In order to meet more application scenarios and market demand, 3GPP in Re-14 Dui NB-IoT we conducted a series of enhancements in June 2017 and completed the core specification. Enhancement technique increases the localization and multicasting function, providing a higher data rate, random access and paging on the non-anchor carrier mobility enhancing connected state, the lower support UE power class. details as follows:
Positioning functions : location services are a lot of things the basis of the needs of business, location-based information can be derived from many value-added services. NB-IoT OTDOA introduced and enhanced E-CID positioning technology. The terminal may report its location technology supported by the network, including those based OTDOA, A-GNSS, E- CID, WLAN and Bluetooth positioning technology, the network side and the current capacity of the wireless environment of the terminal, select the appropriate positioning technology.
Multicast function : In order to more effectively support the message sending, software upgrades and other functions, NB-IoT enhance the introduction of multicast techniques. Multicasting is based on the LTE SC-PTM, traffic data receiving terminal by mass of SC-MTCH.
Enhance data rate : Rel-14 introduces a new level of capability UE Category NB2, Cat NB2 UE supports a maximum uplink and downlink transport block up to 2536 bits, a downlink non-anchor carrier peak rate can be increased to 140/125 kbps.
Non-anchor carrier enhanced : In order to obtain better load balancing, Rel-14 added to the paging functions and the random access on a non-anchor carrier. Such networks can better support big connection, reducing the probability of collision of random access.
Enhanced Mobility : Rel-14 in the NB-IoT CIoT EPS control plane optimization scheme introduces the RRC connection reestablishment procedure and S1 eNB Relocation Indication. When the RRC connection reestablishment, the original base station may not issued by the NAS data back to the MME S1 eNB Relocation Indication process, by the MME and then sent to the new base station UE. User plane CIoT EPS optimization when a radio link failure, data forwarding function using the existing LTE handover process.
Lower UE power class : Rel-14 in the original 23 / 20dBm power level on the introduction of the UE power class 14dBm. So no need to meet some of the extreme conditions of coverage, but requires a small capacity battery application scenarios.