# Flooding Message Mitigation of Wireless Content Centric Networking for Last-Mile Smart-Grid +
## 1 Introduction  
Power grid management strategy, such as Smart Grid (SG), is rapidly evolving with ICT paradigm. In the SG, reliable smart metering data transmission has to be guaranteed to calculate control power usage, grid load, price, power generation control, etc. The Last-Mile smart grid Network (LMN) is edge area system of SG. The LMN is designed to collect raw power usage data of electricity consumers and has to process control traffic between SG server and distributed energy resource (DER) devices. Therefore, it has to be robust and cost-effective. In an LMN network, each device periodically generates and transmits a metering data to server and server eventually sends a regional data requests packet. LMN application generally includes remote firmware update, power price update, time-of-use, peak-load data, etc. [1]. In LMN, Power-Line-Communication (PLC) and Wi-SUN communication modems are widely utilized to reduce the infrastructure cost. However, network capacity is strictly designed because PLC and Wi-SUN only provides several kb/s network capacities [2]. Thus, the network efficiency is most critical issues. RPL, 6 LowPAN, IP multicasting can be utilized to improve network efficiency of LMN. However, network stack complexity and overhead such as IP address assignment, routing table management, header compression processing overhead, and various problems have to be optimized [3]. Content Centric Networking (CCN) is one of the solutions to improve LMN communication reliability [4]. CCN is non-IP based communication model and it has recently gained significantrecognition for its abilities to provide efficient end-to-end data dissemination without traditional IP address management overhead. From these advantages, CCN is already being exploited in many kinds of wireless applications and services and bound to be utilized in future networking such as Internet-of-things (IoT) [5]. In CCN LMN, each meter device can create a unique content as metering data of each household and can be a content provider. A device who want to receive a specific data transmits an _Interest_ packet with _unique, persistent, location-independent name_. This interest packet is flooded to all network to make backward path to content requester for a certain time. When a CCN device receives Interest packet from content requester device, it looks for a suitable content in its own cache. If the device finds a related content, then the content will be directly transmitted to content requester via backward path. Each device in a backward path can cache received content packet to send content to requester instead of content originator when a device receives same Interest packet. Especially, CCN can effectively support to broadcast and multicast data dissemination for data offloading of the server. However, the generic form of CCN may also have flaws of its own in wireless LMN environment due to broadcast storming problem because all types of CCN packets are flooded to local network. Wired communication protocols are mandatory to enabling stable AMI system but its installation cost have to be optimized. Power-line-communication protocols are widely installed in AMI LMN environment but that frequently shows instable performance depending on background noise of the power line due to customer's power usage, and power grid network design. To improve smart metering service stability, wireless communication protocols are considered to LMN environment. LTE system is very stable that is widely applied to back-end network area between DCU and Server. However, in wireless LMN environment, there are many candidate long-range wireless communication protocols such as IEEE 802.11 ah, SixFox, NBIoT, LoRa, and IEEE 802.15.4-2015 SUN (a.k.a IEEE 802.15.4g) [6]. SisFox and Lora communication range is longer than IEEE 802.15.4-2015 SUN that can communication few kilometers, but data rate shows only few bps.