connectivity.ppsx

This document provides an overview of computer networks, including their basic components and classifications. It discusses the different types of networks like PAN, LAN, MAN, and WAN and how they are defined by their size and coverage area. Various network architectures like client-server, peer-to-peer and hybrid are also outlined. Finally, common network topologies such as bus, star, ring, mesh and tree are defined along with how they structure the interconnection of nodes.

This document provides an overview of computer networks, including their basic components and classifications. It discusses the different types of networks like PAN, LAN, MAN, and WAN and how they are defined by their size and coverage area. Various network architectures like client-server, peer-to-peer and hybrid are also outlined. Finally, common network topologies such as bus, star, ring, mesh and tree are defined along with how they structure the interconnection of nodes.

Network topology refers to the arrangement of elements in a communication network, such as links and nodes. There are several types of physical network topologies including bus, star, ring, mesh, and hybrid. A bus topology connects all nodes to a single cable or backbone so all data transmission is shared over that medium. In a star topology, all peripheral nodes connect to a central hub. A ring topology connects all nodes in a closed loop so data travels around the ring from node to node. A mesh topology connects all possible nodes to each other. A hybrid topology combines two or more standard topologies.

Network topologies refer to the geometric layout of how computers and devices are arranged and connected in a network. There are several common network topology types including bus, star, ring, mesh, and hybrid. A bus topology connects all nodes to a single cable sharing the same communication channel. A star topology arranges all nodes in a centralized connection through a central hub node. A ring topology connects all nodes in a closed loop with each node directly linked to two others in a ring-shaped formation.

The document provides an overview of road networks and transportation systems. It discusses the importance of roads for trade and mobility in Nigeria. It then covers different aspects of road networks such as their classification, hierarchy, design methods, characteristics, control and operations. The conclusion emphasizes that well-developed transportation infrastructure is crucial for socioeconomic development.

Delay Tolerant Networks (DTNs) where the node connectivity is opportunistic and end-to-end path between any pair of source and destination is not guaranteed most of the time. Hence the messages are transferred from source to destination via intermediate nodes on hop to hop basis using store-carry-forward paradigm. Due to quick advancement in hand held devices such as smart phone and laptop with support of wireless communication interface carried by human being, it is possible in coming days to use DTNs for message dissemination without setting up infrastructure. The routing task becomes challenging in DTNs due to intermittent network connectivity and the connection opportunity arises only when node comes in transmission range of each other. The performance of the routing protocols depend on the selection of appropriate relay node which can deliver the message to final destination in case of source and destination do not meet at all. Many social characteristics are exhibited by the human being like friendship, community, similarity and centrality which can be exploited by the routing protocol in order to take the forwarding decisions. Literature shows that by using these characteristics, the performance of DTN routing protocols have been improved in terms of delivery probability. The existing routing schemes used community detection using aggregated contact duration and contact frequency which does not change over the time period. We propose community detection through Inter Contact Time (ICT) between node pair using power law distribution where the members of community are added and removed dynamically. We also considered single copy of each message in entire network to reduce the network overhead. The proposed routing protocol named Social Based Single Copy Routing (SBSCR) selects the suitable relay node from the community members only based on the social metrics such as similarity and friendship together. ICTs show power law nature in human mobility which is used to detect the community structure at each node. A node maintains its own community and social metrics such as similarity and friendship with other nodes. Whenever node has to select the relay node then it selects from its community with higher value of social metric. The simulations are conducted using ONE simulator on the real traces of campus and conference environments. SBSCR is compared with existing schemes and results show that it outperforms in terms of delivery probability and delivery delay with comparable overhead ratio.