# A Method for 5G-ICN Seamless Mobility Support Based on Router Buffered Data
## 1 Introduction  
With the rapid development of mobile internet and the Internet of Things (IoT), as well as the widespread popularity of smart terminals, the types and quantities of mobile services have exploded, and mobile users' demand for future networks has further increased. The rise of emerging applications such as the IoT and streaming media has triggered a rapid increase in data traffic, prompting an explosive increase in the amount of data transmitted over the network [1]. Ericsson's mobile market report released in 2023 pointed out that in the next few years, the annual growth rate of mobile data traffic is expected to remain between 20-30%, and so mobile data traffic will continue to rise [2]. In order to cope with the explosive growth of mobile data traffic and large-scale device connections, as well as to adapt to emerging services and application scenarios, 5G came into being [3]. In order to meet the challenges of 5G low-latency business requirements, the 5G core network adopts the Control and User Plane Separation (CUPS) architecture. Under the CUPS architecture, the User Plane Function (UPF) can sink to the edge of the network. By deploying UPF in a distributed manner close to the base station, traffic localization can be achieved, data processing within the network can be supported, and end-to-end latency can be effectively reduced to achieve a balance between management costs and user experience. Consider the communication scenario between a User Equipment (UE)and a remote server. When the UE switches across UPFs, the UE's network address will change. However, in the current TCP/IP network architecture, the change of IP address will cause the TCP/IP session to be interrupted. TCP/IP reconnection will seriously affect the continuity of delay-sensitive real-time services. Information-Centric Networking (ICN) [4; 5; 6] is an emerging future network architecture. Different from the traditional TCP/IP network architecture, ICN takes information as the center of communication and separates identity and location. ICN's identity-based routing can naturally support mobility, support in-network caching and multicast, and can achieve more efficient and timely content delivery [5]. Integrating ICN with 5G networks is of great benefit to solving delay-sensitive business continuity. Currently, the industry is exploring 5G and ICN deployment solutions, and ICN can be integrated into Data Network (DN) [7]. Indeed, while ICN as a solution integrated with 5G brings some advantages in handling mobility, the current 5G-ICN fusion solutions have not fully exploited the benefits of ICN in addressing real-time business continuity issues related to changing addresses. There is still research space for optimizing switch paths and reducing packet loss during handover. We roughly divide seamless mobility methods in ICN into three categories, namely broadcast/multicast-based methods, active caching-based methods, and temporary buffer-based methods. When the network loses the location of mobile producers, broadcast/multicast-based methods [8; 9; 10] achieve seamless mobility support by finding mobile producers through multicast/broadcast interests. In larger, denser network environments, multicast/broadcast interests can incur significant network overhead. Broadcast/multicast-based methods [11; 12; 13; 14; 15; 16; 17] use an active caching method to minimize Interest retransmission during handover. These methods assume that the data already exist and proactively push future requests to the network cache before handover. However, this is not the case in real-time communication. Most real-time data (e.g., online gaming, internet phone calls, video conferencing, etc.) are data that are generated and delivered immediately upon request. Therefore, active caching approaches cannot provide seamless mobility support for real-time applications. Temporary buffer-based methods [18; 19; 20; 21; 22] minimize packet loss during handover by buffering packets for a period of time on the access device.