Archive for the ‘Research and Development’ Category
BroadBit joins ETSI
BroadBit is pleased to announce its joining of the European Telecommunications Standardization Institute (ETSI). Taking part in ETSI’s standardization work is one way through which BroadBit’s expertise in designing and testing vehicular communications networks supports its industrial partners. BroadBit will primarily contribute to the work of ETSI’s Intelligent Transportation Systems (ITS) committee.
Space propulsion publication
Article published in the Astrophysics and Space Sciences Transactions journal:
We describe a solution for generating spacecraft on-board electricity in the 5kW – 500 kW power range. The introduced thermo-photovoltaic electricity generation works without magnets or external cooling; it combines operational simplicity with a good power per mass ratio.
Once in orbit, the system shall be capable of powering numerous missions within the inner solar system or a single long range mission.
Space exploration today is limited by the length of time and amount of fuel required for reaching desired destinations. An ideal propulsion design simultaneously features high Isp, high thrust power, and limited engine weight. Recent advances in nano-scale fabrication open up new possibilities for thermo-photovoltaic electricity generator design, and allow a the use of high-trust electric propulsion technologies. High-powered on-board electricity generation is key to reducing travel times to nearby planets and to the the expansion of space exploration horizons. The following sections describe each component of the proposed on-board electricity generator. …
Download: AndrasKovacs and Dr Pekka Janhunen: Thermo-photovoltaic spacecraft electricity
Vehicular communication publications
Resource Sharing Principles for Vehicular Communications
This paper proposes a suitable scalability principle for each major vehicular communication scenario: periodic safety broadcasts, event-driven safety broadcasts, and unicast message forwarding. Each scenario section investigates an appropriate design of individual congestion control tools for the implementation of related scalability principle.
Estimation of Channel Utilization at the Beaconing Edge
Estimating channel utilization at beaconing edge is important, so that power control feedback can be based on comparing this utilization rate to a target level. The beaconing edge channel utilization estimate presented in the ‘Resource Sharing Principles for Vehicular Communications’ paper is revised with the following aspects;
– taking an estimate of link asymmetry into account,
– interpolating on link attenuation metric instead of distance metric.
GeoMapped Timing of Beacons and Unicast Messages
This paper proposes a timing algorithm for assignment of beacon transmissions. The proposed geographically derived beacon timer solves the problem of ‘hidden-terminal’ packet collisions for periodic broadcasts and certain unicast messages, regardless of particular road network topology details.
Laminar traffic flows and dynamic hard shoulder utilization
There is an ongoing contest of ideas for reducing urban traffic congestions, called ‘ITS Congestion Challenge‘. The submission is open for all, and judging ideas is through community method, so this may give a sense of what solution is favored by the general public. The idea entry is open till end of July, and ranking will be done during August. The best ranked idea will emerge in September, the winner will be announced at the Stockholm ITS World Congress.
Proposed solutions can be viewed and voted through following link, after registering:
http://www.vencorps.com
Traffic flows are greatly enhanced when unnecessary lane changes are eliminated and the hard shoulder is safely taken into use during peak hours. This results in better use of existing infrastructure. Analogy: smooth and turbulent flow of air.
BroadBit a submitted a proposal to this challenge called ‘Laminar traffic flows and dynamic hard shoulder utilization’, which promotes better use of existing urban roads through intelligent sensor infrastructure. Vote it if you like it.
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Executive summary:
As first step, let’s consider what happens on urban roads before congestion arises:
- Different lanes develop different speeds. Some cars switch lanes as they hunt for fastest lane, hindering everyone else during the merging.
- Some cars switch more than one lane as they head to a highway exit from an inner lane, causing more hold-up than a foresighted driver.
- At some critical point the free-flow pauses, and later restarts. On hard-shouldered highways the outermost emergency lane is left unused during all these congestions because of safety regulations – except for occasional rogue drivers zipping by. There surely must be a way to make better use of this under-utilized road surface – and without incurring any safety risks.
