MIoTy Overview: a Mathematical Description of the Physical layer

MIoTy is a relatively new Low Power Wide Area Network system. The aim of the thesis is to get an overall understanding of the system and an in-depth understanding of the Physical Layer. In particular, a mathematical description of the physical layer is the final aim, Telegram Splitting Multiple Access (TSMA) is the main invention in the MIoTy the technology uses an algorithm to parse the data packets to be transmitted into small sub-packets at the transmission source. MIoTy is based on the protocol family telegram splitting ultra narrowband (TS-UNB) of the ETSI TS 103 357 standards. These TSMA systems have a data rate of 512 bit/s. The UNB telegram is divided at the physical layer into multiple sub-packets, each equal in size. Each of which is randomly sent on a different carrier frequency and at a different time. The sub-packets are much smaller than the original telegram and only require an on-air time of 16 ms. The total air-time of all the sub-packets for a 10-byte telegram is about 390 ms. The risk of suffering data loss resulting from interference is substantially reduced due to a combination of the virtually random distribution of sub-packet transmissions through time and varying frequencies. And, as a result of the use of sophisticated forward error correction (FEC) techniques, the receiver needs only about 50% of the packets to reconstruct the original telegram completely.MIoTy is a relatively new Low Power Wide Area Network system. The aim of the thesis is to get an overall understanding of the system and an in-depth understanding of the Physical Layer. In particular, a mathematical description of the physical layer is the final aim, Telegram Splitting Multiple Access (TSMA) is the main invention in the MIoTy the technology uses an algorithm to parse the data packets to be transmitted into small sub-packets at the transmission source. MIoTy is based on the protocol family telegram splitting ultra narrowband (TS-UNB) of the ETSI TS 103 357 standards. These TSMA systems have a data rate of 512 bit/s. The UNB telegram is divided at the physical layer into multiple sub-packets, each equal in size. Each of which is randomly sent on a different carrier frequency and at a different time. The sub-packets are much smaller than the original telegram and only require an on-air time of 16 ms. The total air-time of all the sub-packets for a 10-byte telegram is about 390 ms. The risk of suffering data loss resulting from interference is substantially reduced due to a combination of the virtually random distribution of sub-packet transmissions through time and varying frequencies. And, as a result of the use of sophisticated forward error correction (FEC) techniques, the receiver needs only about 50% of the packets to reconstruct the original telegram completely

Overview of Risk Mitigation for Safety-Critical Computer-Based Systems

This report presents a high-level overview of a general strategy to mitigate the risks from threats to safety-critical computer-based systems. In this context, a safety threat is a process or phenomenon that can cause operational safety hazards in the form of computational system failures. This report is intended to provide insight into the safety-risk mitigation problem and the characteristics of potential solutions. The limitations of the general risk mitigation strategy are discussed and some options to overcome these limitations are provided. This work is part of an ongoing effort to enable well-founded assurance of safety-related properties of complex safety-critical computer-based aircraft systems by developing an effective capability to model and reason about the safety implications of system requirements and design