Routing in opportunistic networks: Taxonomy, survey

The accelerated growth of wireless communication such as personal digital assistants, tablets, smart phones, that are carried by the people may arrange themselves in to a special network for the communication of messages. The moving nodes communicate with the nearby nodes using node contact opportunity through Wi-Fi or blue tooth. These nodes suffer from frequent disconnections. The network with frequent disconnections is known as opportunistic network or intermittently connected network. It is a unique wireless network architecture which enables the mobile nodes to have communication with each other in environment where there is no continuous route exists between source and destination. Such networks espouse store-carry-forward habit for the message transfer and utilize mobility of moving nodes for message communication. These networks are featured with network topology which is unstable and also long latency. Routing requires the nearby neighborhood nodes information for the message transfer. Depending on the routing action, we categorize routing schemes as social aware information schemes and social zero information schemes. The schemes such as social zero information do not require any past information of the nodes behavior. Subject to the content of information, social aware schemes are furthermore categorized as microscopic and macroscopic schemes. Microscopic schemes utilize mobile user's movement. Whereas macroscopic schemes have integrated social relationship with the mobile user's movement. We explicate about the routing solutions for the microscopic and macroscopic schemes. Additionally we briefly discussed evaluations in routing schemes.