Single registration mode support for interworking between 5gc and epc

Abstract

Systems and methods of enabling intersystem changes between 4G and 5G are described. The UE in single registration mode handles default EPS bearer contexts and PDU session contexts as if the N26 interface were supported before making the determination whether N26 interface is supported or not during an initial EPS Attach procedure. After determining that the N26 interface is unsupported, the UE maps active PDU session contexts to default EPS bearer contexts and modifies the PDU session context state from active to inactive before completing the intersystem change. The UE either acts as if the N26 interface were supported and loses all the PDN connections or PDU sessions during the intersystem change, or enters a modified single registration mode in which the states of the EPC and 5G system are partially isolated from each other during the intersystem change.

Description

PRIORITY CLAIM[0001]This application claims the benefit of priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application Ser. No. 62 / 588,787, filed Nov. 20, 2017, which is incorporated herein by reference in its entirety.TECHNICAL FIELD[0002]Embodiments pertain to radio access networks (RANs). Some embodiments relate to cellular and wireless local area network (WLAN) networks, including Third Generation Partnership Project Long Term Evolution (3GPP LTE) networks and LTE advanced (LTE-A) networks as well as legacy networks, 4th generation (4G) networks and 5th generation (5G) networks. Some embodiments relate to improvements in interworking between heterogeneous communication networks.BACKGROUND[0003]The use of various types of systems has increased due to both an increase in the types of devices user equipment (UEs) using network resources as well as the amount of data and bandwidth being used by various applications, such as video streaming, operating on these UEs. To incr...

AI Technical Summary

Benefits of technology

The patent text describes various embodiments related to radio access networks and cellular networks. It discusses the use of different technologies and standards for these networks, as well as the interworking between them. The technical effects of the patent include improving interworking between heterogeneous communication networks, addressing issues with registration in multiple networks, and enhancing the ability of networks to contend with the explosion in network use and variation. The patent also describes the architecture of a system of a network and a flowcharts for intersystem change. Overall, the patent aims to provide solutions for better managing the use of multiple networks and ensuring seamless connectivity for users.

Problems solved by technology

While the advent of any new technology, especially the introduction of a complex new communication system engenders a large number of problems both in the system itself and in compatibility with previous systems and devices, issues continue to abound in existing systems.

For example, registration issues may occur when the UE is capable of registering both with a 4G / LTE network and a next generation / 5G network.

The above discussion concentrates primarily on LTE networks, however, 5G networks will soon start to be deployed, leading to interoperability challenges. FIG. 7 illustrates 5G architecture in accordance with some embodiments.

Due to the immediate lack of 5G UEs and 5G cells, interworking between the LTE architecture and 5G architecture, as well as UE registration with one or both systems, may be challenging. FIG. 8 illustrates combined communication system in accordance with some embodiments.

However, support of interworking when the UE is in the single registration mode may be hampered somewhat by the requirements of the 3GPP standard.

Moreover, if UE moves to the DEREGISTERED state on 5GC then the UE may lose all session management context and PDU sessions.

As the new core network may be unable to retrieve the session management contexts from the old core network, the UE may lose all its PDN connections or PDU sessions during the intersystem change.

However, this may just be in line with the status on the network side, because the MME does not have any subscriber context for the UE and the MME may also not be able to retrieve subscriber context from anywhere other than the HSS.

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