Optimal Placement of User Plane Functions in 5G Networks

Abstract

Because of developments in society and technology, new services and use cases have emerged, such as vehicle-to-everything communication and smart manufacturing. Some of these services have stringent requirements in terms of reliability, bandwidth, and network response time and to meet them, deploying network functions (NFs) closer to users is necessary. Doing so will lead to an increase in costs and the number of NFs. Under such circumstances, the use of optimization strategies for the placement of NFs is crucial to offer Quality of Service (QoS) in a cost-effective manner. In this vein, this paper addresses the User Plane Functions Placement (UPFP) problem in 5G networks. The UPFP is modeled as a Mixed-Integer Linear Programming (MILP) problem aimed at determining the optimal number and location of User Plane Functions (UPFs). Two optimization models are proposed that considered various parameters, such as latency, reliability and user mobility. To evaluate their performance, two services under the Ultra-Reliable and Low-Latency Communication (URLLC) category were selected. The acquired results showcase the effectiveness of our solutions.

Dynamic Scheduling and Optimal Reconfiguration of UPF Placement in 5G Networks

“…The 5G UPFs represent the evolution of traditional Serving and Packet Gateways (SGWs and PGWs) from EPC to 5G networks under the CUPS concept. The placement of these network functions has been addressed in a wide variety of research works [13,14,[16][17][18]. In [16], the effects of centralized and distributed SGW placement strategies on the backhaul bandwidth are studied.…”

“…Their main objective is to minimize the user plane response time as well as SGW relocations. In [13] and [14], the UPF placement in a native 5G architecture is addressed. These two works conceive various placement strategies target at reducing deployment and operational expenditures while satisfying 5G service requirements.…”

“…Expression (13) stipulates that a UPF instance can be migrated to one location at most during the placement reevaluation. In addition, inequality (14) forces the assignment of a UPF instance already deployed (𝑢 ∈ 𝑁 𝑢 ) to just one candidate location.…”

Placement of Logical Functionalities in 5G/B5G Networks

“…Several studies have been devoted to the placement of Virtual Network Functions and Service Function Chains, e.g., [1], [2], and much less on the placement of 5G logical functionalities. On the one hand, there are studies on the placement of DU and CU ( [3], [4], [5]), then on UPF [6] on the other hand, but none on all the logical functionalities of 5G.…”