# QoS-Aware Resource Management in 5G and 6G Cloud-Based Architectures with Priorities
###### Abstract  
Fifth-generation and more importantly the forthcoming sixth-generation networks have been given special care for latency and are designed to support low latency applications including a high flexibility New Radio (NIR) interface that can be configured to utilize different subcarrier spacings (SCS), slot durations, special scheduling optional features (mini-slot scheduling), cloud- and virtual-based transport network infrastructures including slicing, and finally intelligent radio and transport packet retransmissions mechanisms. QoS analysis with emphasis on the determination of the transmitted packets' average waiting time is therefore crucial for both network performance and user applications. Most preferred implementations to optimize transmission network rely on the cloud architectures with star network topology. In this paper, as part of our original and innovative contribution, a two-stage queue model is proposed and analytically investigated. Firstly, a two-dimension queue is proposed in order to estimate the expected delay on priority scheduling decisions over the IP/Ethernet MAC layer of IP packet transmissions between gNB and the core network. Furthermore, a one-dimension queue is proposed to estimate the average packet waiting time on the RLC radio buffer before being scheduled mainly due to excessive traffic load and designed transmission bandwidth availability.  
Keywords:6G; 5G; network topology; latency; broadband wireless networks; service class; QoS +
Footnote †: journal: Information  
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and peak throughputs, precedence, delivery delay, and Signaling Data Units (SDU) error ratio. In addition to those proposals, the expected deep convergence of information, communication, and data technologies (ICDT) imposes higher efficiency on the network architecture [6; 7; 8; 9].  
The requirements of 5G and 6G, compared to previous LTE mobile broadband network, pose strong demands on radio throughput and transmission latency. This could be easily achieved by employing an OFDM technique over air interface together with a more simplified network architecture [10; 11]. Several gNodeB interconnected topologies have been proposed in order to simplify transmission network implementation and also to minimize expected IP packet transmission delays [10]. In IP/Ethernet gNodeB cloud-based star topology, the transmission equipment MAC scheduler packets are initially prioritized into different buffers and then transmitted over the IP LAN, following the well-known First-in First-out (FIFO) transmission technique, as shown in Figure 1.  
In our proposed scheme, on the basis of the aforementioned analysis, the expected delay is split into two components; the first component considers the expected delay due to MAC scheduling priority of differentiated services with pre-emption vulnerabilities of pre-empted packets, whereas the second component considers the expected delay due to queue waiting transmission time in the transmission buffers.  
This paper considers the most recent 5G and proposed 6G virtualized and cloud-based star topology, where lower layer gNodeBs are interconnected over a centralized gNodeB aggregator to forward IP packets to the EPC core network, as shown in Figure 1. An analytical solution is proposed to estimate the expected delay. Our scheme is based on Radio Resource Management (RRM) pre-emption queue priorities in order to estimate the IP/Ethernet MAC priority with pre-empted packets delay together with a queue loss model in order to estimate the expected delay of the packet transmission due to buffer FIFO and IP packet segmentations.