# A Method for 5G-ICN Seamless Mobility Support Based on Router Buffered Data
## 2 Related Work
### Seamless Mobility Support in ICN
SCaN-Mob [14] minimizes the impact of mobile producer unavailability in NDN by creating Interest forwarding strategies and cache replacement strategies to achieve seamless switching of producer in wireless networks. In [15], the authors proposed a cooperative caching mechanism based on neighbor message propagation, making full use of the nodes on the forwarding path from the source AP to the destination AP to cache fresh and popular content at high-value nodes. In addition, in the field of Internet of Vehicles, active caching also plays a big role. [PERSON] et al. [16] proposes a new active caching scheme that uses prior information of vehicle requirements and mobility patterns, considers RSU cooperation modes and non-cooperation modes, and minimizes communication delays in a vehicular ad-hoc network (VANET). In [17], the authors propose a framework in 5G and networks that are beyond heterogeneous to enhance support for mobile users' QoE. The framework utilizes user mobility prediction, user preference inference and fine-grained resource reservation to improve overall user QoE through personalized data caching and dissemination in HetNet. These methods assume that the data already exist and proactively push future requests to the network cache before handover. For communication services that generate data in real time, active caching-based methods are not applicable. In order to provide seamless mobility support, most methods based on temporary data buffering use the access device before handover or the access device after handover to buffer data packets for a period of time. [PERSON] et al. [18] proposed an \"Interest Forwarding\" process to support producer mobility. The mobile producer's Previous Access Router (PAR) buffers the Interest until it receives a virtual Interest from the producer. The PAR then forwards the buffered Interest to the producer. This solution recommends that the life cycle of real-time content is slightly larger than the handover delay (L2 handover delay + RTT/2) to support rapid recovery from packet loss caused by handover. In order to enhance seamless content source mobility support in mobile named Data Network environments, a new locator-based mobility support method is proposed [19]. Once an impending switch event is detected, the content source triggers PAR to buffer Interest destined for the content source until the forwarding update is completed and a new route is established to reach the content source's current location. Furthermore, a study in [20] designed a producer mobility support scheme for real-time multimedia transmission. ProPull [20] focuses on providing continuous multimedia transmission and seamless services. For scenarios where subsequent content needs to be generated in real time, when the producer detects that a switch has occurred, the mobile producer sends a special packet to its connected access router to obtain the router name and trigger the access router buffering Interest before it switches. Once the producer completes the switch, it uses Propaganda Interest (PI) to pull the Interest from the old location to the new location. In addition to reactive data buffering, LPBMMS [21] uses location prediction technology and data buffering technology for anchor-free producer mobility management to support seamless handover. When the mobile producer's received signal strength falls below a specific threshold, it sends an Interest Path Update message (INTEREST_PU) to the old Access Point (oAP) to signal its mobility. The oAP uses INTEREST_PU to predict the new Access Point (nAP) of the mobile producer, and then sends an Interest redirection (INTEREST_RED) to the nAP to redirect the Interest to nAP. Upon detecting the mobile producer connection, the nAP releases buffered Interests. If the nAP prediction fails, the mobile producer broadcasts its new name prefix, prompting the oAP to release buffered replica interests. In [22], the author proposes a new NDN link service called Producer Mobility Link Service (PMLS) to implement mobility support.