# Two Optimization Algorithms for Name-Resolution Server Placement in Information-Centric Networking
## 1 Introduction  
As a network technology, the Internet of Things (IoT) [1; 2; 3] connects a large number of devices that are integrated with sensing, recognition, processing, communication, and networking functions. Through seamless connections and interactions between a large number of heterogeneous devices, the IoT provides a rich range of services and novel applications, changing the way we live and work [4; 5]. In terms of the application area aspect, IoT can be divided into consumer IoT and industrialIoT (IIoT) [6]. With the rapid development of IoT, there will be 50 billion devices connected to the Internet by 2020, among which about 20% will come from the industrial field, according to Cisco Internet Business Solutions Group predictions [2]. By contrast with consumer IoT scenarios, the IIoT has exceptionally high requirements for transmission latency and reliability. Transmission latency and reliability directly affect the stability of industrial real-time monitoring and automatic control, thus determining the accuracy, efficiency, and costs of industrial production. Not only low average latency but also a deterministic upper bound of latency are needed when handing over data in the IIoT [7]. Due to the increase in the number of IoT devices and the amount of the data they generate, as well as the stringent quality of service requirements of the IIoT, current wireless communication networks, such as 4G, fall short in supporting these challenges, restricting further development of the IIoT. Fortunately, fifth-generation (5G) wireless communication technology is expected to break the performance bottleneck of the current communication network. Fifth-generation technology has the potential to address the harshest demands posed by the IIoT since it provides higher data rates, higher density, lower end-to-end latency, better reliability, and higher coverage [2,7]. The integration of 5G and IoT will form new connected ecosystems in the near future, becoming one of the major elements in shaping the future Internet [1]. In order to realize the high-performance indicators of 5G, researchers are working hard to improve and standardize radio air interface technology, as well as considering network architecture optimization as an essential part of this [8]. Information-centric networking (ICN) is an emerging network paradigm. It is under standardization and has the potential to enhance and innovate data delivering services in the 5G network [8, 9, 10]. ICN adopts the paradigm of separation of the identifier and locator, which shifts the communication model from host-centric to information-centric. It has several characteristics, such as in-network caching [11], mobility support, built-in multicast delivery, and inherent security. These characteristics complement the limitations of semantic overloaded due to exposure to the current Transmission Control Protocol (TCP)/Internet Protocol (IP) network architecture [12,13]. In nature, IoT communications and applications are information-based and follow a content-oriented paradigm. The matching of paradigms also enables ICN to show a good capacity to work with the IoT. In ICN, the identifier and locator are split into different naming spaces [14,15], and the name-resolution system (NRS) is a network infrastructure that maps and stores the mappings between them. NRS is an essential component of ICN because the delivery of content cannot be realized unless the name-resolution process is completed. Thus, capabilities of name resolution directly influence the performance of ICN in 5G. Several ICN projects have been proposed, and they offer different solutions to the organization and deployment of the NRS. Most of these solutions deploy NRS in the cloud [16], or organize distributed name-resolution servers based on the distributed hash table (DHT) [17, 18, 19]. The trend of the future network is transferred from best-effort to deterministic data transmission. Consideration of the upper bound of the name resolution's latency is significant, especially in the 5G-IoT scenario.