on is supported. Multiple NB-IoT carriers can be supported for higher IoT capacity. One carrier will be defined as the anchor carrier. This carrier contains NPSS/NSSS/NRS/NPBCH and SIB transmissions. Additional PRBs are configured by RRC signaling. An idle UE camps on the NB-IoT carrier on which the UE has received NPSS/NSSS, NPBCH, and SIB transmissions. An RRC-connected UE can be configured, via UE-specific RRC signaling, to another carrier, for all unicast transmissions. Both anchor and non-anchor PRBs shall be located outside the innermost PRB zone (in-band case). The instantaneous peak rate with the NB-IoT downlink is 170 kbps, while the sus- tained peak rate is 26.2 kbps without considering the NPBCH/NPSS/NSSS overhead, and 19.6 kbps when 25% overhead is taken into account. The uplink instantaneous peak data is 250 kbps with 12 tones. The sustained peak rate is approximately 62.5 kbps with- out considering NPRACH overhead, and 56.3 kbps when 10% overhead is taken into account (Table 14.5). 3GPP Release 13 brought the RRC suspend and resume feature, which is similar to RRC Inactive in 5G radio. Release 14 introduced enhancements to NB-IoT including a new Cat-NB2 UE category supporting higher data rates, supporting two HARQ pro- cesses, multi-cast support using single-cell point-to-multipoint transmission, support for positioning including Enhanced Cell Identity (E-CID) and OTDOA, and support for paging and random access on non-anchor carriers. 14.5 loT Optimization in LTE Core Network IoT optimization in 3GPP is not limited to radio networks, but also there are optimizations included for the core network. The core network improvements can be motivated with the following reasons: 14.6 Coverage S1-MME services eNodeB = Control plane = User plane Figure 14.12 Network architecture for loT optimization. IoT traffic may be very latency tolerant, such as utility reading that can tolerate a latency of minutes or even hours. Mobile broadband traffic is latency critical and needs to be scheduled immediately. IoT traff