology are described. The functionality test includes measurements of communication times and measurements of energy consumption, as well as the preparation of the environment for testing and the development of applications for implementation. The communication time takes into account the data travel time to the application on the server and back. Added to this is the time it takes for the device to transition between RRC states. An advanced power analyzer is used for energy measurements. Data is collected on the open-source IoT platform for further analysis and presentation.
Three sets of measurements were performed. The first used a NIDD transmission and the other two used UDP and TCP transmissions, which utilize the IP stack. Measurements are repeated at three different RSRP signal values, and the signal is manipulated using attenuators. In total the measurements are performed in nine different layouts, the course of each is explained in detail.
The results are presented below and analyzed in detail. The analysis includes checking the correctness of the results and dividing the communication time by the transmission time over wired and wireless media. The analysis and results of the measurements describe that the use of NIDD does not bring significant savings in terms of communication duration or energy consumption and highlights the unsuitability of using TCP for the transmission of small amounts of data.
Finally, from the findings, guidelines for the use of the mentioned transmission methods are presented as well.
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