For many machine-type communication (MTC) based applications, e.g. transmission of picture, meter, or position information, bi-directional communication is not necessary, as it is merely used to coordinate and assure the transmission and to perform medium access control, e.g., as in Bluetooth, WLAN, or LTE. By application of unidirectional (feedback-less) communication from a machine-type- device (MTD) to a base station, the costs for an increased resource requirement as well as the energy consumption and the integration of a receiver into the MTC-node can be saved.
Pure MTC-transmitter networks can be produced on low price and operated on good terms. This is a prerequisite to allow for mass applications of MTC-concepts for the wireless Internet-of-Things. On the contrary, these savings are obtained by the fact, that an MTC node cannot guarantee the target quality-of-service for its data transmission. Furthermore, the network control has no influence on the medium access methods of the individual node. To ensure the required quality-of-service with a certain reliability of the data transmission, it is important to know the performance limits with respect to the MTC node density as well as their quality-of-service requirements in such an uncoordinated and feedback-less network. Additionally, it is important to optimize these limits with suitably parameterized designs. Thus, the target of this proposal is to determine the performance limits in a feedback-less network based on the joint investigation of the physical and medium access control layers. In addition, it targets to design suitable frame structures and mechanisms for service prioritization as well as graceful degradation in overload scenarios. Thereby, the investigation of packet collision effects on the physical layer and their resolution by mechanisms like frame design, channel coding, multiple transmission with different modes, distributed allocation of the transmit energy in time and frequency domain on transmitter side, as well as successive interference cancelation or spatial antenna diversity at receiver side are of importance. Therefore, on the physical layer the favorable properties of a filterbank-multicarrier (FBMC) modulation scheme with respect to the excellent temporal and spectral transmission energy containment will be used in order to optimally detect and separate unsynchronized multi-user uplink signals. The results obtained on the physical layer will be integrated into a network simulator to obtain an assessment of the overall network performance. With these network layer simulations the different quality of service requirements, protocols, node configurations, spatial node distribution as well as the overload behavior will be assessed. Finally a software defined radio testbed will be used to validate the simulation results in a measurement based environment.