Oswald Jumira

Energy-efficient beaconless geographic routing in energy harvested wireless sensor networks

We propose a routing scheme called energy‐efficient beaconless geographic routing with energy supply (EBGRES) for wireless sensor networks. EBGRES provides loop‐free, fully stateless, energy‐efficient source‐to‐sink routing with minimal communication overhead without the help of prior neighborhood knowledge. It locally determines the duty‐cycle of each node, based on an estimated energy budget for each period, which includes the currently available energy, the predicted energy consumption and the energy expected from the harvesting device. In EBGRES, each node sends out the data packet first rather than a control message. By sending a data packet first, EBGRES performs the neighbor selection only among those neighbors that successfully received the data packet. EBGRES uses a three‐way (DATA/ACK/SELECT) handshake and a timer‐assignment function, the Discrete Dynamic Forwarding Delay (DDFD). We investigate the lower and upper bounds on hop count and the upper bound on energy consumption under EBGRES for source‐to‐sink routing. We further demonstrate the expected total energy consumption along a route toward the sink with the proposed EBGRES approach including a lower bound on energy consumption when the node density increases. Copyright

Notice of Violation of IEEE Publication Principles Value chain scenarios for M2M ecosystem

Recently attention has been directed to Machine to Machine (M2M) wireless communications by a number of stakeholders which include device manufacturers, applications developers and mobile network operators across the globe. As voice revenues for most mobile operators enter a decline due to the new data oriented networks and services being availed into the market, there is growing need to adopt new revenue models through adoption of wireless connectivity in a wide range of devices. With the introduction of these new applications and services, new stakeholders come into play in the M2M communications value chain. A way to market these M2M devices can thus involve creating a platform of services that adds value and functionality to the devices and is a result of a combination of synergies between device manufacturers, application developers and mobile operators. This paper discusses several value chain scenarios which form the M2M ecosystem wherein all stakeholders assume different levels of control over the customer relationship and the assets that make up the value proposition.

A Chain-Based Relocation Approach to Maintain Connectivity with a Center of Interest

Mobile nodes within Wireless Sensor Networks (WSNs) open up new challenges such as improved energy efficiency, coverage, target tracking, and fault tolerance. We propose a novel Chain-Based Relocation Approach (CBRA) to relocate mobile sensor nodes from their initial positions within a Region Of Interest (ROI) to cover a particular event happening outside the initial deployment zone called Center a Of Interest (COI). CBRA uses a grid quorum-based solution to propagate the redundant nodes present within the ROI. We propose an energy-based redundant node selection procedure to ensure a balanced energy consumption among the redundant nodes regardless of the location of the redundant nodes with respect to the COI. We evaluate the performance of the CBRA solution using the WSNet simulator. Simulation results show that the network energy consumption and the relocation time increase as the distance separating the COI from the ROI increases. Moreover, the whole network energy consumption improves with the network density while the relocation time decreases with increasing speed of sensor nodes.