Novel 5G and B5G Network Architecture and Protocol for Multi SIM Devices

Abstract

User Equipment (UE) which has Multi SIM Multi Standby (MSMS) capability contains two or more Subscriber Identity Module (SIM) cards, in which each SIM card is associated with one Protocol Stack. The SIM cards could belong to same or different network service provider. Generally, MSMS UEs are built with single Radio Frequency Integrated Circuit (RFIC), time shared between activities of protocol stacks. Based on user preference, one of the SIMs associates with Internet service and enters Packet Switching (PS) Connected mode, while the other SIM(s) are in idle mode monitoring paging channel. Due to limitation of single RFIC, active PS connection has to be intermittently paused to grant idle mode stack(s) to utilize RFIC for monitoring its paging channel or to perform high priority activity. This intermittent pause on PS connection is referred as blackouts. Blackouts results in degradation of throughput performance and wastage of network's Physical Channel Resources (PCR). In the UEs available in market, MSMS capability is implemented without any protocol between UE and Network to manage blackouts, as there are no 3GPP standards for them yet. This makes UE specific implementation inefficient. In this paper, we propose a novel network architecture and underlying protocol to improve the throughput performance of MSMS UEs and reduce network's PCR wastage. In the proposed network architecture, a novel entity called Access Network Coordinator (ANC) is introduced to inter-connect network operators and exchange information to achieve coordination for paging and signaling procedures in MSMS UEs. This reduces blackout duration in PS connected protocol stack and inherently improves throughput performance of MSMS UEs. Since the ongoing activity on other SIM(s) is known to network, it shall refrain from scheduling resources during this period to avoid resource wastage. The analysis and simulation provided reveals ∼49% reduction in blackout duration and up to 84% improvement in throughput on PS activity with the solution proposed, in comparison with existing solutions for Triple SIM Triple Standby (TSTS) UEs.