# OPMSS: Optimal Producer Mobility Support Solution for Named Data Networking
## 2 Related Works
### Overview of Kite Scheme Operation  
Kite is a popular NDN mobility support proposed by [PERSON] et al. as part of the architectural development of the NDN project. In this paper, we categorized Kite as tracing-based mobility support approach reviewed and briefly explained in Section 2.2. To gain a clear understanding of the Kite operation, the following steps describe the process before, during, and after handoff, as shown in Figure 1. Moreover, the name resolution for tracing of mobile producer is normally take place by the anchor router or RS in Kite scenario, however, in Figure 1, the anchor router is used. Steps before the handoff, when the consumer is connected to CR1 and the producer is connected to CR4  
* Step 1: Normally, a consumer sends an interest packet requesting data to CR1. CR1 then checks if the content is available; otherwise, it floods the NDN network with the interest packet. * Step 2: The prefix data name within the interest packet passes through routers to the location of the producer. If the data are cached by any router in the network, the router will immediately respond with the data back to the consumer. Otherwise, the routers along the way will record the interest information in the PIT and the FIB table as entries and forward it until the content producer is reached. The producer then sends the data to the consumer in a breadcumb style. Steps when handoff starts  
* Step 3: The producer suddenly decides to move and connects to CR4. * Step 4: A new content name prefix is formed after the connection, and the producer gets ready to update the anchor router (i.e., CR1 from Figure 1) or RS about the new name prefix. * Step 5: The producer floods the network with the _TI_ packet via the anchor router or the RS to update the system about the new name prefix. * Step 6: The anchor router or the RS respond with trace data packets and establish a trace between the mobile producer and the anchor router or the RS through CR2, CR3, and CR4. * Step 7: The content consumer could not trace the new location of the producer after sending the pending interest packet. * Step 8: The consumer will send the pending interest packet to the well-known location of the anchor router or the RS. Steps after handoff
* Step 9: The anchor router or the RS forward the consumer's interest packet via the established trace to the mobile producer. Step 10: The mobile producer replies to the consumer with the requested data packets via the anchor router or the RS. Despite the advantages of the Kite scheme that outperforms the mapping-based approach in terms of handoff delay with similar signaling overhead when a mobile producer moves frequently, the optimal data path is not guaranteed in such a way that consumer's interest packets always pass through the immobile anchor or RS. Hence, the Kite scheme falls into the category of an indirection-based approach that can make the forwarding path longer than the path computed in the normal NDN routing plane. This is called the path stretching problem, as the provision of the optimal path was not considered, consequently, making the handoff latency higher. Additionally, there is no improvement in signaling cost minimization compared to the mapping-based scheme for both the pull and upload pattern of Kite solution. The proposed OPMSS have more advantages over the existing Kite solution, in such a way that \(MI\) packets alone can easily represent the functionality of \(TI\) and \(TD\) packets of Kite, hence the high signaling caused by the exchange of \(TI\) and \(TD\) can be minimized. Furthermore, the broadcasting strategy proposed in OPMSS provides a solution to the problem of the single point of failure caused by immobile anchor or RS in Kite solution. When \(MI\) packet is broadcasted, there is no need for an RS or an immobile anchor router in the processes of data and interest exchange.