This paper analyzes the reliability and throughput of the telegram-splitting concept in the presence of inter-system and intra-system interference. Using telegram splitting, the data of one telegram is split into multiple sub-packets, which are then transmitted with temporal spacing. As a result, collisions with other telegrams destroy only some sub-packets that can be recovered using forward error correction. Consequently, the reliability of the data transmission in case of inter-and intra-system interference-a significant problem in license-exempt bands-is highly improved. In this paper, probabilities for the resulting telegram error rate of random media access systems using telegram splitting are derived. Furthermore, the achievable throughput is analyzed. The theoretical considerations in addition to simulation results prove the significant gain of the telegram-splitting concept for telemetry systems.

An approach for a more realistic simulation of wireless smart metering networks in smart grid applications is presented in this work. Conventional network simulations usually ignore spectral properties of transmission signals. Thus, adjacent channel interference is ignored, which may lead to unreliable packet loss rate estimations. To overcome this drawback, we introduce a general method to model modulation schemes in a network simulation. The proposed solution is examined in an OMNeT++ simulation with two exemplary spectrum models, which differ in their levels of detail. The simulations were conducted for varying channel spacings and load situations for a smart metering network with up to 12,000 radio units. The results show that the use of a detailed spectrum model should be favoured. Since our approach improves adjacent channel interference modelling, it is an important component for more reliable results when evaluating communication protocols in network simulations