# Adjacency-Information-Entropy-Based Cooperative Name Resolution Approach in ICN
## 2 Related Work
### NRS in SEANet  
SEANet uses a combination of GNMRS and LNMRS. GNMRS is a general global information service system, which is usually deployed in the cloud and can also be realized in the network. It mainly guarantees the full storage of identifier-locator mapping records of the whole network, and ensures the searchability of name resolution. LNMRS is a distributed autonomous system for on-site name resolution services. It is usually deployed at the edge of the network. Each name resolution node stores the mapping records of identifiers and locators in the local area and provides name resolution services of different service levels. Service levels are defined as differentiated services based on measurements. In this paper, we use the communication latency between network nodes as a measure of the service level. LNMRS and GNMRS complement each other to provide multifaceted name resolution performance guarantees for users with different requirements.  
As far as we know, LNMRS introduces multi-level deterministic latencies into NRS for the first time. LNMRS constructs a hierarchical structure based on the underlying network topology, it uses a nested tree structure to give a feasible name resolution scheme for deterministic latency requirements in 5G/B5G scenarios while ensuring scalability, showing better flexibility, and supporting dynamic post-address binding in mobile scenarios.  
The structure of LNMRS is key to providing its efficient service assurance. As shown in Figure 1, LNMRS constructs the name resolution nodes into a single-level or a multi-level structure according to the service levels corresponding to the scenario requirements. Among them, name resolution nodes at the same level have the same service level, and name resolution nodes at different levels have different service levels. The higher levels of the structure correspond to the higher service levels, which means larger response latency upper bounds. A name resolution node that can provide a guaranteed name resolution latency upper bound for a user at a service level is called a serviceable node for this user. At each service level, a user may have one or more serviceable nodes, but only one of them is referred to as a master name resolution node, denoted as MN. Each name resolution node records users who take this node as their MN as the set of users of this node. To provide deterministic latency resolution services for each user, the LNMRS restricts the MNs of every user at each level to conform to a nesting relationship. In other words, the user set of the MN at a particular level must be a subset of the user set of this user's MN at a higher level [11]. From the perspective of LNMRS structure management, the nested relationshipsbetween MNs in LNMRS can be represented using a tree structure. The MNs of adjacency service levels can be represented by directly connected parent-child relationships in the tree. All MNs and the nested relationships between them constitute a forest structure.  
To ensure the deterministic latency of name resolution services, LNMRS uses MNs and their nested relationships to provide name resolution services for users, as well as to constrain the system structure. However, there is a limitation for a user to use only its MN as a responder to its name resolution request. For a name resolution request initiated by a user to its MN, it is possible that this MN does not store the required mapping entries locally, or this MN is overload, so there are no available locators in the name resolution response message, which can affect the user's service experience. The above problems have the opportunity to be solved by other serviceable nodes of this user. Therefore, new structures are required to make full use of these neighboring serviceable nodes as a complement to the name resolution methods, to expand the search range of name resolution, and to share the request load of overloaded nodes, thereby improving the name resolution success rate.