Читать книгу Industry 4.0 Vision for the Supply of Energy and Materials - Группа авторов - Страница 44

As mentioned earlier, a number of standard bodies have collaborated on MTC architectures to provide connectivity between shared MTC devices. 3GPP has already specified standardization to promote adaptation and requirements of MTC. There are multiple groups in 3GPP for MTC functions, requirements, and interfaces. The continuous enhancements of 3GPP have appeared in several releases that present ongoing amendments and progresses in standardization works, facilitate introduction of new features, and establish a uniform platform for technologies deployment.

The standardization efforts also focus on optimizing the core network infrastructure to provide efficient delivery of M2M services and minimize operational costs. The first study of 3GPP system architecture (SA1) on MTC was first released in 2007 [132]. In Release 10, 3GPP SA2 put its efforts into identifying MTC communications requirements and system optimizations to address two important challenges in mass-market MTC services: MTC signaling congestion and network overload [133]. Release 10 supports MTC in the Universal Mobile Telecommunications System (UMTS) and LTE core networks. Logical analysis, requirement refinement, and protocol implementation were later introduced in Release 11 [134]. In addition, Release 11 studied network improvements for M2M gateways, P2P communications, co-located M2M devices, and M2M group development. In Release 12, the focus was on identifying key enablers for RF and PHY layer to facilitate LTE deployment in IoT environments [91]. Normative works were pursued in Release 13 to extend MTC coverage and reduce its cost (e.g., bandwidth, transmit power) for cellular IoT deployment. It also focused on identifying multiple categories for new user equipment (UE) [135]. These techniques, namely, NB-IoT and LTE-M, further strengthened in Release 14 and provided novel features such as mobility for service continuity, reduced overhead in network, and support of IoT data in mission-critical use cases [136]. Release 15 and beyond studied additional MTC enhancements for LTE. In 2018, 3GPP foresaw the standardization initiatives and subset of 5G requirements for MTC applications and services.