An Efficient Method to Monitor Downlink Traffic for 4G and 5G Networks

This paper proposes a new scheme that allows the measurement of traffic loads of radio networks by decoding some information about the cell, such as downlink control information (DCI) broadcast on the physical downlink control channel (PDCCH). In the proposed scheme, a client decodes the entire DCI for all user equipments (UEs) with ongoing connections in a cell and extracts some information about the cell, such as the number of active UEs, the number of radio resources occupied, as well as the modulation and coding scheme used by each UE. Based on this information, mobile network carriers can measure exact traffic loads of cells preemptively without affecting ongoing connections. Contrary to an exhaustive searching scheme that attempts to decode DCI with all radio network temporary identifiers (RNTIs), the proposed scheme derives a small set of valid RNTIs by using an inverse function and attempts to decode DCI only with the valid RNTIs instead of the entire set of RNTIs. This reduction enables the client to recover the correct DCI with marginal computational complexity, which allows for real-time decoding of DCI. The simulation results show that the proposed scheme can significantly reduce the complexity required to decode the entire DCI in a cell, compared to the exhaustive searching scheme.