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Cognitive radios (CRs) mainly aim to reuse the spectrum holes in order to efficiently utilize the available scarce radio spectrum. However, current CRs techniques have a throughput limitation problem which ultimately limits telecommunication applications horizons nowadays. Moreover, achieving high throughput will overcome the bottleneck of CRs application limitations to the reporting and browsing applications only. To tackle this emerging throughput limitation issue in the CRs, this paper proposes the online greedy throughput maximization (OGTM) algorithm which overcomes the throughput limitations. OGTM allows the sensing cycle frame to have a variable length according to the assumed decision validity interval. Then, OGTM varies the decision validity interval of secondary users (SUs) based on the primary users (PUs) historical behavior. As a proof of concept, we developed a simulator in order to evaluate the performance of the proposed OGTM technique. The simulation results show that SUs benefit from the limited PU historical behavior learning, which resultantly increases the throughput up to 95% and at the same time decreases the miss detection probability by 50%.

Autonomous agriculture robot is one of the promising solutions for precision agriculture. This paper presents the proposed sensor and vision based agricultural robot for sowing seeds. This prototype can navigate it on any agricultural land and perform seed sowing operation simultaneously. The onboard sensors along with vision system and vision based approaches achieves the navigation and localization tasks. Self-awareness of the robot's position is determined by the global and local maps generated from Global Positioning System (GPS) and on-board vision system paired with a personal computer. This paper also presents the proposed sensor based precision seed metering and sowing mechanism. The proposed robot is a micro planter whose primary task would be to sow seeds at prefixed seeding intervals in the field. The dimensions of the proposed robot are 26.5 × 18.5 × 19.65 mm as L × B × H respectively. A suspension system has been used to maintain the stability of the vehicle and prevent it from toppling in motion.

Presently, emergency vehicles use lights and sirens to alert road users of their approach and presence. Unfortunately, pedestrians and vehicle drivers may react too late or in a wrong way and increase emergency vehicle response times and collisions caused by these emergency vehicles. This paper presents an information dissemination system to clearly report the arrival and destination directions of the emergency vehicle to road users to reduce collisions and response times of emergency vehicles. The proposed information dissemination system is based on a new MAC protocol named Frequency and Distance based Priority MAC (FDP-MAC) to send the emergency messages to the traffic management center and other vehicles with lesser delay. The proposed system is simulated in NS-2. The proposed MAC prioritizes and delivers packets according to their service type and distance between the vehicle and intersection. The performance of the proposed MAC is analyzed and compared with the standard IEEE 802.15.4 and IEEE 802.11p MAC. The results show that the FDP-MAC delivers the emergency messages faster than IEEE 802.15.4 and IEEE 802.11p. Moreover, this work will help the effective dissemination of information, management of emergency vehicles and help reduce their response time as well as number of potential collisions.