In opportunistic networks, the nature of intermittent and disruptive connections degrades the efficiency of routing. Epidemic routing protocol is used as a benchmark for most of routing protocols in opportunistic mobile social networks (OMSNs) due to its high message delivery and latency. However, Epidemic incurs high cost in terms of overhead and hop count. In this paper, we propose a hybrid routing protocol called EpSoc which utilizes the Epidemic routing forwarding strategy and exploits an important social feature, that is, degree centrality. Two techniques are used in EpSoc. Messages’ TTL is adjusted based on the degree centrality of nodes, and the message blocking mechanism is used to control replication. Simulation results show that EpSoc increases the delivery ratio and decreases the overhead ratio, the average latency, and the hop counts as compared to Epidemic and Bubble Rap.

Abstract-Topology change is the main factor that affects the network life time of Wireless Sensor Network (WSN) applications. In static WSN, the topology change is often caused by node failure which is due to energy depletion. However, in the Mobile WSN (MWSN), the main reason of the topology change is caused by the node movement. Since the mobile sensor nodes are limited in power supply and have a low radio frequency coverage, they are easily losing their connection with neighbours, and have difficulties updating their routing tables. The switching process from one coverage area to another consumes more energy that related to transmitting and receiving association packets. Using Ad hoc On-Demand Distance Vector (AODV) routing protocol in MWSN application shows degradation in network performance due to high density and speed of mobile nodes. In this paper, through extensive simulation we evaluated the capability of AODV on how far it can react to network topology change in MWSN. We investigated the performance metrics namely packet loss and energy consumption of mobile nodes with various speed, density and route update interval (RUI). Our performance study demonstrates that by applying the existing AODV in MWSN, the results show a high percentage of packet loss and the reduction in total network energy consumption of mobile nodes if RUI is getting longer due to serious broken link caused by nodes movement. We also identify some key research problems that need to be addressed for successful implementation of AODV in MWSN.

Mobile Multihop Relay (MMR) network is one of the emerging technologies, especially LTE-Advanced, WiMAX and the Smart grid communications. Ensuring security is one of the most imperative and challenging issues in MMR networks. Privacy Key Management (PKM) protocol is proposed to ensure the security measures in MMR networks. However, the protocol still faces several security threats, specifically Denial of Service (DoS), replay attacks, Man in the Middle (MitM) attacks and the interleaving attacks, which is termed as Medium Access Control (MAC) layer attacks. This paper proposed a modified version PKM protocol for both unilateral and mutual authentication, which is termed as Self-organized Efficient Authentication and Key Management Scheme (SEAKS) authentication protocol. This protocol ensures secure end-to-end data transmission using distributed hop-by-hop authentication and localized key management schemes with a very simple and efficient way.

Abstract-In strong mobility the mobile node association with a coordinator (static or mobile) is an important part of IEEE802.15.4 protocol. This research analyzes the mobile node association attempt process flows in detail. This research also proposes an enhanced association procedure names Fast Association Process (FAP) in strong mobility. FAP is introduced with new Association_Data request MAC command that increases the association period and provides fast association process in strong mobility. It reduces the redundant service primitives, avoid collision and decrease association attempt process delay. Comparing FAP with the original IEEE802.15.4 protocol, the number of association service primitives in FAP is 67% less than the original protocol, and the simulation results show that the association attempt time decreases 75%. FAP will get fast association attempt as the number of mobile nodes increased and nodes having strong mobility. It can be widely used in mobile wireless sensor network application.

Saving energy is a very critical issue in wireless sensor networks (WSNs) because sensor nodes have a severe resource constraints such as lack of processing power and limited in power supply. Since the communication is the most energy consuming activities in WSNs, the power use for transmission or reception of packet should be managed properly. Transmission power control (TPC) technique is one of the techniques to reduce energy consumption which has been widely studied in mobile ad-hoc networks (MANETs). This technique is implemented by adjusting the transmission power in communication between nodes. However, as mobile wireless sensor networks (MWSNs) applications emerge, the unique characteristics of this network such as severe resource constraints and frequent topology change suggest that TPC might be useful to reduce energy consumption in MWSN. Therefore, we investigate the impact of TPC on Ad hoc On-Demand Distance Vector (AODV) routing protocol for MWSNs. AODV is used as a medium of communication to assist the investigation of the effects of TPC in multihop communication in MWSNs. The simulation results show that the implementation of TPC technique has some impact on MWSNs in respect to transmission energy consumption and transmission power level required at low node mobility.