ABSTRACT
Long Term Evolution (LTE)-based cellular networks are being deployed around the world to provide public safety with enhanced capabilities and access to broadband technology. In the United States, the First Responder Network Authority (FirstNet) is on the verge of deploying a nationwide network called the National Public Safety Broadband Network (NPSBN). Commercial networks typically aim at maximizing network capacity, i.e. the aggregate data rate, in order to increase revenue. In public safety networks, however, coverage, not capacity, is paramount, especially during an outage when sites are down. Through traffic control and preemption, the service level of low-priority users is reduced or denied, freeing up resources to restore coverage to high-priority users, e.g. users responding to an incident. In this study, we examine the effect of outages on network coverage and throughput. As our main contribution, we propose three traffic-control schemes that exploit variable modulation and coding, a feature that LTE enhances with respect to its 3G predecessors. The schemes differ based on the proportion of low- and high-priority users preempted. We show that indeed the network coverage can be restored significantly and we investigate the tradeoff between the three schemes. Finally, we perform sensitivity analysis to confirm the effectiveness of the schemes across a wide range of scenarios.
Subject(s)
Amphibians/physiology , Bicarbonates/blood , Carbon Dioxide/blood , Fishes/physiology , Hydrogen-Ion Concentration , Oxygen/blood , Reptiles/physiology , Animals , Anura , Bufo marinus , Catheterization , Eels , Microelectrodes , Oxygen Consumption , Partial Pressure , Snakes , Temperature , TurtlesABSTRACT
California scorpionfish, Scorpaena guttata, were implanted with a pair of thermodes which straddled the anterior brainstem. When the fish were in water of about 20 degrees C, warming the thermodes to temperatures above 20 degrees C caused a proportional increase in the ventilatory minute volume. Cooling the thermodes below 20 degrees C caused a proportional decrease in the ventilatory minute volume. It is concluded that the anterior brainstem temperature provides an important input to the respiratory control center in teleost fish.
