Content Centric Mobile Social Networks
Content Centric Networks
To develop MSNs in 5G, a new network structure is required, since the existing network architecture was designed based on the assumption that content delivery relies on the IP address of the content. However, with the rapid spread of multimedia content, in addition to the conventional server with a designated IP address storing the content, different users moving on different sites may also produce and consume content. Nowadays, content has less and less relation with where it is stored. For example, a user may publish the same content to two different communities located in different small cells. Although the content is the same, the existing networks manage it as two different contents due to the different locations. Therefore, the traditional approach to recognize and manage content based on the location specified by IP address will not be efficient now. In fact, current Internet users do not care where the content is from, they care more about what this content is. To face this new challenge, content centric networks (CCNs) [14-16, 22, 23] have been proposed as a new architecture for future networks to replace current networks.
As shown in Fig. 6.2, in CCNs there are many CCN nodes to store replicas of original content. The request for content is not sent to the IP address where this content is originally stored. Instead, an interest for the content is published over the CCNs; if a CCN node has the content where this interest refers, the replica of the content in this CCN node will be sent directly to the user who sent the interest. The interest in this content can be shown by a hierarchical name such as content ID. By sending the interest to the CCN node, the current IP address becomes unimportant, as the content requester need not know where the content was originally stored.
In the above CCN node, the content store (CS) is working with a pending interest table (PIT) and a forwarding information base (FIB). The content store caches the replicas of content. If a user sends an interest and the replica of this content is available in the content store, this replica will be provided to the user directly. Otherwise, the CCN node will check whether there is a pending interest for this content in the pending interest table. If there is still no matching interest, the CCN node will check the forwarding information base to wait for the wanted content fetched by a suggested delivering path. With cooperation among the content store, the pending interest table, and the forwarding information base, the content can be delivered according to the interest.
Fig. 6.2 Network architecture of content centric networks