ng the physical layer downlink control signalling without having to use the full system bandwidth as with the Release 8-based DPCCH as covered in Chapter 2. Another dimension is also definition of a UE with smaller power class. Going to, for example, 20 dBm power class would allow more integrated implementation compared to the current 23 dBm power class, since smaller power amplifier is easier to integrate in the chip itself. With 200 kHz 23 dBm is needed to maintain the link budget. Besides the cost, MTC work in 3GPP is also addressing the coverage aspects. This is driven by the fact that many metering applications are located in difficult conditions with large indoor penetration loss impacting the link budget. Such locations include basements and other underground facilities for gas, water and electricity metering applications. The work in Release 13 is targeting for 15 dB improvement for the link budget. Since latency is not that critical with metering applications, solutions impacting latency could be used to enhance the link budget. The following methods are being considered: Longer total transmission time, which could be achieved with TTI bundling for data channels and repetition signalling channels. Hybrid Automatic Repeat-reQuest (HARQ) could be used, enabling more transmission to be combined for data channels. Allocating more power in frequency domain for critical transmissions to an MTC UE with Power Spectral Density (PSD) boosting. Further some of the channels could be decoded even with weaker signal conditions as of today assuming some of the performance requirements could be relaxed for the UE or eNodeB reception. The expected UE categories for Release 13 foreseen to be as in Table 3.3, as presented in [3]. The work in 3GPP for Release 13 LTE MTC (often referred as LTE-M for 1.4 MHz case and NB-LTE or NB-IoT for 200 kHz case) is scheduled to be completed by the end of 2015 as visible in [4], while work for NB-LTE likely to finalize in 1H/2016. Table 3.3 Expected Release 13 MTC UE categories Rel-13 Re